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-visibility "hidden" }
   6    { dg-require-alias "" }
   7    { dg-require-weak "" } */
   8
   9 #define ATTR(...)   __attribute__ ((__VA_ARGS__))
  10 #define ASRT(expr)   _Static_assert (expr, #expr)
  11
  12 #define ASMNAME(cname)  ASMNAME2 (__USER_LABEL_PREFIX__, cname)
  13 #define ASMNAME2(prefix, cname) STRING (prefix) cname
  14 #define STRING(x)    #x
  15
  16 /* Variable that is local to this translation unit but that can
  17    be modified from other units by calling reset_unit_local().  */
  18 static int unit_local;
  19
  20 void reset_unit_local (void)
  21 {
  22   unit_local = 0;
  23 }
  24
  25 /* Attribute leaf implies that fleaf() doesn't modify unit_local().  */
  26 ATTR (leaf, returns_nonnull)
  27 void* fleaf_retnz (void);
  28
  29 /* Verify both attributes have been applied.  */
  30 ASRT (__builtin_has_attribute (fleaf_retnz, leaf));
  31 ASRT (__builtin_has_attribute (fleaf_retnz, returns_nonnull));
  32
  33 /* Verify that attribute leaf has the expected effect.  */
  34 void call_fleaf_retnz (void)
  35 {
  36   int i = unit_local;
  37   void *p = fleaf_retnz ();
  38
  39   /* Expect both tests to be folded to false and the calls eliminated.  */
  40   extern void call_fleaf_retnz_test_leaf_eliminated (void);
  41   if (i != unit_local)
  42     call_fleaf_retnz_test_leaf_eliminated ();
  43
  44   extern void call_fleaf_retnz_test_nonnull_eliminated (void);
  45   if (p == 0)
  46     call_fleaf_retnz_test_nonnull_eliminated ();
  47 }
  48
  49
  50 /* Verify that attribute copy copies the returns_nonnull attribute
  51    but doesn't try to copy attribute leaf which only applies to extern
  52    function.  */
  53 static ATTR (copy (fleaf_retnz), weakref ("fleaf_retnz"))
  54 void* fweakref_fleaf_retnz_copy (void);
  55
  56 ASRT (!__builtin_has_attribute (fweakref_fleaf_retnz_copy, leaf));
  57 ASRT (__builtin_has_attribute (fweakref_fleaf_retnz_copy, returns_nonnull));
  58
  59 void call_fweakref_fleaf_retnz_copy (void)
  60 {
  61   int i = unit_local;
  62   void *p = fweakref_fleaf_retnz_copy ();
  63
  64   /* Since leaf is not copied, expect the following test not to be
  65      folded and the call to be emitted.  */
  66   extern void call_fweakref_test_leaf_emitted (void);
  67   if (i != unit_local)
  68     call_fweakref_test_leaf_emitted ();
  69
  70   /* Expect the following test to be folded to false and the call
  71      eliminated.  */
  72   extern void call_fweakref_fleaf_nonnull_eliminated (void);
  73   if (p == 0)
  74     call_fweakref_fleaf_nonnull_eliminated ();
  75 }
  76
  77 /* This is reduced from libgfortran/runtime/error.c.  Verify it
  78    doesn't trigger warnings and that the noreturn bit is copied
  79    to the alias by verifying that calling the alias in a non-void
  80    function with no return statement isn't diagnosed.  */
  81
  82 extern _Noreturn void fnoreturn (void);
  83
  84 extern __typeof (fnoreturn)
  85   ATTR (visibility ("hidden"))
  86   fnoreturn __asm__ (ASMNAME ("fnoreturn_name"));
  87
  88 void fnoreturn (void)
  89 {
  90   __builtin_abort ();
  91 }
  92
  93 extern __typeof (fnoreturn)
  94   ATTR (alias ("fnoreturn_name"), copy (fnoreturn))
  95   fnoreturn_alias;
  96
  97 int call_fnoreturn_alias (void)
  98 {
  99   fnoreturn_alias ();
 100 }