335 lines · cpp
1//===--- TidyProvider.cpp - create options for running clang-tidy----------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "TidyProvider.h"10#include "../clang-tidy/ClangTidyModuleRegistry.h"11#include "../clang-tidy/ClangTidyOptions.h"12#include "Config.h"13#include "support/FileCache.h"14#include "support/Logger.h"15#include "support/Path.h"16#include "support/ThreadsafeFS.h"17#include "llvm/ADT/STLExtras.h"18#include "llvm/ADT/SmallString.h"19#include "llvm/ADT/StringExtras.h"20#include "llvm/ADT/StringSet.h"21#include "llvm/Support/Allocator.h"22#include "llvm/Support/Process.h"23#include "llvm/Support/SourceMgr.h"24#include <memory>25#include <optional>26 27namespace clang {28namespace clangd {29namespace {30 31// Access to config from a .clang-tidy file, caching IO and parsing.32class DotClangTidyCache : private FileCache {33 // We cache and expose shared_ptr to avoid copying the value on every lookup34 // when we're ultimately just going to pass it to mergeWith.35 mutable std::shared_ptr<const tidy::ClangTidyOptions> Value;36 37public:38 DotClangTidyCache(PathRef Path) : FileCache(Path) {}39 40 std::shared_ptr<const tidy::ClangTidyOptions>41 get(const ThreadsafeFS &TFS,42 std::chrono::steady_clock::time_point FreshTime) const {43 std::shared_ptr<const tidy::ClangTidyOptions> Result;44 read(45 TFS, FreshTime,46 [this](std::optional<llvm::StringRef> Data) {47 Value.reset();48 if (Data && !Data->empty()) {49 auto Diagnostics = [](const llvm::SMDiagnostic &D) {50 switch (D.getKind()) {51 case llvm::SourceMgr::DK_Error:52 elog("tidy-config error at {0}:{1}:{2}: {3}", D.getFilename(),53 D.getLineNo(), D.getColumnNo(), D.getMessage());54 break;55 case llvm::SourceMgr::DK_Warning:56 log("tidy-config warning at {0}:{1}:{2}: {3}", D.getFilename(),57 D.getLineNo(), D.getColumnNo(), D.getMessage());58 break;59 case llvm::SourceMgr::DK_Note:60 case llvm::SourceMgr::DK_Remark:61 vlog("tidy-config note at {0}:{1}:{2}: {3}", D.getFilename(),62 D.getLineNo(), D.getColumnNo(), D.getMessage());63 break;64 }65 };66 if (auto Parsed = tidy::parseConfigurationWithDiags(67 llvm::MemoryBufferRef(*Data, path()), Diagnostics))68 Value = std::make_shared<const tidy::ClangTidyOptions>(69 std::move(*Parsed));70 else71 elog("Error parsing clang-tidy configuration in {0}: {1}", path(),72 Parsed.getError().message());73 }74 },75 [&]() { Result = Value; });76 return Result;77 }78};79 80// Access to combined config from .clang-tidy files governing a source file.81// Each config file is cached and the caches are shared for affected sources.82//83// FIXME: largely duplicates config::Provider::fromAncestorRelativeYAMLFiles.84// Potentially useful for compile_commands.json too. Extract?85class DotClangTidyTree {86 const ThreadsafeFS &FS;87 std::string RelPath;88 std::chrono::steady_clock::duration MaxStaleness;89 90 mutable std::mutex Mu;91 // Keys are the ancestor directory, not the actual config path within it.92 // We only insert into this map, so pointers to values are stable forever.93 // Mutex guards the map itself, not the values (which are threadsafe).94 mutable llvm::StringMap<DotClangTidyCache> Cache;95 96public:97 DotClangTidyTree(const ThreadsafeFS &FS)98 : FS(FS), RelPath(".clang-tidy"), MaxStaleness(std::chrono::seconds(5)) {}99 100 void apply(tidy::ClangTidyOptions &Result, PathRef AbsPath) {101 namespace path = llvm::sys::path;102 assert(path::is_absolute(AbsPath));103 104 // Compute absolute paths to all ancestors (substrings of P.Path).105 // Ensure cache entries for each ancestor exist in the map.106 llvm::SmallVector<DotClangTidyCache *> Caches;107 {108 std::lock_guard<std::mutex> Lock(Mu);109 for (auto Ancestor = absoluteParent(AbsPath); !Ancestor.empty();110 Ancestor = absoluteParent(Ancestor)) {111 