/* C-compiler utilities for types and variables storage layout
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1996, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
#include "langhooks.h"
#include "regs.h"
#include "params.h"
+#include "cgraph.h"
+#include "tree-inline.h"
+#include "tree-dump.h"
+#include "gimple.h"
/* Data type for the expressions representing sizes of data types.
It is the first integer type laid out. */
called only by a front end. */
static int reference_types_internal = 0;
+static tree self_referential_size (tree);
static void finalize_record_size (record_layout_info);
static void finalize_type_size (tree);
static void place_union_field (record_layout_info, tree);
{
tree save;
+ /* Obviously. */
+ if (TREE_CONSTANT (size))
+ return size;
+
+ /* If the size is self-referential, we can't make a SAVE_EXPR (see
+ save_expr for the rationale). But we can do something else. */
+ if (CONTAINS_PLACEHOLDER_P (size))
+ return self_referential_size (size);
+
/* If the language-processor is to take responsibility for variable-sized
items (e.g., languages which have elaboration procedures like Ada),
- just return SIZE unchanged. Likewise for self-referential sizes and
- constant sizes. */
- if (TREE_CONSTANT (size)
- || lang_hooks.decls.global_bindings_p () < 0
- || CONTAINS_PLACEHOLDER_P (size))
+ just return SIZE unchanged. */
+ if (lang_hooks.decls.global_bindings_p () < 0)
return size;
size = save_expr (size);
return size;
}
+
+/* An array of functions used for self-referential size computation. */
+static GTY(()) VEC (tree, gc) *size_functions;
+
+/* Similar to copy_tree_r but do not copy component references involving
+ PLACEHOLDER_EXPRs. These nodes are spotted in find_placeholder_in_expr
+ and substituted in substitute_in_expr. */
+
+static tree
+copy_self_referential_tree_r (tree *tp, int *walk_subtrees, void *data)
+{
+ enum tree_code code = TREE_CODE (*tp);
+
+ /* Stop at types, decls, constants like copy_tree_r. */
+ if (TREE_CODE_CLASS (code) == tcc_type
+ || TREE_CODE_CLASS (code) == tcc_declaration
+ || TREE_CODE_CLASS (code) == tcc_constant)
+ {
+ *walk_subtrees = 0;
+ return NULL_TREE;
+ }
+
+ /* This is the pattern built in ada/make_aligning_type. */
+ else if (code == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (*tp, 0)) == PLACEHOLDER_EXPR)
+ {
+ *walk_subtrees = 0;
+ return NULL_TREE;
+ }
+
+ /* Default case: the component reference. */
+ else if (code == COMPONENT_REF)
+ {
+ tree inner;
+ for (inner = TREE_OPERAND (*tp, 0);
+ REFERENCE_CLASS_P (inner);
+ inner = TREE_OPERAND (inner, 0))
+ ;
+
+ if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
+ {
+ *walk_subtrees = 0;
+ return NULL_TREE;
+ }
+ }
+
+ /* We're not supposed to have them in self-referential size trees
+ because we wouldn't properly control when they are evaluated.
