Add `-verify-ignore-unexpected` option to ignore unexpected diagnostics in VerifyDiagnosticsConsumer

Summary:
The goal of this patch is to make `-verify` easier to use when testing libc++. The `notes` attached to compile error diagnostics are numerous and relatively unstable when they reference libc++ header internals. This patch allows libc++ to write stable compilation failure tests by allowing unexpected diagnostic messages to be ignored where they are not relevant.

This patch adds a new CC1 flag called `-verify-ignore-unexpected`. `-verify-ignore-unexpected` tells `VerifyDiagnosticsConsumer` to ignore *all* unexpected diagnostic messages. `-verify-ignore-unexpected=<LevelList>` can be used to only ignore certain diagnostic levels. `<LevelList>` is a comma separated list of diagnostic levels to ignore. The supported levels are `note`, `remark`, `warning` and `error`.



Reviewers: bogner, grosser, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D10138

llvm-svn: 239665
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 930c771..f4480bb 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -321,6 +321,29 @@
   return Pattern;
 }
 
+static bool parseDiagnosticLevelMask(StringRef FlagName,
+                                     const std::vector<std::string> &Levels,
+                                     DiagnosticsEngine *Diags,
+                                     DiagnosticLevelMask &M) {
+  bool Success = true;
+  for (const auto &Level : Levels) {
+    DiagnosticLevelMask const PM =
+      llvm::StringSwitch<DiagnosticLevelMask>(Level)
+        .Case("note",    DiagnosticLevelMask::Note)
+        .Case("remark",  DiagnosticLevelMask::Remark)
+        .Case("warning", DiagnosticLevelMask::Warning)
+        .Case("error",   DiagnosticLevelMask::Error)
+        .Default(DiagnosticLevelMask::None);
+    if (PM == DiagnosticLevelMask::None) {
+      Success = false;
+      if (Diags)
+        Diags->Report(diag::err_drv_invalid_value) << FlagName << Level;
+    }
+    M = M | PM;
+  }
+  return Success;
+}
+
 static void parseSanitizerKinds(StringRef FlagName,
                                 const std::vector<std::string> &Sanitizers,
                                 DiagnosticsEngine &Diags, SanitizerSet &S) {
@@ -748,11 +771,18 @@
       << Args.getLastArg(OPT_fdiagnostics_format)->getAsString(Args)
       << Format;
   }
-  
+
   Opts.ShowSourceRanges = Args.hasArg(OPT_fdiagnostics_print_source_range_info);
   Opts.ShowParseableFixits = Args.hasArg(OPT_fdiagnostics_parseable_fixits);
   Opts.ShowPresumedLoc = !Args.hasArg(OPT_fno_diagnostics_use_presumed_location);
   Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
+  DiagnosticLevelMask DiagMask = DiagnosticLevelMask::None;
+  Success &= parseDiagnosticLevelMask("-verify-ignore-unexpected=",
+    Args.getAllArgValues(OPT_verify_ignore_unexpected_EQ),
+    Diags, DiagMask);
+  if (Args.hasArg(OPT_verify_ignore_unexpected))
+    DiagMask = DiagnosticLevelMask::All;
+  Opts.setVerifyIgnoreUnexpected(DiagMask);
   Opts.ElideType = !Args.hasArg(OPT_fno_elide_type);
   Opts.ShowTemplateTree = Args.hasArg(OPT_fdiagnostics_show_template_tree);
   Opts.ErrorLimit = getLastArgIntValue(Args, OPT_ferror_limit, 0, Diags);
diff --git a/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
index 910e394..55df936 100644
--- a/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -691,7 +691,8 @@
                            const char *Label,
                            DirectiveList &Left,
                            const_diag_iterator d2_begin,
-                           const_diag_iterator d2_end) {
+                           const_diag_iterator d2_end,
+                           bool IgnoreUnexpected) {
   std::vector<Directive *> LeftOnly;
   DiagList Right(d2_begin, d2_end);
 
