2004-08-26 Richard Henderson <rth@redhat.com>
+ * c-typeck.c (build_offsetof): Remove.
+ * c-tree.h (build_offsetof): Remove.
+ * c-common.c (fold_offsetof_1, fold_offsetof): New.
+ * c-common.h (fold_offsetof): Declare.
+ * c-parse.in (offsetof_base): New.
+ (offsetof_member_designator): Use it. Build references, not just
+ a tree list.
+ (primary): Use fold_offsetof, not build_offsetof.
+
+2004-08-26 Richard Henderson <rth@redhat.com>
+
* tree.c (staticp): Return the static object.
* tree.h (staticp): Update decl.
* langhooks.h (struct lang_hooks): Change staticp return type to tree.
}
}
+/* Build the result of __builtin_offsetof. EXPR is a nested sequence of
+ component references, with an INDIRECT_REF at the bottom; much like
+ the traditional rendering of offsetof as a macro. Returns the folded
+ and properly cast result. */
+
+static tree
+fold_offsetof_1 (tree expr)
+{
+ enum tree_code code = PLUS_EXPR;
+ tree base, off, t;
+
+ switch (TREE_CODE (expr))
+ {
+ case ERROR_MARK:
+ return expr;
+
+ case INDIRECT_REF:
+ return size_zero_node;
+
+ case COMPONENT_REF:
+ base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
+ if (base == error_mark_node)
+ return base;
+
+ t = TREE_OPERAND (expr, 1);
+ if (DECL_C_BIT_FIELD (t))
+ {
+ error ("attempt to take address of bit-field structure "
+ "member `%s'", IDENTIFIER_POINTER (DECL_NAME (t)));
+ return error_mark_node;
+ }
+ off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t),
+ size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1)
+ / BITS_PER_UNIT));
+ break;
+
+ case ARRAY_REF:
+ base = fold_offsetof_1 (TREE_OPERAND (expr, 0));
+ if (base == error_mark_node)
+ return base;
+
+ t = TREE_OPERAND (expr, 1);
+ if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0)
+ {
+ code = MINUS_EXPR;
+ t = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
+ }
+ t = convert (sizetype, t);
+ off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
+ break;
+
+ default:
+ abort ();
+ }
+
+ return size_binop (code, base, off);
+}
+
+tree
+fold_offsetof (tree expr)
+{
+ /* Convert back from the internal sizetype to size_t. */
+ return convert (size_type_node, fold_offsetof_1 (expr));
+}
+
#include "gt-c-common.h"
extern void verify_sequence_points (tree);
+extern tree fold_offsetof (tree);
+
/* In c-gimplify.c */
extern void c_genericize (tree);
extern int c_gimplify_expr (tree *, tree *, tree *);
all_prefix_attributes. */
static GTY(()) tree declspec_stack;
+/* INDIRECT_REF with a TREE_TYPE of the type being queried for offsetof. */
+static tree offsetof_base;
+
/* PUSH_DECLSPEC_STACK is called from setspecs; POP_DECLSPEC_STACK
should be called from the productions making use of setspecs. */
#define PUSH_DECLSPEC_STACK \
{ $$.value = build_va_arg ($3.value, groktypename ($5));
$$.original_code = ERROR_MARK; }
- | OFFSETOF '(' typename ',' offsetof_member_designator ')'
- { $$.value = build_offsetof (groktypename ($3), $5);
+ | OFFSETOF '(' typename ','
+ { tree type = groktypename ($3);
+ if (type == error_mark_node)
+ offsetof_base = error_mark_node;
+ else
+ offsetof_base = build1 (INDIRECT_REF, type, NULL);
+ }
+ offsetof_member_designator ')'
+ { $$.value = fold_offsetof ($6);
$$.original_code = ERROR_MARK; }
| OFFSETOF '(' error ')'
{ $$.value = error_mark_node; $$.original_code = ERROR_MARK; }
/* This is the second argument to __builtin_offsetof. We must have one
identifier, and beyond that we want to accept sub structure and sub
- array references. We return tree list where each element has
- PURPOSE set for component refs or VALUE set for array refs. We'll
- turn this into something real inside build_offsetof. */
+ array references. */
offsetof_member_designator:
identifier
- { $$ = tree_cons ($1, NULL_TREE, NULL_TREE); }
+ { $$ = build_component_ref (offsetof_base, $1); }
| offsetof_member_designator '.' identifier
- { $$ = tree_cons ($3, NULL_TREE, $1); }
+ { $$ = build_component_ref ($1, $3); }
| offsetof_member_designator '[' expr ']'
- { $$ = tree_cons (NULL_TREE, $3.value, $1); }
+ { $$ = build_array_ref ($1, $3.value); }
;
old_style_parm_decls:
extern tree c_finish_bc_stmt (tree *, bool);
extern tree c_finish_goto_label (tree);
extern tree c_finish_goto_ptr (tree);
-extern tree build_offsetof (tree, tree);
/* Set to 0 at beginning of a function definition, set to 1 if
a return statement that specifies a return value is seen. */
return result;
}
}
-
-/* Build the result of __builtin_offsetof. TYPE is the first argument to
- offsetof, i.e. a type. LIST is a tree_list that encodes component and
- array references; PURPOSE is set for the former and VALUE is set for
- the later. */
-
-tree
-build_offsetof (tree type, tree list)
-{
- tree t;
-
- /* Build "*(type *)0". */
- t = convert (build_pointer_type (type), null_pointer_node);
- t = build_indirect_ref (t, "");
-
- /* Build COMPONENT and ARRAY_REF expressions as needed. */
- for (list = nreverse (list); list ; list = TREE_CHAIN (list))
- if (TREE_PURPOSE (list))
- t = build_component_ref (t, TREE_PURPOSE (list));
- else
- t = build_array_ref (t, TREE_VALUE (list));
-
- /* Finalize the offsetof expression. For now all we need to do is take
- the address of the expression we created, and cast that to an integer
- type; this mirrors the traditional macro implementation of offsetof. */
- t = build_unary_op (ADDR_EXPR, t, 0);
- return convert (size_type_node, t);
-}
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