+ However, not creating superfluous SAVE_EXPRs requires accurate
+ tracking of readonly-ness all the way down to here, which we
+ cannot always guarantee in practice. So punt in this case. */
+ else if (code == SAVE_EXPR)
+ return error_mark_node;
+
+ return copy_tree_r (tp, walk_subtrees, data);
+}
+
+/* Given a SIZE expression that is self-referential, return an equivalent
+ expression to serve as the actual size expression for a type. */
+
+static tree
+self_referential_size (tree size)
+{
+ static unsigned HOST_WIDE_INT fnno = 0;
+ VEC (tree, heap) *self_refs = NULL;
+ tree param_type_list = NULL, param_decl_list = NULL, arg_list = NULL;
+ tree t, ref, return_type, fntype, fnname, fndecl;
+ unsigned int i;
+ char buf[128];
+
+ /* Do not factor out simple operations. */
+ t = skip_simple_arithmetic (size);
+ if (TREE_CODE (t) == CALL_EXPR)
+ return size;
+
+ /* Collect the list of self-references in the expression. */
+ find_placeholder_in_expr (size, &self_refs);
+ gcc_assert (VEC_length (tree, self_refs) > 0);
+
+ /* Obtain a private copy of the expression. */
+ t = size;
+ if (walk_tree (&t, copy_self_referential_tree_r, NULL, NULL) != NULL_TREE)
+ return size;
+ size = t;
+
+ /* Build the parameter and argument lists in parallel; also
+ substitute the former for the latter in the expression. */
+ for (i = 0; VEC_iterate (tree, self_refs, i, ref); i++)
+ {
+ tree subst, param_name, param_type, param_decl;
+
+ if (DECL_P (ref))
+ {
+ /* We shouldn't have true variables here. */
+ gcc_assert (TREE_READONLY (ref));
+ subst = ref;
+ }
+ /* This is the pattern built in ada/make_aligning_type. */
+ else if (TREE_CODE (ref) == ADDR_EXPR)
+ subst = ref;
+ /* Default case: the component reference. */
+ else
+ subst = TREE_OPERAND (ref, 1);
+
+ sprintf (buf, "p%d", i);
+ param_name = get_identifier (buf);
+ param_type = TREE_TYPE (ref);
+ param_decl
+ = build_decl (input_location, PARM_DECL, param_name, param_type);
+ if (targetm.calls.promote_prototypes (NULL_TREE)
+ && INTEGRAL_TYPE_P (param_type)
+ && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
+ DECL_ARG_TYPE (param_decl) = integer_type_node;
+ else
+ DECL_ARG_TYPE (param_decl) = param_type;
+ DECL_ARTIFICIAL (param_decl) = 1;
+ TREE_READONLY (param_decl) = 1;
+
+ size = substitute_in_expr (size, subst, param_decl);
+
+ param_type_list = tree_cons (NULL_TREE, param_type, param_type_list);
+ param_decl_list = chainon (param_decl, param_decl_list);
+ arg_list = tree_cons (NULL_TREE, ref, arg_list);
+ }
+
+ VEC_free (tree, heap, self_refs);
+
+ /* Append 'void' to indicate that the number of parameters is fixed. */
+ param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
+
+ /* The 3 lists have been created in reverse order. */
+ param_type_list = nreverse (param_type_list);
+ param_decl_list = nreverse (param_decl_list);
+ arg_list = nreverse (arg_list);
+
+ /* Build the function type. */
+ return_type = TREE_TYPE (size);
+ fntype = build_function_type (return_type, param_type_list);
+
+ /* Build the function declaration. */
+ sprintf (buf, "SZ"HOST_WIDE_INT_PRINT_UNSIGNED, fnno++);
+ fnname = get_file_function_name (buf);
+ fndecl = build_decl (input_location, FUNCTION_DECL, fnname, fntype);
+ for (t = param_decl_list; t; t = TREE_CHAIN (t))
+ DECL_CONTEXT (t) = fndecl;
+ DECL_ARGUMENTS (fndecl) = param_decl_list;
+ DECL_RESULT (fndecl)
+ = build_decl (input_location, RESULT_DECL, 0, return_type);
+ DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
+
+ /* The function has been created by the compiler and we don't
+ want to emit debug info for it. */
+ DECL_ARTIFICIAL (fndecl) = 1;
+ DECL_IGNORED_P (fndecl) = 1;
+
+ /* It is supposed to be "const" and never throw. */
+ TREE_READONLY (fndecl) = 1;
+ TREE_NOTHROW (fndecl) = 1;
+
+ /* We want it to be inlined when this is deemed profitable, as
+ well as discarded if every call has been integrated. */
+ DECL_DECLARED_INLINE_P (fndecl) = 1;
+
+ /* It is made up of a unique return statement. */
+ DECL_INITIAL (fndecl) = make_node (BLOCK);
+ BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl;
+ t = build2 (MODIFY_EXPR, return_type, DECL_RESULT (fndecl), size);
+ DECL_SAVED_TREE (fndecl) = build1 (RETURN_EXPR, void_type_node, t);
+ TREE_STATIC (fndecl) = 1;
+
+ /* Put it onto the list of size functions. */
+ VEC_safe_push (tree, gc, size_functions, fndecl);
+
+ /* Replace the original expression with a call to the size function. */
+ return build_function_call_expr (input_location, fndecl, arg_list);
+}
+
+/* Take, queue and compile all the size functions. It is essential that
+ the size functions be gimplified at the very end of the compilation
+ in order to guarantee transparent handling of self-referential sizes.