@@ -727,7 +728,8 @@
   }
   // Now all that's left in Right are those that were not matched.
   unsigned num = PrintExpected(Diags, SourceMgr, LeftOnly, Label);
-  num += PrintUnexpected(Diags, &SourceMgr, Right.begin(), Right.end(), Label);
+  if (!IgnoreUnexpected)
+    num += PrintUnexpected(Diags, &SourceMgr, Right.begin(), Right.end(), Label);
   return num;
 }
 
@@ -745,21 +747,28 @@
   //   Seen \ Expected - set seen but not expected
   unsigned NumProblems = 0;
 
+  const DiagnosticLevelMask DiagMask =
+    Diags.getDiagnosticOptions().getVerifyIgnoreUnexpected();
+
   // See if there are error mismatches.
   NumProblems += CheckLists(Diags, SourceMgr, "error", ED.Errors,
-                            Buffer.err_begin(), Buffer.err_end());
+                            Buffer.err_begin(), Buffer.err_end(),
+                            bool(DiagnosticLevelMask::Error & DiagMask));
 
   // See if there are warning mismatches.
   NumProblems += CheckLists(Diags, SourceMgr, "warning", ED.Warnings,
-                            Buffer.warn_begin(), Buffer.warn_end());
+                            Buffer.warn_begin(), Buffer.warn_end(),
+                            bool(DiagnosticLevelMask::Warning & DiagMask));
 
   // See if there are remark mismatches.
   NumProblems += CheckLists(Diags, SourceMgr, "remark", ED.Remarks,
-                            Buffer.remark_begin(), Buffer.remark_end());
+                            Buffer.remark_begin(), Buffer.remark_end(),
+                            bool(DiagnosticLevelMask::Remark & DiagMask));
 
   // See if there are note mismatches.
   NumProblems += CheckLists(Diags, SourceMgr, "note", ED.Notes,
-                            Buffer.note_begin(), Buffer.note_end());
+                            Buffer.note_begin(), Buffer.note_end(),
+                            bool(DiagnosticLevelMask::Note & DiagMask));
 
   return NumProblems;
 }
@@ -854,12 +863,20 @@
     // Check that the expected diagnostics occurred.
     NumErrors += CheckResults(Diags, *SrcManager, *Buffer, ED);
   } else {
-    NumErrors += (PrintUnexpected(Diags, nullptr, Buffer->err_begin(),
-                                  Buffer->err_end(), "error") +
-                  PrintUnexpected(Diags, nullptr, Buffer->warn_begin(),
-                                  Buffer->warn_end(), "warn") +
-                  PrintUnexpected(Diags, nullptr, Buffer->note_begin(),
-                                  Buffer->note_end(), "note"));
+    const DiagnosticLevelMask DiagMask =
+        ~Diags.getDiagnosticOptions().getVerifyIgnoreUnexpected();
+    if (bool(DiagnosticLevelMask::Error & DiagMask))
+      NumErrors += PrintUnexpected(Diags, nullptr, Buffer->err_begin(),
+                                   Buffer->err_end(), "error");
+    if (bool(DiagnosticLevelMask::Warning & DiagMask))
+      NumErrors += PrintUnexpected(Diags, nullptr, Buffer->warn_begin(),
+                                   Buffer->warn_end(), "warn");
+    if (bool(DiagnosticLevelMask::Remark & DiagMask))
+      NumErrors += PrintUnexpected(Diags, nullptr, Buffer->remark_begin(),
+                                   Buffer->remark_end(), "remark");
+    if (bool(DiagnosticLevelMask::Note & DiagMask))
+      NumErrors += PrintUnexpected(Diags, nullptr, Buffer->note_begin(),
+                                   Buffer->note_end(), "note");
   }
 
   Diags.setClient(CurClient, Owner.release() != nullptr);