1//===--- SystemIncludeExtractor.cpp ------------------------------*- C++-*-===//
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// Some compiler drivers have implicit search mechanism for system headers.
9// This compilation database implementation tries to extract that information by
10// executing the driver in verbose mode. gcc-compatible drivers print something
11// like:
12// ....
13// ....
14// #include <...> search starts here:
15// /usr/lib/gcc/x86_64-linux-gnu/7/include
16// /usr/local/include
17// /usr/lib/gcc/x86_64-linux-gnu/7/include-fixed
18// /usr/include/x86_64-linux-gnu
19// /usr/include
20// End of search list.
21// ....
22// ....
23// This component parses that output and adds each path to command line args
24// provided by Base, after prepending them with -isystem. Therefore current
25// implementation would not work with a driver that is not gcc-compatible.
26//
27// First argument of the command line received from underlying compilation
28// database is used as compiler driver path. Due to this arbitrary binary
29// execution, this mechanism is not used by default and only executes binaries
30// in the paths that are explicitly included by the user.
31
32#include "CompileCommands.h"
33#include "GlobalCompilationDatabase.h"
34#include "support/Logger.h"
35#include "support/Threading.h"
36#include "support/Trace.h"
37#include "clang/Basic/Diagnostic.h"
38#include "clang/Basic/DiagnosticIDs.h"
39#include "clang/Basic/DiagnosticOptions.h"
40#include "clang/Basic/TargetInfo.h"
41#include "clang/Basic/TargetOptions.h"
42#include "clang/Driver/Types.h"
43#include "clang/Tooling/CompilationDatabase.h"
44#include "llvm/ADT/ArrayRef.h"
45#include "llvm/ADT/DenseMap.h"
46#include "llvm/ADT/Hashing.h"
47#include "llvm/ADT/IntrusiveRefCntPtr.h"
48#include "llvm/ADT/STLExtras.h"
49#include "llvm/ADT/ScopeExit.h"
50#include "llvm/ADT/SmallString.h"
51#include "llvm/ADT/SmallVector.h"
52#include "llvm/ADT/StringExtras.h"
53#include "llvm/ADT/StringRef.h"
54#include "llvm/Support/ErrorHandling.h"
55#include "llvm/Support/FileSystem.h"
56#include "llvm/Support/MemoryBuffer.h"
57#include "llvm/Support/Path.h"
58#include "llvm/Support/Program.h"
59#include "llvm/Support/Regex.h"
60#include "llvm/Support/ScopedPrinter.h"
61#include "llvm/Support/raw_ostream.h"
62#include <cassert>
63#include <cstddef>
64#include <iterator>
65#include <memory>
66#include <optional>
67#include <string>
68#include <tuple>
69#include <utility>
70#include <vector>
71
72namespace clang::clangd {
73namespace {
74
75struct DriverInfo {
76 std::vector<std::string> SystemIncludes;
77 std::string Target;
78};
79
80struct DriverArgs {
81 // Name of the driver program to execute or absolute path to it.
82 std::string Driver;
83 // Whether certain includes should be part of query.
84 bool StandardIncludes = true;
85 bool StandardCXXIncludes = true;
86 bool BuiltinIncludes = true;
87 // Language to use while querying.
88 std::string Lang;
89 std::string Sysroot;
90 std::string ISysroot;
91
92 bool operator==(const DriverArgs &RHS) const {
93 return std::tie(Driver, StandardIncludes, StandardCXXIncludes,
94 BuiltinIncludes, Lang, Sysroot, ISysroot) ==
95 std::tie(RHS.Driver, RHS.StandardIncludes, RHS.StandardCXXIncludes,
96 RHS.BuiltinIncludes, RHS.Lang, RHS.Sysroot, ISysroot);
97 }
98
99 DriverArgs(const tooling::CompileCommand &Cmd, llvm::StringRef File) {
100 llvm::SmallString<128> Driver(Cmd.CommandLine.front());
101 // Driver is a not a single executable name but instead a path (either
102 // relative or absolute).
103 if (llvm::any_of(Driver,
104 [](char C) { return llvm::sys::path::is_separator(C); })) {
105 llvm::sys::fs::make_absolute(Cmd.Directory, Driver);
106 }
107 this->Driver = Driver.str().str();
108 for (size_t I = 0, E = Cmd.CommandLine.size(); I < E; ++I) {
109 llvm::StringRef Arg = Cmd.CommandLine[I];
110
111 // Look for Language related flags.
112 if (Arg.consume_front("-x")) {
113 if (Arg.empty() && I + 1 < E)
114 Lang = Cmd.CommandLine[I + 1];
115 else
116 Lang = Arg.str();
117 }
118 // Look for standard/builtin includes.