+ Otherwise the GENERIC inliner would not be able to inline them back
+ at each of their call sites, thus creating artificial non-constant
+ size expressions which would trigger nasty problems later on. */
+
+void
+finalize_size_functions (void)
+{
+ unsigned int i;
+ tree fndecl;
+
+ for (i = 0; VEC_iterate(tree, size_functions, i, fndecl); i++)
+ {
+ dump_function (TDI_original, fndecl);
+ gimplify_function_tree (fndecl);
+ dump_function (TDI_generic, fndecl);
+ cgraph_finalize_function (fndecl, false);
+ }
+
+ VEC_free (tree, gc, size_functions);
+}
\f
#ifndef MAX_FIXED_MODE_SIZE
#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
tree type = TREE_TYPE (decl);
enum tree_code code = TREE_CODE (decl);
rtx rtl = NULL_RTX;
+ location_t loc = DECL_SOURCE_LOCATION (decl);
if (code == CONST_DECL)
return;
}
else if (DECL_SIZE_UNIT (decl) == 0)
DECL_SIZE_UNIT (decl)
- = fold_convert (sizetype, size_binop (CEIL_DIV_EXPR, DECL_SIZE (decl),
- bitsize_unit_node));
+ = fold_convert_loc (loc, sizetype,
+ size_binop_loc (loc, CEIL_DIV_EXPR, DECL_SIZE (decl),
+ bitsize_unit_node));
if (code != FIELD_DECL)
/* For non-fields, update the alignment from the type. */
if (TREE_CODE (rli->t) == UNION_TYPE)
rli->offset = size_binop (MAX_EXPR, rli->offset, DECL_SIZE_UNIT (field));
else if (TREE_CODE (rli->t) == QUAL_UNION_TYPE)
- rli->offset = fold_build3 (COND_EXPR, sizetype,
+ rli->offset = fold_build3_loc (input_location, COND_EXPR, sizetype,
DECL_QUALIFIER (field),
DECL_SIZE_UNIT (field), rli->offset);
}
&& TREE_CODE (field) == FIELD_DECL
&& type != error_mark_node
&& DECL_BIT_FIELD (field)
- && ! DECL_PACKED (field)
+ && (! DECL_PACKED (field)
+ /* Enter for these packed fields only to issue a warning. */
+ || TYPE_ALIGN (type) <= BITS_PER_UNIT)
&& maximum_field_alignment == 0
&& ! integer_zerop (DECL_SIZE (field))
&& host_integerp (DECL_SIZE (field), 1)
/* A bit field may not span more units of alignment of its type
than its type itself. Advance to next boundary if necessary. */
if (excess_unit_span (offset, bit_offset, field_size, type_align, type))
- rli->bitpos = round_up (rli->bitpos, type_align);
+ {
+ if (DECL_PACKED (field))
+ {
+ if (warn_packed_bitfield_compat == 1)
+ inform
+ (input_location,
+ "Offset of packed bit-field %qD has changed in GCC 4.4",
+ field);
+ }
+ else
+ rli->bitpos = round_up_loc (input_location, rli->bitpos, type_align);
+ }
- TYPE_USER_ALIGN (rli->t) |= TYPE_USER_ALIGN (type);
+ if (! DECL_PACKED (field))
+ TYPE_USER_ALIGN (rli->t) |= TYPE_USER_ALIGN (type);
}
#endif
if (maximum_field_alignment != 0)
type_align = MIN (type_align, maximum_field_alignment);
- rli->bitpos = round_up (rli->bitpos, type_align);
+ rli->bitpos = round_up_loc (input_location, rli->bitpos, type_align);
/* If we really aligned, don't allow subsequent bitfields
to undo that. */
= size_binop (PLUS_EXPR, unpadded_size_unit, size_one_node);
/* Round the size up to be a multiple of the required alignment. */
- TYPE_SIZE (rli->t) = round_up (unpadded_size, TYPE_ALIGN (rli->t));
+ TYPE_SIZE (rli->t) = round_up_loc (input_location, unpadded_size,
+ TYPE_ALIGN (rli->t));
TYPE_SIZE_UNIT (rli->t)
- = round_up (unpadded_size_unit, TYPE_ALIGN_UNIT (rli->t));
+ = round_up_loc (input_location, unpadded_size_unit, TYPE_ALIGN_UNIT (rli->t));
