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-exception
6//
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 lookup
34 // 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 Parse: [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(Fmt: "tidy-config error at {0}:{1}:{2}: {3}", Vals: D.getFilename(),
53 Vals: D.getLineNo(), Vals: D.getColumnNo(), Vals: D.getMessage());
54 break;
55 case llvm::SourceMgr::DK_Warning:
56 log(Fmt: "tidy-config warning at {0}:{1}:{2}: {3}", Vals: D.getFilename(),
57 Vals: D.getLineNo(), Vals: D.getColumnNo(), Vals: D.getMessage());
58 break;
59 case llvm::SourceMgr::DK_Note:
60 case llvm::SourceMgr::DK_Remark:
61 vlog(Fmt: "tidy-config note at {0}:{1}:{2}: {3}", Vals: D.getFilename(),
62 Vals: D.getLineNo(), Vals: D.getColumnNo(), Vals: D.getMessage());
63 break;
64 }
65 };
66 if (auto Parsed = tidy::parseConfigurationWithDiags(
67 Config: llvm::MemoryBufferRef(*Data, path()), Handler: Diagnostics))
68 Value = std::make_shared<const tidy::ClangTidyOptions>(
69 args: std::move(*Parsed));
70 else
71 elog(Fmt: "Error parsing clang-tidy configuration in {0}: {1}", Vals: path(),
72 Vals: Parsed.getError().message());
73 }
74 },
75 Read: [&]() { 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(Path: AbsPath); !Ancestor.empty();
110 Ancestor = absoluteParent(Path: Ancestor)) {
111 auto It = Cache.find(Key: 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(path&: ConfigPath, a: RelPath);
116 It = Cache.try_emplace(Key: Ancestor, Args: ConfigPath.str()).first;
117 }
118 Caches.push_back(Elt: &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(TFS: FS, FreshTime)) {
129 OptionStack.push_back(Elt: std::move(Config));
130 if (!OptionStack.back()->InheritParentConfig.value_or(u: false))
131 break;
132 }
133 unsigned Order = 1u;
134 for (auto &Option : llvm::reverse(C&: OptionStack))
135 Result.mergeWith(Other: *Option, Order: Order++);
136 }
137};
138
139} // namespace
140
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(args&: List);
147 return;
148 }
149 *Checks = llvm::join_items(Separator: ",", Items&: *Checks, Items&: List);
150}
151
152TidyProvider provideEnvironment() {
153 static const std::optional<std::string> User = [] {
154 std::optional<std::string> Ret = llvm::sys::Process::GetEnv(name: "USER");
155#ifdef _WIN32
156 if (!Ret)
157 return llvm::sys::Process::GetEnv("USERNAME");
158#endif
159 return Ret;
160 }();
161
162 if (User)
163 return
164 [](tidy::ClangTidyOptions &Opts, llvm::StringRef) { Opts.User = User; };
165 // FIXME: Once function_ref and unique_function operator= operators handle
166 // 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 rate
173 // - providing a lot of value
174 // - being reasonably efficient
175 static const std::string DefaultChecks = llvm::join_items(
176 Separator: ",", Items: "readability-misleading-indentation", Items: "readability-deleted-default",
177 Items: "bugprone-integer-division", Items: "bugprone-sizeof-expression",
178 Items: "bugprone-suspicious-missing-comma", Items: "bugprone-unused-raii",
179 Items: "bugprone-unused-return-value", Items: "misc-unused-using-decls",
180 Items: "misc-unused-alias-decls", Items: "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(Checks&: Opts.Checks, List: Checks);
193 mergeCheckList(Checks&: Opts.WarningsAsErrors, List: 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 to
202 // simplify appending in the lambda. So including an
203 // empty string here will force that.
204 Items: "",
205 // include-cleaner is directly integrated in IncludeCleaner.cpp
206 Items: "-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 Items: "-llvm-header-guard", Items: "-modernize-macro-to-enum",
213 Items: "-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 clangd
219 // tries to build an AST.
220 Items: "-bugprone-use-after-move",
221 // Alias for bugprone-use-after-move.
222 Items: "-hicpp-invalid-access-moved",
223 // Check uses dataflow analysis, which might hang/crash unexpectedly on
224 // incomplete code.
225 Items: "-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(res: 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(c: '-');
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(str: 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(Checks&: Opts.Checks, List: CurTidyConfig.Checks);
260
261 for (const auto &CheckOption : CurTidyConfig.CheckOptions)
262 Opts.CheckOptions.insert_or_assign(Key: CheckOption.getKey(),
263 Val: tidy::ClangTidyOptions::ClangTidyValue(
264 CheckOption.getValue(), 10000U));
265 };
266}
267
268TidyProvider provideClangTidyFiles(ThreadsafeFS &TFS) {
269 return [Tree = std::make_unique<DotClangTidyTree>(args&: TFS)](
270 tidy::ClangTidyOptions &Opts, llvm::StringRef Filename) {
271 Tree->apply(Result&: Opts, AbsPath: Filename);
272 };
273}
274
275TidyProvider combine(std::vector<TidyProvider> Providers) {
276 // FIXME: Once function_ref and unique_function operator= operators handle
277 // null values, we should filter out any Providers that are null. Right now we
278 // 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 link
289 // 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(CheckFactories&: Factories);
314 for (const auto &Factory : Factories)
315 Result.insert(key: Factory.getKey());
316 return Result;
317 }();
318
319 return AllChecks.contains(key: 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(Key: Check); It != Fast.end())
329 return It->second;
330 return std::nullopt;
331}
332
333} // namespace clangd
334} // namespace clang
335

source code of clang-tools-extra/clangd/TidyProvider.cpp