[clangd] Fix use-after-free issues in TidyProvider.cpp (#114808)

Author: hokein

clang-tools-extra/clangd/TidyProvider.cpp

@@ -46,7 +46,7 @@ class DotClangTidyCache : private FileCache {
         [this](std::optional<llvm::StringRef> Data) {
           Value.reset();
           if (Data && !Data->empty()) {
-            tidy::DiagCallback Diagnostics = [](const llvm::SMDiagnostic &D) {
+            auto Diagnostics = [](const llvm::SMDiagnostic &D) {
               switch (D.getKind()) {
               case llvm::SourceMgr::DK_Error:
                 elog("tidy-config error at {0}:{1}:{2}: {3}", D.getFilename(),
@@ -149,7 +149,7 @@ static void mergeCheckList(std::optional<std::string> &Checks,
   *Checks = llvm::join_items(",", *Checks, List);
 }
 
-TidyProviderRef provideEnvironment() {
+TidyProvider provideEnvironment() {
   static const std::optional<std::string> User = [] {
     std::optional<std::string> Ret = llvm::sys::Process::GetEnv("USER");
 #ifdef _WIN32
@@ -167,7 +167,7 @@ TidyProviderRef provideEnvironment() {
   return [](tidy::ClangTidyOptions &, llvm::StringRef) {};
 }
 
-TidyProviderRef provideDefaultChecks() {
+TidyProvider provideDefaultChecks() {
   // These default checks are chosen for:
   //  - low false-positive rate
   //  - providing a lot of value
@@ -251,7 +251,7 @@ TidyProvider disableUnusableChecks(llvm::ArrayRef<std::string> ExtraBadChecks) {
   };
 }
 
-TidyProviderRef provideClangdConfig() {
+TidyProvider provideClangdConfig() {
   return [](tidy::ClangTidyOptions &Opts, llvm::StringRef) {
     const auto &CurTidyConfig = Config::current().Diagnostics.ClangTidy;
     if (!CurTidyConfig.Checks.empty())

clang-tools-extra/clangd/TidyProvider.h

@@ -30,11 +30,11 @@ using TidyProviderRef = llvm::function_ref<void(tidy::ClangTidyOptions &,
 TidyProvider combine(std::vector<TidyProvider> Providers);
 
 /// Provider that just sets the defaults.
-TidyProviderRef provideEnvironment();
+TidyProvider provideEnvironment();
 
 /// Provider that will enable a nice set of default checks if none are
 /// specified.
-TidyProviderRef provideDefaultChecks();
+TidyProvider provideDefaultChecks();
 
 /// Provider the enables a specific set of checks and warnings as errors.
 TidyProvider addTidyChecks(llvm::StringRef Checks,
@@ -51,7 +51,7 @@ disableUnusableChecks(llvm::ArrayRef<std::string> ExtraBadChecks = {});
 TidyProvider provideClangTidyFiles(ThreadsafeFS &);
 
 // Provider that uses clangd configuration files.
-TidyProviderRef provideClangdConfig();
+TidyProvider provideClangdConfig();
 
 tidy::ClangTidyOptions getTidyOptionsForFile(TidyProviderRef Provider,
                                              llvm::StringRef Filename);