if (TREE_CONSTANT (unpadded_size)
&& simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0)
rli->unpacked_align = MAX (TYPE_ALIGN (rli->t), rli->unpacked_align);
#endif
- unpacked_size = round_up (TYPE_SIZE (rli->t), rli->unpacked_align);
+ unpacked_size = round_up_loc (input_location, TYPE_SIZE (rli->t), rli->unpacked_align);
if (simple_cst_equal (unpacked_size, TYPE_SIZE (rli->t)))
{
TYPE_PACKED (rli->t) = 0;
if (TYPE_NAME (rli->t))
{
- const char *name;
+ tree name;
if (TREE_CODE (TYPE_NAME (rli->t)) == IDENTIFIER_NODE)
- name = IDENTIFIER_POINTER (TYPE_NAME (rli->t));
+ name = TYPE_NAME (rli->t);
else
- name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (rli->t)));
+ name = DECL_NAME (TYPE_NAME (rli->t));
if (STRICT_ALIGNMENT)
warning (OPT_Wpacked, "packed attribute causes inefficient "
- "alignment for %qs", name);
+ "alignment for %qE", name);
else
warning (OPT_Wpacked,
- "packed attribute is unnecessary for %qs", name);
+ "packed attribute is unnecessary for %qE", name);
}
else
{
if (TYPE_SIZE (type) != 0)
{
- TYPE_SIZE (type) = round_up (TYPE_SIZE (type), TYPE_ALIGN (type));
- TYPE_SIZE_UNIT (type) = round_up (TYPE_SIZE_UNIT (type),
+ TYPE_SIZE (type) = round_up_loc (input_location,
+ TYPE_SIZE (type), TYPE_ALIGN (type));
+ TYPE_SIZE_UNIT (type) = round_up_loc (input_location, TYPE_SIZE_UNIT (type),
TYPE_ALIGN_UNIT (type));
}
#if 0 /* not yet, should get fixed properly later */
TYPE_NAME (type) = make_type_decl (get_identifier (name), type);
#else
- TYPE_NAME (type) = build_decl (TYPE_DECL, get_identifier (name), type);
+ TYPE_NAME (type) = build_decl (BUILTINS_LOCATION,
+ TYPE_DECL, get_identifier (name), type);
#endif
TYPE_STUB_DECL (type) = TYPE_NAME (type);
layout_decl (TYPE_NAME (type), 0);
that (possible) negative values are handled appropriately. */
length = size_binop (PLUS_EXPR, size_one_node,
fold_convert (sizetype,
- fold_build2 (MINUS_EXPR,
+ fold_build2_loc (input_location,
+ MINUS_EXPR,
TREE_TYPE (lb),
ub, lb)));
void
set_sizetype (tree type)
{
+ tree t;
int oprecision = TYPE_PRECISION (type);
/* The *bitsizetype types use a precision that avoids overflows when
calculating signed sizes / offsets in bits. However, when
cross-compiling from a 32 bit to a 64 bit host, we are limited to 64 bit
precision. */
- int precision = MIN (MIN (oprecision + BITS_PER_UNIT_LOG + 1,
- MAX_FIXED_MODE_SIZE),
- 2 * HOST_BITS_PER_WIDE_INT);
- tree t;
+ int precision
+ = MIN (oprecision + BITS_PER_UNIT_LOG + 1, MAX_FIXED_MODE_SIZE);
+ precision
+ = GET_MODE_PRECISION (smallest_mode_for_size (precision, MODE_INT));
+ if (precision > HOST_BITS_PER_WIDE_INT * 2)
+ precision = HOST_BITS_PER_WIDE_INT * 2;
gcc_assert (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (sizetype));
/* Replace our original stub sizetype. */
memcpy (sizetype, t, tree_size (sizetype));
TYPE_MAIN_VARIANT (sizetype) = sizetype;
+ TYPE_CANONICAL (sizetype) = sizetype;
t = make_node (INTEGER_TYPE);
TYPE_NAME (t) = get_identifier ("bit_size_type");
/* Replace our original stub bitsizetype. */
memcpy (bitsizetype, t, tree_size (bitsizetype));
TYPE_MAIN_VARIANT (bitsizetype) = bitsizetype;
+ TYPE_CANONICAL (bitsizetype) = bitsizetype;
if (TYPE_UNSIGNED (type))
{
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