1 //===--- Tooling.cpp - Running clang standalone tools ---------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements functions to run clang tools standalone instead
11 //  of running them as a plugin.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Tooling/Tooling.h"
16 #include "clang/AST/ASTConsumer.h"
17 #include "clang/Driver/Compilation.h"
18 #include "clang/Driver/Driver.h"
19 #include "clang/Driver/Tool.h"
20 #include "clang/Frontend/ASTUnit.h"
21 #include "clang/Frontend/CompilerInstance.h"
22 #include "clang/Frontend/FrontendDiagnostic.h"
23 #include "clang/Frontend/TextDiagnosticPrinter.h"
24 #include "clang/Tooling/ArgumentsAdjusters.h"
25 #include "clang/Tooling/CompilationDatabase.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/Config/llvm-config.h"
28 #include "llvm/Option/Option.h"
29 #include "llvm/Support/Debug.h"
30 #include "llvm/Support/FileSystem.h"
31 #include "llvm/Support/Host.h"
32 #include "llvm/Support/raw_ostream.h"
33 
34 // For chdir, see the comment in ClangTool::run for more information.
35 #ifdef LLVM_ON_WIN32
36 #  include <direct.h>
37 #else
38 #  include <unistd.h>
39 #endif
40 
41 #define DEBUG_TYPE "clang-tooling"
42 
43 namespace clang {
44 namespace tooling {
45 
46 ToolAction::~ToolAction() {}
47 
48 FrontendActionFactory::~FrontendActionFactory() {}
49 
50 // FIXME: This file contains structural duplication with other parts of the
51 // code that sets up a compiler to run tools on it, and we should refactor
52 // it to be based on the same framework.
53 
54 /// \brief Builds a clang driver initialized for running clang tools.
55 static clang::driver::Driver *newDriver(clang::DiagnosticsEngine *Diagnostics,
56                                         const char *BinaryName) {
57   clang::driver::Driver *CompilerDriver = new clang::driver::Driver(
58       BinaryName, llvm::sys::getDefaultTargetTriple(), *Diagnostics);
59   CompilerDriver->setTitle("clang_based_tool");
60   return CompilerDriver;
61 }
62 
63 /// \brief Retrieves the clang CC1 specific flags out of the compilation's jobs.
64 ///
65 /// Returns NULL on error.
66 static const llvm::opt::ArgStringList *getCC1Arguments(
67     clang::DiagnosticsEngine *Diagnostics,
68     clang::driver::Compilation *Compilation) {
69   // We expect to get back exactly one Command job, if we didn't something
70   // failed. Extract that job from the Compilation.
71   const clang::driver::JobList &Jobs = Compilation->getJobs();
72   if (Jobs.size() != 1 || !isa<clang::driver::Command>(**Jobs.begin())) {
73     SmallString<256> error_msg;
74     llvm::raw_svector_ostream error_stream(error_msg);
75     Jobs.Print(error_stream, "; ", true);
76     Diagnostics->Report(clang::diag::err_fe_expected_compiler_job)
77         << error_stream.str();
78     return nullptr;
79   }
80 
81   // The one job we find should be to invoke clang again.
82   const clang::driver::Command &Cmd =
83       cast<clang::driver::Command>(**Jobs.begin());
84   if (StringRef(Cmd.getCreator().getName()) != "clang") {
85     Diagnostics->Report(clang::diag::err_fe_expected_clang_command);
86     return nullptr;
87   }
88 
89   return &Cmd.getArguments();
90 }
91 
92 /// \brief Returns a clang build invocation initialized from the CC1 flags.
