re PR c++/30566 (-Wshadow warns about clashes between nested function parameters in C++)

gcc/cp/
2010-05-14  Shujing Zhao  <pearly.zhao@oracle.com>

        PR c++/30566
        * name-lookup.c (pushdecl_maybe_friend): Avoid the warnings about
        shadowing the outer parameter or variables by the declaration of
        nested function in nested structure or class. Warn the shadowing by
        the declaration of nested lambda expression.

gcc/testsuite/
2010-05-14  Shujing Zhao  <pearly.zhao@oracle.com>

        PR c++/30566
        * testsuite/g++.dg/warn/Wshadow-4.C: Adjust.
        * testsuite/g++.dg/warn/Wshadow-5.C: New test.
        * testsuite/g++.dg/warn/Wshadow-6.C: New test.

From-SVN: r159383

6 files changed, 129 insertions, 22 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cd8dfd2..d21c713 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2010-05-14  Shujing Zhao  <pearly.zhao@oracle.com>
+
+	PR c++/30566
+	* name-lookup.c (pushdecl_maybe_friend): Avoid the warnings about
+	shadowing the outer parameter or variables by the declaration of
+	nested function in nested structure or class. Warn the shadowing by
+	the declaration of nested lambda expression.
+
 2010-05-13  Jason Merrill  <jason@redhat.com>
 
 	* typeck.c (cp_build_array_ref): Factor out from...
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 88a3e39..405bf16 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -1016,15 +1016,18 @@ pushdecl_maybe_friend (tree x, bool is_friend)
 	  else if (oldlocal != NULL_TREE && !DECL_EXTERNAL (x)
 		   /* Inline decls shadow nothing.  */
 		   && !DECL_FROM_INLINE (x)
-		   && TREE_CODE (oldlocal) == PARM_DECL
+		   && (TREE_CODE (oldlocal) == PARM_DECL
+		       || TREE_CODE (oldlocal) == VAR_DECL)
 		   /* Don't check the `this' parameter.  */
-		   && !DECL_ARTIFICIAL (oldlocal))
+		   && !DECL_ARTIFICIAL (oldlocal)
+		   && !DECL_ARTIFICIAL (x))
 	    {
-	      bool err = false;
+	      bool nowarn = false;
 
 	      /* Don't complain if it's from an enclosing function.  */
 	      if (DECL_CONTEXT (oldlocal) == current_function_decl
-		  && TREE_CODE (x) != PARM_DECL)
+		  && TREE_CODE (x) != PARM_DECL
+		  && TREE_CODE (oldlocal) == PARM_DECL)
 		{
 		  /* Go to where the parms should be and see if we find
 		     them there.  */
@@ -1038,16 +1041,41 @@ pushdecl_maybe_friend (tree x, bool is_friend)
 		  if (b->kind == sk_function_parms)
 		    {
 		      error ("declaration of %q#D shadows a parameter", x);
-		      err = true;
+		      nowarn = true;
 		    }
 		}
 
-	      if (warn_shadow && !err)
+	      /* The local structure or class can't use parameters of
+		 the containing function anyway.  */
+	      if (DECL_CONTEXT (oldlocal) != current_function_decl)
 		{
-		  warning_at (input_location, OPT_Wshadow,
-			      "declaration of %q#D shadows a parameter", x);
-		  warning_at (DECL_SOURCE_LOCATION (oldlocal), OPT_Wshadow,
-			      "shadowed declaration is here");
+		  cxx_scope *scope = current_binding_level;
+		  tree context = DECL_CONTEXT (oldlocal);
+		  for (; scope; scope = scope->level_chain)
+		   {
+		     if (scope->kind == sk_function_parms
+			 && scope->this_entity == context)
+		      break;
+		     if (scope->kind == sk_class
+			 && !LAMBDA_TYPE_P (scope->this_entity))
+		       {
+			 nowarn = true;
+			 break;
+		       }
+		   }
+		}
+
+	      if (warn_shadow && !nowarn)
+		{
+		  if (TREE_CODE (oldlocal) == PARM_DECL)
+		    warning_at (input_location, OPT_Wshadow,
+				"declaration of %q#D shadows a parameter", x);
+		  else
+		    warning_at (input_location, OPT_Wshadow,
+				"declaration of %qD shadows a previous local",
+				x);
+		   warning_at (DECL_SOURCE_LOCATION (oldlocal), OPT_Wshadow,
+			       "shadowed declaration is here");
 		}
 	    }
 
