[NewPM] Catch sanitizers passed to -fsanitize that haven't been implemented

[philip.pfaffe]

Summary

Currently clang's new-pm driver silently breaks sanitizers. Make using a not implemented sanitizer a hard failuer.

On drawback is that when you try to use a group that's not implemented, such as -fsanitize=undefined, it will complain about the first member of the group that's not available, Alignment in this case. Is that worth fixing?

clang/lib/CodeGen/BackendUtil.cpp

if (CodeGenOpts.OptimizationLevel == 0) {
         MPM.addPass(CanonicalizeAliasesPass());
         MPM.addPass(NameAnonGlobalPass());
       }
     } else {
       // Map our optimization levels into one of the distinct levels used to
       // configure the pipeline.
       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 
-      // Register callbacks to schedule sanitizer passes at the appropriate part of
-      // the pipeline.
-      // FIXME: either handle asan/the remaining sanitizers or error out
+      // Register callbacks to schedule sanitizer passes at the appropriate part
+      // of the pipeline.
+      //
+      // FIXME: Handle the remaining sanitizers. This throws a fatal error when
+      // one is selected that's not implemented in the meantime. Update the
+      // following list as appropriate.
+      SanitizerMask ImplementedSanitizers = SanitizerKind::LocalBounds |
+                                            SanitizerKind::Memory |
+                                            SanitizerKind::Thread;
+#define SANITIZER(NAME, ID)                                                    \
+  if (LangOpts.Sanitize.hasOneOf(SanitizerKind::ID & ~ImplementedSanitizers))  \
+    report_fatal_error("Trying to use the " NAME                               \
+                       " sanitizer, which is not implemented.");
+#define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
+  SANITIZER(NAME, ID##Group) SANITIZER(NAME, ID)
+#include "clang/Basic/Sanitizers.def"
+
       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
         PB.registerScalarOptimizerLateEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(BoundsCheckingPass());
             });
       if (LangOpts.Sanitize.has(SanitizerKind::Memory))
         PB.registerOptimizerLastEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {