clang-tools  15.0.0git
QueryDriverDatabase.cpp
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1 //===--- QueryDriverDatabase.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"
34 #include "support/Logger.h"
35 #include "support/Path.h"
36 #include "support/Trace.h"
37 #include "clang/Basic/Diagnostic.h"
38 #include "clang/Basic/TargetInfo.h"
39 #include "clang/Basic/TargetOptions.h"
40 #include "clang/Driver/Types.h"
41 #include "clang/Tooling/CompilationDatabase.h"
42 #include "llvm/ADT/ScopeExit.h"
43 #include "llvm/ADT/SmallString.h"
44 #include "llvm/ADT/StringExtras.h"
45 #include "llvm/ADT/StringRef.h"
46 #include "llvm/Support/FileSystem.h"
47 #include "llvm/Support/MemoryBuffer.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/Program.h"
50 #include "llvm/Support/Regex.h"
51 #include "llvm/Support/ScopedPrinter.h"
52 #include <algorithm>
53 #include <map>
54 #include <string>
55 #include <vector>
56 
57 namespace clang {
58 namespace clangd {
59 namespace {
60 
61 struct DriverInfo {
62  std::vector<std::string> SystemIncludes;
63  std::string Target;
64 };
65 
66 bool isValidTarget(llvm::StringRef Triple) {
67  std::shared_ptr<TargetOptions> TargetOpts(new TargetOptions);
68  TargetOpts->Triple = Triple.str();
69  DiagnosticsEngine Diags(new DiagnosticIDs, new DiagnosticOptions,
70  new IgnoringDiagConsumer);
71  IntrusiveRefCntPtr<TargetInfo> Target =
72  TargetInfo::CreateTargetInfo(Diags, TargetOpts);
73  return bool(Target);
74 }
75 
76 llvm::Optional<DriverInfo> parseDriverOutput(llvm::StringRef Output) {
77  DriverInfo Info;
78  const char SIS[] = "#include <...> search starts here:";
79  const char SIE[] = "End of search list.";
80  const char TS[] = "Target: ";
81  llvm::SmallVector<llvm::StringRef> Lines;
82  Output.split(Lines, '\n', /*MaxSplit=*/-1, /*KeepEmpty=*/false);
83 
84  enum {
85  Initial, // Initial state: searching for target or includes list.
86  IncludesExtracting, // Includes extracting.
87  Done // Includes and target extraction done.
88  } State = Initial;
89  bool SeenIncludes = false;
90  bool SeenTarget = false;
91  for (auto *It = Lines.begin(); State != Done && It != Lines.end(); ++It) {
92  auto Line = *It;
93  switch (State) {
94  case Initial:
95  if (!SeenIncludes && Line.trim() == SIS) {
96  SeenIncludes = true;
97  State = IncludesExtracting;
98  } else if (!SeenTarget && Line.trim().startswith(TS)) {
99  SeenTarget = true;
100  llvm::StringRef TargetLine = Line.trim();
101  TargetLine.consume_front(TS);
102  // Only detect targets that clang understands
103  if (!isValidTarget(TargetLine)) {
104  elog("System include extraction: invalid target \"{0}\", ignoring",
105  TargetLine);
106  } else {
107  Info.Target = TargetLine.str();
108  vlog("System include extraction: target extracted: \"{0}\"",
109  TargetLine);
110  }
111  }
112  break;
113  case IncludesExtracting:
114  if (Line.trim() == SIE) {
115  State = SeenTarget ? Done : Initial;
116  } else {
117  Info.SystemIncludes.push_back(Line.trim().str());
118  vlog("System include extraction: adding {0}", Line);
119  }
120  break;
121  default:
122  llvm_unreachable("Impossible state of the driver output parser");
123  break;
124  }
125  }
126  if (!SeenIncludes) {
127  elog("System include extraction: start marker not found: {0}", Output);
128  return llvm::None;
129  }
130  if (State == IncludesExtracting) {
131  elog("System include extraction: end marker missing: {0}", Output);
132  return llvm::None;
133  }
134  return std::move(Info);
135 }
136 
137 llvm::Optional<DriverInfo>
138 extractSystemIncludesAndTarget(llvm::SmallString<128> Driver,
139  llvm::StringRef Lang,
140  llvm::ArrayRef<std::string> CommandLine,
141  const llvm::Regex &QueryDriverRegex) {
142  trace::Span Tracer("Extract system includes and target");
143 
144  if (!llvm::sys::path::is_absolute(Driver)) {
145  assert(llvm::none_of(
146  Driver, [](char C) { return llvm::sys::path::is_separator(C); }));
147  auto DriverProgram = llvm::sys::findProgramByName(Driver);
