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::mapVirtualFile(StringRef FilePath, StringRef Content) {
190   SmallString<1024> PathStorage;
191   llvm::sys::path::native(FilePath, PathStorage);
192   MappedFileContents[PathStorage] = Content;
193 }
194 
195 bool ToolInvocation::run() {
196   std::vector<const char*> Argv;
197   for (const std::string &Str : CommandLine)
198     Argv.push_back(Str.c_str());
199   const char *const BinaryName = Argv[0];
200   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
201   TextDiagnosticPrinter DiagnosticPrinter(
202       llvm::errs(), &*DiagOpts);
203   DiagnosticsEngine Diagnostics(
204       IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
205       DiagConsumer ? DiagConsumer : &DiagnosticPrinter, false);
206 
207   const std::unique_ptr<clang::driver::Driver> Driver(
208       newDriver(&Diagnostics, BinaryName));
209   // Since the input might only be virtual, don't check whether it exists.
210   Driver->setCheckInputsExist(false);
211   const std::unique_ptr<clang::driver::Compilation> Compilation(
212       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
213   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
214       &Diagnostics, Compilation.get());
215   if (!CC1Args) {
216     return false;
217   }
218   std::unique_ptr<clang::CompilerInvocation> Invocation(
219       newInvocation(&Diagnostics, *CC1Args));
220   for (const auto &It : MappedFileContents) {
221     // Inject the code as the given file name into the preprocessor options.
222     std::unique_ptr<llvm::MemoryBuffer> Input =
223         llvm::MemoryBuffer::getMemBuffer(It.getValue());
224     Invocation->getPreprocessorOpts().addRemappedFile(It.getKey(),
225                                                       Input.release());
226   }
227   return runInvocation(BinaryName, Compilation.get(), Invocation.release());
228 }
229 
230 bool ToolInvocation::runInvocation(
231     const char *BinaryName,
232     clang::driver::Compilation *Compilation,
233     clang::CompilerInvocation *Invocation) {
234   // Show the invocation, with -v.
235   if (Invocation->getHeaderSearchOpts().Verbose) {
236     llvm::errs() << "clang Invocation:\n";
237     Compilation->getJobs().Print(llvm::errs(), "\n", true);
238     llvm::errs() << "\n";
239   }
240 
241   return Action->runInvocation(Invocation, Files, DiagConsumer);
242 }
243 
244 bool FrontendActionFactory::runInvocation(CompilerInvocation *Invocation,
245                                           FileManager *Files,
246                                           DiagnosticConsumer *DiagConsumer) {
247   // Create a compiler instance to handle the actual work.
248   clang::CompilerInstance Compiler;
249   Compiler.setInvocation(Invocation);
250   Compiler.setFileManager(Files);
251 
252   // The FrontendAction can have lifetime requirements for Compiler or its
253   // members, and we need to ensure it's deleted earlier than Compiler. So we
254   // pass it to an std::unique_ptr declared after the Compiler variable.
255   std::unique_ptr<FrontendAction> ScopedToolAction(create());
256 
257   // Create the compiler's actual diagnostics engine.
258   Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
259   if (!Compiler.hasDiagnostics())
260     return false;
261 
262   Compiler.createSourceManager(*Files);
263 
264   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
265 
266   Files->clearStatCaches();
267   return Success;
268 }
269 
270 ClangTool::ClangTool(const CompilationDatabase &Compilations,
271                      ArrayRef<std::string> SourcePaths)
272     : Compilations(Compilations), SourcePaths(SourcePaths),
273       Files(new FileManager(FileSystemOptions())), DiagConsumer(nullptr) {
274   appendArgumentsAdjuster(new ClangStripOutputAdjuster());
275   appendArgumentsAdjuster(new ClangSyntaxOnlyAdjuster());
276 }
277 
278 ClangTool::~ClangTool() {}
279 
280 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
281   MappedFileContents.push_back(std::make_pair(FilePath, Content));
282 }
283 
284 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster *Adjuster) {
285   ArgsAdjusters.push_back(std::unique_ptr<ArgumentsAdjuster>(Adjuster));
286 }
287 
288 void ClangTool::clearArgumentsAdjusters() {
289   ArgsAdjusters.clear();
290 }
291 
292 int ClangTool::run(ToolAction *Action) {
293   // Exists solely for the purpose of lookup of the resource path.
294   // This just needs to be some symbol in the binary.
295   static int StaticSymbol;
296   // The driver detects the builtin header path based on the path of the
297   // executable.
298   // FIXME: On linux, GetMainExecutable is independent of the value of the
299   // first argument, thus allowing ClangTool and runToolOnCode to just
300   // pass in made-up names here. Make sure this works on other platforms.
