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8sa1-gcc/gcc/ada/utils.c
Eric Botcazou c8945d5632 gigi.h: (tree_code_for_record_type): Declare. 
2006-10-31  Eric Botcazou  <ebotcazou@adacore.com>
	    Nicolas Setton  <setton@adacore.com>
	    Olivier Hainque  <hainque@adacore.com>
	    Gary Dismukes  <dismukes@adacore.com>

	* gigi.h: (tree_code_for_record_type): Declare.
	(add_global_renaming_pointer): Rename to record_global_renaming_pointer.
	(get_global_renaming_pointers): Rename to
	invalidate_global_renaming_pointers.
	(static_ctors): Delete.
	(static_dtors): Likewise.
	(gnat_write_global_declarations): Declare.
	(create_var_decl): Adjust descriptive comment to indicate that the
	subprogram may return a CONST_DECL node.
	(create_true_var_decl): Declare new function, similar to
	create_var_decl but forcing the creation of a VAR_DECL node.
	(get_global_renaming_pointers): Declare.
	(add_global_renaming_pointer): Likewise.

	* ada-tree.h (DECL_READONLY_ONCE_ELAB): New macro.

	* decl.c (gnat_to_gnu_entity) <case E_Function>: Don't copy the type
	tree before setting TREE_ADDRESSABLE for by-reference return mechanism
	processing.
	(gnat_to_gnu_entity): Remove From_With_Type from computation for
	imported_p.
	<E_Access_Type>: Use the Non_Limited_View as the full view of the
	designated type if the pointer comes from a limited_with clause.  Make
	incomplete designated type if it is in the main unit and has a freeze
	node.
	<E_Incomplete_Type>: Rework to treat Non_Limited_View, Full_View, and
	Underlying_Full_View similarly.  Return earlier if the full view already
	has an associated tree.
	(gnat_to_gnu_entity) <E_Record_Type>: Restore comment.
	(gnat_to_gnu_entity) <E_Record_Type>: Do not use a dummy type.
	(gnat_to_gnu_entity) <E_Variable>: Set TYPE_REF_CAN_ALIAS_ALL on the
	reference type built for objects with an address clause.
	Use create_true_var_decl with const_flag set for
	DECL_CONST_CORRESPONDING_VARs, ensuring a VAR_DECL is created with
	TREE_READONLY set.
	(gnat_to_gnu_entity, case E_Enumeration_Type): Set TYPE_NAME
	for Character and Wide_Character types. This info is read by the
	dwarf-2 writer, and is needed to be able to use the command "ptype
	character" in the debugger.
	(gnat_to_gnu_entity): When generating a type representing
	a Character or Wide_Character type, set the flag TYPE_STRING_FLAG,
	so that debug writers can distinguish it from ordinary integers.
	(elaborate_expression_1): Test the DECL_READONLY_ONCE_ELAB flag in
	addition to TREE_READONLY to assert the constantness of variables for
	elaboration purposes.
	(gnat_to_gnu_entity, subprogram cases): Change loops on formal
	parameters to call new Einfo function First_Formal_With_Extras.
	(gnat_to_gnu_entity): In type_annotate mode, replace a discriminant of a
	protected type with its corresponding discriminant, to obtain a usable
	declaration
	(gnat_to_gnu_entity) <E_Access_Protected_Subprogram_Type>: Be prepared
	for a multiple elaboration of the "equivalent" type.
	(gnat_to_gnu_entity): Adjust for renaming of add_global_renaming_pointer
	into record_global_renaming_pointer.
	(gnat_to_gnu_entity) <E_Array_Type>: Do not force
	TYPE_NONALIASED_COMPONENT to 0 if the element type is an aggregate.
	<E_Array_Subtype>: Likewise.
	(gnat_to_gnu_entity) <E_Incomplete_Subtype>: Add support for regular
	incomplete subtypes and incomplete subtypes of incomplete types visible
	through a limited with clause.
	(gnat_to_gnu_entity) <E_Array_Subtype>: Take into account the bounds of
	the base index type for the maximum size of the array only if they are
	constant.
	(gnat_to_gnu_entity, renaming object case): Do not wrap up the
	expression into a SAVE_EXPR if stabilization failed.

	* utils.c (create_subprog_decl): Turn TREE_ADDRESSABLE on the type of
	a result decl into DECL_BY_REFERENCE on this decl, now what is expected
	by lower level compilation passes.
	(gnat_genericize): New function, lowering a function body to GENERIC.
	Turn the type of RESULT_DECL into a real reference type if the decl
	has been marked DECL_BY_REFERENCE, and adjust references to the latter
	accordingly.
	(gnat_genericize_r): New function. Tree walking callback for
	gnat_genericize.
	(convert_from_reference, is_byref_result): New functions. Helpers for
	gnat_genericize_r.
	(create_type_decl): Call gnat_pushdecl before calling
	rest_of_decl_compilation, to make sure that field TYPE_NAME of
	type_decl is properly set before calling the debug information writers.
	(write_record_type_debug_info): The heuristics which compute the
	alignment of a field in a variant record might not be accurate. Add a
	safety test to make sure no alignment is set to a smaller value than
	the alignment of the field type.
	(make_dummy_type): Use the Non_Limited_View as the underlying type if
	the type comes from a limited_with clause. Do not loop on the full view.
	(GET_GNU_TREE, SET_GNU_TREE, PRESENT_GNU_TREE): New macros.
	(dummy_node_table): New global variable, moved from decl.c.
	(GET_DUMMY_NODE, SET_DUMMY_NODE, PRESENT_DUMMY_NODE): New macros.
	(save_gnu_tree): Use above macros.
	(get_gnu_tree): Likewise.
	(present_gnu_tree): Likewise.
	(init_dummy_type): New function, moved from decl.c. Use above macros.
	(make_dummy_type): Likewise.
	(tree_code_for_record_type): New function extracted from make_dummy_type
	(init_gigi_decls): Set DECL_IS_MALLOC on gnat_malloc.
	(static_ctors): Change it to a vector, make static.
	(static_dtors): Likewise.
	(end_subprog_body): Adjust for above change.
	(build_global_cdtor): Moved from trans.c.
	(gnat_write_global_declarations): Emit global constructor and
	destructor, and call cgraph_optimize before emitting debug info for
	global declarations.
	(global_decls): New global variable.
	(gnat_pushdecl): Store the global declarations in global_decls, for
	later use.
	(gnat_write_global_declarations): Emit debug information for global
	 declarations.
	(create_var_decl_1): Former create_var_decl, with an extra argument to
	 state whether the creation of a CONST_DECL is allowed.
	(create_var_decl): Behavior unchanged. Now a wrapper around
	create_var_decl_1 allowing CONST_DECL creation.
	(create_true_var_decl): New function, similar to create_var_decl but
	forcing the creation of a VAR_DECL node (CONST_DECL not allowed).
	(create_field_decl): Do not always mark the field as addressable
	if its type is an aggregate.
	(global_renaming_pointers): New static variable.
	(add_global_renaming_pointer): New function.
	(get_global_renaming_pointers): Likewise.

	* misc.c (gnat_dwarf_name): New function.
	(LANG_HOOKS_DWARF_NAME): Define to gnat_dwarf_name.
	(gnat_post_options): Add comment about structural alias analysis.
	(gnat_parse_file): Do not call cgraph_optimize here.
	(LANG_HOOKS_WRITE_GLOBALS): Define to gnat_write_global_declarations.

	* trans.c (process_freeze_entity): Don't abort if we already have a
	non dummy GCC tree for a Concurrent_Record_Type, as it might
	legitimately have been elaborated while processing the associated
	Concurrent_Type prior to this explicit freeze node.
	(Identifier_to_gnu): Do not make a variable referenced in a SJLJ
	exception handler volatile if it is of variable size.
	(process_type): Remove bypass for types coming from a limited_with
	clause.
	(call_to_gnu): When processing the copy-out of a N_Type_Conversion GNAT
	actual, convert the corresponding gnu_actual to the real destination
	type when necessary.
	(add_decl_expr): Set the DECL_READONLY_ONCE_ELAB flag on variables
	originally TREE_READONLY but whose elaboration cannot be performed
	statically.
	Part of fix for F504-021.
	(tree_transform, subprogram cases): Change loops on formal parameters to
	call new Einfo function First_Formal_With_Extras.
	(gnat_to_gnu) <N_Op_Shift_Right_Arithmetic>: Ignore constant overflow
	stemming from type conversion for the lhs.
	(Attribute_to_gnu) <Attr_Alignment>: Also divide the alignment by the
	number of bits per unit for components of records.
	(gnat_to_gnu) <N_Code_Statement>: Mark operands addressable if needed.
	(Handled_Sequence_Of_Statements_to_gnu): Register the cleanup associated
	with At_End_Proc after the SJLJ EH cleanup.
	(Compilation_Unit_to_gnu): Call elaborate_all_entities only on the main
	compilation unit.
	(elaborate_all_entities): Do not retest type_annotate_only.
	(tree_transform) <N_Abstract_Subprogram_Declaration>: Process the
	result type of an abstract subprogram, which may be an itype associated
	with an anonymous access result (related to AI-318-02).
	(build_global_cdtor): Move to utils.c.
	(Case_Statement_to_gnu): Avoid adding the choice of a when statement if
	this choice is not a null tree nor an integer constant.
	(gigi): Run unshare_save_expr via walk_tree_without_duplicates
	on the body of elaboration routines instead of mark_unvisited.
	(add_stmt): Do not mark the tree.
	(add_decl_expr): Tweak comment.
	(mark_unvisited): Delete.
	(unshare_save_expr): New static function.
	(call_to_gnu): Issue an error when making a temporary around a
	procedure call because of non-addressable actual parameter if the
	type of the formal is by_reference.
	(Compilation_Unit_to_gnu): Invalidate the global renaming pointers
	after building the elaboration routine.

From-SVN: r118331
2006-10-31 19:19:52 +01:00

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/****************************************************************************
* *
* GNAT COMPILER COMPONENTS *
* *
* U T I L S *
* *
* C Implementation File *
* *
* Copyright (C) 1992-2006, Free Software Foundation, Inc. *
* *
* GNAT is free software; you can redistribute it and/or modify it under *
* terms of the GNU General Public License as published by the Free Soft- *
* ware Foundation; either version 2, or (at your option) any later ver- *
* sion. GNAT is distributed in the hope that it will be useful, but WITH- *
* OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
* for more details. You should have received a copy of the GNU General *
* Public License distributed with GNAT; see file COPYING. If not, write *
* to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
* Boston, MA 02110-1301, USA. *
* *
* GNAT was originally developed by the GNAT team at New York University. *
* Extensive contributions were provided by Ada Core Technologies Inc. *
* *
****************************************************************************/
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "flags.h"
#include "defaults.h"
#include "toplev.h"
#include "output.h"
#include "ggc.h"
#include "debug.h"
#include "convert.h"
#include "target.h"
#include "function.h"
#include "cgraph.h"
#include "tree-inline.h"
#include "tree-gimple.h"
#include "tree-dump.h"
#include "pointer-set.h"
#include "ada.h"
#include "types.h"
#include "atree.h"
#include "elists.h"
#include "namet.h"
#include "nlists.h"
#include "stringt.h"
#include "uintp.h"
#include "fe.h"
#include "sinfo.h"
#include "einfo.h"
#include "ada-tree.h"
#include "gigi.h"
#ifndef MAX_FIXED_MODE_SIZE
#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
#endif
#ifndef MAX_BITS_PER_WORD
#define MAX_BITS_PER_WORD BITS_PER_WORD
#endif
/* If nonzero, pretend we are allocating at global level. */
int force_global;
/* Tree nodes for the various types and decls we create. */
tree gnat_std_decls[(int) ADT_LAST];
/* Functions to call for each of the possible raise reasons. */
tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
/* Forward declarations for handlers of attributes. */
static tree handle_const_attribute (tree *, tree, tree, int, bool *);
static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
/* Table of machine-independent internal attributes for Ada. We support
this minimal set of attributes to accommodate the Alpha back-end which
unconditionally puts them on its builtins. */
const struct attribute_spec gnat_internal_attribute_table[] =
{
/* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
{ "const", 0, 0, true, false, false, handle_const_attribute },
{ "nothrow", 0, 0, true, false, false, handle_nothrow_attribute },
{ NULL, 0, 0, false, false, false, NULL }
};
/* Associates a GNAT tree node to a GCC tree node. It is used in
`save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
of `save_gnu_tree' for more info. */
static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
#define GET_GNU_TREE(GNAT_ENTITY) \
associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
#define SET_GNU_TREE(GNAT_ENTITY,VAL) \
associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
#define PRESENT_GNU_TREE(GNAT_ENTITY) \
(associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
/* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
static GTY((length ("max_gnat_nodes"))) tree *dummy_node_table;
#define GET_DUMMY_NODE(GNAT_ENTITY) \
dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
#define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
#define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
(dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
/* This variable keeps a table for types for each precision so that we only
allocate each of them once. Signed and unsigned types are kept separate.
Note that these types are only used when fold-const requests something
special. Perhaps we should NOT share these types; we'll see how it
goes later. */
static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
/* Likewise for float types, but record these by mode. */
static GTY(()) tree float_types[NUM_MACHINE_MODES];
/* For each binding contour we allocate a binding_level structure to indicate
the binding depth. */
struct gnat_binding_level GTY((chain_next ("%h.chain")))
{
/* The binding level containing this one (the enclosing binding level). */
struct gnat_binding_level *chain;
/* The BLOCK node for this level. */
tree block;
/* If nonzero, the setjmp buffer that needs to be updated for any
variable-sized definition within this context. */
tree jmpbuf_decl;
};
/* The binding level currently in effect. */
static GTY(()) struct gnat_binding_level *current_binding_level;
/* A chain of gnat_binding_level structures awaiting reuse. */
static GTY((deletable)) struct gnat_binding_level *free_binding_level;
/* An array of global declarations. */
static GTY(()) VEC (tree,gc) *global_decls;
/* An array of global renaming pointers. */
static GTY(()) VEC (tree,gc) *global_renaming_pointers;
/* Arrays of functions called automatically at the beginning and
end of execution, on targets without .ctors/.dtors sections. */
static GTY(()) VEC (tree,gc) *static_ctors;
static GTY(()) VEC (tree,gc) *static_dtors;
/* A chain of unused BLOCK nodes. */
static GTY((deletable)) tree free_block_chain;
struct language_function GTY(())
{
int unused;
};
static void gnat_install_builtins (void);
static tree merge_sizes (tree, tree, tree, bool, bool);
static tree compute_related_constant (tree, tree);
static tree split_plus (tree, tree *);
static bool value_zerop (tree);
static void gnat_gimplify_function (tree);
static tree float_type_for_precision (int, enum machine_mode);
static tree convert_to_fat_pointer (tree, tree);
static tree convert_to_thin_pointer (tree, tree);
static tree make_descriptor_field (const char *,tree, tree, tree);
static bool potential_alignment_gap (tree, tree, tree);
/* Initialize the association of GNAT nodes to GCC trees. */
void
init_gnat_to_gnu (void)
{
associate_gnat_to_gnu
= (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
}
/* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
which is to be associated with GNAT_ENTITY. Such GCC tree node is always
a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed.
