Tooling.cpp revision cf3ce5d89628b3955c638fb102c8dc4c24e1986d 
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 "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/SmallString.h"
18#include "llvm/Support/CommandLine.h"
19#include "llvm/Support/Host.h"
20#include "llvm/Support/MemoryBuffer.h"
21#include "llvm/Support/ManagedStatic.h"
22#include "llvm/Support/Path.h"
23#include "llvm/Support/raw_ostream.h"
24#include "clang/Basic/DiagnosticIDs.h"
25#include "clang/Driver/Compilation.h"
26#include "clang/Driver/Driver.h"
27#include "clang/Driver/Tool.h"
28#include "clang/Frontend/CompilerInstance.h"
29#include "clang/Frontend/FrontendAction.h"
30#include "clang/Frontend/FrontendDiagnostic.h"
31#include "clang/Frontend/TextDiagnosticPrinter.h"
32
33#include <string>
34#include <map>
35#include <vector>
36
37namespace clang {
38namespace tooling {
39
40// FIXME: This file contains structural duplication with other parts of the
41// code that sets up a compiler to run tools on it, and we should refactor
42// it to be based on the same framework.
43
44static clang::Diagnostic* NewTextDiagnostics() {
45  llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> DiagIDs(
46      new clang::DiagnosticIDs());
47  clang::TextDiagnosticPrinter *DiagClient = new clang::TextDiagnosticPrinter(
48      llvm::errs(), clang::DiagnosticOptions());
49  return new clang::Diagnostic(DiagIDs, DiagClient);
50}
51
52// Exists solely for the purpose of lookup of the main executable.
53static int StaticSymbol;
54
55/// \brief Builds a clang driver initialized for running clang tools.
56static clang::driver::Driver* NewDriver(clang::Diagnostic* Diagnostics,
57                                        const char* BinaryName) {
58  // This just needs to be some symbol in the binary.
59  void* const SymbolAddr = &StaticSymbol;
60  const llvm::sys::Path ExePath =
61      llvm::sys::Path::GetMainExecutable(BinaryName, SymbolAddr);
62
63  const std::string DefaultOutputName = "a.out";
64  clang::driver::Driver* CompilerDriver = new clang::driver::Driver(
65      ExePath.str(), llvm::sys::getHostTriple(),
66      DefaultOutputName, false, false, *Diagnostics);
67  CompilerDriver->setTitle("clang_based_tool");
68  return CompilerDriver;
69}
70
71/// \brief Retrieves the clang CC1 specific flags out of the compilation's jobs.
72/// Returns NULL on error.
73static const clang::driver::ArgStringList* GetCC1Arguments(
74    clang::Diagnostic* Diagnostics, clang::driver::Compilation* Compilation) {
75  // We expect to get back exactly one Command job, if we didn't something
76  // failed. Extract that job from the Compilation.
77  const clang::driver::JobList &Jobs = Compilation->getJobs();
78  if (Jobs.size() != 1 || !isa<clang::driver::Command>(*Jobs.begin())) {
79    llvm::SmallString<256> error_msg;
80    llvm::raw_svector_ostream error_stream(error_msg);
81    Compilation->PrintJob(error_stream, Compilation->getJobs(), "; ", true);
82    Diagnostics->Report(clang::diag::err_fe_expected_compiler_job)
83        << error_stream.str();
84    return NULL;
85  }
86
87  // The one job we find should be to invoke clang again.
88  const clang::driver::Command *Cmd =
89      cast<clang::driver::Command>(*Jobs.begin());
90  if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
91    Diagnostics->Report(clang::diag::err_fe_expected_clang_command);
92    return NULL;
93  }
94
95  return &Cmd->getArguments();
96}
97
98/// \brief Returns a clang build invocation initialized from the CC1 flags.
99static clang::CompilerInvocation* NewInvocation(
100    clang::Diagnostic* Diagnostics,
101    const clang::driver::ArgStringList& CC1Args) {
102  clang::CompilerInvocation* Invocation = new clang::CompilerInvocation;
103  clang::CompilerInvocation::CreateFromArgs(
104      *Invocation, CC1Args.data(), CC1Args.data() + CC1Args.size(),
105      *Diagnostics);
106  Invocation->getFrontendOpts().DisableFree = false;
107  return Invocation;
108}
109
110/// \brief Runs the specified clang tool action and returns whether it executed
111/// successfully.
112static bool RunInvocation(const char* BinaryName,
113                          clang::driver::Compilation* Compilation,
114                          clang::CompilerInvocation* Invocation,
115                          const clang::driver::ArgStringList& CC1Args,
116                          clang::FrontendAction* ToolAction) {
117  llvm::OwningPtr<clang::FrontendAction> ScopedToolAction(ToolAction);
118  // Show the invocation, with -v.