301   std::string MainExecutable =
302       llvm::sys::fs::getMainExecutable("clang_tool", &StaticSymbol);
303 
304   bool ProcessingFailed = false;
305   for (const auto &SourcePath : SourcePaths) {
306     std::string File(getAbsolutePath(SourcePath));
307 
308     std::vector<CompileCommand> CompileCommandsForFile =
309         Compilations.getCompileCommands(File);
310     if (CompileCommandsForFile.empty()) {
311       // FIXME: There are two use cases here: doing a fuzzy
312       // "find . -name '*.cc' |xargs tool" match, where as a user I don't care
313       // about the .cc files that were not found, and the use case where I
314       // specify all files I want to run over explicitly, where this should
315       // be an error. We'll want to add an option for this.
316       llvm::errs() << "Skipping " << File << ". Compile command not found.\n";
317       continue;
318     }
319     for (CompileCommand &CompileCommand : CompileCommandsForFile) {
320       // FIXME: chdir is thread hostile; on the other hand, creating the same
321       // behavior as chdir is complex: chdir resolves the path once, thus
322       // guaranteeing that all subsequent relative path operations work
323       // on the same path the original chdir resulted in. This makes a
324       // difference for example on network filesystems, where symlinks might be
325       // switched during runtime of the tool. Fixing this depends on having a
326       // file system abstraction that allows openat() style interactions.
327       if (chdir(CompileCommand.Directory.c_str()))
328         llvm::report_fatal_error("Cannot chdir into \"" +
329                                  Twine(CompileCommand.Directory) + "\n!");
330       std::vector<std::string> CommandLine = CompileCommand.CommandLine;
331       for (const auto &Adjuster : ArgsAdjusters)
332         CommandLine = Adjuster->Adjust(CommandLine);
333       assert(!CommandLine.empty());
334       CommandLine[0] = MainExecutable;
335       // FIXME: We need a callback mechanism for the tool writer to output a
336       // customized message for each file.
337       DEBUG({ llvm::dbgs() << "Processing: " << File << ".\n"; });
338       ToolInvocation Invocation(std::move(CommandLine), Action, Files.get());
339       Invocation.setDiagnosticConsumer(DiagConsumer);
340       for (const auto &MappedFile : MappedFileContents) {
341         Invocation.mapVirtualFile(MappedFile.first, MappedFile.second);
342       }
343       if (!Invocation.run()) {
344         // FIXME: Diagnostics should be used instead.
345         llvm::errs() << "Error while processing " << File << ".\n";
346         ProcessingFailed = true;
347       }
348     }
349   }
350   return ProcessingFailed ? 1 : 0;
351 }
352 
353 namespace {
354 
355 class ASTBuilderAction : public ToolAction {
356   std::vector<std::unique_ptr<ASTUnit>> &ASTs;
357 
358 public:
359   ASTBuilderAction(std::vector<std::unique_ptr<ASTUnit>> &ASTs) : ASTs(ASTs) {}
360 
361   bool runInvocation(CompilerInvocation *Invocation, FileManager *Files,
362                      DiagnosticConsumer *DiagConsumer) override {
363     // FIXME: This should use the provided FileManager.
364     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
365         Invocation, CompilerInstance::createDiagnostics(
366                         &Invocation->getDiagnosticOpts(), DiagConsumer,
367                         /*ShouldOwnClient=*/false));
368     if (!AST)
369       return false;
370 
371     ASTs.push_back(std::move(AST));
372     return true;
373   }
374 };
375 
376 }
377 
378 int ClangTool::buildASTs(std::vector<std::unique_ptr<ASTUnit>> &ASTs) {
379   ASTBuilderAction Action(ASTs);
380   return run(&Action);
381 }
382 
383 std::unique_ptr<ASTUnit> buildASTFromCode(const Twine &Code,
384                                           const Twine &FileName) {
385   return buildASTFromCodeWithArgs(Code, std::vector<std::string>(), FileName);
386 }
387 
388 std::unique_ptr<ASTUnit>
389 buildASTFromCodeWithArgs(const Twine &Code,
390                          const std::vector<std::string> &Args,
391                          const Twine &FileName) {
392   SmallString<16> FileNameStorage;
393   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
394 
395   std::vector<std::unique_ptr<ASTUnit>> ASTs;
396   ASTBuilderAction Action(ASTs);
397   ToolInvocation Invocation(getSyntaxOnlyToolArgs(Args, FileNameRef), &Action,
398                             nullptr);
399 
400   SmallString<1024> CodeStorage;
401   Invocation.mapVirtualFile(FileNameRef,
402                             Code.toNullTerminatedStringRef(CodeStorage));
403   if (!Invocation.run())
404     return nullptr;
405 
406   assert(ASTs.size() == 1);
407   return std::move(ASTs[0]);
408 }
409 
410 } // end namespace tooling
411 } // end namespace clang
412