If GNU_DECL is zero, a previous association is to be reset. */
void
save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check)
{
/* Check that GNAT_ENTITY is not already defined and that it is being set
to something which is a decl. Raise gigi 401 if not. Usually, this
means GNAT_ENTITY is defined twice, but occasionally is due to some
Gigi problem. */
gcc_assert (!(gnu_decl
&& (PRESENT_GNU_TREE (gnat_entity)
|| (!no_check && !DECL_P (gnu_decl)))));
SET_GNU_TREE (gnat_entity, gnu_decl);
}
/* GNAT_ENTITY is a GNAT tree node for a defining identifier.
Return the ..._DECL node that was associated with it. If there is no tree
node associated with GNAT_ENTITY, abort.
In some cases, such as delayed elaboration or expressions that need to
be elaborated only once, GNAT_ENTITY is really not an entity. */
tree
get_gnu_tree (Entity_Id gnat_entity)
{
gcc_assert (PRESENT_GNU_TREE (gnat_entity));
return GET_GNU_TREE (gnat_entity);
}
/* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
bool
present_gnu_tree (Entity_Id gnat_entity)
{
return PRESENT_GNU_TREE (gnat_entity);
}
/* Initialize the association of GNAT nodes to GCC trees as dummies. */
void
init_dummy_type (void)
{
dummy_node_table
= (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
}
/* Make a dummy type corresponding to GNAT_TYPE. */
tree
make_dummy_type (Entity_Id gnat_type)
{
Entity_Id gnat_underlying;
tree gnu_type;
enum tree_code code;
/* Find a full type for GNAT_TYPE, taking into account any class wide
types. */
if (Is_Class_Wide_Type (gnat_type) && Present (Equivalent_Type (gnat_type)))
gnat_type = Equivalent_Type (gnat_type);
else if (Ekind (gnat_type) == E_Class_Wide_Type)
gnat_type = Root_Type (gnat_type);
/* Find a full view for GNAT_TYPE, looking through any incomplete or
private types. */
if (IN (Ekind (gnat_type), Incomplete_Kind)
&& From_With_Type (gnat_type))
gnat_underlying = Non_Limited_View (gnat_type);
else if (IN (Ekind (gnat_type), Incomplete_Or_Private_Kind)
&& Present (Full_View (gnat_type)))
gnat_underlying = Full_View (gnat_type);
else
gnat_underlying = gnat_type;
/* If it there already a dummy type, use that one. Else make one. */
if (PRESENT_DUMMY_NODE (gnat_underlying))
return GET_DUMMY_NODE (gnat_underlying);
/* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
it an ENUMERAL_TYPE. */
if (Is_Record_Type (gnat_underlying))
code = tree_code_for_record_type (gnat_underlying);
else
code = ENUMERAL_TYPE;
gnu_type = make_node (code);
TYPE_NAME (gnu_type) = get_entity_name (gnat_type);
TYPE_DUMMY_P (gnu_type) = 1;
if (AGGREGATE_TYPE_P (gnu_type))
TYPE_STUB_DECL (gnu_type) = build_decl (TYPE_DECL, NULL_TREE, gnu_type);
SET_DUMMY_NODE (gnat_underlying, gnu_type);
return gnu_type;
}
/* Return nonzero if we are currently in the global binding level. */
int
global_bindings_p (void)
{
return ((force_global || !current_function_decl) ? -1 : 0);
}
/* Enter a new binding level. */
void
gnat_pushlevel ()
{
struct gnat_binding_level *newlevel = NULL;
/* Reuse a struct for this binding level, if there is one. */
if (free_binding_level)
{
newlevel = free_binding_level;
free_binding_level = free_binding_level->chain;
}
else
newlevel
= (struct gnat_binding_level *)
ggc_alloc (sizeof (struct gnat_binding_level));
/* Use a free BLOCK, if any; otherwise, allocate one. */
if (free_block_chain)
{
newlevel->block = free_block_chain;
free_block_chain = TREE_CHAIN (free_block_chain);
TREE_CHAIN (newlevel->block) = NULL_TREE;
}
else
newlevel->block = make_node (BLOCK);
/* Point the BLOCK we just made to its parent. */
if (current_binding_level)
BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block;
BLOCK_VARS (newlevel->block) = BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE;
TREE_USED (newlevel->block) = 1;
/* Add this level to the front of the chain (stack) of levels that are
active. */
newlevel->chain = current_binding_level;
newlevel->jmpbuf_decl = NULL_TREE;
current_binding_level = newlevel;
}
/* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
and point FNDECL to this BLOCK. */
void
set_current_block_context (tree fndecl)
{
BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
DECL_INITIAL (fndecl) = current_binding_level->block;
}
/* Set the jmpbuf_decl for the current binding level to DECL. */
void
set_block_jmpbuf_decl (tree decl)
{
current_binding_level->jmpbuf_decl = decl;
}
/* Get the jmpbuf_decl, if any, for the current binding level. */
tree
get_block_jmpbuf_decl ()
{
return current_binding_level->jmpbuf_decl;
}
/* Exit a binding level. Set any BLOCK into the current code group. */
void
gnat_poplevel ()
{
struct gnat_binding_level *level = current_binding_level;
tree block = level->block;
BLOCK_VARS (block) = nreverse (BLOCK_VARS (block));
BLOCK_SUBBLOCKS (block) = nreverse (BLOCK_SUBBLOCKS (block));
/* If this is a function-level BLOCK don't do anything. Otherwise, if there
are no variables free the block and merge its subblocks into those of its
parent block. Otherwise, add it to the list of its parent. */
if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)
;
else if (BLOCK_VARS (block) == NULL_TREE)
{
BLOCK_SUBBLOCKS (level->chain->block)
= chainon (BLOCK_SUBBLOCKS (block),
BLOCK_SUBBLOCKS (level->chain->block));
TREE_CHAIN (block) = free_block_chain;
free_block_chain = block;
}
else
{
TREE_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block);
BLOCK_SUBBLOCKS (level->chain->block) = block;
TREE_USED (block) = 1;
set_block_for_group (block);
}
/* Free this binding structure. */
current_binding_level = level->chain;
level->chain = free_binding_level;
free_binding_level = level;
}
/* Insert BLOCK at the end of the list of subblocks of the
current binding level. This is used when a BIND_EXPR is expanded,
to handle the BLOCK node inside the BIND_EXPR. */
void
insert_block (tree block)
{
TREE_USED (block) = 1;
TREE_CHAIN (block) = BLOCK_SUBBLOCKS (current_binding_level->block);
BLOCK_SUBBLOCKS (current_binding_level->block) = block;
}
/* Records a ..._DECL node DECL as belonging to the current lexical scope
and uses GNAT_NODE for location information and propagating flags. */
void
gnat_pushdecl (tree decl, Node_Id gnat_node)
{
/* If at top level, there is no context. But PARM_DECLs always go in the
level of its function. */
if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL)
DECL_CONTEXT (decl) = 0;
else
{
DECL_CONTEXT (decl) = current_function_decl;
/* Functions imported in another function are not really nested. */
if (TREE_CODE (decl) == FUNCTION_DECL && TREE_PUBLIC (decl))
DECL_NO_STATIC_CHAIN (decl) = 1;
}
TREE_NO_WARNING (decl) = (gnat_node == Empty || Warnings_Off (gnat_node));
/* Set the location of DECL and emit a declaration for it. */
if (Present (gnat_node))
Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl));
add_decl_expr (decl, gnat_node);
/* Put the declaration on the list. The list of declarations is in reverse
order. The list will be reversed later. Put global variables in the
globals list. Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into the
list, as they will cause trouble with the debugger and aren't needed
anyway. */
if (TREE_CODE (decl) != TYPE_DECL
|| TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE)
{
if (global_bindings_p ())
VEC_safe_push (tree, gc, global_decls, decl);
else
{
TREE_CHAIN (decl) = BLOCK_VARS (current_binding_level->block);
BLOCK_VARS (current_binding_level->block) = decl;
}
}
/* For the declaration of a type, set its name if it either is not already
set, was set to an IDENTIFIER_NODE, indicating an internal name,
or if the previous type name was not derived from a source name.
We'd rather have the type named with a real name and all the pointer
types to the same object have the same POINTER_TYPE node. Code in this
function in c-decl.c makes a copy of the type node here, but that may
cause us trouble with incomplete types, so let's not try it (at least
for now). */
if (TREE_CODE (decl) == TYPE_DECL
&& DECL_NAME (decl)
&& (!TYPE_NAME (TREE_TYPE (decl))
|| TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == IDENTIFIER_NODE
|| (TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == TYPE_DECL
&& DECL_ARTIFICIAL (TYPE_NAME (TREE_TYPE (decl)))
&& !DECL_ARTIFICIAL (decl))))
TYPE_NAME (TREE_TYPE (decl)) = decl;
/* if (TREE_CODE (decl) != CONST_DECL)
rest_of_decl_compilation (decl, global_bindings_p (), 0); */
}
/* Do little here. Set up the standard declarations later after the
front end has been run. */
void
gnat_init_decl_processing (void)
{
input_line = 0;
/* Make the binding_level structure for global names. */
current_function_decl = 0;
current_binding_level = 0;
free_binding_level = 0;
gnat_pushlevel ();
build_common_tree_nodes (true, true);
/* In Ada, we use a signed type for SIZETYPE. Use the signed type
corresponding to the size of Pmode. In most cases when ptr_mode and
Pmode differ, C will use the width of ptr_mode as sizetype. But we get
far better code using the width of Pmode. Make this here since we need
this before we can expand the GNAT types. */
size_type_node = gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0);
set_sizetype (size_type_node);
build_common_tree_nodes_2 (0);
/* Give names and make TYPE_DECLs for common types. */
gnat_pushdecl (build_decl (TYPE_DECL, get_identifier (SIZE_TYPE), sizetype),
Empty);
gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("integer"),
integer_type_node),
Empty);
gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
char_type_node),
Empty);
gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("long integer"),
long_integer_type_node),
Empty);
ptr_void_type_node = build_pointer_type (void_type_node);
gnat_install_builtins ();
}
/* Install the builtin functions the middle-end needs. */
static void
gnat_install_builtins ()
{
/* Builtins used by generic optimizers. */
build_common_builtin_nodes ();
/* Target specific builtins, such as the AltiVec family on ppc. */
targetm.init_builtins ();
}
/* Create the predefined scalar types such as `integer_type_node' needed
in the gcc back-end and initialize the global binding level. */
void
init_gigi_decls (tree long_long_float_type, tree exception_type)
{
tree endlink, decl;
unsigned int i;
/* Set the types that GCC and Gigi use from the front end. We would like
to do this for char_type_node, but it needs to correspond to the C
char type. */
if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE)
{
/* In this case, the builtin floating point types are VAX float,
so make up a type for use. */
longest_float_type_node = make_node (REAL_TYPE);
TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE;
layout_type (longest_float_type_node);
create_type_decl (get_identifier ("longest float type"),
longest_float_type_node, NULL, false, true, Empty);
}
else
longest_float_type_node = TREE_TYPE (long_long_float_type);
except_type_node = TREE_TYPE (exception_type);
unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1);
create_type_decl (get_identifier ("unsigned int"), unsigned_type_node,
NULL, false, true, Empty);
void_type_decl_node = create_type_decl (get_identifier ("void"),
void_type_node, NULL, false, true,
Empty);
void_ftype = build_function_type (void_type_node, NULL_TREE);
ptr_void_ftype = build_pointer_type (void_ftype);
/* Now declare runtime functions. */
endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
/* malloc is a function declaration tree for a function to allocate
memory. */
malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"),
NULL_TREE,
build_function_type (ptr_void_type_node,
tree_cons (NULL_TREE,
sizetype,
endlink)),
NULL_TREE, false, true, true, NULL,
Empty);
DECL_IS_MALLOC (malloc_decl) = 1;
/* free is a function declaration tree for a function to free memory. */
free_decl
= create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, false, true, true, NULL, Empty);
/* Make the types and functions used for exception processing. */
jmpbuf_type
= build_array_type (gnat_type_for_mode (Pmode, 0),
build_index_type (build_int_cst (NULL_TREE, 5)));
create_type_decl (get_identifier ("JMPBUF_T"), jmpbuf_type, NULL,
false, true, Empty);
jmpbuf_ptr_type = build_pointer_type (jmpbuf_type);
/* Functions to get and set the jumpbuf pointer for the current thread. */
get_jmpbuf_decl
= create_subprog_decl
(get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE),
NULL_TREE, false, true, true, NULL, Empty);
/* Avoid creating superfluous edges to __builtin_setjmp receivers. */
DECL_IS_PURE (get_jmpbuf_decl) = 1;
set_jmpbuf_decl
= create_subprog_decl
(get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
NULL_TREE, false, true, true, NULL, Empty);
/* Function to get the current exception. */
get_excptr_decl
= create_subprog_decl
(get_identifier ("system__soft_links__get_gnat_exception"),
NULL_TREE,
build_function_type (build_pointer_type (except_type_node), NULL_TREE),
NULL_TREE, false, true, true, NULL, Empty);
/* Avoid creating superfluous edges to __builtin_setjmp receivers. */
DECL_IS_PURE (get_excptr_decl) = 1;
/* Functions that raise exceptions. */
raise_nodefer_decl
= create_subprog_decl
(get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type (except_type_node),
endlink)),
NULL_TREE, false, true, true, NULL, Empty);
/* Dummy objects to materialize "others" and "all others" in the exception
tables. These are exported by a-exexpr.adb, so see this unit for the
types to use. */
others_decl
= create_var_decl (get_identifier ("OTHERS"),
get_identifier ("__gnat_others_value"),
integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
all_others_decl
= create_var_decl (get_identifier ("ALL_OTHERS"),
get_identifier ("__gnat_all_others_value"),
integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
/* Hooks to call when entering/leaving an exception handler. */
begin_handler_decl
= create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, false, true, true, NULL, Empty);
end_handler_decl
= create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, false, true, true, NULL, Empty);
/* If in no exception handlers mode, all raise statements are redirected to
__gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since
this procedure will never be called in this mode. */
if (No_Exception_Handlers_Set ())
{
decl
= create_subprog_decl
(get_identifier ("__gnat_last_chance_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type (char_type_node),
tree_cons (NULL_TREE,
integer_type_node,
endlink))),
NULL_TREE, false, true, true, NULL, Empty);
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
gnat_raise_decls[i] = decl;
}
else
/* Otherwise, make one decl for each exception reason. */
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
{
char name[17];
sprintf (name, "__gnat_rcheck_%.2d", i);
gnat_raise_decls[i]
= create_subprog_decl
(get_identifier (name), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type
(char_type_node),
tree_cons (NULL_TREE,
integer_type_node,
endlink))),
NULL_TREE, false, true, true, NULL, Empty);
}
/* Indicate that these never return. */
TREE_THIS_VOLATILE (raise_nodefer_decl) = 1;
TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1;
TREE_TYPE (raise_nodefer_decl)
= build_qualified_type (TREE_TYPE (raise_nodefer_decl),
TYPE_QUAL_VOLATILE);
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
{
TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1;
TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1;
TREE_TYPE (gnat_raise_decls[i])
= build_qualified_type (TREE_TYPE (gnat_raise_decls[i]),
TYPE_QUAL_VOLATILE);
}
/* setjmp returns an integer and has one operand, which is a pointer to
a jmpbuf. */
setjmp_decl
= create_subprog_decl
(get_identifier ("__builtin_setjmp"), NULL_TREE,
build_function_type (integer_type_node,
tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
NULL_TREE, false, true, true, NULL, Empty);
DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
/* update_setjmp_buf updates a setjmp buffer from the current stack pointer
address. */
update_setjmp_buf_decl
= create_subprog_decl
(get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
NULL_TREE, false, true, true, NULL, Empty);
DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL;
DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF;
main_identifier_node = get_identifier ("main");
}
/* Given a record type (RECORD_TYPE) and a chain of FIELD_DECL nodes
(FIELDLIST), finish constructing the record or union type. If HAS_REP is
true, this record has a rep clause; don't call layout_type but merely set
the size and alignment ourselves. If DEFER_DEBUG is true, do not call
the debugging routines on this type; it will be done later. */
void
finish_record_type (tree record_type, tree fieldlist, bool has_rep,
bool defer_debug)
{
enum tree_code code = TREE_CODE (record_type);
tree ada_size = bitsize_zero_node;
tree size = bitsize_zero_node;
bool var_size = false;
bool had_size = TYPE_SIZE (record_type) != 0;
bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0;
tree field;
TYPE_FIELDS (record_type) = fieldlist;
TYPE_STUB_DECL (record_type)
= build_decl (TYPE_DECL, NULL_TREE, record_type);
/* We don't need both the typedef name and the record name output in
the debugging information, since they are the same. */
DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1;
/* Globally initialize the record first. If this is a rep'ed record,
that just means some initializations; otherwise, layout the record. */
if (has_rep)
{
TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
TYPE_MODE (record_type) = BLKmode;
if (!had_size_unit)
TYPE_SIZE_UNIT (record_type) = size_zero_node;
if (!had_size)
TYPE_SIZE (record_type) = bitsize_zero_node;
/* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
out just like a UNION_TYPE, since the size will be fixed. */
else if (code == QUAL_UNION_TYPE)
code = UNION_TYPE;
}
else
{
/* Ensure there isn't a size already set. There can be in an error
case where there is a rep clause but all fields have errors and
no longer have a position. */
TYPE_SIZE (record_type) = 0;
layout_type (record_type);
}
/* At this point, the position and size of each field is known. It was
either set before entry by a rep clause, or by laying out the type above.
