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[PATCH] Accept -> in offsetof member-designator (the same as `[0].', PR c/32084)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: "Joseph S. Myers" <joseph at codesourcery dot com>, Jason Merrill <jason at redhat dot com>, Mark Mitchell <mark at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 7 Jan 2009 22:34:01 +0100
- Subject: [PATCH] Accept -> in offsetof member-designator (the same as `[0].', PR c/32084)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
For struct S { struct T { int i; } t[2]; } is
offsetof (struct S, t->i) valid, as with static struct S s;
&s.t->i is a valid address constant. The following patch parses
it in both C and C++ FEs as [0]. Bootstrapped/regtested on x86_64-linux,
ok for trunk?
2009-01-07 Jakub Jelinek <jakub@redhat.com>
PR c/32084
* c-parser.c (c_parser_postfix_expression): Allow `->' in
offsetof member-designator, handle it as `[0].'.
* parser.c (cp_parser_builtin_offsetof): Allow `->' in
offsetof member-designator, handle it as `[0].'.
* gcc.dg/pr32084.c: New test.
* g++.dg/parse/offsetof9.C: New test.
--- gcc/c-parser.c.jj 2009-01-02 09:32:56.000000000 +0100
+++ gcc/c-parser.c 2009-01-07 16:07:13.000000000 +0100
@@ -5273,10 +5273,21 @@ c_parser_postfix_expression (c_parser *p
c_parser_consume_token (parser);
while (c_parser_next_token_is (parser, CPP_DOT)
|| c_parser_next_token_is (parser,
- CPP_OPEN_SQUARE))
+ CPP_OPEN_SQUARE)
+ || c_parser_next_token_is (parser,
+ CPP_DEREF))
{
- if (c_parser_next_token_is (parser, CPP_DOT))
+ if (c_parser_next_token_is (parser, CPP_DEREF))
+ {
+ loc = c_parser_peek_token (parser)->location;
+ offsetof_ref = build_array_ref (offsetof_ref,
+ integer_zero_node,
+ loc);
+ goto do_dot;
+ }
+ else if (c_parser_next_token_is (parser, CPP_DOT))
{
+ do_dot:
c_parser_consume_token (parser);
if (c_parser_next_token_is_not (parser,
CPP_NAME))
--- gcc/cp/parser.c.jj 2009-01-02 09:32:55.000000000 +0100
+++ gcc/cp/parser.c 2009-01-07 16:20:08.000000000 +0100
@@ -1,6 +1,6 @@
/* C++ Parser.
Copyright (C) 2000, 2001, 2002, 2003, 2004,
- 2005, 2007, 2008 Free Software Foundation, Inc.
+ 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
Written by Mark Mitchell <mark@codesourcery.com>.
This file is part of GCC.
@@ -6627,7 +6627,8 @@ cp_parser_constant_expression (cp_parser
offsetof-member-designator:
id-expression
| offsetof-member-designator "." id-expression
- | offsetof-member-designator "[" expression "]" */
+ | offsetof-member-designator "[" expression "]"
+ | offsetof-member-designator "->" id-expression */
static tree
cp_parser_builtin_offsetof (cp_parser *parser)
@@ -6670,11 +6671,16 @@ cp_parser_builtin_offsetof (cp_parser *p
expr = cp_parser_postfix_open_square_expression (parser, expr, true);
break;
+ case CPP_DEREF:
+ /* offsetof-member-designator "->" identifier */
+ expr = grok_array_decl (expr, integer_zero_node);
+ /* FALLTHRU */
+
case CPP_DOT:
/* offsetof-member-designator "." identifier */
cp_lexer_consume_token (parser->lexer);
- expr = cp_parser_postfix_dot_deref_expression (parser, CPP_DOT, expr,
- true, &dummy,
+ expr = cp_parser_postfix_dot_deref_expression (parser, CPP_DOT,
+ expr, true, &dummy,
token->location);
break;
--- gcc/testsuite/gcc.dg/pr32084.c.jj 2009-01-07 16:23:55.000000000 +0100
+++ gcc/testsuite/gcc.dg/pr32084.c 2009-01-07 16:11:54.000000000 +0100
@@ -0,0 +1,12 @@
+/* PR c/32084 */
+/* { dg-do compile } */
+
+struct S
+{
+ int c;
+ struct { float f; } sa[2];
+};
+
+char a[__builtin_offsetof (struct S, sa->f)
+ == __builtin_offsetof (struct S, sa[0].f) ? 1 : -1];
+
--- gcc/testsuite/g++.dg/parse/offsetof9.C.jj 2009-01-07 16:31:23.000000000 +0100
+++ gcc/testsuite/g++.dg/parse/offsetof9.C 2009-01-07 16:34:48.000000000 +0100
@@ -0,0 +1,32 @@
+/* PR c/32084 */
+/* { dg-do run } */
+
+struct S
+{
+ int c;
+ struct { float f; } sa[2];
+};
+
+char a[__builtin_offsetof (S, sa->f)
+ == __builtin_offsetof (S, sa[0].f) ? 1 : -1];
+
+template <int N>
+struct T
+{
+ int c[N];
+ struct { float f; } sa[N];
+ static int foo () { return __builtin_offsetof (T, sa->f); }
+ static int bar () { return __builtin_offsetof (T, sa[0].f); }
+};
+
+char b[__builtin_offsetof (T<5>, sa->f)
+ == __builtin_offsetof (T<5>, sa[0].f) ? 1 : -1];
+
+int
+main ()
+{
+ if (T<1>::foo () != T<1>::bar ())
+ __builtin_abort ();
+ if (T<7>::foo () != T<7>::bar ())
+ __builtin_abort ();
+}
Jakub