From: Marek Polacek <polacek@redhat.com>
Date: Wed, 10 Jun 2020 14:49:08 +0000 (-0400)
Subject: c++: Fix ICE with delayed parsing of noexcept-specifier [PR95562]
X-Git-Tag: releases/gcc-10.2.0~246
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=977a173c196dc5ba5ac2e1b890083beb0451cf60;p=thirdparty%2Fgcc.git

c++: Fix ICE with delayed parsing of noexcept-specifier [PR95562]

Here we ICE because a DEFERRED_PARSE expression leaked to tsubst_copy.
We create these expressions for deferred noexcept-specifiers in
cp_parser_save_noexcept; they are supposed to be re-parsed in
cp_parser_late_noexcept_specifier.  In this case we never got around
to re-parsing it because the noexcept-specifier was attached to a
pointer to a function, not to a function declaration.  But we should
not have delayed the parsing here in the first place; we already
avoid delaying the parsing for alias-decls, typedefs, and friend
function declarations.  (Clang++ also doesn't delay the parsing
for pointers to function.)

gcc/cp/ChangeLog:

	PR c++/95562
	* parser.c (cp_parser_direct_declarator): Clear
	CP_PARSER_FLAGS_DELAY_NOEXCEPT if the declarator kind is not
	cdk_id.

gcc/testsuite/ChangeLog:

	PR c++/95562
	* g++.dg/cpp0x/noexcept60.C: New test.
---

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 4daec18a2e97..42d7b1c03361 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -21225,6 +21225,12 @@ cp_parser_direct_declarator (cp_parser* parser,
 		  ref_qual = cp_parser_ref_qualifier_opt (parser);
 		  /* Parse the tx-qualifier.  */
 		  tree tx_qual = cp_parser_tx_qualifier_opt (parser);
+
+		  /* If it turned out that this is e.g. a pointer to a
+		     function, we don't want to delay noexcept parsing.  */
+		  if (declarator == NULL || declarator->kind != cdk_id)
+		    flags &= ~CP_PARSER_FLAGS_DELAY_NOEXCEPT;
+
 		  /* And the exception-specification.  */
 		  exception_specification
 		    = cp_parser_exception_specification_opt (parser,
diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept60.C b/gcc/testsuite/g++.dg/cpp0x/noexcept60.C
new file mode 100644
index 000000000000..d8efe1a24cb4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/noexcept60.C
@@ -0,0 +1,13 @@
+// PR c++/95562
+// { dg-do compile { target c++11 } }
+
+template <bool Nothrow>
+struct Functions
+{
+  void (*func)(void*) noexcept(Nothrow);
+};
+
+void test()
+{
+  Functions<true> f{};
+}