We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
to compute the Ada size; the GCC size and alignment (for rep'ed records
that are not padding types); and the mode (for rep'ed records). We also
clear the DECL_BIT_FIELD indication for the cases we know have not been
handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
if (code == QUAL_UNION_TYPE)
fieldlist = nreverse (fieldlist);
for (field = fieldlist; field; field = TREE_CHAIN (field))
{
tree pos = bit_position (field);
tree type = TREE_TYPE (field);
tree this_size = DECL_SIZE (field);
tree this_ada_size = DECL_SIZE (field);
/* We need to make an XVE/XVU record if any field has variable size,
whether or not the record does. For example, if we have a union,
it may be that all fields, rounded up to the alignment, have the
same size, in which case we'll use that size. But the debug
output routines (except Dwarf2) won't be able to output the fields,
so we need to make the special record. */
if (TREE_CODE (this_size) != INTEGER_CST)
var_size = true;
if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
|| TREE_CODE (type) == QUAL_UNION_TYPE)
&& !TYPE_IS_FAT_POINTER_P (type)
&& !TYPE_CONTAINS_TEMPLATE_P (type)
&& TYPE_ADA_SIZE (type))
this_ada_size = TYPE_ADA_SIZE (type);
/* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
if (DECL_BIT_FIELD (field) && !STRICT_ALIGNMENT
&& value_factor_p (pos, BITS_PER_UNIT)
&& operand_equal_p (this_size, TYPE_SIZE (type), 0))
DECL_BIT_FIELD (field) = 0;
/* If we still have DECL_BIT_FIELD set at this point, we know the field
is technically not addressable. Except that it can actually be
addressed if the field is BLKmode and happens to be properly
aligned. */
DECL_NONADDRESSABLE_P (field)
|= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode;
if (has_rep && !DECL_BIT_FIELD (field))
TYPE_ALIGN (record_type)
= MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
switch (code)
{
case UNION_TYPE:
ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
size = size_binop (MAX_EXPR, size, this_size);
break;
case QUAL_UNION_TYPE:
ada_size
= fold (build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
this_ada_size, ada_size));
size = fold (build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
this_size, size));
break;
case RECORD_TYPE:
/* Since we know here that all fields are sorted in order of
increasing bit position, the size of the record is one
higher than the ending bit of the last field processed
unless we have a rep clause, since in that case we might
have a field outside a QUAL_UNION_TYPE that has a higher ending
position. So use a MAX in that case. Also, if this field is a
QUAL_UNION_TYPE, we need to take into account the previous size in
the case of empty variants. */
ada_size
= merge_sizes (ada_size, pos, this_ada_size,
TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
size = merge_sizes (size, pos, this_size,
TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
break;
default:
gcc_unreachable ();
}
}
if (code == QUAL_UNION_TYPE)
nreverse (fieldlist);
/* If this is a padding record, we never want to make the size smaller than
what was specified in it, if any. */
if (TREE_CODE (record_type) == RECORD_TYPE
&& TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type))
size = TYPE_SIZE (record_type);
/* Now set any of the values we've just computed that apply. */
if (!TYPE_IS_FAT_POINTER_P (record_type)
&& !TYPE_CONTAINS_TEMPLATE_P (record_type))
SET_TYPE_ADA_SIZE (record_type, ada_size);
if (has_rep)
{
tree size_unit
= (had_size_unit ? TYPE_SIZE_UNIT (record_type)
: convert (sizetype, size_binop (CEIL_DIV_EXPR, size,
bitsize_unit_node)));
TYPE_SIZE (record_type)
= variable_size (round_up (size, TYPE_ALIGN (record_type)));
TYPE_SIZE_UNIT (record_type)
= variable_size (round_up (size_unit,
TYPE_ALIGN (record_type) / BITS_PER_UNIT));
compute_record_mode (record_type);
}
if (!defer_debug)
write_record_type_debug_info (record_type);
}
/* Output the debug information associated to a record type. */
void
write_record_type_debug_info (tree record_type)
{
tree fieldlist = TYPE_FIELDS (record_type);
tree field;
bool var_size = false;
for (field = fieldlist; field; field = TREE_CHAIN (field))
{
/* We need to make an XVE/XVU record if any field has variable size,
whether or not the record does. For example, if we have a union,
it may be that all fields, rounded up to the alignment, have the
same size, in which case we'll use that size. But the debug
output routines (except Dwarf2) won't be able to output the fields,
so we need to make the special record. */
if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST)
{
var_size = true;
break;
}
}
/* If this record is of variable size, rename it so that the
debugger knows it is and make a new, parallel, record
that tells the debugger how the record is laid out. See
exp_dbug.ads. But don't do this for records that are padding
since they confuse GDB. */
if (var_size
&& !(TREE_CODE (record_type) == RECORD_TYPE
&& TYPE_IS_PADDING_P (record_type)))
{
tree new_record_type
= make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
? UNION_TYPE : TREE_CODE (record_type));
tree orig_name = TYPE_NAME (record_type);
tree orig_id
= (TREE_CODE (orig_name) == TYPE_DECL ? DECL_NAME (orig_name)
: orig_name);
tree new_id
= concat_id_with_name (orig_id,
TREE_CODE (record_type) == QUAL_UNION_TYPE
? "XVU" : "XVE");
tree last_pos = bitsize_zero_node;
tree old_field;
tree prev_old_field = 0;
TYPE_NAME (new_record_type) = new_id;
TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
TYPE_STUB_DECL (new_record_type)
= build_decl (TYPE_DECL, NULL_TREE, new_record_type);
DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1;
DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
= DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
TYPE_SIZE_UNIT (new_record_type)
= size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT);
/* Now scan all the fields, replacing each field with a new
field corresponding to the new encoding. */
for (old_field = TYPE_FIELDS (record_type); old_field;
old_field = TREE_CHAIN (old_field))
{
tree field_type = TREE_TYPE (old_field);
tree field_name = DECL_NAME (old_field);
tree new_field;
tree curpos = bit_position (old_field);
bool var = false;
unsigned int align = 0;
tree pos;
/* See how the position was modified from the last position.
There are two basic cases we support: a value was added
to the last position or the last position was rounded to
a boundary and they something was added. Check for the
first case first. If not, see if there is any evidence
of rounding. If so, round the last position and try
again.
If this is a union, the position can be taken as zero. */
if (TREE_CODE (new_record_type) == UNION_TYPE)
pos = bitsize_zero_node, align = 0;
else
pos = compute_related_constant (curpos, last_pos);
if (!pos && TREE_CODE (curpos) == MULT_EXPR
&& TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST)
{
align = TREE_INT_CST_LOW (TREE_OPERAND (curpos, 1));
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
else if (!pos && TREE_CODE (curpos) == PLUS_EXPR
&& TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
&& host_integerp (TREE_OPERAND
(TREE_OPERAND (curpos, 0), 1),
1))
{
align
= tree_low_cst
(TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
else if (potential_alignment_gap (prev_old_field, old_field,
pos))
{
align = TYPE_ALIGN (field_type);
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
/* If we can't compute a position, set it to zero.
??? We really should abort here, but it's too much work
to get this correct for all cases. */
if (!pos)
pos = bitsize_zero_node;
/* See if this type is variable-size and make a new type
and indicate the indirection if so. */
if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
{
field_type = build_pointer_type (field_type);
var = true;
}
/* The heuristics above might get the alignment wrong.
Adjust the obvious case where align is smaller than the
alignments necessary for objects of field_type. */
if (align < TYPE_ALIGN(field_type))
align = TYPE_ALIGN(field_type);
/* Make a new field name, if necessary. */
if (var || align != 0)
{
char suffix[6];
if (align != 0)
sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
align / BITS_PER_UNIT);
else
strcpy (suffix, "XVL");
field_name = concat_id_with_name (field_name, suffix);
}
new_field = create_field_decl (field_name, field_type,
new_record_type, 0,
DECL_SIZE (old_field), pos, 0);
TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
TYPE_FIELDS (new_record_type) = new_field;
/* If old_field is a QUAL_UNION_TYPE, take its size as being
zero. The only time it's not the last field of the record
is when there are other components at fixed positions after
it (meaning there was a rep clause for every field) and we
want to be able to encode them. */
last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
(TREE_CODE (TREE_TYPE (old_field))
== QUAL_UNION_TYPE)
? bitsize_zero_node
: DECL_SIZE (old_field));
prev_old_field = old_field;
}
TYPE_FIELDS (new_record_type)
= nreverse (TYPE_FIELDS (new_record_type));
rest_of_type_compilation (new_record_type, global_bindings_p ());
}
rest_of_type_compilation (record_type, global_bindings_p ());
}
/* Utility function of above to merge LAST_SIZE, the previous size of a record
with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero
if this represents a QUAL_UNION_TYPE in which case we must look for
COND_EXPRs and replace a value of zero with the old size. If HAS_REP
is nonzero, we must take the MAX of the end position of this field
with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE.
We return an expression for the size. */
static tree
merge_sizes (tree last_size, tree first_bit, tree size, bool special,
bool has_rep)
{
tree type = TREE_TYPE (last_size);
tree new;
if (!special || TREE_CODE (size) != COND_EXPR)
{
new = size_binop (PLUS_EXPR, first_bit, size);
if (has_rep)
new = size_binop (MAX_EXPR, last_size, new);
}
else
new = fold (build3 (COND_EXPR, type, TREE_OPERAND (size, 0),
integer_zerop (TREE_OPERAND (size, 1))
? last_size : merge_sizes (last_size, first_bit,
TREE_OPERAND (size, 1),
1, has_rep),
integer_zerop (TREE_OPERAND (size, 2))
? last_size : merge_sizes (last_size, first_bit,
TREE_OPERAND (size, 2),
1, has_rep)));
/* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
when fed through substitute_in_expr) into thinking that a constant
size is not constant. */
while (TREE_CODE (new) == NON_LVALUE_EXPR)
new = TREE_OPERAND (new, 0);
return new;
}
/* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
related by the addition of a constant. Return that constant if so. */
static tree
compute_related_constant (tree op0, tree op1)
{
tree op0_var, op1_var;
tree op0_con = split_plus (op0, &op0_var);
tree op1_con = split_plus (op1, &op1_var);
tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
if (operand_equal_p (op0_var, op1_var, 0))
return result;
else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
return result;
else
return 0;
}
/* Utility function of above to split a tree OP which may be a sum, into a
constant part, which is returned, and a variable part, which is stored
in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
bitsizetype. */
static tree
split_plus (tree in, tree *pvar)
{
/* Strip NOPS in order to ease the tree traversal and maximize the
potential for constant or plus/minus discovery. We need to be careful
to always return and set *pvar to bitsizetype trees, but it's worth
the effort. */
STRIP_NOPS (in);
*pvar = convert (bitsizetype, in);
if (TREE_CODE (in) == INTEGER_CST)
{
*pvar = bitsize_zero_node;
return convert (bitsizetype, in);
}
else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
{
tree lhs_var, rhs_var;
tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
if (lhs_var == TREE_OPERAND (in, 0)
&& rhs_var == TREE_OPERAND (in, 1))
return bitsize_zero_node;
*pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
return size_binop (TREE_CODE (in), lhs_con, rhs_con);
}
else
return bitsize_zero_node;
}
/* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
subprogram. If it is void_type_node, then we are dealing with a procedure,
otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
copy-in/copy-out list to be stored into TYPE_CICO_LIST.
RETURNS_UNCONSTRAINED is nonzero if the function returns an unconstrained
object. RETURNS_BY_REF is nonzero if the function returns by reference.
