On 4/7/21 5:58 PM, Marek Polacek wrote:
In explicit17.C, we weren't detecting an unexpanded parameter pack in
explicit(bool), so we crashed on a TEMPLATE_PARM_INDEX in constexpr.
I noticed the same is true for noexcept(), but only since my patch to
implement delayed parsing of noexcept. Previously, we would detect the
unexpanded pack in push_template_decl but now the noexcept expression
has not yet been parsed, so we need to do it a bit later.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
OK.
gcc/cp/ChangeLog:
PR c++/99844
* decl.c (build_explicit_specifier): Call
check_for_bare_parameter_packs.
* except.c (build_noexcept_spec): Likewise.
gcc/testsuite/ChangeLog:
PR c++/99844
* g++.dg/cpp2a/explicit16.C: Use c++20.
* g++.dg/cpp0x/noexcept66.C: New test.
* g++.dg/cpp2a/explicit17.C: New test.
---
gcc/cp/decl.c | 3 +++
gcc/cp/except.c | 2 ++
gcc/testsuite/g++.dg/cpp0x/noexcept66.C | 13 +++++++++++++
gcc/testsuite/g++.dg/cpp2a/explicit16.C | 2 +-
gcc/testsuite/g++.dg/cpp2a/explicit17.C | 9 +++++++++
5 files changed, 28 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept66.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit17.C
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index edab147c78d..3294b4fa943 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -17991,6 +17991,9 @@ require_deduced_type (tree decl, tsubst_flags_t
complain)
tree
build_explicit_specifier (tree expr, tsubst_flags_t complain)
{
+ if (check_for_bare_parameter_packs (expr))
+ return error_mark_node;
+
if (instantiation_dependent_expression_p (expr))
/* Wait for instantiation, tsubst_function_decl will handle it. */
return expr;
diff --git a/gcc/cp/except.c b/gcc/cp/except.c
index 0bbc229490e..cbafc09629b 100644
--- a/gcc/cp/except.c
+++ b/gcc/cp/except.c
@@ -1228,6 +1228,8 @@ type_throw_all_p (const_tree type)
tree
build_noexcept_spec (tree expr, tsubst_flags_t complain)
{
+ if (check_for_bare_parameter_packs (expr))
+ return error_mark_node;
if (TREE_CODE (expr) != DEFERRED_NOEXCEPT
&& !value_dependent_expression_p (expr))
{
diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept66.C
b/gcc/testsuite/g++.dg/cpp0x/noexcept66.C
new file mode 100644
index 00000000000..6c76d9146ad
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/noexcept66.C
@@ -0,0 +1,13 @@
+// PR c++/99844
+// { dg-do compile { target c++11 } }
+
+template <bool... B>
+struct S {
+ void fn() noexcept(B); // { dg-error "parameter packs not expanded" }
+};
+
+void fn ()
+{
+ S<true> s;
+ s.fn();
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit16.C
b/gcc/testsuite/g++.dg/cpp2a/explicit16.C
index 9d95b0d669e..9c20f6332e9 100644
--- a/gcc/testsuite/g++.dg/cpp2a/explicit16.C
+++ b/gcc/testsuite/g++.dg/cpp2a/explicit16.C
@@ -1,5 +1,5 @@
// PR c++/95066 - explicit malfunction with dependent expression.
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++20 } }
template <typename T>
struct Foo {
diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit17.C
b/gcc/testsuite/g++.dg/cpp2a/explicit17.C
new file mode 100644
index 00000000000..38a61f4a273
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/explicit17.C
@@ -0,0 +1,9 @@
+// PR c++/99844
+// { dg-do compile { target c++20 } }
+
+template <bool... B>
+struct S {
+ constexpr explicit(B) S() {} // { dg-error "parameter packs not expanded" }
+};
+
+constexpr S<true> s;
base-commit: 2f3d9104610cb2058cf091707a20c1c6eff8d470