93 static clang::CompilerInvocation *newInvocation(
94     clang::DiagnosticsEngine *Diagnostics,
95     const llvm::opt::ArgStringList &CC1Args) {
96   assert(!CC1Args.empty() && "Must at least contain the program name!");
97   clang::CompilerInvocation *Invocation = new clang::CompilerInvocation;
98   clang::CompilerInvocation::CreateFromArgs(
99       *Invocation, CC1Args.data() + 1, CC1Args.data() + CC1Args.size(),
100       *Diagnostics);
101   Invocation->getFrontendOpts().DisableFree = false;
102   Invocation->getCodeGenOpts().DisableFree = false;
103   Invocation->getDependencyOutputOpts() = DependencyOutputOptions();
104   return Invocation;
105 }
106 
107 bool runToolOnCode(clang::FrontendAction *ToolAction, const Twine &Code,
108                    const Twine &FileName) {
109   return runToolOnCodeWithArgs(
110       ToolAction, Code, std::vector<std::string>(), FileName);
111 }
112 
113 static std::vector<std::string>
114 getSyntaxOnlyToolArgs(const std::vector<std::string> &ExtraArgs,
115                       StringRef FileName) {
116   std::vector<std::string> Args;
117   Args.push_back("clang-tool");
118   Args.push_back("-fsyntax-only");
119   Args.insert(Args.end(), ExtraArgs.begin(), ExtraArgs.end());
120   Args.push_back(FileName.str());
121   return Args;
122 }
123 
124 bool runToolOnCodeWithArgs(clang::FrontendAction *ToolAction, const Twine &Code,
125                            const std::vector<std::string> &Args,
126                            const Twine &FileName) {
127   SmallString<16> FileNameStorage;
128   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
129   llvm::IntrusiveRefCntPtr<FileManager> Files(
130       new FileManager(FileSystemOptions()));
131   ToolInvocation Invocation(getSyntaxOnlyToolArgs(Args, FileNameRef), ToolAction,
132                             Files.get());
133 
134   SmallString<1024> CodeStorage;
135   Invocation.mapVirtualFile(FileNameRef,
136                             Code.toNullTerminatedStringRef(CodeStorage));
137   return Invocation.run();
138 }
139 
140 std::string getAbsolutePath(StringRef File) {
141   StringRef RelativePath(File);
142   // FIXME: Should '.\\' be accepted on Win32?
143   if (RelativePath.startswith("./")) {
144     RelativePath = RelativePath.substr(strlen("./"));
145   }
146 
147   SmallString<1024> AbsolutePath = RelativePath;
148   std::error_code EC = llvm::sys::fs::make_absolute(AbsolutePath);
149   assert(!EC);
150   (void)EC;
151   llvm::sys::path::native(AbsolutePath);
152   return AbsolutePath.str();
153 }
154 
155 namespace {
156 
157 class SingleFrontendActionFactory : public FrontendActionFactory {
158   FrontendAction *Action;
159 
160 public:
161   SingleFrontendActionFactory(FrontendAction *Action) : Action(Action) {}
162 
163   FrontendAction *create() override { return Action; }
164 };
165 
166 }
167 
168 ToolInvocation::ToolInvocation(std::vector<std::string> CommandLine,
169                                ToolAction *Action, FileManager *Files)
170     : CommandLine(std::move(CommandLine)),
171       Action(Action),
172       OwnsAction(false),
173       Files(Files),
174       DiagConsumer(nullptr) {}
175 
176 ToolInvocation::ToolInvocation(std::vector<std::string> CommandLine,
177                                FrontendAction *FAction, FileManager *Files)
178     : CommandLine(std::move(CommandLine)),
179       Action(new SingleFrontendActionFactory(FAction)),
180       OwnsAction(true),
181       Files(Files),
182       DiagConsumer(nullptr) {}
183 
184 ToolInvocation::~ToolInvocation() {
185   if (OwnsAction)
186     delete Action;
187 }
188 
189 void ToolInvocation::setDiagnosticConsumer(DiagnosticConsumer *D) {
190   DiagConsumer = D;
191 }
192 
193 void ToolInvocation::mapVirtualFile(StringRef FilePath, StringRef Content) {
194   SmallString<1024> PathStorage;
195   llvm::sys::path::native(FilePath, PathStorage);
196   MappedFileContents[PathStorage] = Content;
197 }
198 
199 bool ToolInvocation::run() {
200   std::vector<const char*> Argv;
201   for (const std::string &Str : CommandLine)
202     Argv.push_back(Str.c_str());
203   const char *const BinaryName = Argv[0];
204   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
205   TextDiagnosticPrinter DiagnosticPrinter(
206       llvm::errs(), &*DiagOpts);
207   DiagnosticsEngine Diagnostics(
208       IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
209       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
210 
211   const std::unique_ptr<clang::driver::Driver> Driver(
212       newDriver(&Diagnostics, BinaryName));
213   // Since the input might only be virtual, don't check whether it exists.