RETURNS_WITH_DSP is nonzero if the function is to return with a
depressed stack pointer. RETURNS_BY_TARGET_PTR is true if the function
is to be passed (as its first parameter) the address of the place to copy
its result. */
tree
create_subprog_type (tree return_type, tree param_decl_list, tree cico_list,
bool returns_unconstrained, bool returns_by_ref,
bool returns_with_dsp, bool returns_by_target_ptr)
{
/* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of
the subprogram formal parameters. This list is generated by traversing the
input list of PARM_DECL nodes. */
tree param_type_list = NULL;
tree param_decl;
tree type;
for (param_decl = param_decl_list; param_decl;
param_decl = TREE_CHAIN (param_decl))
param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl),
param_type_list);
/* The list of the function parameter types has to be terminated by the void
type to signal to the back-end that we are not dealing with a variable
parameter subprogram, but that the subprogram has a fixed number of
parameters. */
param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
/* The list of argument types has been created in reverse
so nreverse it. */
param_type_list = nreverse (param_type_list);
type = build_function_type (return_type, param_type_list);
/* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST
or the new type should, make a copy of TYPE. Likewise for
RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */
if (TYPE_CI_CO_LIST (type) || cico_list
|| TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained
|| TYPE_RETURNS_BY_REF_P (type) != returns_by_ref
|| TYPE_RETURNS_BY_TARGET_PTR_P (type) != returns_by_target_ptr)
type = copy_type (type);
TYPE_CI_CO_LIST (type) = cico_list;
TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained;
TYPE_RETURNS_STACK_DEPRESSED (type) = returns_with_dsp;
TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
TYPE_RETURNS_BY_TARGET_PTR_P (type) = returns_by_target_ptr;
return type;
}
/* Return a copy of TYPE but safe to modify in any way. */
tree
copy_type (tree type)
{
tree new = copy_node (type);
/* copy_node clears this field instead of copying it, because it is
aliased with TREE_CHAIN. */
TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
TYPE_POINTER_TO (new) = 0;
TYPE_REFERENCE_TO (new) = 0;
TYPE_MAIN_VARIANT (new) = new;
TYPE_NEXT_VARIANT (new) = 0;
return new;
}
/* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
TYPE_INDEX_TYPE is INDEX. */
tree
create_index_type (tree min, tree max, tree index)
{
/* First build a type for the desired range. */
tree type = build_index_2_type (min, max);
/* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it
doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE
is set, but not to INDEX, make a copy of this type with the requested
index type. Note that we have no way of sharing these types, but that's
only a small hole. */
if (TYPE_INDEX_TYPE (type) == index)
return type;
else if (TYPE_INDEX_TYPE (type))
type = copy_type (type);
SET_TYPE_INDEX_TYPE (type, index);
create_type_decl (NULL_TREE, type, NULL, true, false, Empty);
return type;
}
/* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
string) and TYPE is a ..._TYPE node giving its data type.
ARTIFICIAL_P is true if this is a declaration that was generated
by the compiler. DEBUG_INFO_P is true if we need to write debugging
information about this type. GNAT_NODE is used for the position of
the decl. */
tree
create_type_decl (tree type_name, tree type, struct attrib *attr_list,
bool artificial_p, bool debug_info_p, Node_Id gnat_node)
{
tree type_decl = build_decl (TYPE_DECL, type_name, type);
enum tree_code code = TREE_CODE (type);
DECL_ARTIFICIAL (type_decl) = artificial_p;
if (!TYPE_IS_DUMMY_P (type))
gnat_pushdecl (type_decl, gnat_node);
process_attributes (type_decl, attr_list);
/* Pass type declaration information to the debugger unless this is an
UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support,
and ENUMERAL_TYPE or RECORD_TYPE which is handled separately, or
type for which debugging information was not requested. */
if (code == UNCONSTRAINED_ARRAY_TYPE || ! debug_info_p)
DECL_IGNORED_P (type_decl) = 1;
if (code == UNCONSTRAINED_ARRAY_TYPE || TYPE_IS_DUMMY_P (type)
|| !debug_info_p)
DECL_IGNORED_P (type_decl) = 1;
else if (code != ENUMERAL_TYPE && code != RECORD_TYPE
&& !((code == POINTER_TYPE || code == REFERENCE_TYPE)
&& TYPE_IS_DUMMY_P (TREE_TYPE (type))))
rest_of_decl_compilation (type_decl, global_bindings_p (), 0);
return type_decl;
}
/* Helper for create_var_decl and create_true_var_decl. Returns a GCC VAR_DECL
or CONST_DECL node.
VAR_NAME gives the name of the variable. ASM_NAME is its assembler name
(if provided). TYPE is its data type (a GCC ..._TYPE node). VAR_INIT is
the GCC tree for an optional initial expression; NULL_TREE if none.
CONST_FLAG is true if this variable is constant, in which case we might
return a CONST_DECL node unless CONST_DECL_ALLOWED_FLAG is false.
PUBLIC_FLAG is true if this definition is to be made visible outside of
the current compilation unit. This flag should be set when processing the
variable definitions in a package specification. EXTERN_FLAG is nonzero
when processing an external variable declaration (as opposed to a
definition: no storage is to be allocated for the variable here).
STATIC_FLAG is only relevant when not at top level. In that case
it indicates whether to always allocate storage to the variable.
GNAT_NODE is used for the position of the decl. */
static tree
create_var_decl_1 (tree var_name, tree asm_name, tree type, tree var_init,
bool const_flag, bool const_decl_allowed_flag,
bool public_flag, bool extern_flag, bool static_flag,
struct attrib *attr_list, Node_Id gnat_node)
{
bool init_const
= (!var_init
? false
: (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
&& (global_bindings_p () || static_flag
? 0 != initializer_constant_valid_p (var_init,
TREE_TYPE (var_init))
: TREE_CONSTANT (var_init))));
tree var_decl
= build_decl ((const_flag && const_decl_allowed_flag && init_const
/* Only make a CONST_DECL for sufficiently-small objects.
We consider complex double "sufficiently-small" */
&& TYPE_SIZE (type) != 0
&& host_integerp (TYPE_SIZE_UNIT (type), 1)
&& 0 >= compare_tree_int (TYPE_SIZE_UNIT (type),
GET_MODE_SIZE (DCmode)))
? CONST_DECL : VAR_DECL, var_name, type);
/* If this is external, throw away any initializations unless this is a
CONST_DECL (meaning we have a constant); they will be done elsewhere.
If we are defining a global here, leave a constant initialization and
save any variable elaborations for the elaboration routine. If we are
just annotating types, throw away the initialization if it isn't a
constant. */
if ((extern_flag && TREE_CODE (var_decl) != CONST_DECL)
|| (type_annotate_only && var_init && !TREE_CONSTANT (var_init)))
var_init = NULL_TREE;
/* At the global level, an initializer requiring code to be generated
produces elaboration statements. Check that such statements are allowed,
that is, not violating a No_Elaboration_Code restriction. */
if (global_bindings_p () && var_init != 0 && ! init_const)
Check_Elaboration_Code_Allowed (gnat_node);
/* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
try to fiddle with DECL_COMMON. However, on platforms that don't
support global BSS sections, uninitialized global variables would
go in DATA instead, thus increasing the size of the executable. */
if (!flag_no_common
&& TREE_CODE (var_decl) == VAR_DECL
&& !have_global_bss_p ())
DECL_COMMON (var_decl) = 1;
DECL_INITIAL (var_decl) = var_init;
TREE_READONLY (var_decl) = const_flag;
DECL_EXTERNAL (var_decl) = extern_flag;
TREE_PUBLIC (var_decl) = public_flag || extern_flag;
TREE_CONSTANT (var_decl) = TREE_CODE (var_decl) == CONST_DECL;
TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
= TYPE_VOLATILE (type);
/* If it's public and not external, always allocate storage for it.
At the global binding level we need to allocate static storage for the
variable if and only if it's not external. If we are not at the top level
we allocate automatic storage unless requested not to. */
TREE_STATIC (var_decl)
= public_flag || (global_bindings_p () ? !extern_flag : static_flag);
if (asm_name && VAR_OR_FUNCTION_DECL_P (var_decl))
SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
process_attributes (var_decl, attr_list);
/* Add this decl to the current binding level. */
gnat_pushdecl (var_decl, gnat_node);
if (TREE_SIDE_EFFECTS (var_decl))
TREE_ADDRESSABLE (var_decl) = 1;
if (TREE_CODE (var_decl) != CONST_DECL)
rest_of_decl_compilation (var_decl, global_bindings_p (), 0);
else
/* expand CONST_DECLs to set their MODE, ALIGN, SIZE and SIZE_UNIT,
which we need for later back-annotations. */
expand_decl (var_decl);
return var_decl;
}
/* Wrapper around create_var_decl_1 for cases where we don't care whether
a VAR or a CONST decl node is created. */
tree
create_var_decl (tree var_name, tree asm_name, tree type, tree var_init,
bool const_flag, bool public_flag, bool extern_flag,
bool static_flag, struct attrib *attr_list,
Node_Id gnat_node)
{
return create_var_decl_1 (var_name, asm_name, type, var_init,
const_flag, true,
public_flag, extern_flag, static_flag,
attr_list, gnat_node);
}
/* Wrapper around create_var_decl_1 for cases where a VAR_DECL node is
required. The primary intent is for DECL_CONST_CORRESPONDING_VARs, which
must be VAR_DECLs and on which we want TREE_READONLY set to have them
possibly assigned to a readonly data section. */
tree
create_true_var_decl (tree var_name, tree asm_name, tree type, tree var_init,
bool const_flag, bool public_flag, bool extern_flag,
bool static_flag, struct attrib *attr_list,
Node_Id gnat_node)
{
return create_var_decl_1 (var_name, asm_name, type, var_init,
const_flag, false,
public_flag, extern_flag, static_flag,
attr_list, gnat_node);
}
/* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
this field is in a record type with a "pragma pack". If SIZE is nonzero
it is the specified size for this field. If POS is nonzero, it is the bit
position. If ADDRESSABLE is nonzero, it means we are allowed to take
the address of this field for aliasing purposes. If it is negative, we
should not make a bitfield, which is used by make_aligning_type. */
tree
create_field_decl (tree field_name, tree field_type, tree record_type,
int packed, tree size, tree pos, int addressable)
{
tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
DECL_CONTEXT (field_decl) = record_type;
TREE_READONLY (field_decl) = TYPE_READONLY (field_type);
/* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
byte boundary since GCC cannot handle less-aligned BLKmode bitfields. */
if (packed && TYPE_MODE (field_type) == BLKmode)
DECL_ALIGN (field_decl) = BITS_PER_UNIT;
/* If a size is specified, use it. Otherwise, if the record type is packed
compute a size to use, which may differ from the object's natural size.
We always set a size in this case to trigger the checks for bitfield
creation below, which is typically required when no position has been
specified. */
if (size)
size = convert (bitsizetype, size);
else if (packed == 1)
{
size = rm_size (field_type);
/* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
byte. */
if (TREE_CODE (size) == INTEGER_CST
&& compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
size = round_up (size, BITS_PER_UNIT);
}
/* If we may, according to ADDRESSABLE, make a bitfield if a size is
specified for two reasons: first if the size differs from the natural
size. Second, if the alignment is insufficient. There are a number of
ways the latter can be true.
We never make a bitfield if the type of the field has a nonconstant size,
because no such entity requiring bitfield operations should reach here.
We do *preventively* make a bitfield when there might be the need for it
but we don't have all the necessary information to decide, as is the case
of a field with no specified position in a packed record.
We also don't look at STRICT_ALIGNMENT here, and rely on later processing
in layout_decl or finish_record_type to clear the bit_field indication if
it is in fact not needed. */
if (addressable >= 0
&& size
&& TREE_CODE (size) == INTEGER_CST
&& TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
&& (!operand_equal_p (TYPE_SIZE (field_type), size, 0)
|| (pos && !value_factor_p (pos, TYPE_ALIGN (field_type)))
|| packed
|| (TYPE_ALIGN (record_type) != 0
&& TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
{
DECL_BIT_FIELD (field_decl) = 1;
DECL_SIZE (field_decl) = size;
if (!packed && !pos)
DECL_ALIGN (field_decl)
= (TYPE_ALIGN (record_type) != 0
? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
: TYPE_ALIGN (field_type));
}
DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed;
DECL_ALIGN (field_decl)
= MAX (DECL_ALIGN (field_decl),
DECL_BIT_FIELD (field_decl) ? 1
: packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT
: TYPE_ALIGN (field_type));
if (pos)
{
/* We need to pass in the alignment the DECL is known to have.
This is the lowest-order bit set in POS, but no more than
the alignment of the record, if one is specified. Note
that an alignment of 0 is taken as infinite. */
unsigned int known_align;
if (host_integerp (pos, 1))
known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
else
known_align = BITS_PER_UNIT;
if (TYPE_ALIGN (record_type)
&& (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
known_align = TYPE_ALIGN (record_type);
layout_decl (field_decl, known_align);
SET_DECL_OFFSET_ALIGN (field_decl,
host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
: BITS_PER_UNIT);
pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
&DECL_FIELD_BIT_OFFSET (field_decl),
DECL_OFFSET_ALIGN (field_decl), pos);
DECL_HAS_REP_P (field_decl) = 1;
}
/* If the field type is passed by reference, we will have pointers to the
field, so it is addressable. */
if (must_pass_by_ref (field_type) || default_pass_by_ref (field_type))
addressable = 1;
/* Mark the decl as nonaddressable if it is indicated so semantically,
meaning we won't ever attempt to take the address of the field.
