PR c++/65043

	* call.c (standard_conversion): Set check_narrowing.
	* typeck2.c (check_narrowing): Use CP_INTEGRAL_TYPE_P rather
	than comparing with INTEGER_TYPE.

	* g++.dg/concepts/pr67595.C: Add dg-warning.
	* g++.dg/cpp0x/Wnarrowing11.C: New test.
	* g++.dg/cpp0x/Wnarrowing12.C: New test.
	* g++.dg/cpp0x/rv-cast5.C: Add static_cast.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@263739 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 80 insertions, 3 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index fc1b2555dc0..44be980985d 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,10 @@
 2018-08-21  Marek Polacek  <polacek@redhat.com>
 
+	PR c++/65043
+	* call.c (standard_conversion): Set check_narrowing.
+	* typeck2.c (check_narrowing): Use CP_INTEGRAL_TYPE_P rather
+	than comparing with INTEGER_TYPE.
+
 	* cp-tree.h: Fix typo.
 
 2018-08-20  David Malcolm  <dmalcolm@redhat.com>
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 1f72ac863bd..626830c0d9a 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -1388,6 +1388,8 @@ standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
 	    conv->rank = cr_pbool;
 	  if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING))
 	    conv->bad_p = true;
+	  if (flags & LOOKUP_NO_NARROWING)
+	    conv->check_narrowing = true;
 	  return conv;
 	}
 
diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c
index f42f0c2bf07..1e899ab17a1 100644
--- a/gcc/cp/typeck2.c
+++ b/gcc/cp/typeck2.c
@@ -913,7 +913,7 @@ check_narrowing (tree type, tree init, tsubst_flags_t complain, bool const_only)
   if (const_only && !TREE_CONSTANT (init))
     return ok;
 
-  if (TREE_CODE (type) == INTEGER_TYPE
+  if (CP_INTEGRAL_TYPE_P (type)
       && TREE_CODE (ftype) == REAL_TYPE)
     ok = false;
   else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6a6e2267a94..7b54bc0a868 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2018-08-21  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/65043
+	* g++.dg/concepts/pr67595.C: Add dg-warning.
+	* g++.dg/cpp0x/Wnarrowing11.C: New test.
+	* g++.dg/cpp0x/Wnarrowing12.C: New test.
+	* g++.dg/cpp0x/rv-cast5.C: Add static_cast.
+
 2018-08-21  Ed Schonberg  <schonberg@adacore.com>
 
 	* gnat.dg/expr_func7.adb, gnat.dg/expr_func7.ads: New testcase.
diff --git a/gcc/testsuite/g++.dg/concepts/pr67595.C b/gcc/testsuite/g++.dg/concepts/pr67595.C
index 63162fb4c72..76d1fe62132 100644
--- a/gcc/testsuite/g++.dg/concepts/pr67595.C
+++ b/gcc/testsuite/g++.dg/concepts/pr67595.C
@@ -4,7 +4,7 @@ template <class X> concept bool allocatable = requires{{new X}->X * };
 template <class X> concept bool semiregular = allocatable<X>;
 template <class X> concept bool readable = requires{requires semiregular<X>};
 template <class> int weak_input_iterator = requires{{0}->readable};
-template <class X> bool input_iterator{weak_input_iterator<X>};
+template <class X> bool input_iterator{weak_input_iterator<X>}; // { dg-warning "narrowing conversion" }
 template <class X> bool forward_iterator{input_iterator<X>};
 template <class X> bool bidirectional_iterator{forward_iterator<X>};
 template <class X>
diff --git a/gcc/testsuite/g++.dg/cpp0x/Wnarrowing11.C b/gcc/testsuite/g++.dg/cpp0x/Wnarrowing11.C
new file mode 100644
index 00000000000..5b7323633c7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/Wnarrowing11.C
@@ -0,0 +1,30 @@
+// PR c++/65043
+// { dg-do compile { target c++11 } }
+
+struct X
+{
+  X(bool) { }
+};
+
+struct Y
+{
+  Y(char) { }
+};
+
+struct Z
+{
+  Z(char16_t) { }
+};
+
+struct W
+{
+  W(char32_t) { }
+};
+
+int main() 
+{
+  X x{1.2}; // { dg-error "narrowing conversion" }
+  Y y{1.2}; // { dg-error "narrowing conversion" }
+  Z z{1.2}; // { dg-error "narrowing conversion" }
+  W w{1.2}; // { dg-error "narrowing conversion" }
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/Wnarrowing12.C b/gcc/testsuite/g++.dg/cpp0x/Wnarrowing12.C
new file mode 100644
index 00000000000..83b4d3a58c6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/Wnarrowing12.C
@@ -0,0 +1,32 @@
+// PR c++/65043
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wnarrowing" }
+
+struct X
+{
+  X(bool) { }
+};
+
+struct Y
+{
+  Y(char) { }
+};
+
+struct Z
+{
+  Z(char16_t) { }
+};
+
+struct W
+{
+  W(char32_t) { }
+};
+
+int main() 
+{
+  double d = 1.2;
+  X x{d}; // { dg-warning "narrowing conversion" }
+  Y y{d}; // { dg-warning "narrowing conversion" }
+  Z z{d}; // { dg-warning "narrowing conversion" }
+  W w{d}; // { dg-warning "narrowing conversion" }
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C b/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C
index c2473e266b6..5233078f7b4 100644
--- a/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C
@@ -8,5 +8,5 @@ struct hold {
 
 int main()
 {
-  hold<bool&&>{42}();
+  hold<bool&&>{static_cast<bool>(42)}();
 }