[Sema][ObjC] Disable -Wunused-parameter for ObjC methods

The warning isn't very useful when the function is an ObjC method.

rdar://problem/41561853

Differential Revision: https://reviews.llvm.org/D61147

llvm-svn: 359864

clang/lib/Sema/SemaDecl.cpp

@@ -13353,8 +13353,6 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
     assert(MD == getCurMethodDecl() && "Method parsing confused");
     MD->setBody(Body);
     if (!MD->isInvalidDecl()) {
-      if (!MD->hasSkippedBody())
-        DiagnoseUnusedParameters(MD->parameters());
       DiagnoseSizeOfParametersAndReturnValue(MD->parameters(),
                                              MD->getReturnType(), MD);
 

clang/test/SemaObjC/method-unused-attribute.m

@@ -1,5 +1,9 @@
 // RUN: %clang_cc1  -fsyntax-only -Wunused-parameter -verify -Wno-objc-root-class %s
 
+// -Wunused-parameter ignores ObjC method parameters that are unused.
+
+// expected-no-diagnostics
+
 @interface INTF
 - (void) correct_use_of_unused: (void *) notice : (id)another_arg;
 - (void) will_warn_unused_arg: (void *) notice : (id)warn_unused;
@@ -9,7 +13,7 @@ - (void) unused_attr_on_decl_ignored: (void *)  __attribute__((unused)) will_war
 @implementation INTF
 - (void) correct_use_of_unused: (void *)  __attribute__((unused)) notice : (id) __attribute__((unused)) newarg{
 }
-- (void) will_warn_unused_arg: (void *) __attribute__((unused))  notice : (id)warn_unused {}  // expected-warning {{unused parameter 'warn_unused'}}
-- (void) unused_attr_on_decl_ignored: (void *)  will_warn{}  // expected-warning {{unused parameter 'will_warn'}}
+- (void) will_warn_unused_arg: (void *) __attribute__((unused))  notice : (id)warn_unused {}
+- (void) unused_attr_on_decl_ignored: (void *)  will_warn{}
 @end
 

clang/test/SemaObjC/unused.m

@@ -33,7 +33,7 @@ - (int) meth: (int)x: // expected-warning {{'x' used as the name of the previous
                       // expected-note {{introduce a parameter name to make 'x' part of the selector}} \
                       // expected-note {{or insert whitespace before ':' to use 'x' as parameter name and have an empty entry in the selector}}
 
-(int)y:  // expected-warning {{unused}}  expected-warning {{'y' used as the name of the previous parameter rather than as part of the selector}} \
+(int)y:  // expected-warning {{'y' used as the name of the previous parameter rather than as part of the selector}} \
          // expected-note {{introduce a parameter name to make 'y' part of the selector}} \
          // expected-note {{or insert whitespace before ':' to use 'y' as parameter name and have an empty entry in the selector}}
 (int) __attribute__((unused))z { return x; }