cgraph: Adjust verify_corresponds_to_fndecl [PR106061]

Message ID Y9OTCEBcvrMQeQqy@tucnak
State Unresolved
Headers
Series cgraph: Adjust verify_corresponds_to_fndecl [PR106061] |

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Context Check Description
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Commit Message

Jakub Jelinek Jan. 27, 2023, 9:02 a.m. UTC
  Hi!

IPA passes redirect some calls in what it determines to be unreachable code
to builtin_decl_unreachable.  But that function returns sometimes
builtin_decl_explicit (BUILT_IN_UNREACHABLE) (which was what GCC 12
and earlier did always), or builtin_decl_explicit (BUILT_IN_TRAP)
(e.g. for -funreachable-traps, -O0, -Og).
Now the cgraph verification code has a code to verify cgraph edges
and has there an exception for these redirections to BUILT_IN_UNREACHABLE,
but doesn't have for BUILT_IN_TRAP, so e.g. the following testcase
ICEs during that verification.

The following patch just adds BUILT_IN_TRAP to those exceptions.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2023-01-27  Jakub Jelinek  <jakub@redhat.com>

	PR ipa/106061
	* cgraph.cc (cgraph_edge::verify_corresponds_to_fndecl): Allow
	redirection of calls to __builtin_trap in addition to redirection
	to __builtin_unreachable.

	* gcc.dg/pr106061.c: New test.


	Jakub
  

Comments

Richard Biener Jan. 27, 2023, 9:59 a.m. UTC | #1
On Fri, 27 Jan 2023, Jakub Jelinek wrote:

> Hi!
> 
> IPA passes redirect some calls in what it determines to be unreachable code
> to builtin_decl_unreachable.  But that function returns sometimes
> builtin_decl_explicit (BUILT_IN_UNREACHABLE) (which was what GCC 12
> and earlier did always), or builtin_decl_explicit (BUILT_IN_TRAP)
> (e.g. for -funreachable-traps, -O0, -Og).
> Now the cgraph verification code has a code to verify cgraph edges
> and has there an exception for these redirections to BUILT_IN_UNREACHABLE,
> but doesn't have for BUILT_IN_TRAP, so e.g. the following testcase
> ICEs during that verification.
> 
> The following patch just adds BUILT_IN_TRAP to those exceptions.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

> 2023-01-27  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR ipa/106061
> 	* cgraph.cc (cgraph_edge::verify_corresponds_to_fndecl): Allow
> 	redirection of calls to __builtin_trap in addition to redirection
> 	to __builtin_unreachable.
> 
> 	* gcc.dg/pr106061.c: New test.
> 
> --- gcc/cgraph.cc.jj	2023-01-19 09:58:50.000000000 +0100
> +++ gcc/cgraph.cc	2023-01-26 15:30:50.422759246 +0100
> @@ -3248,9 +3248,11 @@ cgraph_edge::verify_corresponds_to_fndec
>    node = node->ultimate_alias_target ();
>  
>    /* Optimizers can redirect unreachable calls or calls triggering undefined
> -     behavior to builtin_unreachable.  */
> +     behavior to __builtin_unreachable or __builtin_trap.  */
>  
> -  if (fndecl_built_in_p (callee->decl, BUILT_IN_UNREACHABLE))
> +  if (fndecl_built_in_p (callee->decl, BUILT_IN_NORMAL)
> +      && (DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_UNREACHABLE
> +	  || DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_TRAP))
>      return false;
>  
>    if (callee->former_clone_of != node->decl
> --- gcc/testsuite/gcc.dg/pr106061.c.jj	2023-01-26 15:40:06.002721103 +0100
> +++ gcc/testsuite/gcc.dg/pr106061.c	2023-01-26 15:41:32.553468886 +0100
> @@ -0,0 +1,18 @@
> +/* PR ipa/106061 */
> +/* { dg-do compile } */
> +/* { dg-options "-Og" } */
> +
> +extern void foo (void);
> +
> +inline void
> +bar (int x)
> +{
> +  if (x)
> +    foo ();
> +}
> +
> +void
> +baz (void)
> +{
> +  bar (0);
> +}
> 
> 	Jakub
> 
>
  

Patch

--- gcc/cgraph.cc.jj	2023-01-19 09:58:50.000000000 +0100
+++ gcc/cgraph.cc	2023-01-26 15:30:50.422759246 +0100
@@ -3248,9 +3248,11 @@  cgraph_edge::verify_corresponds_to_fndec
   node = node->ultimate_alias_target ();
 
   /* Optimizers can redirect unreachable calls or calls triggering undefined
-     behavior to builtin_unreachable.  */
+     behavior to __builtin_unreachable or __builtin_trap.  */
 
-  if (fndecl_built_in_p (callee->decl, BUILT_IN_UNREACHABLE))
+  if (fndecl_built_in_p (callee->decl, BUILT_IN_NORMAL)
+      && (DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_UNREACHABLE
+	  || DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_TRAP))
     return false;
 
   if (callee->former_clone_of != node->decl
--- gcc/testsuite/gcc.dg/pr106061.c.jj	2023-01-26 15:40:06.002721103 +0100
+++ gcc/testsuite/gcc.dg/pr106061.c	2023-01-26 15:41:32.553468886 +0100
@@ -0,0 +1,18 @@ 
+/* PR ipa/106061 */
+/* { dg-do compile } */
+/* { dg-options "-Og" } */
+
+extern void foo (void);
+
+inline void
+bar (int x)
+{
+  if (x)
+    foo ();
+}
+
+void
+baz (void)
+{
+  bar (0);
+}