From: Patrick Palka <ppalka@redhat.com>
Date: Tue, 14 Apr 2026 19:36:54 +0000 (-0400)
Subject: c++: reference to static local meta::info as targ [PR124824]
X-Git-Tag: basepoints/gcc-17~124
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0943fcaca7dd3415546f68397c24e38afaffaf3d;p=thirdparty%2Fgcc.git

c++: reference to static local meta::info as targ [PR124824]

Here we're crashing in discriminator_for_local_entity during mangling
of f<&M>() because determine_local_discriminator is never called for
the static local meta::info M.  The relevant code path in cp_finish_decl
was disabled for consteval-only types in the main Reflection commit
r16-6808 to avoid creating a varpool_node for such types.

This patch naively fixes this by moving the consteval_only_p check so
that we still call determine_local_discriminator for such types.

	PR c++/124824

gcc/cp/ChangeLog:

	* decl.cc (cp_finish_decl): Sink !consteval_only_p check to
	only guard the varpool_node::get_create call.

gcc/testsuite/ChangeLog:

	* g++.dg/reflect/mangle6.C: New test.

Reviewed-by: Jason Merrill <jason@redhat.com>
---

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index ecdefe300d5..7e40226d739 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -9885,8 +9885,7 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	 variable.  */
       if (DECL_FUNCTION_SCOPE_P (decl)
 	  && TREE_STATIC (decl)
-	  && !DECL_ARTIFICIAL (decl)
-	  && !consteval_only_p (decl))
+	  && !DECL_ARTIFICIAL (decl))
 	{
 	  /* The variable holding an anonymous union will have had its
 	     discriminator set in finish_anon_union, after which it's
@@ -9904,9 +9903,10 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	      walk_tree (&init, notice_forced_label_r, NULL, NULL);
 	      add_local_decl (cfun, decl);
 	    }
-	  /* And make sure it's in the symbol table for
-	     c_parse_final_cleanups to find.  */
-	  varpool_node::get_create (decl);
+	  if (!consteval_only_p (decl))
+	    /* And make sure it's in the symbol table for
+	       c_parse_final_cleanups to find.  */
+	    varpool_node::get_create (decl);
 	}
 
       if (flag_openmp
diff --git a/gcc/testsuite/g++.dg/reflect/mangle6.C b/gcc/testsuite/g++.dg/reflect/mangle6.C
new file mode 100644
index 00000000000..23030f77e4c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/reflect/mangle6.C
@@ -0,0 +1,19 @@
+// PR c++/124824
+// { dg-do compile { target c++26 } }
+// { dg-additional-options "-freflection" }
+
+template<auto V> void f() { }
+
+int main() {
+  {
+    static constexpr auto M = ^^int;
+    f<&M>();
+  }
+  {
+    static constexpr auto M = ^^int;
+    f<&M>();
+  }
+}
+
+// { dg-final { scan-assembler "_Z1fITnDaXadL_ZZ4mainE1MEEEvv" } }
+// { dg-final { scan-assembler "_Z1fITnDaXadL_ZZ4mainE1M_0EEEvv" } }