From: Marek Polacek <polacek@redhat.com>
Date: Thu, 22 Mar 2018 08:08:07 +0000 (+0000)
Subject: re PR c++/84854 (ICE: unexpected expression in cxx_eval_constant_expression, at cp... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=08ad2797c60b66f8a6ca54652cdead0aa6ea721f;p=gcc.git

re PR c++/84854 (ICE: unexpected expression in cxx_eval_constant_expression, at cp/constexpr.c:4774)

	PR c++/84854
	* semantics.c (finish_if_stmt_cond): Check if the type of the condition
	is boolean.

	* g++.dg/cpp1z/constexpr-if15.C: New test.
	* g++.dg/cpp1z/constexpr-if16.C: New test.

From-SVN: r258756
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 44de2fb5b37..f9e7a57ec03 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2018-03-22  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/84854
+	* semantics.c (finish_if_stmt_cond): Check if the type of the condition
+	is boolean.
+
 2018-03-21  Jason Merrill  <jason@redhat.com>
 
 	PR c++/81311 - wrong C++17 overload resolution.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 4b9fc277436..97fa57ae94e 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -733,7 +733,10 @@ finish_if_stmt_cond (tree cond, tree if_stmt)
   if (IF_STMT_CONSTEXPR_P (if_stmt)
       && !type_dependent_expression_p (cond)
       && require_constant_expression (cond)
-      && !value_dependent_expression_p (cond))
+      && !value_dependent_expression_p (cond)
+      /* Wait until instantiation time, since only then COND has been
+	 converted to bool.  */
+      && TREE_TYPE (cond) == boolean_type_node)
     {
       cond = instantiate_non_dependent_expr (cond);
       cond = cxx_constant_value (cond, NULL_TREE);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cc4cbbc857f..00b804c7018 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2018-03-22  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/84854
+	* g++.dg/cpp1z/constexpr-if15.C: New test.
+	* g++.dg/cpp1z/constexpr-if16.C: New test.
+
 2018-03-21  Joseph Myers  <joseph@codesourcery.com>
 
 	* gcc.dg/builtin-tgmath-3.c: New test.
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if15.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-if15.C
new file mode 100644
index 00000000000..9a9053c3305
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if15.C
@@ -0,0 +1,11 @@
+// PR c++/84854
+// { dg-options -std=c++17 }
+
+constexpr int foo () { return 1; }
+constexpr int foo (int) { return 2; }
+
+template <typename>
+void a()
+{
+  if constexpr(foo) { };
+}
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if16.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-if16.C
new file mode 100644
index 00000000000..31a149702fd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if16.C
@@ -0,0 +1,20 @@
+// { dg-options -std=c++17 }
+
+struct A
+{
+  constexpr operator bool () { return true; }
+  int i;
+};
+
+A a;
+
+template <class T> void f()
+{
+  constexpr bool b = a;
+  if constexpr (a) { }
+}
+
+int main()
+{
+  f<int>();
+}