The attached patch avoids an ICE when using
the CLASSTYPE_IMPLICIT_INSTANTIATION() macro with an argument
that is not a class type but rather a typename_type.
The test case should trigger a warning but doesn't because
the code doesn't fully handle explicit instantiations.
Martin
Check for class type before assuming a type is one [PR103703].
Resolves:
PR c++/103703 - ICE with -Wmismatched-tags with friends and templates
gcc/cp/ChangeLog:
PR c++/103703
* parser.c (class_decl_loc_t::diag_mismatched_tags):
gcc/testsuite/ChangeLog:
PR c++/103703
* g++.dg/warn/Wmismatched-tags-9.C: New test.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 52225d46d4e..d21e1d9de6d 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -33536,7 +33536,7 @@ class_decl_loc_t::diag_mismatched_tags (tree type_decl)
class_decl_loc_t *cdlguide = this;
tree type = TREE_TYPE (type_decl);
- if (CLASSTYPE_IMPLICIT_INSTANTIATION (type))
+ if (CLASS_TYPE_P (type) && CLASSTYPE_IMPLICIT_INSTANTIATION (type))
{
/* For implicit instantiations of a primary template look up
the primary or partial specialization and use it as
diff --git a/gcc/testsuite/g++.dg/warn/Wmismatched-tags-9.C b/gcc/testsuite/g++.dg/warn/Wmismatched-tags-9.C
new file mode 100644
index 000..2712c4de1f6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wmismatched-tags-9.C
@@ -0,0 +1,32 @@
+/* PR c++/103703 - ICE with -Wmismatched-tags with friends and templates
+ { dg-do compile }
+ { dg-options "-Wall -Wmismatched-tags" } */
+
+template
+struct A
+{
+ struct B { };
+};
+
+template
+struct C
+{
+ friend class A::B; // { dg-warning "-Wmismatched-tags" "pr102036" { xfail *-*-* } }
+};
+
+template struct C;
+
+
+template
+struct D
+{
+ friend class A::B; // okay, specialized as class below
+};
+
+template <>
+struct A
+{
+ class B { };
+};
+
+template struct D;