It may also be "technically" nonaddressable, meaning that even if we
attempt to take the field's address we will actually get the address of a
copy. This is the case for true bitfields, but the DECL_BIT_FIELD value
we have at this point is not accurate enough, so we don't account for
this here and let finish_record_type decide. */
DECL_NONADDRESSABLE_P (field_decl) = !addressable;
return field_decl;
}
/* Subroutine of previous function: return nonzero if EXP, ignoring any side
effects, has the value of zero. */
static bool
value_zerop (tree exp)
{
if (TREE_CODE (exp) == COMPOUND_EXPR)
return value_zerop (TREE_OPERAND (exp, 1));
return integer_zerop (exp);
}
/* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
PARAM_TYPE is its type. READONLY is true if the parameter is
readonly (either an IN parameter or an address of a pass-by-ref
parameter). */
tree
create_param_decl (tree param_name, tree param_type, bool readonly)
{
tree param_decl = build_decl (PARM_DECL, param_name, param_type);
/* Honor targetm.calls.promote_prototypes(), as not doing so can
lead to various ABI violations. */
if (targetm.calls.promote_prototypes (param_type)
&& (TREE_CODE (param_type) == INTEGER_TYPE
|| TREE_CODE (param_type) == ENUMERAL_TYPE)
&& TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
{
/* We have to be careful about biased types here. Make a subtype
of integer_type_node with the proper biasing. */
if (TREE_CODE (param_type) == INTEGER_TYPE
&& TYPE_BIASED_REPRESENTATION_P (param_type))
{
param_type
= copy_type (build_range_type (integer_type_node,
TYPE_MIN_VALUE (param_type),
TYPE_MAX_VALUE (param_type)));
TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
}
else
param_type = integer_type_node;
}
DECL_ARG_TYPE (param_decl) = param_type;
TREE_READONLY (param_decl) = readonly;
return param_decl;
}
/* Given a DECL and ATTR_LIST, process the listed attributes. */
void
process_attributes (tree decl, struct attrib *attr_list)
{
for (; attr_list; attr_list = attr_list->next)
switch (attr_list->type)
{
case ATTR_MACHINE_ATTRIBUTE:
decl_attributes (&decl, tree_cons (attr_list->name, attr_list->args,
NULL_TREE),
ATTR_FLAG_TYPE_IN_PLACE);
break;
case ATTR_LINK_ALIAS:
if (! DECL_EXTERNAL (decl))
{
TREE_STATIC (decl) = 1;
assemble_alias (decl, attr_list->name);
}
break;
case ATTR_WEAK_EXTERNAL:
if (SUPPORTS_WEAK)
declare_weak (decl);
else
post_error ("?weak declarations not supported on this target",
attr_list->error_point);
break;
case ATTR_LINK_SECTION:
if (targetm.have_named_sections)
{
DECL_SECTION_NAME (decl)
= build_string (IDENTIFIER_LENGTH (attr_list->name),
IDENTIFIER_POINTER (attr_list->name));
DECL_COMMON (decl) = 0;
}
else
post_error ("?section attributes are not supported for this target",
attr_list->error_point);
break;
case ATTR_LINK_CONSTRUCTOR:
DECL_STATIC_CONSTRUCTOR (decl) = 1;
TREE_USED (decl) = 1;
break;
case ATTR_LINK_DESTRUCTOR:
DECL_STATIC_DESTRUCTOR (decl) = 1;
TREE_USED (decl) = 1;
break;
}
}
/* Record a global renaming pointer. */
void
record_global_renaming_pointer (tree decl)
{
gcc_assert (DECL_RENAMED_OBJECT (decl));
VEC_safe_push (tree, gc, global_renaming_pointers, decl);
}
/* Invalidate the global renaming pointers. */
void
invalidate_global_renaming_pointers (void)
{
unsigned int i;
tree iter;
for (i = 0; VEC_iterate(tree, global_renaming_pointers, i, iter); i++)
SET_DECL_RENAMED_OBJECT (iter, NULL_TREE);
VEC_free (tree, gc, global_renaming_pointers);
}
/* Return true if VALUE is a known to be a multiple of FACTOR, which must be
a power of 2. */
bool
value_factor_p (tree value, HOST_WIDE_INT factor)
{
if (host_integerp (value, 1))
return tree_low_cst (value, 1) % factor == 0;
if (TREE_CODE (value) == MULT_EXPR)
return (value_factor_p (TREE_OPERAND (value, 0), factor)
|| value_factor_p (TREE_OPERAND (value, 1), factor));
return 0;
}
/* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
unless we can prove these 2 fields are laid out in such a way that no gap
exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
is the distance in bits between the end of PREV_FIELD and the starting
position of CURR_FIELD. It is ignored if null. */
static bool
potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
{
/* If this is the first field of the record, there cannot be any gap */
if (!prev_field)
return false;
/* If the previous field is a union type, then return False: The only
time when such a field is not the last field of the record is when
there are other components at fixed positions after it (meaning there
was a rep clause for every field), in which case we don't want the
alignment constraint to override them. */
if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
return false;
/* If the distance between the end of prev_field and the beginning of
curr_field is constant, then there is a gap if the value of this
constant is not null. */
if (offset && host_integerp (offset, 1))
return !integer_zerop (offset);
/* If the size and position of the previous field are constant,
then check the sum of this size and position. There will be a gap
iff it is not multiple of the current field alignment. */
if (host_integerp (DECL_SIZE (prev_field), 1)
&& host_integerp (bit_position (prev_field), 1))
return ((tree_low_cst (bit_position (prev_field), 1)
+ tree_low_cst (DECL_SIZE (prev_field), 1))
% DECL_ALIGN (curr_field) != 0);
/* If both the position and size of the previous field are multiples
of the current field alignment, there cannot be any gap. */
if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
&& value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
return false;
/* Fallback, return that there may be a potential gap */
return true;
}
/* Returns a LABEL_DECL node for LABEL_NAME. */
tree
create_label_decl (tree label_name)
{
tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
DECL_CONTEXT (label_decl) = current_function_decl;
DECL_MODE (label_decl) = VOIDmode;
DECL_SOURCE_LOCATION (label_decl) = input_location;
return label_decl;
}
/* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
PARM_DECL nodes chained through the TREE_CHAIN field).
INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
appropriate fields in the FUNCTION_DECL. GNAT_NODE gives the location. */
tree
create_subprog_decl (tree subprog_name, tree asm_name,
tree subprog_type, tree param_decl_list, bool inline_flag,
bool public_flag, bool extern_flag,
struct attrib *attr_list, Node_Id gnat_node)
{
tree return_type = TREE_TYPE (subprog_type);
tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
/* If this is a function nested inside an inlined external function, it
means we aren't going to compile the outer function unless it is
actually inlined, so do the same for us. */
if (current_function_decl && DECL_INLINE (current_function_decl)
&& DECL_EXTERNAL (current_function_decl))
extern_flag = true;
DECL_EXTERNAL (subprog_decl) = extern_flag;
TREE_PUBLIC (subprog_decl) = public_flag;
TREE_STATIC (subprog_decl) = 1;
TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
DECL_ARGUMENTS (subprog_decl) = param_decl_list;
DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
DECL_ARTIFICIAL (DECL_RESULT (subprog_decl)) = 1;
DECL_IGNORED_P (DECL_RESULT (subprog_decl)) = 1;
/* TREE_ADDRESSABLE is set on the result type to request the use of the
target by-reference return mechanism. This is not supported all the
way down to RTL expansion with GCC 4, which ICEs on temporary creation
attempts with such a type and expects DECL_BY_REFERENCE to be set on
the RESULT_DECL instead - see gnat_genericize for more details. */
if (TREE_ADDRESSABLE (TREE_TYPE (DECL_RESULT (subprog_decl))))
{
tree result_decl = DECL_RESULT (subprog_decl);
TREE_ADDRESSABLE (TREE_TYPE (result_decl)) = 0;
DECL_BY_REFERENCE (result_decl) = 1;
}
if (inline_flag)
DECL_DECLARED_INLINE_P (subprog_decl) = 1;
if (asm_name)
SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
process_attributes (subprog_decl, attr_list);
/* Add this decl to the current binding level. */
gnat_pushdecl (subprog_decl, gnat_node);
/* Output the assembler code and/or RTL for the declaration. */
rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0);
return subprog_decl;
}
/* Set up the framework for generating code for SUBPROG_DECL, a subprogram
body. This routine needs to be invoked before processing the declarations
appearing in the subprogram. */
void
begin_subprog_body (tree subprog_decl)
{
tree param_decl;
current_function_decl = subprog_decl;
announce_function (subprog_decl);
/* Enter a new binding level and show that all the parameters belong to
this function. */
gnat_pushlevel ();
for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl;
param_decl = TREE_CHAIN (param_decl))
DECL_CONTEXT (param_decl) = subprog_decl;
make_decl_rtl (subprog_decl);
/* We handle pending sizes via the elaboration of types, so we don't need to
save them. This causes them to be marked as part of the outer function
and then discarded. */
get_pending_sizes ();
}
/* Helper for the genericization callback. Return a dereference of VAL
if it is of a reference type. */
static tree
convert_from_reference (tree val)
{
tree value_type, ref;
if (TREE_CODE (TREE_TYPE (val)) != REFERENCE_TYPE)
return val;
value_type = TREE_TYPE (TREE_TYPE (val));
ref = build1 (INDIRECT_REF, value_type, val);
/* See if what we reference is CONST or VOLATILE, which requires
looking into array types to get to the component type. */
while (TREE_CODE (value_type) == ARRAY_TYPE)
value_type = TREE_TYPE (value_type);
TREE_READONLY (ref)
= (TYPE_QUALS (value_type) & TYPE_QUAL_CONST);
TREE_THIS_VOLATILE (ref)
= (TYPE_QUALS (value_type) & TYPE_QUAL_VOLATILE);
TREE_SIDE_EFFECTS (ref)
= (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val));
return ref;
}
/* Helper for the genericization callback. Returns true if T denotes
a RESULT_DECL with DECL_BY_REFERENCE set. */
static inline bool
is_byref_result (tree t)
{
return (TREE_CODE (t) == RESULT_DECL && DECL_BY_REFERENCE (t));
}
/* Tree walking callback for gnat_genericize. Currently ...
o Adjust references to the function's DECL_RESULT if it is marked
DECL_BY_REFERENCE and so has had its type turned into a reference
type at the end of the function compilation. */
static tree
gnat_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
{
/* This implementation is modeled after what the C++ front-end is
doing, basis of the downstream passes behavior. */
tree stmt = *stmt_p;
struct pointer_set_t *p_set = (struct pointer_set_t*) data;
/* If we have a direct mention of the result decl, dereference. */
if (is_byref_result (stmt))
{
*stmt_p = convert_from_reference (stmt);
*walk_subtrees = 0;
return NULL;
}
/* Otherwise, no need to walk the the same tree twice. */
if (pointer_set_contains (p_set, stmt))
{
*walk_subtrees = 0;
return NULL_TREE;
}
/* If we are taking the address of what now is a reference, just get the
reference value. */
if (TREE_CODE (stmt) == ADDR_EXPR
&& is_byref_result (TREE_OPERAND (stmt, 0)))
{
*stmt_p = convert (TREE_TYPE (stmt), TREE_OPERAND (stmt, 0));
*walk_subtrees = 0;
}
/* Don't dereference an by-reference RESULT_DECL inside a RETURN_EXPR. */
else if (TREE_CODE (stmt) == RETURN_EXPR
&& TREE_OPERAND (stmt, 0)
&& is_byref_result (TREE_OPERAND (stmt, 0)))
*walk_subtrees = 0;
/* Don't look inside trees that cannot embed references of interest. */
else if (IS_TYPE_OR_DECL_P (stmt))
*walk_subtrees = 0;
pointer_set_insert (p_set, *stmt_p);
return NULL;
}
/* Perform lowering of Ada trees to GENERIC. In particular:
o Turn a DECL_BY_REFERENCE RESULT_DECL into a real by-reference decl
and adjust all the references to this decl accordingly. */
static void
gnat_genericize (tree fndecl)
{
/* Prior to GCC 4, an explicit By_Reference result mechanism for a function
was handled by simply setting TREE_ADDRESSABLE on the result type.
Everything required to actually pass by invisible ref using the target
mechanism (e.g. extra parameter) was handled at RTL expansion time.
This doesn't work with GCC 4 any more for several reasons. First, the
gimplification process might need the creation of temporaries of this
type, and the gimplifier ICEs on such attempts. Second, the middle-end
now relies on a different attribute for such cases (DECL_BY_REFERENCE on
RESULT/PARM_DECLs), and expects the user invisible by-reference-ness to
be explicitely accounted for by the front-end in the function body.
We achieve the complete transformation in two steps:
1/ create_subprog_decl performs early attribute tweaks: it clears
TREE_ADDRESSABLE from the result type and sets DECL_BY_REFERENCE on
the result decl. The former ensures that the bit isn't set in the GCC
tree saved for the function, so prevents ICEs on temporary creation.
The latter we use here to trigger the rest of the processing.
2/ This function performs the type transformation on the result decl
and adjusts all the references to this decl from the function body
accordingly.
Clearing TREE_ADDRESSABLE from the type differs from the C++ front-end
strategy, which escapes the gimplifier temporary creation issues by
creating it's own temporaries using TARGET_EXPR nodes. Our way relies
on simple specific support code in aggregate_value_p to look at the
target function result decl explicitely. */
struct pointer_set_t *p_set;
tree decl_result = DECL_RESULT (fndecl);
if (!DECL_BY_REFERENCE (decl_result))
return;
/* Make the DECL_RESULT explicitely by-reference and adjust all the
occurrences in the function body using the common tree-walking facility.
We want to see every occurrence of the result decl to adjust the
referencing tree, so need to use our own pointer set to control which
trees should be visited again or not. */
p_set = pointer_set_create ();
TREE_TYPE (decl_result) = build_reference_type (TREE_TYPE (decl_result));
TREE_ADDRESSABLE (decl_result) = 0;
relayout_decl (decl_result);
walk_tree (&DECL_SAVED_TREE (fndecl), gnat_genericize_r, p_set, NULL);
pointer_set_destroy (p_set);
}
/* Finish the definition of the current subprogram and compile it all the way
to assembler language output. BODY is the tree corresponding to
the subprogram. */
void
end_subprog_body (tree body)
{
tree fndecl = current_function_decl;
/* Mark the BLOCK for this level as being for this function and pop the
level. Since the vars in it are the parameters, clear them. */
BLOCK_VARS (current_binding_level->block) = 0;
BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
DECL_INITIAL (fndecl) = current_binding_level->block;
gnat_poplevel ();
/* Deal with inline. If declared inline or we should default to inline,
set the flag in the decl. */
DECL_INLINE (fndecl)
= DECL_DECLARED_INLINE_P (fndecl) || flag_inline_trees == 2;
/* We handle pending sizes via the elaboration of types, so we don't
need to save them. */
get_pending_sizes ();
/* Mark the RESULT_DECL as being in this subprogram. */
DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
DECL_SAVED_TREE (fndecl) = body;
current_function_decl = DECL_CONTEXT (fndecl);
cfun = NULL;
/* If we're only annotating types, don't actually compile this function. */
if (type_annotate_only)
return;
/* If we don't have .ctors/.dtors sections, and this is a static
constructor or destructor, it must be recorded now. */
if (DECL_STATIC_CONSTRUCTOR (fndecl) && !targetm.have_ctors_dtors)
VEC_safe_push (tree, gc, static_ctors, fndecl);
if (DECL_STATIC_DESTRUCTOR (fndecl) && !targetm.have_ctors_dtors)
VEC_safe_push (tree, gc, static_dtors, fndecl);
/* Perform the required pre-gimplfication transformations on the tree. */
gnat_genericize (fndecl);
/* We do different things for nested and non-nested functions.