148  if (DriverProgram) {
149  vlog("System include extraction: driver {0} expanded to {1}", Driver,
150  *DriverProgram);
151  Driver = *DriverProgram;
152  } else {
153  elog("System include extraction: driver {0} not found in PATH", Driver);
154  return llvm::None;
155  }
156  }
157 
158  SPAN_ATTACH(Tracer, "driver", Driver);
159  SPAN_ATTACH(Tracer, "lang", Lang);
160 
161  if (!QueryDriverRegex.match(Driver)) {
162  vlog("System include extraction: not allowed driver {0}", Driver);
163  return llvm::None;
164  }
165 
166  llvm::SmallString<128> StdErrPath;
167  if (auto EC = llvm::sys::fs::createTemporaryFile("system-includes", "clangd",
168  StdErrPath)) {
169  elog("System include extraction: failed to create temporary file with "
170  "error {0}",
171  EC.message());
172  return llvm::None;
173  }
174  auto CleanUp = llvm::make_scope_exit(
175  [&StdErrPath]() { llvm::sys::fs::remove(StdErrPath); });
176 
177  llvm::Optional<llvm::StringRef> Redirects[] = {{""}, {""}, StdErrPath.str()};
178 
179  llvm::SmallVector<llvm::StringRef> Args = {Driver, "-E", "-x",
180  Lang, "-", "-v"};
181 
182  // These flags will be preserved
183  const llvm::StringRef FlagsToPreserve[] = {
184  "-nostdinc", "--no-standard-includes", "-nostdinc++", "-nobuiltininc"};
185  // Preserves these flags and their values, either as separate args or with an
186  // equalsbetween them
187  const llvm::StringRef ArgsToPreserve[] = {"--sysroot", "-isysroot"};
188 
189  for (size_t I = 0, E = CommandLine.size(); I < E; ++I) {
190  llvm::StringRef Arg = CommandLine[I];
191  if (llvm::any_of(FlagsToPreserve,
192  [&Arg](llvm::StringRef S) { return S == Arg; })) {
193  Args.push_back(Arg);
194  } else {
195  const auto *Found =
196  llvm::find_if(ArgsToPreserve, [&Arg](llvm::StringRef S) {
197  return Arg.startswith(S);
198  });
199  if (Found == std::end(ArgsToPreserve))
200  continue;
201  Arg = Arg.drop_front(Found->size());
202  if (Arg.empty() && I + 1 < E) {
203  Args.push_back(CommandLine[I]);
204  Args.push_back(CommandLine[++I]);
205  } else if (Arg.startswith("=")) {
206  Args.push_back(CommandLine[I]);
207  }
208  }
209  }
210 
211  std::string ErrMsg;
212  if (int RC = llvm::sys::ExecuteAndWait(Driver, Args, /*Env=*/llvm::None,
213  Redirects, /*SecondsToWait=*/0,
214  /*MemoryLimit=*/0, &ErrMsg)) {
215  elog("System include extraction: driver execution failed with return code: "
216  "{0} - '{1}'. Args: [{2}]",
217  llvm::to_string(RC), ErrMsg, printArgv(Args));
218  return llvm::None;
219  }
220 
221  auto BufOrError = llvm::MemoryBuffer::getFile(StdErrPath);
222  if (!BufOrError) {
223  elog("System include extraction: failed to read {0} with error {1}",
224  StdErrPath, BufOrError.getError().message());
225  return llvm::None;
226  }
227 
228  llvm::Optional<DriverInfo> Info =
229  parseDriverOutput(BufOrError->get()->getBuffer());
230  if (!Info)
231  return llvm::None;
232  log("System includes extractor: successfully executed {0}\n\tgot includes: "
233  "\"{1}\"\n\tgot target: \"{2}\"",
234  Driver, llvm::join(Info->SystemIncludes, ", "), Info->Target);
235  return Info;
236 }
237 
238 tooling::CompileCommand &
239 addSystemIncludes(tooling::CompileCommand &Cmd,
240  llvm::ArrayRef<std::string> SystemIncludes) {
241  for (llvm::StringRef Include : SystemIncludes) {
242  // FIXME(kadircet): This doesn't work when we have "--driver-mode=cl"
243  Cmd.CommandLine.push_back("-isystem");
244  Cmd.CommandLine.push_back(Include.str());
245  }
246  return Cmd;
247 }
248 
249 tooling::CompileCommand &setTarget(tooling::CompileCommand &Cmd,
250  const std::string &Target) {
251  if (!Target.empty()) {
252  // We do not want to override existing target with extracted one.
253  for (llvm::StringRef Arg : Cmd.CommandLine) {
254  if (Arg == "-target" || Arg.startswith("--target="))
255  return Cmd;
256  }
257  Cmd.CommandLine.push_back("--target=" + Target);
258  }
259  return Cmd;
260 }
261 
262 /// Converts a glob containing only ** or * into a regex.
