[clang-tidy] Introduced new option --dump-yaml-schema

Since YAML Generate Schema was added, it can be used to dump
current clang-tidy's YAML's schema.

Author: tgs-sc

clang-tools-extra/clang-tidy/ClangTidyOptions.cpp

@@ -16,6 +16,7 @@
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/MemoryBufferRef.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/YAMLGenerateSchema.h"
 #include "llvm/Support/YAMLTraits.h"
 #include <algorithm>
 #include <optional>
@@ -87,7 +88,7 @@ struct NOptionMap {
 template <>
 void yamlize(IO &IO, ClangTidyOptions::OptionMap &Val, bool,
              EmptyContext &Ctx) {
-  if (IO.outputting()) {
+  if (IO.getKind() == IOKind::Outputting) {
     // Ensure check options are sorted
     std::vector<std::pair<StringRef, StringRef>> SortedOptions;
     SortedOptions.reserve(Val.size());
@@ -108,7 +109,7 @@ void yamlize(IO &IO, ClangTidyOptions::OptionMap &Val, bool,
       IO.postflightKey(SaveInfo);
     }
     IO.endMapping();
-  } else {
+  } else if (IO.getKind() == IOKind::Inputting) {
     // We need custom logic here to support the old method of specifying check
     // options using a list of maps containing key and value keys.
     auto &I = reinterpret_cast<Input &>(IO);
@@ -128,6 +129,11 @@ void yamlize(IO &IO, ClangTidyOptions::OptionMap &Val, bool,
     } else {
       IO.setError("expected a sequence or map");
     }
+  } else {
+    MappingNormalization<NOptionMap, ClangTidyOptions::OptionMap> NOpts(IO,
+                                                                        Val);
+    EmptyContext Ctx;
+    yamlize(IO, NOpts->Options, true, Ctx);
   }
 }
 
@@ -182,7 +188,7 @@ struct ChecksVariant {
 };
 
 template <> void yamlize(IO &IO, ChecksVariant &Val, bool, EmptyContext &Ctx) {
-  if (!IO.outputting()) {
+  if (IO.getKind() == IOKind::Inputting) {
     // Special case for reading from YAML
     // Must support reading from both a string or a list
     auto &I = reinterpret_cast<Input &>(IO);
@@ -195,6 +201,9 @@ template <> void yamlize(IO &IO, ChecksVariant &Val, bool, EmptyContext &Ctx) {
     } else {
       IO.setError("expected string or sequence");
     }
+  } else if (IO.getKind() == IOKind::GeneratingSchema) {
+    Val.AsVector = std::vector<std::string>();
+    yamlize(IO, *Val.AsVector, true, Ctx);
   }
 }
 
@@ -541,6 +550,12 @@ parseConfiguration(llvm::MemoryBufferRef Config) {
   return Options;
 }
 
+void dumpConfigurationYAMLSchema(llvm::raw_fd_ostream &Stream) {
+  ClangTidyOptions Options;
+  llvm::yaml::GenerateSchema GS(Stream);
+  GS << Options;
+}
+
 static void diagHandlerImpl(const llvm::SMDiagnostic &Diag, void *Ctx) {
   (*reinterpret_cast<DiagCallback *>(Ctx))(Diag);
 }

clang-tools-extra/clang-tidy/ClangTidyOptions.h

@@ -343,6 +343,9 @@ std::error_code parseLineFilter(llvm::StringRef LineFilter,
 llvm::ErrorOr<ClangTidyOptions>
 parseConfiguration(llvm::MemoryBufferRef Config);
 
+/// Dumps configuration YAML Schema to \p Stream
+void dumpConfigurationYAMLSchema(llvm::raw_fd_ostream &Stream);
+
 using DiagCallback = llvm::function_ref<void(const llvm::SMDiagnostic &)>;
 
 llvm::ErrorOr<ClangTidyOptions>

clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp

@@ -355,6 +355,12 @@ see https://clang.llvm.org/extra/clang-tidy/QueryBasedCustomChecks.html.
                                               cl::init(false),
                                               cl::cat(ClangTidyCategory));
 
+static cl::opt<bool> DumpYAMLSchema("dump-yaml-schema", desc(R"(
+Dumps configuration YAML Schema in JSON format to
+stdout.
+)"),
+                                    cl::init(false),
+                                    cl::cat(ClangTidyCategory));
 namespace clang::tidy {
 
 static void printStats(const ClangTidyStats &Stats) {
@@ -684,6 +690,11 @@ int clangTidyMain(int argc, const char **argv) {
     return 0;
   }
 
+  if (DumpYAMLSchema) {
+    dumpConfigurationYAMLSchema(llvm::outs());
+    return 0;
+  }
+
   if (VerifyConfig) {
     std::vector<ClangTidyOptionsProvider::OptionsSource> RawOptions =
         OptionsProvider->getRawOptions(FileName);