??? This should be in cgraph. */
if (!DECL_CONTEXT (fndecl))
{
gnat_gimplify_function (fndecl);
cgraph_finalize_function (fndecl, false);
}
else
/* Register this function with cgraph just far enough to get it
added to our parent's nested function list. */
(void) cgraph_node (fndecl);
}
/* Convert FNDECL's code to GIMPLE and handle any nested functions. */
static void
gnat_gimplify_function (tree fndecl)
{
struct cgraph_node *cgn;
dump_function (TDI_original, fndecl);
gimplify_function_tree (fndecl);
dump_function (TDI_generic, fndecl);
/* Convert all nested functions to GIMPLE now. We do things in this order
so that items like VLA sizes are expanded properly in the context of the
correct function. */
cgn = cgraph_node (fndecl);
for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
gnat_gimplify_function (cgn->decl);
}
tree
gnat_builtin_function (tree decl)
{
gnat_pushdecl (decl, Empty);
return decl;
}
/* Handle a "const" attribute; arguments as in
struct attribute_spec.handler. */
static tree
handle_const_attribute (tree *node, tree ARG_UNUSED (name),
tree ARG_UNUSED (args), int ARG_UNUSED (flags),
bool *no_add_attrs)
{
if (TREE_CODE (*node) == FUNCTION_DECL)
TREE_READONLY (*node) = 1;
else
*no_add_attrs = true;
return NULL_TREE;
}
/* Handle a "nothrow" attribute; arguments as in
struct attribute_spec.handler. */
static tree
handle_nothrow_attribute (tree *node, tree ARG_UNUSED (name),
tree ARG_UNUSED (args), int ARG_UNUSED (flags),
bool *no_add_attrs)
{
if (TREE_CODE (*node) == FUNCTION_DECL)
TREE_NOTHROW (*node) = 1;
else
*no_add_attrs = true;
return NULL_TREE;
}
/* Return an integer type with the number of bits of precision given by
PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
it is a signed type. */
tree
gnat_type_for_size (unsigned precision, int unsignedp)
{
tree t;
char type_name[20];
if (precision <= 2 * MAX_BITS_PER_WORD
&& signed_and_unsigned_types[precision][unsignedp])
return signed_and_unsigned_types[precision][unsignedp];
if (unsignedp)
t = make_unsigned_type (precision);
else
t = make_signed_type (precision);
if (precision <= 2 * MAX_BITS_PER_WORD)
signed_and_unsigned_types[precision][unsignedp] = t;
if (!TYPE_NAME (t))
{
sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
TYPE_NAME (t) = get_identifier (type_name);
}
return t;
}
/* Likewise for floating-point types. */
static tree
float_type_for_precision (int precision, enum machine_mode mode)
{
tree t;
char type_name[20];
if (float_types[(int) mode])
return float_types[(int) mode];
float_types[(int) mode] = t = make_node (REAL_TYPE);
TYPE_PRECISION (t) = precision;
layout_type (t);
gcc_assert (TYPE_MODE (t) == mode);
if (!TYPE_NAME (t))
{
sprintf (type_name, "FLOAT_%d", precision);
TYPE_NAME (t) = get_identifier (type_name);
}
return t;
}
/* Return a data type that has machine mode MODE. UNSIGNEDP selects
an unsigned type; otherwise a signed type is returned. */
tree
gnat_type_for_mode (enum machine_mode mode, int unsignedp)
{
if (mode == BLKmode)
return NULL_TREE;
else if (mode == VOIDmode)
return void_type_node;
else if (COMPLEX_MODE_P (mode))
return NULL_TREE;
else if (SCALAR_FLOAT_MODE_P (mode))
return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
else if (SCALAR_INT_MODE_P (mode))
return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
else
return NULL_TREE;
}
/* Return the unsigned version of a TYPE_NODE, a scalar type. */
tree
gnat_unsigned_type (tree type_node)
{
tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
{
type = copy_node (type);
TREE_TYPE (type) = type_node;
}
else if (TREE_TYPE (type_node)
&& TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
&& TYPE_MODULAR_P (TREE_TYPE (type_node)))
{
type = copy_node (type);
TREE_TYPE (type) = TREE_TYPE (type_node);
}
return type;
}
/* Return the signed version of a TYPE_NODE, a scalar type. */
tree
gnat_signed_type (tree type_node)
{
tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
{
type = copy_node (type);
TREE_TYPE (type) = type_node;
}
else if (TREE_TYPE (type_node)
&& TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
&& TYPE_MODULAR_P (TREE_TYPE (type_node)))
{
type = copy_node (type);
TREE_TYPE (type) = TREE_TYPE (type_node);
}
return type;
}
/* Return a type the same as TYPE except unsigned or signed according to
UNSIGNEDP. */
tree
gnat_signed_or_unsigned_type (int unsignedp, tree type)
{
if (!INTEGRAL_TYPE_P (type) || TYPE_UNSIGNED (type) == unsignedp)
return type;
else
return gnat_type_for_size (TYPE_PRECISION (type), unsignedp);
}
/* EXP is an expression for the size of an object. If this size contains
discriminant references, replace them with the maximum (if MAX_P) or
minimum (if !MAX_P) possible value of the discriminant. */
tree
max_size (tree exp, bool max_p)
{
enum tree_code code = TREE_CODE (exp);
tree type = TREE_TYPE (exp);
switch (TREE_CODE_CLASS (code))
{
case tcc_declaration:
case tcc_constant:
return exp;
case tcc_exceptional:
if (code == TREE_LIST)
return tree_cons (TREE_PURPOSE (exp),
max_size (TREE_VALUE (exp), max_p),
TREE_CHAIN (exp)
? max_size (TREE_CHAIN (exp), max_p) : NULL_TREE);
break;
case tcc_reference:
/* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
modify. Otherwise, we treat it like a variable. */
if (!CONTAINS_PLACEHOLDER_P (exp))
return exp;
type = TREE_TYPE (TREE_OPERAND (exp, 1));
return
max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), true);
case tcc_comparison:
return max_p ? size_one_node : size_zero_node;
case tcc_unary:
case tcc_binary:
case tcc_expression:
switch (TREE_CODE_LENGTH (code))
{
case 1:
if (code == NON_LVALUE_EXPR)
return max_size (TREE_OPERAND (exp, 0), max_p);
else
return
fold (build1 (code, type,
max_size (TREE_OPERAND (exp, 0),
code == NEGATE_EXPR ? !max_p : max_p)));
case 2:
if (code == COMPOUND_EXPR)
return max_size (TREE_OPERAND (exp, 1), max_p);
/* Calculate "(A ? B : C) - D" as "A ? B - D : C - D" which
may provide a tighter bound on max_size. */
if (code == MINUS_EXPR
&& TREE_CODE (TREE_OPERAND (exp, 0)) == COND_EXPR)
{
tree lhs = fold_build2 (MINUS_EXPR, type,
TREE_OPERAND (TREE_OPERAND (exp, 0), 1),
TREE_OPERAND (exp, 1));
tree rhs = fold_build2 (MINUS_EXPR, type,
TREE_OPERAND (TREE_OPERAND (exp, 0), 2),
TREE_OPERAND (exp, 1));
return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
max_size (lhs, max_p),
max_size (rhs, max_p));
}
{
tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
tree rhs = max_size (TREE_OPERAND (exp, 1),
code == MINUS_EXPR ? !max_p : max_p);
/* Special-case wanting the maximum value of a MIN_EXPR.
In that case, if one side overflows, return the other.
sizetype is signed, but we know sizes are non-negative.
Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
overflowing or the maximum possible value and the RHS
a variable. */
if (max_p
&& code == MIN_EXPR
&& TREE_CODE (rhs) == INTEGER_CST
&& TREE_OVERFLOW (rhs))
return lhs;
else if (max_p
&& code == MIN_EXPR
&& TREE_CODE (lhs) == INTEGER_CST
&& TREE_OVERFLOW (lhs))
return rhs;
else if ((code == MINUS_EXPR || code == PLUS_EXPR)
&& ((TREE_CODE (lhs) == INTEGER_CST
&& TREE_OVERFLOW (lhs))
|| operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
&& !TREE_CONSTANT (rhs))
return lhs;
else
return fold (build2 (code, type, lhs, rhs));
}
case 3:
if (code == SAVE_EXPR)
return exp;
else if (code == COND_EXPR)
return fold (build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
max_size (TREE_OPERAND (exp, 1), max_p),
max_size (TREE_OPERAND (exp, 2), max_p)));
else if (code == CALL_EXPR && TREE_OPERAND (exp, 1))
return build3 (CALL_EXPR, type, TREE_OPERAND (exp, 0),
max_size (TREE_OPERAND (exp, 1), max_p), NULL);
}
/* Other tree classes cannot happen. */
default:
break;
}
gcc_unreachable ();
}
/* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
Return a constructor for the template. */
tree
build_template (tree template_type, tree array_type, tree expr)
{
tree template_elts = NULL_TREE;
tree bound_list = NULL_TREE;
tree field;
if (TREE_CODE (array_type) == RECORD_TYPE
&& (TYPE_IS_PADDING_P (array_type)
|| TYPE_JUSTIFIED_MODULAR_P (array_type)))
array_type = TREE_TYPE (TYPE_FIELDS (array_type));
if (TREE_CODE (array_type) == ARRAY_TYPE
|| (TREE_CODE (array_type) == INTEGER_TYPE
&& TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
bound_list = TYPE_ACTUAL_BOUNDS (array_type);
/* First make the list for a CONSTRUCTOR for the template. Go down the
field list of the template instead of the type chain because this
array might be an Ada array of arrays and we can't tell where the
nested arrays stop being the underlying object. */
for (field = TYPE_FIELDS (template_type); field;
(bound_list
? (bound_list = TREE_CHAIN (bound_list))
: (array_type = TREE_TYPE (array_type))),
field = TREE_CHAIN (TREE_CHAIN (field)))
{
tree bounds, min, max;
/* If we have a bound list, get the bounds from there. Likewise
for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
This will give us a maximum range. */
if (bound_list)
bounds = TREE_VALUE (bound_list);
else if (TREE_CODE (array_type) == ARRAY_TYPE)
bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
else if (expr && TREE_CODE (expr) == PARM_DECL
&& DECL_BY_COMPONENT_PTR_P (expr))
bounds = TREE_TYPE (field);
else
gcc_unreachable ();
min = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MIN_VALUE (bounds));
max = convert (TREE_TYPE (field), TYPE_MAX_VALUE (bounds));
/* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
substitute it from OBJECT. */
min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr);
max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr);
template_elts = tree_cons (TREE_CHAIN (field), max,
tree_cons (field, min, template_elts));
}
return gnat_build_constructor (template_type, nreverse (template_elts));
}
/* Build a VMS descriptor from a Mechanism_Type, which must specify
a descriptor type, and the GCC type of an object. Each FIELD_DECL
in the type contains in its DECL_INITIAL the expression to use when
a constructor is made for the type. GNAT_ENTITY is an entity used
to print out an error message if the mechanism cannot be applied to
an object of that type and also for the name. */
tree
build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
{
tree record_type = make_node (RECORD_TYPE);
tree field_list = 0;
int class;
int dtype = 0;
tree inner_type;
int ndim;
int i;
tree *idx_arr;
tree tem;
/* If TYPE is an unconstrained array, use the underlying array type. */
if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
/* If this is an array, compute the number of dimensions in the array,
get the index types, and point to the inner type. */
if (TREE_CODE (type) != ARRAY_TYPE)
ndim = 0;
else
for (ndim = 1, inner_type = type;
TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
&& TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
ndim++, inner_type = TREE_TYPE (inner_type))
;
idx_arr = (tree *) alloca (ndim * sizeof (tree));
if (mech != By_Descriptor_NCA
&& TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
for (i = ndim - 1, inner_type = type;
i >= 0;
i--, inner_type = TREE_TYPE (inner_type))
idx_arr[i] = TYPE_DOMAIN (inner_type);
else
for (i = 0, inner_type = type;
i < ndim;
i++, inner_type = TREE_TYPE (inner_type))
idx_arr[i] = TYPE_DOMAIN (inner_type);
/* Now get the DTYPE value. */
switch (TREE_CODE (type))
{
case INTEGER_TYPE:
case ENUMERAL_TYPE:
if (TYPE_VAX_FLOATING_POINT_P (type))
switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
{
case 6:
dtype = 10;
break;
case 9:
dtype = 11;
break;
case 15:
dtype = 27;
break;
}
else
switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
{
case 8:
dtype = TYPE_UNSIGNED (type) ? 2 : 6;
break;
case 16:
dtype = TYPE_UNSIGNED (type) ? 3 : 7;
break;
case 32:
dtype = TYPE_UNSIGNED (type) ? 4 : 8;
break;
case 64:
dtype = TYPE_UNSIGNED (type) ? 5 : 9;
break;
case 128:
dtype = TYPE_UNSIGNED (type) ? 25 : 26;
break;
}
break;
case REAL_TYPE:
dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
break;
case COMPLEX_TYPE:
if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
&& TYPE_VAX_FLOATING_POINT_P (type))
switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
{
case 6:
dtype = 12;
break;
case 9:
dtype = 13;
break;
case 15:
dtype = 29;
}
else
dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
break;
case ARRAY_TYPE:
dtype = 14;
break;
default:
break;
}
/* Get the CLASS value. */
switch (mech)
{
case By_Descriptor_A:
class = 4;
break;
case By_Descriptor_NCA:
class = 10;
break;
case By_Descriptor_SB:
class = 15;
break;
default:
class = 1;
}
/* Make the type for a descriptor for VMS. The first four fields
are the same for all types. */
field_list
= chainon (field_list,
make_descriptor_field
("LENGTH", gnat_type_for_size (16, 1), record_type,
size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
field_list = chainon (field_list,
make_descriptor_field ("DTYPE",
gnat_type_for_size (8, 1),
record_type, size_int (dtype)));
field_list = chainon (field_list,
make_descriptor_field ("CLASS",
gnat_type_for_size (8, 1),
record_type, size_int (class)));
field_list
= chainon (field_list,
make_descriptor_field
("POINTER",
build_pointer_type_for_mode (type, SImode, false), record_type,
build1 (ADDR_EXPR,
build_pointer_type_for_mode (type, SImode, false),
build0 (PLACEHOLDER_EXPR, type))));
switch (mech)
{
case By_Descriptor:
case By_Descriptor_S:
break;
case By_Descriptor_SB:
field_list
= chainon (field_list,
make_descriptor_field
("SB_L1", gnat_type_for_size (32, 1), record_type,
TREE_CODE (type) == ARRAY_TYPE
? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
field_list
= chainon (field_list,
make_descriptor_field
("SB_L2", gnat_type_for_size (32, 1), record_type,
TREE_CODE (type) == ARRAY_TYPE
? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
break;
case By_Descriptor_A:
case By_Descriptor_NCA:
field_list = chainon (field_list,
make_descriptor_field ("SCALE",
gnat_type_for_size (8, 1),
record_type,
size_zero_node));
field_list = chainon (field_list,
make_descriptor_field ("DIGITS",
gnat_type_for_size (8, 1),
record_type,
size_zero_node));
field_list
= chainon (field_list,
make_descriptor_field
("AFLAGS", gnat_type_for_size (8, 1), record_type,
size_int (mech == By_Descriptor_NCA
? 0
/* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
: (TREE_CODE (type) == ARRAY_TYPE
&& TYPE_CONVENTION_FORTRAN_P (type)
? 224 : 192))));
field_list = chainon (field_list,
make_descriptor_field ("DIMCT",
gnat_type_for_size (8, 1),
record_type,
size_int (ndim)));
field_list = chainon (field_list,
make_descriptor_field ("ARSIZE",
gnat_type_for_size (32, 1),
record_type,
size_in_bytes (type)));
/* Now build a pointer to the 0,0,0... element. */
tem = build0 (PLACEHOLDER_EXPR, type);
for (i = 0, inner_type = type; i < ndim;
i++, inner_type = TREE_TYPE (inner_type))
tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem,
convert (TYPE_DOMAIN (inner_type), size_zero_node),
NULL_TREE, NULL_TREE);
field_list
= chainon (field_list,
make_descriptor_field
("A0",
build_pointer_type_for_mode (inner_type, SImode, false),
record_type,
build1 (ADDR_EXPR,
build_pointer_type_for_mode (inner_type, SImode,
false),
tem)));
/* Next come the addressing coefficients. */
tem = size_int (1);
for (i = 0; i < ndim; i++)
{
char fname[3];
tree idx_length
= size_binop (MULT_EXPR, tem,
size_binop (PLUS_EXPR,
size_binop (MINUS_EXPR,
TYPE_MAX_VALUE (idx_arr[i]),
TYPE_MIN_VALUE (idx_arr[i])),
size_int (1)));
fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
fname[1] = '0' + i, fname[2] = 0;
field_list
= chainon (field_list,
make_descriptor_field (fname,
gnat_type_for_size (32, 1),
record_type, idx_length));
if (mech == By_Descriptor_NCA)
tem = idx_length;
}
/* Finally here are the bounds. */
for (i = 0; i < ndim; i++)
{
char fname[3];
fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
field_list
= chainon (field_list,
make_descriptor_field
(fname, gnat_type_for_size (32, 1), record_type,
TYPE_MIN_VALUE (idx_arr[i])));
fname[0] = 'U';
field_list
= chainon (field_list,
make_descriptor_field
(fname, gnat_type_for_size (32, 1), record_type,
TYPE_MAX_VALUE (idx_arr[i])));
}
break;
default:
post_error ("unsupported descriptor type for &", gnat_entity);
}
finish_record_type (record_type, field_list, false, true);
create_type_decl (create_concat_name (gnat_entity, "DESC"), record_type,
NULL, true, false, gnat_entity);
return record_type;
}
/* Utility routine for above code to make a field. */
static tree
make_descriptor_field (const char *name, tree type,
tree rec_type, tree initial)
{
tree field
= create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
DECL_INITIAL (field) = initial;
return field;
}
/* Build a type to be used to represent an aliased object whose nominal
type is an unconstrained array. This consists of a RECORD_TYPE containing
a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
is used to represent an arbitrary unconstrained object. Use NAME
as the name of the record. */
tree
build_unc_object_type (tree template_type, tree object_type, tree name)
{
tree type = make_node (RECORD_TYPE);
tree template_field = create_field_decl (get_identifier ("BOUNDS"),
template_type, type, 0, 0, 0, 1);
tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
type, 0, 0, 0, 1);
TYPE_NAME (type) = name;
TYPE_CONTAINS_TEMPLATE_P (type) = 1;
finish_record_type (type,
chainon (chainon (NULL_TREE, template_field),
array_field),
false, false);
return type;
}
/* Same, taking a thin or fat pointer type instead of a template type. */
tree
build_unc_object_type_from_ptr (tree thin_fat_ptr_type, tree object_type,
tree name)
{
tree template_type;
gcc_assert (TYPE_FAT_OR_THIN_POINTER_P (thin_fat_ptr_type));
template_type
= (TYPE_FAT_POINTER_P (thin_fat_ptr_type)
? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (thin_fat_ptr_type))))
: TREE_TYPE (TYPE_FIELDS (TREE_TYPE (thin_fat_ptr_type))));
return build_unc_object_type (template_type, object_type, name);
}
/* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In
the normal case this is just two adjustments, but we have more to do
if NEW is an UNCONSTRAINED_ARRAY_TYPE. */
void
update_pointer_to (tree old_type, tree new_type)
{
tree ptr = TYPE_POINTER_TO (old_type);
tree ref = TYPE_REFERENCE_TO (old_type);
tree ptr1, ref1;
tree type;
/* If this is the main variant, process all the other variants first. */
if (TYPE_MAIN_VARIANT (old_type) == old_type)
for (type = TYPE_NEXT_VARIANT (old_type); type;
type = TYPE_NEXT_VARIANT (type))
update_pointer_to (type, new_type);
/* If no pointer or reference, we are done. */
if (!ptr && !ref)
return;
/* Merge the old type qualifiers in the new type.
