gcc/patches/gcc47-c++-builtin-redecl.patch0

   1 2007-10-02  Jakub Jelinek  <jakub@redhat.com>
   2
   3         * decl.c (duplicate_decls): When redeclaring a builtin function,
   4         keep the merged decl builtin whenever types match, even if new
   5         decl defines a function.
   6
   7         * gcc.dg/builtins-85.c: New test.
   8         * g++.dg/ext/builtin30.C: New test.
   9
  10 --- gcc/cp/decl.c.jj    2007-10-01 22:11:09.000000000 +0200
  11 +++ gcc/cp/decl.c       2007-10-02 11:39:46.000000000 +0200
  12 @@ -2137,39 +2137,37 @@ duplicate_decls (tree newdecl, tree oldd
  13           DECL_ARGUMENTS (olddecl) = DECL_ARGUMENTS (newdecl);
  14           DECL_RESULT (olddecl) = DECL_RESULT (newdecl);
  15         }
  16 +      /* If redeclaring a builtin function, it stays built in.  */
  17 +      if (types_match && DECL_BUILT_IN (olddecl))
  18 +       {
  19 +         DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl);
  20 +         DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl);
  21 +         /* If we're keeping the built-in definition, keep the rtl,
  22 +            regardless of declaration matches.  */
  23 +         COPY_DECL_RTL (olddecl, newdecl);
  24 +         if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL)
  25 +           {
  26 +             enum built_in_function fncode = DECL_FUNCTION_CODE (newdecl);
  27 +             switch (fncode)
  28 +               {
  29 +                 /* If a compatible prototype of these builtin functions
  30 +                    is seen, assume the runtime implements it with the
  31 +                    expected semantics.  */
  32 +               case BUILT_IN_STPCPY:
  33 +                 if (builtin_decl_explicit_p (fncode))
  34 +                   set_builtin_decl_implicit_p (fncode, true);
  35 +                 break;
  36 +               default:
  37 +                 break;
  38 +               }
  39 +           }
  40 +       }
  41        if (new_defines_function)
  42         /* If defining a function declared with other language
  43            linkage, use the previously declared language linkage.  */
  44         SET_DECL_LANGUAGE (newdecl, DECL_LANGUAGE (olddecl));
  45        else if (types_match)
  46         {
  47 -         /* If redeclaring a builtin function, and not a definition,
  48 -            it stays built in.  */
  49 -         if (DECL_BUILT_IN (olddecl))
  50 -           {
  51 -             DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl);
  52 -             DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl);
  53 -             /* If we're keeping the built-in definition, keep the rtl,
  54 -                regardless of declaration matches.  */
  55 -             COPY_DECL_RTL (olddecl, newdecl);
  56 -             if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL)
  57 -               {
  58 -                 enum built_in_function fncode = DECL_FUNCTION_CODE (newdecl);
  59 -                 switch (fncode)
  60 -                   {
  61 -                     /* If a compatible prototype of these builtin functions
  62 -                        is seen, assume the runtime implements it with the
  63 -                        expected semantics.  */
  64 -                   case BUILT_IN_STPCPY:
  65 -                     if (builtin_decl_explicit_p (fncode))
  66 -                       set_builtin_decl_implicit_p (fncode, true);
  67 -                     break;
  68 -                   default:
  69 -                     break;
  70 -                   }
  71 -               }
  72 -           }
  73 -
  74           DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
  75           /* Don't clear out the arguments if we're just redeclaring a
  76              function.  */
  77 --- gcc/testsuite/gcc.dg/builtins-85.c.jj       2007-10-02 11:23:51.000000000 +0200
  78 +++ gcc/testsuite/gcc.dg/builtins-85.c  2007-10-02 11:24:12.000000000 +0200
  79 @@ -0,0 +1,25 @@
  80 +/* { dg-do compile } */
  81 +/* { dg-options "-O2" } */
  82 +
  83 +typedef __SIZE_TYPE__ size_t;
  84 +extern void __chk_fail (void);
  85 +extern int snprintf (char *, size_t, const char *, ...);
  86 +extern inline __attribute__((gnu_inline, always_inline)) int snprintf (char *a, size_t b, const char *fmt, ...)
  87 +{
  88 +  if (__builtin_object_size (a, 0) != -1UL && __builtin_object_size (a, 0) < b)
  89 +    __chk_fail ();
  90 +  return __builtin_snprintf (a, b, fmt, __builtin_va_arg_pack ());
  91 +}
  92 +extern int snprintf (char *, size_t, const char *, ...) __asm ("mysnprintf");
  93 +
  94 +char buf[10];
  95 +
  96 +int
  97 +main (void)
  98 +{
  99 +  snprintf (buf, 10, "%d%d\n", 10, 10);
 100 +  return 0;
 101 +}
 102 +
 103 +/* { dg-final { scan-assembler "mysnprintf" } } */
 104 +/* { dg-final { scan-assembler-not "__chk_fail" } } */
 105 --- gcc/testsuite/g++.dg/ext/builtin30.C.jj     2007-10-02 11:19:45.000000000 +0200
 106 +++ gcc/testsuite/g++.dg/ext/builtin30.C        2007-10-02 11:23:26.000000000 +0200
 107 @@ -0,0 +1,27 @@
 108 +// { dg-do compile }
 109 +// { dg-options "-O2" }
 110 +
 111 +typedef __SIZE_TYPE__ size_t;
 112 +extern "C" {
 113 +extern void __chk_fail (void);
 114 +extern int snprintf (char *, size_t, const char *, ...);
 115 +extern inline __attribute__((gnu_inline, always_inline)) int snprintf (char *a, size_t b, const char *fmt, ...)
 116 +{
 117 +  if (__builtin_object_size (a, 0) != -1UL && __builtin_object_size (a, 0) < b)
 118 +    __chk_fail ();
 119 +  return __builtin_snprintf (a, b, fmt, __builtin_va_arg_pack ());
 120 +}
 121 +extern int snprintf (char *, size_t, const char *, ...) __asm ("mysnprintf");
 122 +}
 123 +
 124 +char buf[10];
 125 +
 126 +int
 127 +main (void)
 128 +{
 129 +  snprintf (buf, 10, "%d%d\n", 10, 10);
 130 +  return 0;
 131 +}
 132 +
 133 +// { dg-final { scan-assembler "mysnprintf" } }
 134 +// { dg-final { scan-assembler-not "__chk_fail" } }