119 else if (Arg == "-nostdinc" || Arg == "--no-standard-includes")
120 StandardIncludes = false;
121 else if (Arg == "-nostdinc++")
122 StandardCXXIncludes = false;
123 else if (Arg == "-nobuiltininc")
124 BuiltinIncludes = false;
125 // Figure out sysroot
126 else if (Arg.consume_front("--sysroot")) {
127 if (Arg.consume_front("="))
128 Sysroot = Arg.str();
129 else if (Arg.empty() && I + 1 < E)
130 Sysroot = Cmd.CommandLine[I + 1];
131 } else if (Arg.consume_front("-isysroot")) {
132 if (Arg.empty() && I + 1 < E)
133 ISysroot = Cmd.CommandLine[I + 1];
134 else
135 ISysroot = Arg.str();
136 }
137 }
138
139 // Downgrade objective-c++-header (used in clangd's fallback flags for .h
140 // files) to c++-header, as some drivers may fail to run the extraction
141 // command if it contains `-xobjective-c++-header` and objective-c++ support
142 // is not installed.
143 // In practice, we don't see different include paths for the two on
144 // clang+mac, which is the most common objectve-c compiler.
145 if (Lang == "objective-c++-header") {
146 Lang = "c++-header";
147 }
148
149 // If language is not explicit in the flags, infer from the file.
150 // This is important as we want to cache each language separately.
151 if (Lang.empty()) {
152 llvm::StringRef Ext = llvm::sys::path::extension(File).trim('.');
153 auto Type = driver::types::lookupTypeForExtension(Ext);
154 if (Type == driver::types::TY_INVALID) {
155 elog("System include extraction: invalid file type for {0}", Ext);
156 } else {
157 Lang = driver::types::getTypeName(Type);
158 }
159 }
160 }
161 llvm::SmallVector<llvm::StringRef> render() const {
162 // FIXME: Don't treat lang specially?
163 assert(!Lang.empty());
164 llvm::SmallVector<llvm::StringRef> Args = {"-x", Lang};
165 if (!StandardIncludes)
166 Args.push_back("-nostdinc");
167 if (!StandardCXXIncludes)
168 Args.push_back("-nostdinc++");
169 if (!BuiltinIncludes)
170 Args.push_back("-nobuiltininc++");
171 if (!Sysroot.empty())
172 Args.append({"--sysroot", Sysroot});
173 if (!ISysroot.empty())
174 Args.append({"-isysroot", ISysroot});
175 return Args;
176 }
177
178 static DriverArgs getEmpty() { return {}; }
179
180private:
181 DriverArgs() = default;
182};
183} // namespace
184} // namespace clang::clangd
185namespace llvm {
186using DriverArgs = clang::clangd::DriverArgs;
187template <> struct DenseMapInfo<DriverArgs> {
188 static DriverArgs getEmptyKey() {
189 auto Driver = DriverArgs::getEmpty();
190 Driver.Driver = "EMPTY_KEY";
191 return Driver;
192 }
193 static DriverArgs getTombstoneKey() {
194 auto Driver = DriverArgs::getEmpty();
195 Driver.Driver = "TOMBSTONE_KEY";
196 return Driver;
197 }
198 static unsigned getHashValue(const DriverArgs &Val) {
199 return llvm::hash_value(std::tuple{
200 Val.Driver,
201 Val.StandardIncludes,
202 Val.StandardCXXIncludes,
203 Val.BuiltinIncludes,
204 Val.Lang,
205 Val.Sysroot,
206 Val.ISysroot,
207 });
208 }
209 static bool isEqual(const DriverArgs &LHS, const DriverArgs &RHS) {
210 return LHS == RHS;
211 }
212};
213} // namespace llvm
214namespace clang::clangd {
215namespace {
216bool isValidTarget(llvm::StringRef Triple) {
217 std::shared_ptr<TargetOptions> TargetOpts(new TargetOptions);
218 TargetOpts->Triple = Triple.str();
219 DiagnosticsEngine Diags(new DiagnosticIDs, new DiagnosticOptions,
220 new IgnoringDiagConsumer);
221 llvm::IntrusiveRefCntPtr<TargetInfo> Target =
222 TargetInfo::CreateTargetInfo(Diags, TargetOpts);
223 return bool(Target);
224}
225
226std::optional<DriverInfo> parseDriverOutput(llvm::StringRef Output) {
227 DriverInfo Info;
228 const char SIS[] = "#include <...> search starts here:";
229 const char SIE[] = "End of search list.";
230 const char TS[] = "Target: ";
231 llvm::SmallVector<llvm::StringRef> Lines;