Each old variant has qualifiers for specific reasons, and the new
designated type as well. Each set of qualifiers represents useful
information grabbed at some point, and merging the two simply unifies
these inputs into the final type description.
Consider for instance a volatile type frozen after an access to constant
type designating it. After the designated type freeze, we get here with a
volatile new_type and a dummy old_type with a readonly variant, created
when the access type was processed. We shall make a volatile and readonly
designated type, because that's what it really is.
We might also get here for a non-dummy old_type variant with different
qualifiers than the new_type ones, for instance in some cases of pointers
to private record type elaboration (see the comments around the call to
this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the
qualifiers in thoses cases too, to avoid accidentally discarding the
initial set, and will often end up with old_type == new_type then. */
new_type = build_qualified_type (new_type,
TYPE_QUALS (old_type)
| TYPE_QUALS (new_type));
/* If the new type and the old one are identical, there is nothing to
update. */
if (old_type == new_type)
return;
/* Otherwise, first handle the simple case. */
if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
{
TYPE_POINTER_TO (new_type) = ptr;
TYPE_REFERENCE_TO (new_type) = ref;
for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr))
for (ptr1 = TYPE_MAIN_VARIANT (ptr); ptr1;
ptr1 = TYPE_NEXT_VARIANT (ptr1))
TREE_TYPE (ptr1) = new_type;
for (; ref; ref = TYPE_NEXT_REF_TO (ref))
for (ref1 = TYPE_MAIN_VARIANT (ref); ref1;
ref1 = TYPE_NEXT_VARIANT (ref1))
TREE_TYPE (ref1) = new_type;
}
/* Now deal with the unconstrained array case. In this case the "pointer"
is actually a RECORD_TYPE where the types of both fields are
pointers to void. In that case, copy the field list from the
old type to the new one and update the fields' context. */
else if (TREE_CODE (ptr) != RECORD_TYPE || !TYPE_IS_FAT_POINTER_P (ptr))
gcc_unreachable ();
else
{
tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
tree ptr_temp_type;
tree new_ref;
tree var;
SET_DECL_ORIGINAL_FIELD (TYPE_FIELDS (ptr),
TYPE_FIELDS (TYPE_POINTER_TO (new_type)));
SET_DECL_ORIGINAL_FIELD (TREE_CHAIN (TYPE_FIELDS (ptr)),
TREE_CHAIN (TYPE_FIELDS
(TYPE_POINTER_TO (new_type))));
TYPE_FIELDS (ptr) = TYPE_FIELDS (TYPE_POINTER_TO (new_type));
DECL_CONTEXT (TYPE_FIELDS (ptr)) = ptr;
DECL_CONTEXT (TREE_CHAIN (TYPE_FIELDS (ptr))) = ptr;
/* Rework the PLACEHOLDER_EXPR inside the reference to the
template bounds.
??? This is now the only use of gnat_substitute_in_type, which
is now a very "heavy" routine to do this, so it should be replaced
at some point. */
ptr_temp_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (ptr)));
new_ref = build3 (COMPONENT_REF, ptr_temp_type,
build0 (PLACEHOLDER_EXPR, ptr),
TREE_CHAIN (TYPE_FIELDS (ptr)), NULL_TREE);
update_pointer_to
(TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
gnat_substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
TREE_CHAIN (TYPE_FIELDS (ptr)), new_ref));
for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
{
SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
/* This may seem a bit gross, in particular wrt DECL_CONTEXT, but
actually is in keeping with what build_qualified_type does. */
TYPE_FIELDS (var) = TYPE_FIELDS (ptr);
}
TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
= TREE_TYPE (new_type) = ptr;
/* Now handle updating the allocation record, what the thin pointer
points to. Update all pointers from the old record into the new
one, update the types of the fields, and recompute the size. */
update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
TREE_TYPE (TYPE_FIELDS (new_obj_rec)) = TREE_TYPE (ptr_temp_type);
TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)));
DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TYPE_SIZE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
TYPE_SIZE (new_obj_rec)
= size_binop (PLUS_EXPR,
DECL_SIZE (TYPE_FIELDS (new_obj_rec)),
DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
TYPE_SIZE_UNIT (new_obj_rec)
= size_binop (PLUS_EXPR,
DECL_SIZE_UNIT (TYPE_FIELDS (new_obj_rec)),
DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
rest_of_type_compilation (ptr, global_bindings_p ());
}
}
/* Convert a pointer to a constrained array into a pointer to a fat
pointer. This involves making or finding a template. */
static tree
convert_to_fat_pointer (tree type, tree expr)
{
tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
tree template, template_addr;
tree etype = TREE_TYPE (expr);
/* If EXPR is a constant of zero, we make a fat pointer that has a null
pointer to the template and array. */
if (integer_zerop (expr))
return
gnat_build_constructor
(type,
tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
convert (build_pointer_type (template_type),
expr),
NULL_TREE)));
/* If EXPR is a thin pointer, make the template and data from the record. */
else if (TYPE_THIN_POINTER_P (etype))
{
tree fields = TYPE_FIELDS (TREE_TYPE (etype));
expr = save_expr (expr);
if (TREE_CODE (expr) == ADDR_EXPR)
expr = TREE_OPERAND (expr, 0);
else
expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
template = build_component_ref (expr, NULL_TREE, fields, false);
expr = build_unary_op (ADDR_EXPR, NULL_TREE,
build_component_ref (expr, NULL_TREE,
TREE_CHAIN (fields), false));
}
else
/* Otherwise, build the constructor for the template. */
template = build_template (template_type, TREE_TYPE (etype), expr);
template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
/* The result is a CONSTRUCTOR for the fat pointer.
If expr is an argument of a foreign convention subprogram, the type it
points to is directly the component type. In this case, the expression
type may not match the corresponding FIELD_DECL type at this point, so we
call "convert" here to fix that up if necessary. This type consistency is
required, for instance because it ensures that possible later folding of
component_refs against this constructor always yields something of the
same type as the initial reference.
Note that the call to "build_template" above is still fine, because it
will only refer to the provided template_type in this case. */
return
gnat_build_constructor
(type, tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
template_addr, NULL_TREE)));
}
/* Convert to a thin pointer type, TYPE. The only thing we know how to convert
is something that is a fat pointer, so convert to it first if it EXPR
is not already a fat pointer. */
static tree
convert_to_thin_pointer (tree type, tree expr)
{
if (!TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
expr
= convert_to_fat_pointer
(TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
/* We get the pointer to the data and use a NOP_EXPR to make it the
proper GCC type. */
expr = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)),
false);
expr = build1 (NOP_EXPR, type, expr);
return expr;
}
/* Create an expression whose value is that of EXPR,
converted to type TYPE. The TREE_TYPE of the value
is always TYPE. This function implements all reasonable
conversions; callers should filter out those that are
not permitted by the language being compiled. */
tree
convert (tree type, tree expr)
{
enum tree_code code = TREE_CODE (type);
tree etype = TREE_TYPE (expr);
enum tree_code ecode = TREE_CODE (etype);
/* If EXPR is already the right type, we are done. */
if (type == etype)
return expr;
/* If the input type has padding, remove it by doing a component reference
to the field. If the output type has padding, make a constructor
to build the record. If both input and output have padding and are
of variable size, do this as an unchecked conversion. */
else if (ecode == RECORD_TYPE && code == RECORD_TYPE
&& TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
&& (!TREE_CONSTANT (TYPE_SIZE (type))
|| !TREE_CONSTANT (TYPE_SIZE (etype))))
;
else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
{
/* If we have just converted to this padded type, just get
the inner expression. */
if (TREE_CODE (expr) == CONSTRUCTOR
&& !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (expr))
&& VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->index
== TYPE_FIELDS (etype))
return VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->value;
else
return convert (type,
build_component_ref (expr, NULL_TREE,
TYPE_FIELDS (etype), false));
}
else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
{
/* If we previously converted from another type and our type is
of variable size, remove the conversion to avoid the need for
variable-size temporaries. */
if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
&& !TREE_CONSTANT (TYPE_SIZE (type)))
expr = TREE_OPERAND (expr, 0);
/* If we are just removing the padding from expr, convert the original
object if we have variable size. That will avoid the need
for some variable-size temporaries. */
if (TREE_CODE (expr) == COMPONENT_REF
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
&& TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
&& !TREE_CONSTANT (TYPE_SIZE (type)))
return convert (type, TREE_OPERAND (expr, 0));
/* If the result type is a padded type with a self-referentially-sized
field and the expression type is a record, do this as an
unchecked conversion. */
else if (TREE_CODE (etype) == RECORD_TYPE
&& CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
return unchecked_convert (type, expr, false);
else
return
gnat_build_constructor (type,
tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE
(TYPE_FIELDS (type)),
expr),
NULL_TREE));
}
/* If the input is a biased type, adjust first. */
if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
return convert (type, fold (build2 (PLUS_EXPR, TREE_TYPE (etype),
fold_convert (TREE_TYPE (etype),
expr),
TYPE_MIN_VALUE (etype))));
/* If the input is a justified modular type, we need to extract the actual
object before converting it to any other type with the exceptions of an
unconstrained array or of a mere type variant. It is useful to avoid the
extraction and conversion in the type variant case because it could end
up replacing a VAR_DECL expr by a constructor and we might be about the
take the address of the result. */
if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)
&& code != UNCONSTRAINED_ARRAY_TYPE
&& TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (etype))
return convert (type, build_component_ref (expr, NULL_TREE,
TYPE_FIELDS (etype), false));
/* If converting to a type that contains a template, convert to the data
type and then build the template. */
if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
{
tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
/* If the source already has a template, get a reference to the
associated array only, as we are going to rebuild a template
for the target type anyway. */
expr = maybe_unconstrained_array (expr);
return
gnat_build_constructor
(type,
tree_cons (TYPE_FIELDS (type),
build_template (TREE_TYPE (TYPE_FIELDS (type)),
obj_type, NULL_TREE),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
convert (obj_type, expr), NULL_TREE)));
}
/* There are some special cases of expressions that we process
specially. */
switch (TREE_CODE (expr))
{
case ERROR_MARK:
return expr;
case NULL_EXPR:
/* Just set its type here. For TRANSFORM_EXPR, we will do the actual
conversion in gnat_expand_expr. NULL_EXPR does not represent
and actual value, so no conversion is needed. */
expr = copy_node (expr);
TREE_TYPE (expr) = type;
return expr;
case STRING_CST:
/* If we are converting a STRING_CST to another constrained array type,
just make a new one in the proper type. */
if (code == ecode && AGGREGATE_TYPE_P (etype)
&& !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
&& TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
{
expr = copy_node (expr);
TREE_TYPE (expr) = type;
return expr;
}
break;
case UNCONSTRAINED_ARRAY_REF:
/* Convert this to the type of the inner array by getting the address of
the array from the template. */
expr = build_unary_op (INDIRECT_REF, NULL_TREE,
build_component_ref (TREE_OPERAND (expr, 0),
get_identifier ("P_ARRAY"),
NULL_TREE, false));
etype = TREE_TYPE (expr);
ecode = TREE_CODE (etype);
break;
case VIEW_CONVERT_EXPR:
{
/* GCC 4.x is very sensitive to type consistency overall, and view
conversions thus are very frequent. Even though just "convert"ing
the inner operand to the output type is fine in most cases, it
might expose unexpected input/output type mismatches in special
circumstances so we avoid such recursive calls when we can. */
tree op0 = TREE_OPERAND (expr, 0);
/* If we are converting back to the original type, we can just
lift the input conversion. This is a common occurrence with
switches back-and-forth amongst type variants. */
if (type == TREE_TYPE (op0))
return op0;
/* Otherwise, if we're converting between two aggregate types, we
might be allowed to substitute the VIEW_CONVERT target type in
place or to just convert the inner expression. */
if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype))
{
/* If we are converting between type variants, we can just
substitute the VIEW_CONVERT in place. */
if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
return build1 (VIEW_CONVERT_EXPR, type, op0);
/* Otherwise, we may just bypass the input view conversion unless
one of the types is a fat pointer, which is handled by
specialized code below which relies on exact type matching. */
else if (!TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
return convert (type, op0);
}
}
break;
case INDIRECT_REF:
/* If both types are record types, just convert the pointer and
make a new INDIRECT_REF.
