Re: [PATCH 2/3] Implement CALL_EXPR_MUST_TAIL_CALL

[Andreas Schwab <schwab at linux-m68k dot org>]

David Malcolm <dmalcolm@redhat.com> writes:

> diff --git a/gcc/testsuite/gcc.dg/plugin/must-tail-call-2.c b/gcc/testsuite/gcc.dg/plugin/must-tail-call-2.c
> new file mode 100644
> index 0000000..c5504f8
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/plugin/must-tail-call-2.c
> @@ -0,0 +1,58 @@
> +/* Allow nested functions.  */
> +/* { dg-options "-Wno-pedantic" } */
> +
> +struct box { char field[64]; int i; };
> +
> +struct box __attribute__((noinline,noclone))
> +returns_struct (int i)
> +{
> +  struct box b;
> +  b.i = i * i;
> +  return b;
> +}
> +
> +int __attribute__((noinline,noclone))
> +test_1 (int i)
> +{
> +  return returns_struct (i * 5).i; /* { dg-error "cannot tail-call: callee returns a structure" } */
> +}
> +
> +int __attribute__((noinline,noclone))
> +test_2_callee (int i, struct box b)
> +{
> +  if (b.field[0])
> +    return 5;
> +  return i * i;
> +}
> +
> +int __attribute__((noinline,noclone))
> +test_2_caller (int i)
> +{
> +  struct box b;
> +  return test_2_callee (i + 1, b); /* { dg-error "cannot tail-call: callee required more stack slots than the caller" } */
> +}
> +
> +extern void setjmp (void);
> +void
> +test_3 (void)
> +{
> +  setjmp (); /* { dg-error "cannot tail-call: callee returns twice" } */
> +}
> +
> +void
> +test_4 (void)
> +{
> +  void nested (void)
> +  {
> +  }
> +  nested (); /* { dg-error "cannot tail-call: nested function" } */
> +}
> +
> +typedef void (fn_ptr_t) (void);
> +volatile fn_ptr_t fn_ptr;
> +
> +void
> +test_5 (void)
> +{
> +  fn_ptr (); /* { dg-error "cannot tail-call: callee does not return" } */
> +}

On ia64:

FAIL: gcc.dg/plugin/must-tail-call-2.c -fplugin=./must_tail_call_plugin.so  (test for errors, line 39)
FAIL: gcc.dg/plugin/must-tail-call-2.c -fplugin=./must_tail_call_plugin.so  (test for errors, line 57)
FAIL: gcc.dg/plugin/must-tail-call-2.c -fplugin=./must_tail_call_plugin.so (test for excess errors)
Excess errors:
gcc.dg/plugin/must-tail-call-2.c:39:3: error: cannot tail-call: target is not able to optimize the call into a sibling call
gcc.dg/plugin/must-tail-call-2.c:57:3: error: cannot tail-call: target is not able to optimize the call into a sibling call

On m68k:

FAIL: gcc.dg/plugin/must-tail-call-2.c -fplugin=./must_tail_call_plugin.so  (test for errors, line 48)
FAIL: gcc.dg/plugin/must-tail-call-2.c -fplugin=./must_tail_call_plugin.so (test for excess errors)
Excess errors:
gcc.dg/plugin/must-tail-call-2.c:48:3: error: cannot tail-call: target is not able to optimize the call into a sibling call

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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"And now for something completely different."