add support for -Wextra and -W

llvm-svn: 69236

clang/include/clang/Basic/Diagnostic.td

@@ -34,6 +34,12 @@ class InGroup<DiagGroup G> { DiagGroup Group = G; }
 def ImplicitFunctionDeclare : DiagGroup<"implicit-function-declaration">;
 def Trigraphs : DiagGroup<"trigraphs">;
 
+// Empty DiagGroups: these are recognized by clang but ignored.
+def : DiagGroup<"extra">;
+def : DiagGroup<"">;  // -W
+
+
+
 
 
 

clang/tools/clang-cc/Warnings.cpp

@@ -37,7 +37,7 @@ using namespace clang;
 // driver has stripped off -Wa,foo etc.  The driver has also translated -W to
 // -Wextra, so we don't need to worry about it.
 static llvm::cl::list<std::string>
-OptWarnings("W", llvm::cl::Prefix);
+OptWarnings("W", llvm::cl::Prefix, llvm::cl::ValueOptional);
 
 static llvm::cl::opt<bool> OptPedantic("pedantic");
 static llvm::cl::opt<bool> OptPedanticErrors("pedantic-errors");