214   Driver->setCheckInputsExist(false);
215   const std::unique_ptr<clang::driver::Compilation> Compilation(
216       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
217   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
218       &Diagnostics, Compilation.get());
219   if (!CC1Args) {
220     return false;
221   }
222   std::unique_ptr<clang::CompilerInvocation> Invocation(
223       newInvocation(&Diagnostics, *CC1Args));
224   for (const auto &It : MappedFileContents) {
225     // Inject the code as the given file name into the preprocessor options.
226     std::unique_ptr<llvm::MemoryBuffer> Input =
227         llvm::MemoryBuffer::getMemBuffer(It.getValue());
228     Invocation->getPreprocessorOpts().addRemappedFile(It.getKey(),
229                                                       Input.release());
230   }
231   return runInvocation(BinaryName, Compilation.get(), Invocation.release());
232 }
233 
234 bool ToolInvocation::runInvocation(
235     const char *BinaryName,
236     clang::driver::Compilation *Compilation,
237     clang::CompilerInvocation *Invocation) {
238   // Show the invocation, with -v.
239   if (Invocation->getHeaderSearchOpts().Verbose) {
240     llvm::errs() << "clang Invocation:\n";
241     Compilation->getJobs().Print(llvm::errs(), "\n", true);
242     llvm::errs() << "\n";
243   }
244 
245   return Action->runInvocation(Invocation, Files, DiagConsumer);
246 }
247 
248 bool FrontendActionFactory::runInvocation(CompilerInvocation *Invocation,
249                                           FileManager *Files,
250                                           DiagnosticConsumer *DiagConsumer) {
251   // Create a compiler instance to handle the actual work.
252   clang::CompilerInstance Compiler;
253   Compiler.setInvocation(Invocation);
254   Compiler.setFileManager(Files);
255 
256   // The FrontendAction can have lifetime requirements for Compiler or its
257   // members, and we need to ensure it's deleted earlier than Compiler. So we
258   // pass it to an std::unique_ptr declared after the Compiler variable.
259   std::unique_ptr<FrontendAction> ScopedToolAction(create());
260 
261   // Create the compiler's actual diagnostics engine.
262   Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
263   if (!Compiler.hasDiagnostics())
264     return false;
265 
266   Compiler.createSourceManager(*Files);
267 
268   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
269 
270   Files->clearStatCaches();
271   return Success;
272 }
273 
274 ClangTool::ClangTool(const CompilationDatabase &Compilations,
275                      ArrayRef<std::string> SourcePaths)
276     : Compilations(Compilations), SourcePaths(SourcePaths),
277       Files(new FileManager(FileSystemOptions())), DiagConsumer(nullptr) {
278   ArgsAdjusters.push_back(new ClangStripOutputAdjuster());
279   ArgsAdjusters.push_back(new ClangSyntaxOnlyAdjuster());
280 }
281 
282 void ClangTool::setDiagnosticConsumer(DiagnosticConsumer *D) {
283   DiagConsumer = D;
284 }
285 
286 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
287   MappedFileContents.push_back(std::make_pair(FilePath, Content));
288 }
289 
290 void ClangTool::setArgumentsAdjuster(ArgumentsAdjuster *Adjuster) {
291   clearArgumentsAdjusters();
292   appendArgumentsAdjuster(Adjuster);
293 }
294 
295 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster *Adjuster) {
296   ArgsAdjusters.push_back(Adjuster);
297 }
298 
299 void ClangTool::clearArgumentsAdjusters() {
300   for (unsigned I = 0, E = ArgsAdjusters.size(); I != E; ++I)
301     delete ArgsAdjusters[I];
302   ArgsAdjusters.clear();
303 }
304 
305 int ClangTool::run(ToolAction *Action) {
306   // Exists solely for the purpose of lookup of the resource path.
307   // This just needs to be some symbol in the binary.
308   static int StaticSymbol;
309   // The driver detects the builtin header path based on the path of the
310   // executable.
311   // FIXME: On linux, GetMainExecutable is independent of the value of the
312   // first argument, thus allowing ClangTool and runToolOnCode to just
313   // pass in made-up names here. Make sure this works on other platforms.