119  if (Invocation->getHeaderSearchOpts().Verbose) {
120    llvm::errs() << "clang Invocation:\n";
121    Compilation->PrintJob(llvm::errs(), Compilation->getJobs(), "\n", true);
122    llvm::errs() << "\n";
123  }
124
125  // Create a compiler instance to handle the actual work.
126  clang::CompilerInstance Compiler;
127  Compiler.setInvocation(Invocation);
128
129  // Create the compilers actual diagnostics engine.
130  Compiler.createDiagnostics(CC1Args.size(),
131                             const_cast<char**>(CC1Args.data()));
132  if (!Compiler.hasDiagnostics())
133    return false;
134
135  // Infer the builtin include path if unspecified.
136  if (Compiler.getHeaderSearchOpts().UseBuiltinIncludes &&
137      Compiler.getHeaderSearchOpts().ResourceDir.empty()) {
138    // This just needs to be some symbol in the binary.
139    void* const SymbolAddr = &StaticSymbol;
140    Compiler.getHeaderSearchOpts().ResourceDir =
141        clang::CompilerInvocation::GetResourcesPath(BinaryName, SymbolAddr);
142  }
143
144  const bool Success = Compiler.ExecuteAction(*ToolAction);
145  return Success;
146}
147
148/// \brief Converts a string vector representing a Command line into a C
149/// string vector representing the Argv (including the trailing NULL).
150std::vector<char*> CommandLineToArgv(const std::vector<std::string>* Command) {
151  std::vector<char*> Result(Command->size() + 1);
152  for (std::vector<char*>::size_type I = 0; I < Command->size(); ++I) {
153    Result[I] = const_cast<char*>((*Command)[I].c_str());
154  }
155  Result[Command->size()] = NULL;
156  return Result;
157}
158
159/// \brief Runs 'ToolAction' on the code specified by 'FileContents'.
160///
161/// \param FileContents A mapping from file name to source code. For each
162/// entry a virtual file mapping will be created when running the tool.
163bool RunToolWithFlagsOnCode(
164    const std::vector<std::string>& CommandLine,
165    const std::map<std::string, std::string>& FileContents,
166    clang::FrontendAction* ToolAction) {
167  const std::vector<char*> Argv = CommandLineToArgv(&CommandLine);
168  const char* const BinaryName = Argv[0];
169
170  const llvm::OwningPtr<clang::Diagnostic> Diagnostics(NewTextDiagnostics());
171  const llvm::OwningPtr<clang::driver::Driver> Driver(
172      NewDriver(Diagnostics.get(), BinaryName));
173
174  // Since the Input is only virtual, don't check whether it exists.
175  Driver->setCheckInputsExist(false);
176
177  const llvm::OwningPtr<clang::driver::Compilation> Compilation(
178      Driver->BuildCompilation(llvm::ArrayRef<const char*>(&Argv[0],
179                                                           Argv.size() - 1)));
180  const clang::driver::ArgStringList* const CC1Args = GetCC1Arguments(
181      Diagnostics.get(), Compilation.get());
182  if (CC1Args == NULL) {
183    return false;
184  }
185  llvm::OwningPtr<clang::CompilerInvocation> Invocation(
186      NewInvocation(Diagnostics.get(), *CC1Args));
187
188  for (std::map<std::string, std::string>::const_iterator
189           It = FileContents.begin(), End = FileContents.end();
190       It != End; ++It) {
191    // Inject the code as the given file name into the preprocessor options.
192    const llvm::MemoryBuffer* Input =
193        llvm::MemoryBuffer::getMemBuffer(It->second.c_str());
194    Invocation->getPreprocessorOpts().addRemappedFile(It->first.c_str(), Input);
195  }
196
197  return RunInvocation(BinaryName, Compilation.get(),
198                       Invocation.take(), *CC1Args, ToolAction);
199}
200
201bool RunSyntaxOnlyToolOnCode(
202    clang::FrontendAction *ToolAction, llvm::StringRef Code) {
203  const char* const FileName = "input.cc";
204  const char* const CommandLine[] = {
205      "clang-tool", "-fsyntax-only", FileName
206  };
207  std::map<std::string, std::string> FileContents;
208  FileContents[FileName] = Code;
209  return RunToolWithFlagsOnCode(
210      std::vector<std::string>(
211          CommandLine,
212          CommandLine + sizeof(CommandLine)/sizeof(CommandLine[0])),
213      FileContents, ToolAction);
214}
215
216} // end namespace tooling
217} // end namespace clang
218
219