Index: cfe/trunk/include/clang/Basic/Sanitizers.def
===================================================================
--- cfe/trunk/include/clang/Basic/Sanitizers.def
+++ cfe/trunk/include/clang/Basic/Sanitizers.def
@@ -102,5 +102,9 @@
 SANITIZER("local-bounds", LocalBounds)
 SANITIZER_GROUP("bounds", Bounds, ArrayBounds | LocalBounds)
 
+// Magic group, containing all sanitizers. For example, "-fno-sanitize=all"
+// can be used to disable all the sanitizers.
+SANITIZER_GROUP("all", All, ~0)
+
 #undef SANITIZER
 #undef SANITIZER_GROUP
Index: cfe/trunk/lib/Driver/SanitizerArgs.cpp
===================================================================
--- cfe/trunk/lib/Driver/SanitizerArgs.cpp
+++ cfe/trunk/lib/Driver/SanitizerArgs.cpp
@@ -427,15 +427,24 @@
   assert((A->getOption().matches(options::OPT_fsanitize_EQ) ||
           A->getOption().matches(options::OPT_fno_sanitize_EQ)) &&
          "Invalid argument in parseArgValues!");
-  unsigned Kind = 0;
+  unsigned Kinds = 0;
   for (unsigned I = 0, N = A->getNumValues(); I != N; ++I) {
-    if (unsigned K = parseValue(A->getValue(I)))
-      Kind |= K;
+    const char *Value = A->getValue(I);
+    unsigned Kind;
+    // Special case: don't accept -fsanitize=all.
+    if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
+        0 == strcmp("all", Value))
+      Kind = 0;
+    else
+      Kind = parseValue(Value);
+
+    if (Kind)
+      Kinds |= Kind;
     else if (DiagnoseErrors)
       D.Diag(clang::diag::err_drv_unsupported_option_argument)
-        << A->getOption().getName() << A->getValue(I);
+          << A->getOption().getName() << Value;
   }
-  return Kind;
+  return Kinds;
 }
 
 std::string lastArgumentForMask(const Driver &D, const llvm::opt::ArgList &Args,
Index: cfe/trunk/test/Driver/fsanitize.c
===================================================================
--- cfe/trunk/test/Driver/fsanitize.c
+++ cfe/trunk/test/Driver/fsanitize.c
@@ -15,6 +15,12 @@
 // RUN: %clang -fsanitize=bounds -### -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix=CHECK-BOUNDS
 // CHECK-BOUNDS: "-fsanitize={{((array-bounds|local-bounds),?){2}"}}
 
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=all %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-FSANITIZE-ALL
+// CHECK-FSANITIZE-ALL: error: unsupported argument 'all' to option 'fsanitize='
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=address,undefined -fno-sanitize=all -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-FNO-SANITIZE-ALL
+// CHECK-FNO-SANITIZE-ALL: "-fsanitize=thread"
+
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=thread,undefined -fno-sanitize=thread -fno-sanitize=float-cast-overflow,vptr,bool,enum %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PARTIAL-UNDEFINED
 // CHECK-PARTIAL-UNDEFINED: "-fsanitize={{((signed-integer-overflow|integer-divide-by-zero|float-divide-by-zero|function|shift|unreachable|return|vla-bound|alignment|null|object-size|array-bounds|returns-nonnull-attribute|nonnull-attribute),?){14}"}}