@@ -1074,14 +1102,6 @@ pushdecl_maybe_friend (tree x, bool is_friend)
 		  warning (OPT_Wshadow, "declaration of %qD shadows a member of 'this'",
 			   x);
 		}
-	      else if (oldlocal != NULL_TREE
-		       && TREE_CODE (oldlocal) == VAR_DECL)
-		{
-		  warning_at (input_location, OPT_Wshadow,
-			      "declaration of %qD shadows a previous local", x);
-		  warning_at (DECL_SOURCE_LOCATION (oldlocal), OPT_Wshadow,
-			      "shadowed declaration is here");
-		}
 	      else if (oldglobal != NULL_TREE
 		       && TREE_CODE (oldglobal) == VAR_DECL)
 		/* XXX shadow warnings in outer-more namespaces */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7c50d61..6320390 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2010-05-14  Shujing Zhao  <pearly.zhao@oracle.com>
+
+	PR c++/30566
+	* testsuite/g++.dg/warn/Wshadow-4.C: Adjust.
+	* testsuite/g++.dg/warn/Wshadow-5.C: New test.
+	* testsuite/g++.dg/warn/Wshadow-6.C: New test
+
 2010-05-13  Daniel Franke  <franke.daniel@gmail.com>
 
         PR fortran/35779
diff --git a/gcc/testsuite/g++.dg/warn/Wshadow-4.C b/gcc/testsuite/g++.dg/warn/Wshadow-4.C
index 2238653..c033028 100644
--- a/gcc/testsuite/g++.dg/warn/Wshadow-4.C
+++ b/gcc/testsuite/g++.dg/warn/Wshadow-4.C
@@ -8,13 +8,13 @@ public:
     int GetMainURL() const;
 };
 
-int foo(int infoo)		// { dg-warning "shadowed declaration" }
+int foo(int infoo)		// { dg-bogus "shadowed declaration" }
 {
   int outfoo( INetURLObject( infoo ).GetMainURL()); // { dg-bogus "shadows" }
   extern void f(int infoo);
   struct A
   {
-    void f(int infoo) { }	// { dg-warning "shadows a parameter" }
+    void f(int infoo) { }	// { dg-bogus "shadows a parameter" }
   };
   return outfoo;
 }
@@ -22,11 +22,11 @@ int foo(int infoo)		// { dg-warning "shadowed declaration" }
 // PR c++/39763
 int foo2(void)
 {
-    int infoo = 0;		// { dg-warning "shadowed declaration" }
+    int infoo = 0;		// { dg-bogus "shadowed declaration" }
     int outfoo( INetURLObject( infoo ).GetMainURL()); // { dg-bogus "shadows" }
     struct A
     {
-      void f(int infoo) { }	// { dg-warning "shadows a previous local" }
+      void f(int infoo) { }	// { dg-bogus "shadows a previous local" }
     };
     return outfoo;
 }
diff --git a/gcc/testsuite/g++.dg/warn/Wshadow-5.C b/gcc/testsuite/g++.dg/warn/Wshadow-5.C
new file mode 100644
index 0000000..6623291
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wshadow-5.C
@@ -0,0 +1,33 @@
+// Wshadows was giving warnings for nested function parameters in nested class
+// or structure that we didn't want.
+// { dg-do compile }
+// { dg-options "-Wshadow" }
+
+// PR c++/41825
+int f (int n)
+{
+    int bar (int n) { return n++; } // { dg-error "a function-definition is not allowed here" }
+    return bar (n); // { dg-error "was not declared in this scope" }
+}
+
+int g (int i)
+{
+    struct {
+        int bar (int i) { return i++; } // { dg-bogus "shadows" }
+    } s;
+
+    return s.bar (i);
+}
+
+// PR c++/30566
+void h( int x )
+{
+  class InnerClass
+    {
+      public:
+              static int g( int x ) // { dg-bogus "shadows" }
+                {
+                  // empty
+                }
+    };
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wshadow-6.C b/gcc/testsuite/g++.dg/warn/Wshadow-6.C
new file mode 100644
index 0000000..9b13e3a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wshadow-6.C
@@ -0,0 +1,39 @@
+// Test the declaration of nested lambda function shadows
+// a parameter or previous local.
+// { dg-do compile }
+// { dg-options "-std=c++0x -Wshadow" }
+
+struct S {};
+int f1(int x)   // { dg-warning "shadowed declaration" }
+{
+ int t = 0;
+ int m = 0;     // { dg-warning "shadowed declaration" }
+ [&t] (int x) { // { dg-warning "shadows a parameter" }
+   int m = 1;   // { dg-warning "shadows a previous local" }
+   t = t + x + m;
+ };
+ return t;
+}
+
+void f2(struct S i, int j) {
+  struct A {
+    struct S x;
+    void g(struct S i) { // { dg-warning "shadowed declaration" }
+	  struct S x;    // { dg-warning "shadows a member of" }
+	  struct S y;    // { dg-warning "shadowed declaration" }
+	  int t;
+	   [&t](struct S i){   // { dg-warning "shadows a parameter" }
+		 int j = 1;    // { dg-bogus "shadows" }
+		 struct S y;   // { dg-warning "shadows a previous local" }
+ 		 t = j;
+	   };
+    }
+  };
+}
+
+void f3(int i) {
+ [=]{
+   int j = i;
+   int i; // { dg-warning "shadows a member of" }
+ };
+}