??? Disable this for now since it causes problems with the
code in build_binary_op for MODIFY_EXPR which wants to
strip off conversions. But that code really is a mess and
we need to do this a much better way some time. */
if (0
&& (TREE_CODE (type) == RECORD_TYPE
|| TREE_CODE (type) == UNION_TYPE)
&& (TREE_CODE (etype) == RECORD_TYPE
|| TREE_CODE (etype) == UNION_TYPE)
&& !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
return build_unary_op (INDIRECT_REF, NULL_TREE,
convert (build_pointer_type (type),
TREE_OPERAND (expr, 0)));
break;
default:
break;
}
/* Check for converting to a pointer to an unconstrained array. */
if (TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
return convert_to_fat_pointer (type, expr);
/* If we're converting between two aggregate types that have the same main
variant, just make a VIEW_CONVER_EXPR. */
else if (AGGREGATE_TYPE_P (type)
&& TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
return build1 (VIEW_CONVERT_EXPR, type, expr);
/* In all other cases of related types, make a NOP_EXPR. */
else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
|| (code == INTEGER_CST && ecode == INTEGER_CST
&& (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
return fold_convert (type, expr);
switch (code)
{
case VOID_TYPE:
return build1 (CONVERT_EXPR, type, expr);
case BOOLEAN_TYPE:
return fold_convert (type, gnat_truthvalue_conversion (expr));
case INTEGER_TYPE:
if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
&& (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
|| (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
return unchecked_convert (type, expr, false);
else if (TYPE_BIASED_REPRESENTATION_P (type))
return fold_convert (type,
fold_build2 (MINUS_EXPR, TREE_TYPE (type),
convert (TREE_TYPE (type), expr),
TYPE_MIN_VALUE (type)));
/* ... fall through ... */
case ENUMERAL_TYPE:
return fold (convert_to_integer (type, expr));
case POINTER_TYPE:
case REFERENCE_TYPE:
/* If converting between two pointers to records denoting
both a template and type, adjust if needed to account
for any differing offsets, since one might be negative. */
if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
{
tree bit_diff
= size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
bit_position (TYPE_FIELDS (TREE_TYPE (type))));
tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
sbitsize_int (BITS_PER_UNIT));
expr = build1 (NOP_EXPR, type, expr);
TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
if (integer_zerop (byte_diff))
return expr;
return build_binary_op (PLUS_EXPR, type, expr,
fold (convert_to_pointer (type, byte_diff)));
}
/* If converting to a thin pointer, handle specially. */
if (TYPE_THIN_POINTER_P (type)
&& TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
return convert_to_thin_pointer (type, expr);
/* If converting fat pointer to normal pointer, get the pointer to the
array and then convert it. */
else if (TYPE_FAT_POINTER_P (etype))
expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
NULL_TREE, false);
return fold (convert_to_pointer (type, expr));
case REAL_TYPE:
return fold (convert_to_real (type, expr));
case RECORD_TYPE:
if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype))
return
gnat_build_constructor
(type, tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
NULL_TREE));
/* ... fall through ... */
case ARRAY_TYPE:
/* In these cases, assume the front-end has validated the conversion.
If the conversion is valid, it will be a bit-wise conversion, so
it can be viewed as an unchecked conversion. */
return unchecked_convert (type, expr, false);
case UNION_TYPE:
/* This is a either a conversion between a tagged type and some
subtype, which we have to mark as a UNION_TYPE because of
overlapping fields or a conversion of an Unchecked_Union. */
return unchecked_convert (type, expr, false);
case UNCONSTRAINED_ARRAY_TYPE:
/* If EXPR is a constrained array, take its address, convert it to a
fat pointer, and then dereference it. Likewise if EXPR is a
record containing both a template and a constrained array.
Note that a record representing a justified modular type
always represents a packed constrained array. */
if (ecode == ARRAY_TYPE
|| (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
|| (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
|| (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)))
return
build_unary_op
(INDIRECT_REF, NULL_TREE,
convert_to_fat_pointer (TREE_TYPE (type),
build_unary_op (ADDR_EXPR,
NULL_TREE, expr)));
/* Do something very similar for converting one unconstrained
array to another. */
else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
return
build_unary_op (INDIRECT_REF, NULL_TREE,
convert (TREE_TYPE (type),
build_unary_op (ADDR_EXPR,
NULL_TREE, expr)));
else
gcc_unreachable ();
case COMPLEX_TYPE:
return fold (convert_to_complex (type, expr));
default:
gcc_unreachable ();
}
}
/* Remove all conversions that are done in EXP. This includes converting
from a padded type or to a justified modular type. If TRUE_ADDRESS
is true, always return the address of the containing object even if
the address is not bit-aligned. */
tree
remove_conversions (tree exp, bool true_address)
{
switch (TREE_CODE (exp))
{
case CONSTRUCTOR:
if (true_address
&& TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
&& TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
return
remove_conversions (VEC_index (constructor_elt,
CONSTRUCTOR_ELTS (exp), 0)->value,
true);
break;
case COMPONENT_REF:
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
&& TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
return remove_conversions (TREE_OPERAND (exp, 0), true_address);
break;
case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR:
case NOP_EXPR: case CONVERT_EXPR:
return remove_conversions (TREE_OPERAND (exp, 0), true_address);
default:
break;
}
return exp;
}
/* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P,
likewise return an expression pointing to the underlying array. */
tree
maybe_unconstrained_array (tree exp)
{
enum tree_code code = TREE_CODE (exp);
tree new;
switch (TREE_CODE (TREE_TYPE (exp)))
{
case UNCONSTRAINED_ARRAY_TYPE:
if (code == UNCONSTRAINED_ARRAY_REF)
{
new
= build_unary_op (INDIRECT_REF, NULL_TREE,
build_component_ref (TREE_OPERAND (exp, 0),
get_identifier ("P_ARRAY"),
NULL_TREE, false));
TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp);
return new;
}
else if (code == NULL_EXPR)
return build1 (NULL_EXPR,
TREE_TYPE (TREE_TYPE (TYPE_FIELDS
(TREE_TYPE (TREE_TYPE (exp))))),
TREE_OPERAND (exp, 0));
case RECORD_TYPE:
/* If this is a padded type, convert to the unpadded type and see if
it contains a template. */
if (TYPE_IS_PADDING_P (TREE_TYPE (exp)))
{
new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp);
if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE
&& TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new)))
return
build_component_ref (new, NULL_TREE,
TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))),
0);
}
else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp)))
return
build_component_ref (exp, NULL_TREE,
TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0);
break;
default:
break;
}
return exp;
}
/* Return an expression that does an unchecked conversion of EXPR to TYPE.
If NOTRUNC_P is true, truncation operations should be suppressed. */
tree
unchecked_convert (tree type, tree expr, bool notrunc_p)
{
tree etype = TREE_TYPE (expr);
/* If the expression is already the right type, we are done. */
if (etype == type)
return expr;
/* If both types types are integral just do a normal conversion.
Likewise for a conversion to an unconstrained array. */
if ((((INTEGRAL_TYPE_P (type)
&& !(TREE_CODE (type) == INTEGER_TYPE
&& TYPE_VAX_FLOATING_POINT_P (type)))
|| (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type))
|| (TREE_CODE (type) == RECORD_TYPE
&& TYPE_JUSTIFIED_MODULAR_P (type)))
&& ((INTEGRAL_TYPE_P (etype)
&& !(TREE_CODE (etype) == INTEGER_TYPE
&& TYPE_VAX_FLOATING_POINT_P (etype)))
|| (POINTER_TYPE_P (etype) && !TYPE_THIN_POINTER_P (etype))
|| (TREE_CODE (etype) == RECORD_TYPE
&& TYPE_JUSTIFIED_MODULAR_P (etype))))
|| TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
{
tree rtype = type;
if (TREE_CODE (etype) == INTEGER_TYPE
&& TYPE_BIASED_REPRESENTATION_P (etype))
{
tree ntype = copy_type (etype);
TYPE_BIASED_REPRESENTATION_P (ntype) = 0;
TYPE_MAIN_VARIANT (ntype) = ntype;
expr = build1 (NOP_EXPR, ntype, expr);
}
if (TREE_CODE (type) == INTEGER_TYPE
&& TYPE_BIASED_REPRESENTATION_P (type))
{
rtype = copy_type (type);
TYPE_BIASED_REPRESENTATION_P (rtype) = 0;
TYPE_MAIN_VARIANT (rtype) = rtype;
}
expr = convert (rtype, expr);
if (type != rtype)
expr = build1 (NOP_EXPR, type, expr);
}
/* If we are converting TO an integral type whose precision is not the
same as its size, first unchecked convert to a record that contains
an object of the output type. Then extract the field. */
else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
&& 0 != compare_tree_int (TYPE_RM_SIZE (type),
GET_MODE_BITSIZE (TYPE_MODE (type))))
{
tree rec_type = make_node (RECORD_TYPE);
tree field = create_field_decl (get_identifier ("OBJ"), type,
rec_type, 1, 0, 0, 0);
TYPE_FIELDS (rec_type) = field;
layout_type (rec_type);
expr = unchecked_convert (rec_type, expr, notrunc_p);
expr = build_component_ref (expr, NULL_TREE, field, 0);
}
/* Similarly for integral input type whose precision is not equal to its
size. */
else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype)
&& 0 != compare_tree_int (TYPE_RM_SIZE (etype),
GET_MODE_BITSIZE (TYPE_MODE (etype))))
{
tree rec_type = make_node (RECORD_TYPE);
tree field
= create_field_decl (get_identifier ("OBJ"), etype, rec_type,
1, 0, 0, 0);
TYPE_FIELDS (rec_type) = field;
layout_type (rec_type);
expr = gnat_build_constructor (rec_type, build_tree_list (field, expr));
expr = unchecked_convert (type, expr, notrunc_p);
}
/* We have a special case when we are converting between two
unconstrained array types. In that case, take the address,
convert the fat pointer types, and dereference. */
else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE
&& TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
expr = build_unary_op (INDIRECT_REF, NULL_TREE,
build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type),
build_unary_op (ADDR_EXPR, NULL_TREE,
expr)));
else
{
expr = maybe_unconstrained_array (expr);
/* There's no point in doing two unchecked conversions in a row. */
if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
expr = TREE_OPERAND (expr, 0);
etype = TREE_TYPE (expr);
expr = build1 (VIEW_CONVERT_EXPR, type, expr);
}
/* If the result is an integral type whose size is not equal to
the size of the underlying machine type, sign- or zero-extend
the result. We need not do this in the case where the input is
an integral type of the same precision and signedness or if the output
is a biased type or if both the input and output are unsigned. */
if (!notrunc_p
&& INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
&& !(TREE_CODE (type) == INTEGER_TYPE
&& TYPE_BIASED_REPRESENTATION_P (type))
&& 0 != compare_tree_int (TYPE_RM_SIZE (type),
GET_MODE_BITSIZE (TYPE_MODE (type)))
&& !(INTEGRAL_TYPE_P (etype)
&& TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype)
&& operand_equal_p (TYPE_RM_SIZE (type),
(TYPE_RM_SIZE (etype) != 0
? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)),
0))
&& !(TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype)))
{
tree base_type = gnat_type_for_mode (TYPE_MODE (type),
TYPE_UNSIGNED (type));
tree shift_expr
= convert (base_type,
size_binop (MINUS_EXPR,
bitsize_int
(GET_MODE_BITSIZE (TYPE_MODE (type))),
TYPE_RM_SIZE (type)));
expr
= convert (type,
build_binary_op (RSHIFT_EXPR, base_type,
build_binary_op (LSHIFT_EXPR, base_type,
convert (base_type, expr),
shift_expr),
shift_expr));
}
/* An unchecked conversion should never raise Constraint_Error. The code
below assumes that GCC's conversion routines overflow the same way that
the underlying hardware does. This is probably true. In the rare case
when it is false, we can rely on the fact that such conversions are
erroneous anyway. */
if (TREE_CODE (expr) == INTEGER_CST)
TREE_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (expr) = 0;
/* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
show no longer constant. */
if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
&& !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype),
OEP_ONLY_CONST))
TREE_CONSTANT (expr) = 0;
return expr;
}
/* Search the chain of currently reachable declarations for a builtin
FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
Return the first node found, if any, or NULL_TREE otherwise. */
tree
builtin_decl_for (tree name __attribute__ ((unused)))
{
/* ??? not clear yet how to implement this function in tree-ssa, so
return NULL_TREE for now */
return NULL_TREE;
}
/* Return the appropriate GCC tree code for the specified GNAT type,
the latter being a record type as predicated by Is_Record_Type. */
enum tree_code
tree_code_for_record_type (Entity_Id gnat_type)
{
Node_Id component_list
= Component_List (Type_Definition
(Declaration_Node
(Implementation_Base_Type (gnat_type))));
Node_Id component;
/* Make this a UNION_TYPE unless it's either not an Unchecked_Union or
we have a non-discriminant field outside a variant. In either case,
it's a RECORD_TYPE. */
if (!Is_Unchecked_Union (gnat_type))
return RECORD_TYPE;
for (component = First_Non_Pragma (Component_Items (component_list));
Present (component);
component = Next_Non_Pragma (component))
if (Ekind (Defining_Entity (component)) == E_Component)
return RECORD_TYPE;
return UNION_TYPE;
}
/* Build a global constructor or destructor function. METHOD_TYPE gives
the type of the function and VEC points to the vector of constructor
or destructor functions to be invoked. FIXME: Migrate into cgraph. */
static void
build_global_cdtor (int method_type, tree *vec, int len)
{
tree body = NULL_TREE;
int i;
for (i = 0; i < len; i++)
{
tree fntype = TREE_TYPE (vec[i]);
tree fnaddr = build1 (ADDR_EXPR, build_pointer_type (fntype), vec[i]);
tree fncall = build3 (CALL_EXPR, TREE_TYPE (fntype), fnaddr, NULL_TREE,
NULL_TREE);
append_to_statement_list (fncall, &body);
}
if (body)
cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY);
}
/* Perform final processing on global variables. */
void
gnat_write_global_declarations (void)
{
/* Generate functions to call static constructors and destructors
for targets that do not support .ctors/.dtors sections. These
functions have magic names which are detected by collect2. */
build_global_cdtor ('I', VEC_address (tree, static_ctors),
VEC_length (tree, static_ctors));
build_global_cdtor ('D', VEC_address (tree, static_dtors),
VEC_length (tree, static_dtors));
/* Proceed to optimize and emit assembly.
FIXME: shouldn't be the front end's responsibility to call this. */
cgraph_optimize ();
/* Emit debug info for all global declarations. */
emit_debug_global_declarations (VEC_address (tree, global_decls),
VEC_length (tree, global_decls));
}
#include "gt-ada-utils.h"
#include "gtype-ada.h"
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