re PR c++/67216 (false is still a null pointer constant)

/cp
2015-08-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/67216
	* call.c (null_ptr_cst_p): In C++11 return 'false' for 'false'.

/testsuite
2015-08-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/67216
	* g++.dg/cpp0x/nullptr34.C: New.
	* g++.dg/warn/Wconversion2.C: Adjust.
	* g++.dg/warn/Wnull-conversion-1.C: Likewise.
	* g++.old-deja/g++.other/null3.C: Likewise.

	* g++.dg/cpp0x/pr51313.C: Adjust.

From-SVN: r226956

8 files changed, 58 insertions, 10 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index ca00d03..0bf33c8 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/67216
+	* call.c (null_ptr_cst_p): In C++11 return 'false' for 'false'.
+
 2015-08-17  Jason Merrill  <jason@redhat.com>
 
 	PR c++/67244
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 19ddb91..909ac99 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -524,22 +524,33 @@ struct z_candidate {
 bool
 null_ptr_cst_p (tree t)
 {
+  tree type = TREE_TYPE (t);
+
   /* [conv.ptr]
 
      A null pointer constant is an integral constant expression
      (_expr.const_) rvalue of integer type that evaluates to zero or
      an rvalue of type std::nullptr_t. */
-  if (NULLPTR_TYPE_P (TREE_TYPE (t)))
+  if (NULLPTR_TYPE_P (type))
     return true;
-  if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)))
+
+  if (cxx_dialect >= cxx11)
     {
       /* Core issue 903 says only literal 0 is a null pointer constant.  */
-      if (cxx_dialect < cxx11)
-	t = fold_non_dependent_expr (t);
+      if (TREE_CODE (type) == INTEGER_TYPE
+	  && TREE_CODE (t) == INTEGER_CST
+	  && integer_zerop (t)
+	  && !TREE_OVERFLOW (t))
+	return true;
+    }
+  else if (CP_INTEGRAL_TYPE_P (type))
+    {
+      t = fold_non_dependent_expr (t);
       STRIP_NOPS (t);
       if (integer_zerop (t) && !TREE_OVERFLOW (t))
 	return true;
     }
+
   return false;
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 93aed71..2f1ba25 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2015-08-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/67216
+	* g++.dg/cpp0x/nullptr34.C: New.
+	* g++.dg/warn/Wconversion2.C: Adjust.
+	* g++.dg/warn/Wnull-conversion-1.C: Likewise.
+	* g++.old-deja/g++.other/null3.C: Likewise.
+
+	* g++.dg/cpp0x/pr51313.C: Adjust.
+
 2015-08-17  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/67221
diff --git a/gcc/testsuite/g++.dg/cpp0x/nullptr34.C b/gcc/testsuite/g++.dg/cpp0x/nullptr34.C
new file mode 100644
index 0000000..2fc70a1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/nullptr34.C
@@ -0,0 +1,17 @@
+// PR c++/67216
+// { dg-do compile { target c++11 } }
+
+struct s {
+    s( long ) {}
+};
+
+struct t {
+    t( void * ) {}
+};
+
+void foo(s) {}
+void foo(t) {}
+
+int main() {
+    foo(false);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr51313.C b/gcc/testsuite/g++.dg/cpp0x/pr51313.C
index eb304ba..afd2813 100644
--- a/gcc/testsuite/g++.dg/cpp0x/pr51313.C
+++ b/gcc/testsuite/g++.dg/cpp0x/pr51313.C
@@ -14,5 +14,5 @@ extern ostream cout;
 
 int main()
 {
-  cout << isdigit(0);
+  cout << isdigit(0);  // { dg-error "invalid conversion" }
 }
diff --git a/gcc/testsuite/g++.dg/warn/Wconversion2.C b/gcc/testsuite/g++.dg/warn/Wconversion2.C
index 226dd85..d105d92 100644
--- a/gcc/testsuite/g++.dg/warn/Wconversion2.C
+++ b/gcc/testsuite/g++.dg/warn/Wconversion2.C
@@ -1,3 +1,4 @@
 // { dg-options "-Wconversion-null" }
 void foo(const char *); 
-void bar() { foo(false); } // { dg-warning "pointer type for argument" }
+void bar() { foo(false); } // { dg-warning "pointer type for argument" "" { target { ! c++11 } } }
+// { dg-error "cannot convert" "" { target c++11 } 3 }
diff --git a/gcc/testsuite/g++.dg/warn/Wnull-conversion-1.C b/gcc/testsuite/g++.dg/warn/Wnull-conversion-1.C
index 84a1d38..d350744 100644
--- a/gcc/testsuite/g++.dg/warn/Wnull-conversion-1.C
+++ b/gcc/testsuite/g++.dg/warn/Wnull-conversion-1.C
@@ -6,10 +6,13 @@
 void func1(int* ptr);
 
 void func2() {
-  int* t = false;             // { dg-warning "converting 'false' to pointer" }
+  int* t = false;             // { dg-warning "converting 'false' to pointer" "" { target { ! c++11 } } }
+// { dg-error "cannot convert" "" { target c++11 } 9 }
   int* p;
-  p = false;                  // { dg-warning "converting 'false' to pointer" }
+  p = false;                  // { dg-warning "converting 'false' to pointer" "" { target { ! c++11 } } }
+// { dg-error "cannot convert" "" { target c++11 } 12 }
   int* r = sizeof(char) / 2;  // { dg-error "invalid conversion from" "" { target c++11 } }
-  func1(false);               // { dg-warning "converting 'false' to pointer" }
+  func1(false);               // { dg-warning "converting 'false' to pointer" "" { target { ! c++11 } } }
+// { dg-error "cannot convert" "" { target c++11 } 15 }
   int i = NULL;               // { dg-warning "converting to non-pointer" }
 }
diff --git a/gcc/testsuite/g++.old-deja/g++.other/null3.C b/gcc/testsuite/g++.old-deja/g++.other/null3.C
index 01071f9..ff1d0669 100644
--- a/gcc/testsuite/g++.old-deja/g++.other/null3.C
+++ b/gcc/testsuite/g++.old-deja/g++.other/null3.C
@@ -2,5 +2,6 @@
 
 void x()
 {
- int* p = 1==0;	// { dg-warning "converting 'false' to pointer" }
+ int* p = 1==0;	// { dg-warning "converting 'false' to pointer" "" { target { ! c++11 } } }
+// { dg-error "cannot convert" "" { target c++11 } 5 } 
 }