Hi!
The following testcase ICEs with -fno-weak, because maybe_commonize_var
clears TREE_PUBLIC/DECL_COMMON, but later we assume that if
!DECL_INTERFACE_KNOWN that TREE_PUBLIC is true.
Other spots that clear TREE_PUBLIC also set DECL_INTERFACE_KNOWN,
e.g. twice in optimize.c:
cp/optimize.c- TREE_PUBLIC (fn) = false;
cp/optimize.c- DECL_EXTERNAL (fn) = false;
cp/optimize.c: DECL_INTERFACE_KNOWN (fn) = true;
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-02-20 Jakub Jelinek <ja...@redhat.com>
PR c++/89405
* decl.c (maybe_commonize_var): When clearing TREE_PUBLIC and
DECL_COMMON, set DECL_INTERFACE_KNOWN.
* g++.dg/cpp1z/inline-var5.C: New test.
--- gcc/cp/decl.c.jj 2019-02-14 08:06:37.905546103 +0100
+++ gcc/cp/decl.c 2019-02-20 13:31:07.721873449 +0100
@@ -5634,6 +5634,7 @@ maybe_commonize_var (tree decl)
be merged. */
TREE_PUBLIC (decl) = 0;
DECL_COMMON (decl) = 0;
+ DECL_INTERFACE_KNOWN (decl) = 1;
const char *msg;
if (DECL_INLINE_VAR_P (decl))
msg = G_("sorry: semantics of inline variable "
--- gcc/testsuite/g++.dg/cpp1z/inline-var5.C.jj 2019-02-20 14:25:41.799665033
+0100
+++ gcc/testsuite/g++.dg/cpp1z/inline-var5.C 2019-02-20 14:25:09.813194982
+0100
@@ -0,0 +1,11 @@
+// PR c++/89405
+// { dg-do compile { target c++17 } }
+// { dg-options "-fno-weak" }
+
+template <int N>
+struct S
+{
+ static constexpr int a = N; // { dg-warning "semantics of inline variable" }
+}; // { dg-message "you can work around this" "" {
target *-*-* } .-1 }
+
+const int *x = &S<0>::a;
Jakub
