[Stats] Improve stats tracing readability a little.

Author: graydon

lib/AST/Decl.cpp

@@ -5677,6 +5677,10 @@ struct DeclTraceFormatter : public UnifiedStatsReporter::TraceFormatter {
     const Decl *D = static_cast<const Decl *>(Entity);
     if (auto const *VD = dyn_cast<const ValueDecl>(D)) {
       VD->getFullName().print(OS, false);
+    } else {
+      OS << "<"
+         << Decl::getDescriptiveKindName(D->getDescriptiveKind())
+         << ">";
     }
   }
   void traceLoc(const void *Entity, SourceManager *SM,

lib/ClangImporter/ImportDecl.cpp

@@ -8604,17 +8604,20 @@ struct ClangDeclTraceFormatter : public UnifiedStatsReporter::TraceFormatter {
     const clang::Decl *CD = static_cast<const clang::Decl *>(Entity);
     if (auto const *ND = dyn_cast<const clang::NamedDecl>(CD)) {
       ND->printName(OS);
+    } else {
+      OS << "<unnamed-clang-decl>";
     }
   }
 
-  static inline void printClangShortLoc(raw_ostream &OS,
+  static inline bool printClangShortLoc(raw_ostream &OS,
                                         clang::SourceManager *CSM,
                                         clang::SourceLocation L) {
     if (!L.isValid() || !L.isFileID())
-      return;
+      return false;
     auto PLoc = CSM->getPresumedLoc(L);
     OS << llvm::sys::path::filename(PLoc.getFilename()) << ':' << PLoc.getLine()
        << ':' << PLoc.getColumn();
+    return true;
   }
 
   void traceLoc(const void *Entity, SourceManager *SM,
@@ -8624,8 +8627,8 @@ struct ClangDeclTraceFormatter : public UnifiedStatsReporter::TraceFormatter {
     if (CSM) {
       const clang::Decl *CD = static_cast<const clang::Decl *>(Entity);
       auto Range = CD->getSourceRange();
-      printClangShortLoc(OS, CSM, Range.getBegin());
-      OS << '-';
+      if (printClangShortLoc(OS, CSM, Range.getBegin()))
+        OS << '-';
       printClangShortLoc(OS, CSM, Range.getEnd());
     }
   }