On 10/10/19 2:06 PM, Bernd Edlinger wrote:
On 10/10/19 7:49 PM, Jason Merrill wrote:
On 10/10/19 10:42 AM, Bernd Edlinger wrote:
Hi,
this fixes a crash when -Wshadow=compatible-local is
enabled in the testcase g++.dg/parse/crash68.C
Why does that flag cause this crash?
gcc/cp/name-lookup.c:
if (warn_shadow)
warning_code = OPT_Wshadow;
else if (warn_shadow_local)
warning_code = OPT_Wshadow_local;
else if (warn_shadow_compatible_local
&& (same_type_p (TREE_TYPE (old), TREE_TYPE (decl))
|| (!dependent_type_p (TREE_TYPE (decl))
&& !dependent_type_p (TREE_TYPE (old))
/* If the new decl uses auto, we don't yet know
its type (the old type cannot be using auto
at this point, without also being
dependent). This is an indication we're
(now) doing the shadow checking too
early. */
&& !type_uses_auto (TREE_TYPE (decl))
&& can_convert (TREE_TYPE (old), TREE_TYPE (decl),
tf_none))))
warning_code = OPT_Wshadow_compatible_local;
if -Wshadow=compatible-local is used, the can_convert function crashes
in instantiate_class_template_1.
Right, checking can_convert is problematic here, as it can cause
template instantiations that change the semantics of the program. Or,
in this case, crash.
Jason