auto It = Cache.find(Ancestor);112 // Assemble the actual config file path only if needed.113 if (It == Cache.end()) {114 llvm::SmallString<256> ConfigPath = Ancestor;115 path::append(ConfigPath, RelPath);116 It = Cache.try_emplace(Ancestor, ConfigPath.str()).first;117 }118 Caches.push_back(&It->second);119 }120 }121 // Finally query each individual file.122 // This will take a (per-file) lock for each file that actually exists.123 std::chrono::steady_clock::time_point FreshTime =124 std::chrono::steady_clock::now() - MaxStaleness;125 llvm::SmallVector<std::shared_ptr<const tidy::ClangTidyOptions>>126 OptionStack;127 for (const DotClangTidyCache *Cache : Caches)128 if (auto Config = Cache->get(FS, FreshTime)) {129 OptionStack.push_back(std::move(Config));130 if (!OptionStack.back()->InheritParentConfig.value_or(false))131 break;132 }133 unsigned Order = 1u;134 for (auto &Option : llvm::reverse(OptionStack))135 Result.mergeWith(*Option, Order++);136 }137};138 139} // namespace140 141static void mergeCheckList(std::optional<std::string> &Checks,142 llvm::StringRef List) {143 if (List.empty())144 return;145 if (!Checks || Checks->empty()) {146 Checks.emplace(List);147 return;148 }149 *Checks = llvm::join_items(",", *Checks, List);150}151 152TidyProvider provideEnvironment() {153 static const std::optional<std::string> User = [] {154 std::optional<std::string> Ret = llvm::sys::Process::GetEnv("USER");155#ifdef _WIN32156 if (!Ret)157 return llvm::sys::Process::GetEnv("USERNAME");158#endif159 return Ret;160 }();161 162 if (User)163 return164 [](tidy::ClangTidyOptions &Opts, llvm::StringRef) { Opts.User = User; };165 // FIXME: Once function_ref and unique_function operator= operators handle166 // null values, this can return null.167 return [](tidy::ClangTidyOptions &, llvm::StringRef) {};168}169 170TidyProvider provideDefaultChecks() {171 // These default checks are chosen for:172 // - low false-positive rate173 // - providing a lot of value174 // - being reasonably efficient175 static const std::string DefaultChecks = llvm::join_items(176 ",", "readability-misleading-indentation", "readability-deleted-default",177 "bugprone-integer-division", "bugprone-sizeof-expression",178 "bugprone-suspicious-missing-comma", "bugprone-unused-raii",179 "bugprone-unused-return-value", "misc-unused-using-decls",180 "misc-unused-alias-decls", "misc-definitions-in-headers");181 return [](tidy::ClangTidyOptions &Opts, llvm::StringRef) {182 if (!Opts.Checks || Opts.Checks->empty())183 Opts.Checks = DefaultChecks;184 };185}186 187TidyProvider addTidyChecks(llvm::StringRef Checks,188 llvm::StringRef WarningsAsErrors) {189 return [Checks = std::string(Checks),190 WarningsAsErrors = std::string(WarningsAsErrors)](191 tidy::ClangTidyOptions &Opts, llvm::StringRef) {192 mergeCheckList(Opts.Checks, Checks);193 mergeCheckList(Opts.WarningsAsErrors, WarningsAsErrors);194 };195}196 197TidyProvider disableUnusableChecks(llvm::ArrayRef<std::string> ExtraBadChecks) {198 constexpr llvm::StringLiteral Separator(",");199 static const std::string BadChecks = llvm::join_items(200 Separator,201 // We want this list to start with a separator to202 // simplify appending in the lambda. So including an203 // empty string here will force that.204 "",205 // include-cleaner is directly integrated in IncludeCleaner.cpp206 "-misc-include-cleaner",207 208 // ----- False Positives -----209 210 // Check relies on seeing ifndef/define/endif directives,211 // clangd doesn't replay those when using a preamble.212 "-llvm-header-guard", "-modernize-macro-to-enum",213 "-cppcoreguidelines-macro-to-enum",214 215 // ----- Crashing Checks -----216 217 // Check can choke on invalid (intermediate) c++218 // code, which is often the case when clangd219 // tries to