[Driver] Consider -fno-sanitize=... state when filtering out -fsanitize-coverage=...

[mcgrathr]

Summary

The driver ignores -fsanitize-coverage=... flags when also given
-fsanitize=... flags for sanitizer flavors that don't support the
coverage runtime. This logic failed to account for subsequent
-fno-sanitize=... flags that disable the sanitizer flavors that
conflict with -fsanitize-coverage=... flags.

[phosek]

LGTM

cfe/trunk/lib/Driver/SanitizerArgs.cpp

if (Arg->getOption().matches(options::OPT_fsanitize_coverage)) {
               << Arg->getAsString(Args) << "-fsanitize-coverage=trace-pc-guard";
         }
         continue;
       }
       CoverageFeatures |= parseCoverageFeatures(D, Arg);
 
       // Disable coverage and not claim the flags if there is at least one
       // non-supporting sanitizer.
-      if (!(AllAddedKinds & ~setGroupBits(SupportsCoverage))) {
+      if (!(AllAddedKinds & ~AllRemove & ~setGroupBits(SupportsCoverage))) {
         Arg->claim();
       } else {
         CoverageFeatures = 0;
       }
     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_coverage)) {
       Arg->claim();
       CoverageFeatures &= ~parseCoverageFeatures(D, Arg);
     }

cfe/trunk/test/Driver/fsanitize-coverage.c

 
 // RUN: %clang_cl --target=i386-pc-win32 -fsanitize=address -fsanitize-coverage=func,trace-pc-guard -c -### -- %s 2>&1 | FileCheck %s -check-prefix=CLANG-CL-COVERAGE
 // CLANG-CL-COVERAGE-NOT: error:
 // CLANG-CL-COVERAGE-NOT: warning:
 // CLANG-CL-COVERAGE-NOT: argument unused
 // CLANG-CL-COVERAGE-NOT: unknown argument
 // CLANG-CL-COVERAGE: -fsanitize-coverage-type=1
 // CLANG-CL-COVERAGE: -fsanitize=address
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=safe-stack -fsanitize-coverage=trace-pc-guard %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-VS-SAFESTACK
+// CHECK-VS-SAFESTACK: -fsanitize=safe-stack
+// CHECK-VS-SAFESTACK-NOT: -fsanitize-coverage-trace-pc-guard
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=safe-stack -fsanitize-coverage=trace-pc-guard -fno-sanitize=safe-stack %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-SAFESTACK
+// CHECK-NO-SAFESTACK-NOT: error:
+// CHECK-NO-SAFESTACK-NOT: warning:
+// CHECK-NO-SAFESTACK-NOT: argument unused
+// CHECK-NO-SAFESTACK-NOT: unknown argument
+// CHECK-NO-SAFESTACK-NOT: -fsanitize=safe-stack
+// CHECK-NO-SAFESTACK: -fsanitize-coverage-trace-pc-guard