On Sun, Jan 19, 2020 at 10:00:42PM +0100, Jakub Jelinek wrote:
> On Sun, Jan 19, 2020 at 03:34:48PM -0500, Marek Polacek wrote:
> > Bootstrapped/regtested on x86_64-linux, ok for trunk?
> >
> > * semantics.c (is_std_constant_evaluated_p): Check fndecl.
> >
> > * g++.dg/cpp1z/constexpr-if33.C: New test.
> > ---
> > gcc/cp/semantics.c | 4 ++--
> > gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C | 16 ++++++++++++++++
> > 2 files changed, 18 insertions(+), 2 deletions(-)
> > create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C
> >
> > diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
> > index 3669b247e34..9051a2863e0 100644
> > --- a/gcc/cp/semantics.c
> > +++ b/gcc/cp/semantics.c
> > @@ -734,8 +734,8 @@ is_std_constant_evaluated_p (tree fn)
> > return false;
> >
> > tree fndecl = cp_get_callee_fndecl_nofold (fn);
> > - if (fndecl_built_in_p (fndecl, CP_BUILT_IN_IS_CONSTANT_EVALUATED,
> > - BUILT_IN_FRONTEND))
> > + if (fndecl && fndecl_built_in_p (fndecl,
> > CP_BUILT_IN_IS_CONSTANT_EVALUATED,
> > + BUILT_IN_FRONTEND))
> > return true;
> >
> > if (!decl_in_std_namespace_p (fndecl))
>
> Shouldn't it instead do
> if (fndecl == NULL_TREE)
> return false;
> before the fndecl_built_in_p check?
>
> While decl_in_std_namespace_p apparently will return false for NULL
> argument, relying on that is werid.
Can do that, too.
-- >8 --
This is a crash with constexpr if, when trying to see if the call in
the if-statement is std::is_constant_evaluated.
cp_get_callee_fndecl_nofold can return NULL_TREE and fndecl_built_in_p
doesn't expect to get a null tree, so check FNDECL first.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
* semantics.c (is_std_constant_evaluated_p): Check fndecl.
* g++.dg/cpp1z/constexpr-if33.C: New test.
---
gcc/cp/semantics.c | 3 +++
gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C | 16 ++++++++++++++++
2 files changed, 19 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 3669b247e34..3b88f1520bc 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -734,6 +734,9 @@ is_std_constant_evaluated_p (tree fn)
return false;
tree fndecl = cp_get_callee_fndecl_nofold (fn);
+ if (fndecl == NULL_TREE)
+ return false;
+
if (fndecl_built_in_p (fndecl, CP_BUILT_IN_IS_CONSTANT_EVALUATED,
BUILT_IN_FRONTEND))
return true;
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C
b/gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C
new file mode 100644
index 00000000000..e5ef659932b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if33.C
@@ -0,0 +1,16 @@
+// PR c++/93324 - ICE with -Wall on constexpr if.
+// { dg-do compile { target c++17 } }
+// { dg-options "-Wall" }
+
+struct {
+ template <int>
+ static constexpr bool a() { return 0; }
+} e;
+
+template <typename>
+void d()
+{
+ auto c(e);
+ using b = decltype(c);
+ if constexpr (b::a<2>());
+}
base-commit: bcfc2227c556f2801a657ce3007374732baa8333
--
2.24.1
