3 files changed, 28 insertions, 2 deletions
diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 67ea056417f..eab79d6442d 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -295,6 +295,20 @@ bool DiagnosticsEngine::setDiagnosticGroupErrorAsFatal(StringRef Group,
   return false;
 }
 
+bool DiagnosticsEngine::setMappingToAllDiagnostics(diag::Mapping Map,
+                                                   SourceLocation Loc) {
+  // Get all the diagnostics.
+  llvm::SmallVector<diag::kind, 64> AllDiags;
+  Diags->getAllDiagnostics(AllDiags);
+
+  // Set the mapping.
+  for (unsigned i = 0, e = AllDiags.size(); i != e; ++i)
+    if (Diags->isBuiltinWarningOrExtension(AllDiags[i]))
+      setDiagnosticMapping(AllDiags[i], Map, Loc);
+
+  return false;
+}
+
 void DiagnosticsEngine::Report(const StoredDiagnostic &storedDiag) {
   assert(CurDiagID == ~0U && "Multiple diagnostics in flight at once!");
 
diff --git a/clang/lib/Basic/DiagnosticIDs.cpp b/clang/lib/Basic/DiagnosticIDs.cpp
index b3c4d033c28..9f09f72e868 100644
--- a/clang/lib/Basic/DiagnosticIDs.cpp
+++ b/clang/lib/Basic/DiagnosticIDs.cpp
@@ -682,6 +682,12 @@ bool DiagnosticIDs::getDiagnosticsInGroup(
   return false;
 }
 
+void DiagnosticIDs::getAllDiagnostics(
+                               llvm::SmallVectorImpl<diag::kind> &Diags) const {
+  for (unsigned i = 0; i != StaticDiagInfoSize; ++i)
+    Diags.push_back(StaticDiagInfo[i].DiagID);
+}
+
 StringRef DiagnosticIDs::getNearestWarningOption(StringRef Group) {
   StringRef Best;
   unsigned BestDistance = Group.size() + 1; // Sanity threshold.
diff --git a/clang/lib/Frontend/Warnings.cpp b/clang/lib/Frontend/Warnings.cpp
index 576dd3d4459..f68e03b0d51 100644
--- a/clang/lib/Frontend/Warnings.cpp
+++ b/clang/lib/Frontend/Warnings.cpp
@@ -110,8 +110,14 @@ void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
       // -Weverything is a special case as well.  It implicitly enables all
       // warnings, including ones not explicitly in a warning group.
       if (Opt == "everything") {
-        if (SetDiagnostic)
-          Diags.setEnableAllWarnings(true);
+        if (SetDiagnostic) {
+          if (isPositive) {
+            Diags.setEnableAllWarnings(true);
+          } else {
+            Diags.setEnableAllWarnings(false);
+            Diags.setMappingToAllDiagnostics(diag::MAP_IGNORE);
+          }
+        }
         continue;
       }