232 Output.split(Lines, '\n', /*MaxSplit=*/-1, /*KeepEmpty=*/false);
233
234 enum {
235 Initial, // Initial state: searching for target or includes list.
236 IncludesExtracting, // Includes extracting.
237 Done // Includes and target extraction done.
238 } State = Initial;
239 bool SeenIncludes = false;
240 bool SeenTarget = false;
241 for (auto *It = Lines.begin(); State != Done && It != Lines.end(); ++It) {
242 auto Line = *It;
243 switch (State) {
244 case Initial:
245 if (!SeenIncludes && Line.trim() == SIS) {
246 SeenIncludes = true;
247 State = IncludesExtracting;
248 } else if (!SeenTarget && Line.trim().startswith(TS)) {
249 SeenTarget = true;
250 llvm::StringRef TargetLine = Line.trim();
251 TargetLine.consume_front(TS);
252 // Only detect targets that clang understands
253 if (!isValidTarget(TargetLine)) {
254 elog("System include extraction: invalid target \"{0}\", ignoring",
255 TargetLine);
256 } else {
257 Info.Target = TargetLine.str();
258 vlog("System include extraction: target extracted: \"{0}\"",
259 TargetLine);
260 }
261 }
262 break;
263 case IncludesExtracting:
264 if (Line.trim() == SIE) {
265 State = SeenTarget ? Done : Initial;
266 } else {
267 Info.SystemIncludes.push_back(Line.trim().str());
268 vlog("System include extraction: adding {0}", Line);
269 }
270 break;
271 default:
272 llvm_unreachable("Impossible state of the driver output parser");
273 break;
274 }
275 }
276 if (!SeenIncludes) {
277 elog("System include extraction: start marker not found: {0}", Output);
278 return std::nullopt;
279 }
280 if (State == IncludesExtracting) {
281 elog("System include extraction: end marker missing: {0}", Output);
282 return std::nullopt;
283 }
284 return std::move(Info);
285}
286
287std::optional<DriverInfo>
288extractSystemIncludesAndTarget(const DriverArgs &InputArgs,
289 const llvm::Regex &QueryDriverRegex) {
290 trace::Span Tracer("Extract system includes and target");
291
292 std::string Driver = InputArgs.Driver;
293 if (!llvm::sys::path::is_absolute(Driver)) {
294 auto DriverProgram = llvm::sys::findProgramByName(Driver);
295 if (DriverProgram) {
296 vlog("System include extraction: driver {0} expanded to {1}", Driver,
297 *DriverProgram);
298 Driver = *DriverProgram;
299 } else {
300 elog("System include extraction: driver {0} not found in PATH", Driver);
301 return std::nullopt;
302 }
303 }
304
305 SPAN_ATTACH(Tracer, "driver", Driver);
306 SPAN_ATTACH(Tracer, "lang", InputArgs.Lang);
307
308 if (!QueryDriverRegex.match(Driver)) {
309 vlog("System include extraction: not allowed driver {0}", Driver);
310 return std::nullopt;
311 }
312
313 llvm::SmallString<128> StdErrPath;
314 if (auto EC = llvm::sys::fs::createTemporaryFile("system-includes", "clangd",
315 StdErrPath)) {
316 elog("System include extraction: failed to create temporary file with "
317 "error {0}",
318 EC.message());
319 return std::nullopt;
320 }
321 auto CleanUp = llvm::make_scope_exit(
322 [&StdErrPath]() { llvm::sys::fs::remove(StdErrPath); });
323
324 std::optional<llvm::StringRef> Redirects[] = {{""}, {""}, StdErrPath.str()};
325
326 llvm::SmallVector<llvm::StringRef> Args = {Driver, "-E", "-v"};
327 Args.append(InputArgs.render());
328 // Input needs to go after Lang flags.
329 Args.push_back("-");
330
331 std::string ErrMsg;
332 if (int RC = llvm::sys::ExecuteAndWait(Driver, Args, /*Env=*/std::nullopt,
333 Redirects, /*SecondsToWait=*/0,
334 /*MemoryLimit=*/0, &ErrMsg)) {
335 elog("System include extraction: driver execution failed with return code: "
336 "{0} - '{1}'. Args: [{2}]",
337 llvm::to_string(RC), ErrMsg, printArgv(Args));
338 return std::nullopt;
339 }
340
341 auto BufOrError = llvm::MemoryBuffer::getFile(StdErrPath);
342 if (!BufOrError) {
343 elog("System include extraction: failed to read {0} with error {1}",
344 StdErrPath, BufOrError.getError().message());
345 return std::nullopt;
346 }
347
348 std::optional<DriverInfo> Info =
349 parseDriverOutput(BufOrError->get()->getBuffer());
350 if (!Info)
351 return std::nullopt;
352 log("System includes extractor: successfully executed {0}\n\tgot includes: "
353 "\"{1}\"\n\tgot target: \"{2}\"",
354 Driver, llvm::join(Info->SystemIncludes, ", "), Info->Target);
355 return Info;
356}
357
358tooling::CompileCommand &
359addSystemIncludes(tooling::CompileCommand &Cmd,
360 llvm::ArrayRef<std::string> SystemIncludes) {
361 std::vector<std::string> ToAppend;
362 for (llvm::StringRef Include : SystemIncludes) {
363 // FIXME(kadircet): This doesn't work when we have "--driver-mode=cl"
364 ToAppend.push_back("-isystem");
365 ToAppend.push_back(Include.str());
366 }
367 if (!ToAppend.empty()) {
368 // Just append when `--` isn't present.
