[clang-doc] Add flag to continue after mapping errors

[DiegoAstiazaran]

Summary

The tool used to stop execution if there was an error in the mapping phase. It will now show the error but continue with the files that were mapped correctly if the flag is true.

[jakehehrlich]

What's the use case for this and how do we handle return codes when an error occurs but we continue on?

[DiegoAstiazaran]

A flag has been added to decide if the tool should continue after an error occurs in the mapping phase.

clang-tools-extra/trunk/clang-doc/tool/ClangDocMain.cpp

 
 using namespace clang::ast_matchers;
 using namespace clang::tooling;
 using namespace clang;
 
 static llvm::cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
 static llvm::cl::OptionCategory ClangDocCategory("clang-doc options");
 
+static llvm::cl::opt<bool> IgnoreMappingFailures(
+    "ignore-map-errors",
+    llvm::cl::desc("Continue if files are not mapped correctly."),
+    llvm::cl::init(true), llvm::cl::cat(ClangDocCategory));
+
 static llvm::cl::opt<std::string>
     OutDirectory("output",
                  llvm::cl::desc("Directory for outputting generated files."),
                  llvm::cl::init("docs"), llvm::cl::cat(ClangDocCategory));
 
 static llvm::cl::opt<bool>
     PublicOnly("public", llvm::cl::desc("Document only public declarations."),
                llvm::cl::init(false), llvm::cl::cat(ClangDocCategory));
CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
                                  DefaultStylesheet.str());
   }
 
   // Mapping phase
   llvm::outs() << "Mapping decls...\n";
   auto Err =
       Exec->get()->execute(doc::newMapperActionFactory(CDCtx), ArgAdjuster);
   if (Err) {
+    if (IgnoreMappingFailures)
+      llvm::errs() << "Error mapping decls in files. Clang-doc will ignore "
+                      "these files and continue:\n"
+                   << toString(std::move(Err)) << "\n";
+    else {
       llvm::errs() << toString(std::move(Err)) << "\n";
       return 1;
     }
+  }
 
   // Collect values into output by key.
   // In ToolResults, the Key is the hashed USR and the value is the
   // bitcode-encoded representation of the Info object.
   llvm::outs() << "Collecting infos...\n";
   llvm::StringMap<std::vector<std::unique_ptr<doc::Info>>> USRToInfos;
   if (bitcodeResultsToInfos(*Exec->get()->getToolResults(), USRToInfos))
     return 1;