https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93631
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords|ice-on-valid-code |ice-on-invalid-code
Status|ASSIGNED |NEW
CC| |jsm28 at gcc dot gnu.org,
| |mpolacek at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Component|middle-end |c
Assignee|rguenth at gcc dot gnu.org |unassigned at gcc dot
gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
smaller "invalid" testcase (why don't we diagnose it?):
int f2 ( int x [ strcmp ( ) ] , int b ) { return x[0] - b ; }
it's interesting that if I declare strcmp to avoid an implicit declaration
warning with the following it stops to ICE...
int strcmp();
so somehow the FEs decl merging for an implicit declaration coming from
the argument list is "broken" and doesn't avoid pre-empting the built-in
declaration?
While I have a patch to paper over the issue in the middle-end it would
be nice to avoid the issue in the frontend. The middle-end patch would do
the following, using the canonical built-in declaration for argument
verification. Similar issues exist for target builtins since we also
have a target specific folder. Not sure how the FE deals with user-provided
"bogus" implementations of those (and whether they ever exist in non
__builtin_ obfuscated variants).
diff --git a/gcc/gimple.c b/gcc/gimple.c
index 324e706d508..d64c2a77ea3 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -2698,6 +2698,11 @@ gimple_builtin_call_types_compatible_p (const gimple
*stmt, tree fndecl)
{
gcc_checking_assert (DECL_BUILT_IN_CLASS (fndecl) != NOT_BUILT_IN);
+ /* Use the decl we are actually expecting for comparison, not a possibly
+ bogus one from the user the C frontend is happily marking as builtin. */
+ if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ fndecl = builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl));
+
tree ret = gimple_call_lhs (stmt);
if (ret
&& !useless_type_conversion_p (TREE_TYPE (ret),
CCing C FE folks.