build an AST.220 "-bugprone-use-after-move",221 // Alias for bugprone-use-after-move.222 "-hicpp-invalid-access-moved",223 // Check uses dataflow analysis, which might hang/crash unexpectedly on224 // incomplete code.225 "-bugprone-unchecked-optional-access");226 227 size_t Size = BadChecks.size();228 for (const std::string &Str : ExtraBadChecks) {229 if (Str.empty())230 continue;231 Size += Separator.size();232 if (LLVM_LIKELY(Str.front() != '-'))233 ++Size;234 Size += Str.size();235 }236 std::string DisableGlob;237 DisableGlob.reserve(Size);238 DisableGlob += BadChecks;239 for (const std::string &Str : ExtraBadChecks) {240 if (Str.empty())241 continue;242 DisableGlob += Separator;243 if (LLVM_LIKELY(Str.front() != '-'))244 DisableGlob.push_back('-');245 DisableGlob += Str;246 }247 248 return [DisableList(std::move(DisableGlob))](tidy::ClangTidyOptions &Opts,249 llvm::StringRef) {250 if (Opts.Checks && !Opts.Checks->empty())251 Opts.Checks->append(DisableList);252 };253}254 255TidyProvider provideClangdConfig() {256 return [](tidy::ClangTidyOptions &Opts, llvm::StringRef) {257 const auto &CurTidyConfig = Config::current().Diagnostics.ClangTidy;258 if (!CurTidyConfig.Checks.empty())259 mergeCheckList(Opts.Checks, CurTidyConfig.Checks);260 261 for (const auto &CheckOption : CurTidyConfig.CheckOptions)262 Opts.CheckOptions.insert_or_assign(CheckOption.getKey(),263 tidy::ClangTidyOptions::ClangTidyValue(264 CheckOption.getValue(), 10000U));265 };266}267 268TidyProvider provideClangTidyFiles(ThreadsafeFS &TFS) {269 return [Tree = std::make_unique<DotClangTidyTree>(TFS)](270 tidy::ClangTidyOptions &Opts, llvm::StringRef Filename) {271 Tree->apply(Opts, Filename);272 };273}274 275TidyProvider combine(std::vector<TidyProvider> Providers) {276 // FIXME: Once function_ref and unique_function operator= operators handle277 // null values, we should filter out any Providers that are null. Right now we278 // have to ensure we dont pass any providers that are null.279 return [Providers(std::move(Providers))](tidy::ClangTidyOptions &Opts,280 llvm::StringRef Filename) {281 for (const auto &Provider : Providers)282 Provider(Opts, Filename);283 };284}285 286tidy::ClangTidyOptions getTidyOptionsForFile(TidyProviderRef Provider,287 llvm::StringRef Filename) {288 // getDefaults instantiates all check factories, which are registered at link289 // time. So cache the results once.290 static const auto *DefaultOpts = [] {291 auto *Opts = new tidy::ClangTidyOptions;292 *Opts = tidy::ClangTidyOptions::getDefaults();293 Opts->Checks->clear();294 return Opts;295 }();296 auto Opts = *DefaultOpts;297 if (Provider)298 Provider(Opts, Filename);299 return Opts;300}301 302bool isRegisteredTidyCheck(llvm::StringRef Check) {303 assert(!Check.empty());304 assert(!Check.contains('*') && !Check.contains(',') &&305 "isRegisteredCheck doesn't support globs");306 assert(Check.ltrim().front() != '-');307 308 static const llvm::StringSet<llvm::BumpPtrAllocator> AllChecks = [] {309 llvm::StringSet<llvm::BumpPtrAllocator> Result;310 tidy::ClangTidyCheckFactories Factories;311 for (tidy::ClangTidyModuleRegistry::entry E :312 tidy::ClangTidyModuleRegistry::entries())313 E.instantiate()->addCheckFactories(Factories);314 for (const auto &Factory : Factories)315 Result.insert(Factory.getKey());316 return Result;317 }();318 319 return AllChecks.contains(Check);320}321 322std::optional<bool> isFastTidyCheck(llvm::StringRef Check) {323 static auto &Fast = *new llvm::StringMap<bool>{324#define FAST(CHECK, TIME) {#CHECK,true},325#define SLOW(CHECK, TIME) {#CHECK,false},326#include "TidyFastChecks.inc"327 };328 if (auto It = Fast.find(Check); It != Fast.end())329 return It->second;330 return std::nullopt;331}332 333} // namespace clangd334} // namespace clang335