263 std::string convertGlobToRegex(llvm::StringRef Glob) {
264  std::string RegText;
265  llvm::raw_string_ostream RegStream(RegText);
266  RegStream << '^';
267  for (size_t I = 0, E = Glob.size(); I < E; ++I) {
268  if (Glob[I] == '*') {
269  if (I + 1 < E && Glob[I + 1] == '*') {
270  // Double star, accept any sequence.
271  RegStream << ".*";
272  // Also skip the second star.
273  ++I;
274  } else {
275  // Single star, accept any sequence without a slash.
276  RegStream << "[^/]*";
277  }
278  } else if (llvm::sys::path::is_separator(Glob[I]) &&
279  llvm::sys::path::is_separator('/') &&
280  llvm::sys::path::is_separator('\\')) {
281  RegStream << R"([/\\])"; // Accept either slash on windows.
282  } else {
283  RegStream << llvm::Regex::escape(Glob.substr(I, 1));
284  }
285  }
286  RegStream << '$';
287  RegStream.flush();
288  return RegText;
289 }
290 
291 /// Converts a glob containing only ** or * into a regex.
292 llvm::Regex convertGlobsToRegex(llvm::ArrayRef<std::string> Globs) {
293  assert(!Globs.empty() && "Globs cannot be empty!");
294  std::vector<std::string> RegTexts;
295  RegTexts.reserve(Globs.size());
296  for (llvm::StringRef Glob : Globs)
297  RegTexts.push_back(convertGlobToRegex(Glob));
298 
299  // Tempting to pass IgnoreCase, but we don't know the FS sensitivity.
300  llvm::Regex Reg(llvm::join(RegTexts, "|"));
301  assert(Reg.isValid(RegTexts.front()) &&
302  "Created an invalid regex from globs");
303  return Reg;
304 }
305 
306 /// Extracts system includes from a trusted driver by parsing the output of
307 /// include search path and appends them to the commands coming from underlying
308 /// compilation database.
309 class QueryDriverDatabase : public DelegatingCDB {
310 public:
311  QueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
312  std::unique_ptr<GlobalCompilationDatabase> Base)
313  : DelegatingCDB(std::move(Base)),
314  QueryDriverRegex(convertGlobsToRegex(QueryDriverGlobs)) {}
315 
316  llvm::Optional<tooling::CompileCommand>
317  getCompileCommand(PathRef File) const override {
318  auto Cmd = DelegatingCDB::getCompileCommand(File);
319  if (!Cmd || Cmd->CommandLine.empty())
320  return Cmd;
321 
322  llvm::StringRef Lang;
323  for (size_t I = 0, E = Cmd->CommandLine.size(); I < E; ++I) {
324  llvm::StringRef Arg = Cmd->CommandLine[I];
325  if (Arg == "-x" && I + 1 < E)
326  Lang = Cmd->CommandLine[I + 1];
327  else if (Arg.startswith("-x"))
328  Lang = Arg.drop_front(2).trim();
329  }
330  if (Lang.empty()) {
331  llvm::StringRef Ext = llvm::sys::path::extension(File).trim('.');
332  auto Type = driver::types::lookupTypeForExtension(Ext);
333  if (Type == driver::types::TY_INVALID) {
334  elog("System include extraction: invalid file type for {0}", Ext);
335  return {};
336  }
337  Lang = driver::types::getTypeName(Type);
338  }
339 
340  llvm::SmallString<128> Driver(Cmd->CommandLine.front());
341  if (llvm::any_of(Driver,
342  [](char C) { return llvm::sys::path::is_separator(C); }))
343  // Driver is a not a single executable name but instead a path (either
344  // relative or absolute).
345  llvm::sys::fs::make_absolute(Cmd->Directory, Driver);
346 
347  if (auto Info =
348  QueriedDrivers.get(/*Key=*/(Driver + ":" + Lang).str(), [&] {
349  return extractSystemIncludesAndTarget(
350  Driver, Lang, Cmd->CommandLine, QueryDriverRegex);
351  })) {
352  setTarget(addSystemIncludes(*Cmd, Info->SystemIncludes), Info->Target);
353  }
354  return Cmd;
355  }
356 
357 private:
358  // Caches includes extracted from a driver. Key is driver:lang.
359  Memoize<llvm::StringMap<llvm::Optional<DriverInfo>>> QueriedDrivers;
360  llvm::Regex QueryDriverRegex;
361 };
362 } // namespace
363 
364 std::unique_ptr<GlobalCompilationDatabase>
365 getQueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
366  std::unique_ptr<GlobalCompilationDatabase> Base) {
367  assert(Base && "Null base to SystemIncludeExtractor");
368  if (QueryDriverGlobs.empty())
369  return Base;
370  return std::make_unique<QueryDriverDatabase>(QueryDriverGlobs,
371  std::move(Base));
372 }
373 
374 } // namespace clangd
375 } // namespace clang
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