From: Marek Polacek <polacek@redhat.com>
To: GCC Patches <gcc-patches@gcc.gnu.org>, Jason Merrill <jason@redhat.com>
Subject: C++ PATCH to fix static init with () in a template (PR c++/84582)
Date: Tue, 27 Feb 2018 19:13:00 -0000 [thread overview]
Message-ID: <20180227191313.GN2995@redhat.com> (raw)
My recent change introducing cxx_constant_init caused this code
template <class> class A {
static const long b = 0;
static const unsigned c = (b);
};
to be rejected. The reason is that force_paren_expr turns "b" into "*(const
long int &) &b", where the former is not value-dependent but the latter is
value-dependent. So when we get to maybe_constant_init_1:
5147 if (!is_nondependent_static_init_expression (t))
5148 /* Don't try to evaluate it. */;
it's not evaluated and we get the non-constant initialization error.
(Before we'd always evaluated the expression.)
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2018-02-27 Marek Polacek <polacek@redhat.com>
PR c++/84582
* semantics.c (force_paren_expr): Avoid creating a static cast
when processing a template.
* g++.dg/cpp1z/static1.C: New test.
* g++.dg/template/static37.C: New test.
diff --git gcc/cp/semantics.c gcc/cp/semantics.c
index 35569d0cb0d..b48de2df4e2 100644
--- gcc/cp/semantics.c
+++ gcc/cp/semantics.c
@@ -1697,7 +1697,7 @@ force_paren_expr (tree expr)
expr = build1 (PAREN_EXPR, TREE_TYPE (expr), expr);
else if (VAR_P (expr) && DECL_HARD_REGISTER (expr))
/* We can't bind a hard register variable to a reference. */;
- else
+ else if (!processing_template_decl)
{
cp_lvalue_kind kind = lvalue_kind (expr);
if ((kind & ~clk_class) != clk_none)
diff --git gcc/testsuite/g++.dg/cpp1z/static1.C gcc/testsuite/g++.dg/cpp1z/static1.C
index e69de29bb2d..cb872997c5a 100644
--- gcc/testsuite/g++.dg/cpp1z/static1.C
+++ gcc/testsuite/g++.dg/cpp1z/static1.C
@@ -0,0 +1,19 @@
+// PR c++/84582
+// { dg-options -std=c++17 }
+
+class C {
+ static inline const long b = 0;
+ static inline const unsigned c = (b);
+};
+class D {
+ static inline const long b = 0;
+ static inline const unsigned c = b;
+};
+template <class> class A {
+ static inline const long b = 0;
+ static inline const unsigned c = (b);
+};
+template <class> class B {
+ static inline const long b = 0;
+ static inline const unsigned c = b;
+};
diff --git gcc/testsuite/g++.dg/template/static37.C gcc/testsuite/g++.dg/template/static37.C
index e69de29bb2d..90bc65d2fbc 100644
--- gcc/testsuite/g++.dg/template/static37.C
+++ gcc/testsuite/g++.dg/template/static37.C
@@ -0,0 +1,18 @@
+// PR c++/84582
+
+class C {
+ static const long b = 0;
+ static const unsigned c = (b);
+};
+class D {
+ static const long b = 0;
+ static const unsigned c = b;
+};
+template <class> class A {
+ static const long b = 0;
+ static const unsigned c = (b);
+};
+template <class> class B {
+ static const long b = 0;
+ static const unsigned c = b;
+};
Marek
next reply other threads:[~2018-02-27 19:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-27 19:13 Marek Polacek [this message]
2018-02-27 21:16 ` Jason Merrill
2018-02-28 14:32 ` Marek Polacek
2018-02-28 15:51 ` Jason Merrill
2018-02-28 21:19 ` Marek Polacek
2018-02-28 21:51 ` Jason Merrill
2018-03-01 13:17 ` Marek Polacek
2018-03-01 18:57 ` Jason Merrill
2018-03-01 21:40 ` Marek Polacek
2018-03-01 21:57 ` Jason Merrill
2018-03-02 18:18 ` Jason Merrill
2018-03-02 18:20 ` Marek Polacek
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