gcc/testsuite/gcc.dg/attr-copy-6.c

   1 /* PR middle-end/88546 - Copy attribute unusable for weakrefs
   2    { dg-do compile }
   3    { dg-skip-if "Attributes not supported" { { hppa*-*-hpux* } && { ! lp64 } } }
   4    { dg-options "-O2 -Wall" }
   5    { dg-require-weak "" } */
   6
   7 #define ATTR(...)   __attribute__ ((__VA_ARGS__))
   8 #define ASRT(expr)   _Static_assert (expr, #expr)
   9
  10 /* Variable that is local to this translation unit but that can
  11    be modified from other units by calling reset_unit_local().  */
  12 static int unit_local;
  13
  14 void reset_unit_local (void)
  15 {
  16   unit_local = 0;
  17 }
  18
  19 /* Attribute leaf implies that fleaf() doesn't modify unit_local().  */
  20 ATTR (leaf, returns_nonnull)
  21 void* fleaf_retnz (void);
  22
  23 /* Verify both attributes have been applied.  */
  24 ASRT (__builtin_has_attribute (fleaf_retnz, leaf));
  25 ASRT (__builtin_has_attribute (fleaf_retnz, returns_nonnull));
  26
  27 /* Verify that attribute leaf has the expected effect.  */
  28 void call_fleaf_retnz (void)
  29 {
  30   int i = unit_local;
  31   void *p = fleaf_retnz ();
  32
  33   /* Expect both tests to be folded to false and the calls eliminated.  */
  34   extern void call_fleaf_retnz_test_leaf_eliminated (void);
  35   if (i != unit_local)
  36     call_fleaf_retnz_test_leaf_eliminated ();
  37
  38   extern void call_fleaf_retnz_test_nonnull_eliminated (void);
  39   if (p == 0)
  40     call_fleaf_retnz_test_nonnull_eliminated ();
  41 }
  42
  43
  44 /* Verify that attribute copy copies the returns_nonnull attribute
  45    but doesn't try to copy attribute leaf which only applies to extern
  46    function.  */
  47 static ATTR (copy (fleaf_retnz), weakref ("fleaf_retnz"))
  48 void* fweakref_fleaf_retnz_copy (void);
  49
  50 ASRT (!__builtin_has_attribute (fweakref_fleaf_retnz_copy, leaf));
  51 ASRT (__builtin_has_attribute (fweakref_fleaf_retnz_copy, returns_nonnull));
  52
  53 void call_fweakref_fleaf_retnz_copy (void)
  54 {
  55   int i = unit_local;
  56   void *p = fweakref_fleaf_retnz_copy ();
  57
  58   /* Since leaf is not copied, expect the following test not to be
  59      folded and the call to be emitted.  */
  60   extern void call_fweakref_test_leaf_emitted (void);
  61   if (i != unit_local)
  62     call_fweakref_test_leaf_emitted ();
  63
  64   /* Expect the following test to be folded to false and the call
  65      eliminated.  */
  66   extern void call_fweakref_fleaf_nonnull_eliminated (void);
  67   if (p == 0)
  68     call_fweakref_fleaf_nonnull_eliminated ();
  69 }
  70
  71 /* This is reduced from libgfortran/runtime/error.c.  Verify it
  72    doesn't trigger warnings and that the noreturn bit is copied
  73    to the alias by verifying that calling the alias in a non-void
  74    function with no return statement isn't diagnosed.  */
  75
  76 extern _Noreturn void fnoreturn (void);
  77
  78 extern __typeof (fnoreturn)
  79   ATTR (visibility ("hidden"))
  80   fnoreturn __asm__ ("fnoreturn_name");
  81
  82 void fnoreturn (void)
  83 {
  84   __builtin_abort ();
  85 }
  86
  87 extern __typeof (fnoreturn)
  88   ATTR (alias ("fnoreturn_name"), copy (fnoreturn))
  89   fnoreturn_alias;
  90
  91 int call_fnoreturn_alias (void)
  92 {
  93   fnoreturn_alias ();
  94 }