Dump output file map

Author: ahoppen

include/swift/AST/DiagnosticsFrontend.def

@@ -208,9 +208,9 @@ ERROR(error_unable_to_load_supplementary_output_file_map, none,
       (StringRef, StringRef))
 
 ERROR(error_missing_entry_in_supplementary_output_file_map, none,
-      "supplementary output file map '%0' is missing an entry for '%1' "
+      "supplementary output file map '%0' is missing an entry for '%1' contents: '%2'"
       "(this likely indicates a compiler issue; " SWIFT_BUG_REPORT_MESSAGE ")",
-      (StringRef, StringRef))
+      (StringRef, StringRef, StringRef))
 
 ERROR(error_repl_requires_no_input_files,none,
       "REPL mode requires no input files", ())

lib/Frontend/ArgsToFrontendOutputsConverter.cpp

@@ -672,10 +672,13 @@ SupplementaryOutputPathsComputer::readSupplementaryOutputFileMap() const {
         const TypeToPathMap *mapForInput =
             OFM->getOutputMapForInput(input.getFileName());
         if (!mapForInput) {
+          llvm::SmallString<128> t;
+          llvm::raw_svector_ostream os(t);
+          OFM->dump(os);
           Diags.diagnose(
               SourceLoc(),
               diag::error_missing_entry_in_supplementary_output_file_map,
-              supplementaryFileMapPath, input.getFileName());
+              supplementaryFileMapPath, input.getFileName(), os.str());
           hadError = true;
         }
         outputPaths.push_back(createFromTypeToPathMap(mapForInput));