369 auto InsertAt = llvm::find(Cmd.CommandLine, "--");
370 Cmd.CommandLine.insert(InsertAt, std::make_move_iterator(ToAppend.begin()),
371 std::make_move_iterator(ToAppend.end()));
372 }
373 return Cmd;
374}
375
376tooling::CompileCommand &setTarget(tooling::CompileCommand &Cmd,
377 const std::string &Target) {
378 if (!Target.empty()) {
379 // We do not want to override existing target with extracted one.
380 for (llvm::StringRef Arg : Cmd.CommandLine) {
381 if (Arg == "-target" || Arg.startswith("--target="))
382 return Cmd;
383 }
384 // Just append when `--` isn't present.
385 auto InsertAt = llvm::find(Cmd.CommandLine, "--");
386 Cmd.CommandLine.insert(InsertAt, "--target=" + Target);
387 }
388 return Cmd;
389}
390
391/// Converts a glob containing only ** or * into a regex.
392std::string convertGlobToRegex(llvm::StringRef Glob) {
393 std::string RegText;
394 llvm::raw_string_ostream RegStream(RegText);
395 RegStream << '^';
396 for (size_t I = 0, E = Glob.size(); I < E; ++I) {
397 if (Glob[I] == '*') {
398 if (I + 1 < E && Glob[I + 1] == '*') {
399 // Double star, accept any sequence.
400 RegStream << ".*";
401 // Also skip the second star.
402 ++I;
403 } else {
404 // Single star, accept any sequence without a slash.
405 RegStream << "[^/]*";
406 }
407 } else if (llvm::sys::path::is_separator(Glob[I]) &&
408 llvm::sys::path::is_separator('/') &&
409 llvm::sys::path::is_separator('\\')) {
410 RegStream << R"([/\\])"; // Accept either slash on windows.
411 } else {
412 RegStream << llvm::Regex::escape(Glob.substr(I, 1));
413 }
414 }
415 RegStream << '$';
416 RegStream.flush();
417 return RegText;
418}
419
420/// Converts a glob containing only ** or * into a regex.
421llvm::Regex convertGlobsToRegex(llvm::ArrayRef<std::string> Globs) {
422 assert(!Globs.empty() && "Globs cannot be empty!");
423 std::vector<std::string> RegTexts;
424 RegTexts.reserve(Globs.size());
425 for (llvm::StringRef Glob : Globs)
426 RegTexts.push_back(convertGlobToRegex(Glob));
427
428 // Tempting to pass IgnoreCase, but we don't know the FS sensitivity.
429 llvm::Regex Reg(llvm::join(RegTexts, "|"));
430 assert(Reg.isValid(RegTexts.front()) &&
431 "Created an invalid regex from globs");
432 return Reg;
433}
434
435/// Extracts system includes from a trusted driver by parsing the output of
436/// include search path and appends them to the commands coming from underlying
437/// compilation database.
438class SystemIncludeExtractor {
439public:
440 SystemIncludeExtractor(llvm::ArrayRef<std::string> QueryDriverGlobs)
441 : QueryDriverRegex(convertGlobsToRegex(QueryDriverGlobs)) {}
442
443 void operator()(tooling::CompileCommand &Cmd, llvm::StringRef File) const {
444 if (Cmd.CommandLine.empty())
445 return;
446
447 DriverArgs Args(Cmd, File);
448 if (Args.Lang.empty())
449 return;
450 if (auto Info = QueriedDrivers.get(Args, [&] {
451 return extractSystemIncludesAndTarget(Args, QueryDriverRegex);
452 })) {
453 setTarget(addSystemIncludes(Cmd, Info->SystemIncludes), Info->Target);
454 }
455 }
456
457private:
458 // Caches includes extracted from a driver. Key is driver:lang.
459 Memoize<llvm::DenseMap<DriverArgs, std::optional<DriverInfo>>> QueriedDrivers;
460 llvm::Regex QueryDriverRegex;
461};
462} // namespace
463
464SystemIncludeExtractorFn
465getSystemIncludeExtractor(llvm::ArrayRef<std::string> QueryDriverGlobs) {
466 if (QueryDriverGlobs.empty())
467 return nullptr;
468 return SystemIncludeExtractor(QueryDriverGlobs);
469}
470
471} // namespace clang::clangd
472