314   std::string MainExecutable =
315       llvm::sys::fs::getMainExecutable("clang_tool", &StaticSymbol);
316 
317   bool ProcessingFailed = false;
318   for (const auto &SourcePath : SourcePaths) {
319     std::string File(getAbsolutePath(SourcePath));
320 
321     std::vector<CompileCommand> CompileCommandsForFile =
322         Compilations.getCompileCommands(File);
323     if (CompileCommandsForFile.empty()) {
324       // FIXME: There are two use cases here: doing a fuzzy
325       // "find . -name '*.cc' |xargs tool" match, where as a user I don't care
326       // about the .cc files that were not found, and the use case where I
327       // specify all files I want to run over explicitly, where this should
328       // be an error. We'll want to add an option for this.
329       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
330       continue;
331     }
332     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
333       // FIXME: chdir is thread hostile; on the other hand, creating the same
334       // behavior as chdir is complex: chdir resolves the path once, thus
335       // guaranteeing that all subsequent relative path operations work
336       // on the same path the original chdir resulted in. This makes a
337       // difference for example on network filesystems, where symlinks might be
338       // switched during runtime of the tool. Fixing this depends on having a
339       // file system abstraction that allows openat() style interactions.
340       if (chdir(CompileCommand.Directory.c_str()))
341         llvm::report_fatal_error("Cannot chdir into \"" +
342                                  Twine(CompileCommand.Directory) + "\n!");
343       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
344       for (ArgumentsAdjuster *Adjuster : ArgsAdjusters)
345         CommandLine = Adjuster->Adjust(CommandLine);
346       assert(!CommandLine.empty());
347       CommandLine[0] = MainExecutable;
348       // FIXME: We need a callback mechanism for the tool writer to output a
349       // customized message for each file.
350       DEBUG({ llvm::dbgs() << "Processing: " << File << ".\n"; });
351       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get());
352       Invocation.setDiagnosticConsumer(DiagConsumer);
353       for (const auto &MappedFile : MappedFileContents) {
354         Invocation.mapVirtualFile(MappedFile.first, MappedFile.second);
355       }
356       if (!Invocation.run()) {
357         // FIXME: Diagnostics should be used instead.
358         llvm::errs() << "Error while processing " << File << ".\n";
359         ProcessingFailed = true;
360       }
361     }
362   }
363   return ProcessingFailed ? 1 : 0;
364 }
365 
366 namespace {
367 
368 class ASTBuilderAction : public ToolAction {
369   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
370 
371 public:
372   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
373 
374   bool runInvocation(CompilerInvocation *Invocation, FileManager *Files,
375                      DiagnosticConsumer *DiagConsumer) override {
376     // FIXME: This should use the provided FileManager.
377     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
378         Invocation, CompilerInstance::createDiagnostics(
379                         &Invocation->getDiagnosticOpts(), DiagConsumer,
380                         /*ShouldOwnClient=*/false));
381     if (!AST)
382       return false;
383 
384     ASTs.push_back(std::move(AST));
385     return true;
386   }
387 };
388 
389 }
390 
391 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
392   ASTBuilderAction Action(ASTs);
393   return run(&Action);
394 }
395 
396 std::unique_ptr<ASTUnit> buildASTFromCode(const Twine &Code,
397                                           const Twine &FileName) {
398   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName);
399 }
400 
401 std::unique_ptr<ASTUnit>
402 buildASTFromCodeWithArgs(const Twine &Code,
403                          const std::vector<std::string> &Args,
404                          const Twine &FileName) {
405   SmallString<16> FileNameStorage;
406   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
407 
408   std::vector<std::unique_ptr<ASTUnit>> ASTs;
409   ASTBuilderAction Action(ASTs);
410   ToolInvocation Invocation(getSyntaxOnlyToolArgs(Args, FileNameRef), &Action,
411                             nullptr);
412 
413   SmallString<1024> CodeStorage;
414   Invocation.mapVirtualFile(FileNameRef,
415                             Code.toNullTerminatedStringRef(CodeStorage));
416   if (!Invocation.run())
417     return nullptr;
418 
419   assert(ASTs.size() == 1);
420   return std::move(ASTs[0]);
421 }
422 
423 } // end namespace tooling
424 } // end namespace clang
425