re PR c++/44524 (improve diagnostic for . vs -> typo)

/cp
2011-10-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/44524
	* typeck.c (build_class_member_access_expr): Provide a better error
	message for X.Y where X is a pointer to class type.
	(finish_class_member_access_expr): Likewise.

/testsuite
2011-10-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/44524
	* g++.dg/parse/error41.C: New.
	* g++.dg/parse/error20.C: Adjust.

From-SVN: r180103

5 files changed, 45 insertions, 5 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7e80282..453dce1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2011-10-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/44524
+	* typeck.c (build_class_member_access_expr): Provide a better error
+	message for X.Y where X is a pointer to class type.
+	(finish_class_member_access_expr): Likewise.
+
 2011-10-15  Tom Tromey  <tromey@redhat.com>
 	    Dodji Seketeli  <dodji@redhat.com>
 
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 40cf108..749aa3f 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -2128,8 +2128,16 @@ build_class_member_access_expr (tree object, tree member,
   if (!CLASS_TYPE_P (object_type))
     {
       if (complain & tf_error)
-	error ("request for member %qD in %qE, which is of non-class type %qT",
-	       member, object, object_type);
+	{
+	  if (POINTER_TYPE_P (object_type)
+	      && CLASS_TYPE_P (TREE_TYPE (object_type)))
+	    error ("request for member %qD in %qE, which is of pointer "
+		   "type %qT (maybe you meant to use %<->%> ?)",
+		   member, object, object_type);
+	  else
+	    error ("request for member %qD in %qE, which is of non-class "
+		   "type %qT", member, object, object_type);
+	}
       return error_mark_node;
     }
 
@@ -2508,8 +2516,16 @@ finish_class_member_access_expr (tree object, tree name, bool template_p,
   if (!CLASS_TYPE_P (object_type))
     {
       if (complain & tf_error)
-	error ("request for member %qD in %qE, which is of non-class type %qT",
-	       name, object, object_type);
+	{
+	  if (POINTER_TYPE_P (object_type)
+	      && CLASS_TYPE_P (TREE_TYPE (object_type)))
+	    error ("request for member %qD in %qE, which is of pointer "
+		   "type %qT (maybe you meant to use %<->%> ?)",
+		   name, object, object_type);
+	  else
+	    error ("request for member %qD in %qE, which is of non-class "
+		   "type %qT", name, object, object_type);
+	}
       return error_mark_node;
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b67d0f5..3a6edad 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,11 @@
 2011-10-17  Paolo Carlini  <paolo.carlini@oracle.com>
 
+	PR c++/44524
+	* g++.dg/parse/error41.C: New.
+	* g++.dg/parse/error20.C: Adjust.
+
+2011-10-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
 	PR c++/50757
 	* g++.dg/warn/format7.C: New.
 	* obj-c++.dg/warn7.mm: Likewise.
diff --git a/gcc/testsuite/g++.dg/parse/error20.C b/gcc/testsuite/g++.dg/parse/error20.C
index d2f9353..6119df9 100644
--- a/gcc/testsuite/g++.dg/parse/error20.C
+++ b/gcc/testsuite/g++.dg/parse/error20.C
@@ -12,7 +12,7 @@ struct C {
 };
 int main() {
   C c;
-  A(c.p.i); // { dg-error "9:request for member 'i' in 'c.C::p', which is of non-class type 'B" }
+  A(c.p.i); // { dg-error "9:request for member 'i' in 'c.C::p', which is of pointer type 'B" }
   return 0;
 }
 
diff --git a/gcc/testsuite/g++.dg/parse/error41.C b/gcc/testsuite/g++.dg/parse/error41.C
new file mode 100644
index 0000000..621a2e2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/error41.C
@@ -0,0 +1,11 @@
+// PR c++/44524
+
+template<typename, typename>
+struct map
+{
+  bool empty();
+};
+
+int bar(map<int, float> *X) {
+  return X.empty();  // { dg-error "which is of pointer type 'map" }
+}