From: Marek Polacek <polacek@redhat.com>
Date: Fri, 7 Mar 2025 16:26:46 +0000 (-0500)
Subject: c++: ICE with lambda in fold expression in requires [PR119134]
X-Git-Tag: basepoints/gcc-16~1548
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e47062ce70d147091f1a97ec94bd6efad92bc5e;p=thirdparty%2Fgcc.git

c++: ICE with lambda in fold expression in requires [PR119134]

The r12-8258 fix assumes that DECL_CONTEXT of 'pack' in
check_for_bare_parameter_packs is going to be an operator()
but as this test shows, it can be empty.

	PR c++/119134

gcc/cp/ChangeLog:

	* pt.cc (check_for_bare_parameter_packs): Check DECL_CONTEXT.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/lambda-uneval24.C: New test.

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

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 6ac9e6f163e..8aaae446868 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -4375,6 +4375,7 @@ check_for_bare_parameter_packs (tree t, location_t loc /* = UNKNOWN_LOCATION */)
 	tree pack = TREE_VALUE (parameter_packs);
 	if (is_capture_proxy (pack)
 	    || (TREE_CODE (pack) == PARM_DECL
+		&& DECL_CONTEXT (pack)
 		&& DECL_CONTEXT (DECL_CONTEXT (pack)) == lam))
 	  break;
       }
diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-uneval24.C b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval24.C
new file mode 100644
index 00000000000..a2b45595e47
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval24.C
@@ -0,0 +1,4 @@
+// PR c++/119134
+// { dg-do compile { target c++20 } }
+
+void f(auto... args) requires(([args] {}, ..., true)) {}