From: Jason Merrill <jason@redhat.com>
Date: Fri, 9 May 2014 18:15:57 +0000 (-0400)
Subject: re PR c++/32019 (Conditional operator ?: and ambiguous convertions)
X-Git-Tag: releases/gcc-5.1.0~7667
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5f901ccf18953b699bd290a4a169e2b7c7aa870a;p=thirdparty%2Fgcc.git

re PR c++/32019 (Conditional operator ?: and ambiguous convertions)

	PR c++/32019
	* call.c (build_conditional_expr_1): Improve ambiguity diagnostic.

	PR c++/54348
	* call.c (build_conditional_expr_1): If overload resolution finds
	no match, just say "different types".

From-SVN: r210282
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 232ceec6ed1a..6bddd4974f0a 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,12 @@
 2014-05-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/54348
+	* call.c (build_conditional_expr_1): If overload resolution finds
+	no match, just say "different types".
+
+	PR c++/32019
+	* call.c (build_conditional_expr_1): Improve ambiguity diagnostic.
+
 	PR c++/22434
 	* call.c (build_conditional_expr_1): Don't try to pool cv-quals
 	if we didn't find a conversion.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 691e9e3ce90a..cff7ef32339d 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -4710,8 +4710,16 @@ build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3,
 	  || (conv3 && conv3->kind == ck_ambig))
 	{
 	  if (complain & tf_error)
-	    error_at (loc, "operands to ?: have different types %qT and %qT",
-		      arg2_type, arg3_type);
+	    {
+	      error_at (loc, "operands to ?: have different types %qT and %qT",
+			arg2_type, arg3_type);
+	      if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p)
+		inform (loc, "  and each type can be converted to the other");
+	      else if (conv2 && conv2->kind == ck_ambig)
+		convert_like (conv2, arg2, complain);
+	      else
+		convert_like (conv3, arg3, complain);
+	    }
 	  result = error_mark_node;
 	}
       else if (conv2 && !conv2->bad_p)
@@ -4818,10 +4826,8 @@ build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3,
       if (!any_viable_p)
 	{
           if (complain & tf_error)
-            {
-              op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
-              print_z_candidates (loc, candidates);
-            }
+	    error_at (loc, "operands to ?: have different types %qT and %qT",
+		      arg2_type, arg3_type);
 	  return error_mark_node;
 	}
       cand = tourney (candidates, complain);
diff --git a/gcc/testsuite/g++.dg/cpp0x/explicit3.C b/gcc/testsuite/g++.dg/cpp0x/explicit3.C
index 678076c8e412..6318ade2c0e1 100644
--- a/gcc/testsuite/g++.dg/cpp0x/explicit3.C
+++ b/gcc/testsuite/g++.dg/cpp0x/explicit3.C
@@ -45,6 +45,6 @@ int main()
   f(a);				// { dg-error "" }
   B b2 = { a };			// { dg-error "" }
   a + true;			// { dg-error "5:no match" }
-  b ? a : true;			// { dg-error "5:no match" }
-  a ? a : true;			// { dg-error "5:no match" }
+  b ? a : true;			// { dg-error "5:?:" }
+  a ? a : true;			// { dg-error "5:?:" }
 }
diff --git a/gcc/testsuite/g++.dg/expr/cond10.C b/gcc/testsuite/g++.dg/expr/cond10.C
new file mode 100644
index 000000000000..892576fa8b82
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cond10.C
@@ -0,0 +1,17 @@
+// PR c++/32019
+
+struct C
+{
+  C(const char *);
+  operator const char *();
+};
+
+extern C c;
+extern const char * s;
+
+void
+foo (bool b)
+{
+  b ? c : s;			// { dg-error "?:" }
+  // { dg-message "convert" "" { target *-*-* } 15 }
+}
diff --git a/gcc/testsuite/g++.dg/expr/cond11.C b/gcc/testsuite/g++.dg/expr/cond11.C
new file mode 100644
index 000000000000..7bd122ddac5e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cond11.C
@@ -0,0 +1,20 @@
+struct A;
+struct C
+{
+  operator A();
+};
+
+struct A
+{
+  A(C);
+};
+
+extern A a;
+extern C c;
+
+void
+foo (bool b)
+{
+  b ? c : a;			// { dg-error "?:" }
+  // { dg-message "ambiguous" "" { target *-*-* } 18 }
+}
diff --git a/gcc/testsuite/g++.dg/expr/cond13.C b/gcc/testsuite/g++.dg/expr/cond13.C
new file mode 100644
index 000000000000..90ae904a5d61
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/cond13.C
@@ -0,0 +1,9 @@
+// PR c++/54348
+
+struct A {} a;
+struct B {} b;
+
+void f()
+{
+    false ? a : b;		// { dg-error "different types" }
+}
diff --git a/gcc/testsuite/g++.dg/parse/crash41.C b/gcc/testsuite/g++.dg/parse/crash41.C
index 746dbbca8a1d..c14fbadff9f8 100644
--- a/gcc/testsuite/g++.dg/parse/crash41.C
+++ b/gcc/testsuite/g++.dg/parse/crash41.C
@@ -5,4 +5,4 @@ struct A
   A(int)(); // { dg-error "declared" }
 };
 
-template<int> void foo(bool b, A a) { b ? a : 0; } // { dg-error "no match" }
+template<int> void foo(bool b, A a) { b ? a : 0; } // { dg-error "?:" }