CompilationDatabase.cpp revision 675906eeb54dd2aa8a7cb3b326da07158c931758 
1//===--- CompilationDatabase.cpp - ----------------------------------------===//
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 contains implementations of the CompilationDatabase base class
11//  and the FixedCompilationDatabase.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Tooling/CompilationDatabase.h"
16#include "clang/Tooling/CompilationDatabasePluginRegistry.h"
17#include "clang/Tooling/Tooling.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/Support/Path.h"
20#include "llvm/Support/system_error.h"
21#include <sstream>
22
23#include "clang/Basic/Diagnostic.h"
24#include "clang/Driver/Action.h"
25#include "clang/Driver/Driver.h"
26#include "clang/Driver/DriverDiagnostic.h"
27#include "clang/Driver/Job.h"
28#include "clang/Driver/Compilation.h"
29#include "clang/Frontend/TextDiagnosticPrinter.h"
30#include "llvm/Support/Host.h"
31#include "llvm/Option/Arg.h"
32
33namespace clang {
34namespace tooling {
35
36CompilationDatabase::~CompilationDatabase() {}
37
38CompilationDatabase *
39CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
40                                       std::string &ErrorMessage) {
41  std::stringstream ErrorStream;
42  for (CompilationDatabasePluginRegistry::iterator
43       It = CompilationDatabasePluginRegistry::begin(),
44       Ie = CompilationDatabasePluginRegistry::end();
45       It != Ie; ++It) {
46    std::string DatabaseErrorMessage;
47    OwningPtr<CompilationDatabasePlugin> Plugin(It->instantiate());
48    if (CompilationDatabase *DB =
49        Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
50      return DB;
51    else
52      ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
53  }
54  ErrorMessage = ErrorStream.str();
55  return NULL;
56}
57
58static CompilationDatabase *
59findCompilationDatabaseFromDirectory(StringRef Directory,
60                                     std::string &ErrorMessage) {
61  std::stringstream ErrorStream;
62  bool HasErrorMessage = false;
63  while (!Directory.empty()) {
64    std::string LoadErrorMessage;
65
66    if (CompilationDatabase *DB =
67           CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
68      return DB;
69
70    if (!HasErrorMessage) {
71      ErrorStream << "No compilation database found in " << Directory.str()
72                  << " or any parent directory\n" << LoadErrorMessage;
73      HasErrorMessage = true;
74    }
75
76    Directory = llvm::sys::path::parent_path(Directory);
77  }
78  ErrorMessage = ErrorStream.str();
79  return NULL;
80}
81
82CompilationDatabase *
83CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
84                                          std::string &ErrorMessage) {
85  SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
86  StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);
87
88  CompilationDatabase *DB = findCompilationDatabaseFromDirectory(Directory,
89                                                                 ErrorMessage);
90
91  if (!DB)
92    ErrorMessage = ("Could not auto-detect compilation database for file \"" +
93                   SourceFile + "\"\n" + ErrorMessage).str();
94  return DB;
95}
96
97CompilationDatabase *
98CompilationDatabase::autoDetectFromDirectory(StringRef SourceDir,
99                                             std::string &ErrorMessage) {
100  SmallString<1024> AbsolutePath(getAbsolutePath(SourceDir));
101
102  CompilationDatabase *DB = findCompilationDatabaseFromDirectory(AbsolutePath,
103                                                                 ErrorMessage);
104
105  if (!DB)
106    ErrorMessage = ("Could not auto-detect compilation database from directory \"" +
107                   SourceDir + "\"\n" + ErrorMessage).str();
108  return DB;
109}
110
111CompilationDatabasePlugin::~CompilationDatabasePlugin() {}
112
113// Helper for recursively searching through a chain of actions and collecting
114// all inputs, direct and indirect, of compile jobs.
115struct CompileJobAnalyzer {
116  void run(const driver::Action *A) {
117    runImpl(A, false);
118  }
119
120  SmallVector<std::string, 2> Inputs;
121
122private:
123
124  void runImpl(const driver::Action *A, bool Collect) {
125    bool CollectChildren = Collect;
126    switch (A->getKind()) {
127    case driver::Action::CompileJobClass:
128      CollectChildren = true;
129      break;
130
131    case driver::Action::InputClass: {
132      if (Collect) {
133        const driver::InputAction *IA = cast<driver::InputAction>(A);
134        Inputs.push_back(IA->getInputArg().getSpelling());
135      }
136    } break;
137
138    default:
139      // Don't care about others
140      ;
141    }
142
143    for (driver::ActionList::const_iterator I = A->begin(), E = A->end();
144         I != E; ++I)
145      runImpl(*I, CollectChildren);
146  }
147};
148
149// Special DiagnosticConsumer that looks for warn_drv_input_file_unused
150// diagnostics from the driver and collects the option strings for those unused
151// options.
152class UnusedInputDiagConsumer : public DiagnosticConsumer {
153public:
154  UnusedInputDiagConsumer() : Other(0) {}
155
156  // Useful for debugging, chain diagnostics to another consumer after
157  // recording for our own purposes.
158  UnusedInputDiagConsumer(DiagnosticConsumer *Other) : Other(Other) {}
159
160  virtual void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
161                                const Diagnostic &Info) LLVM_OVERRIDE {
162    if (Info.getID() == clang::diag::warn_drv_input_file_unused) {
163      // Arg 1 for this diagnostic is the option that didn't get used.
164      UnusedInputs.push_back(Info.getArgStdStr(0));
165    }
166    if (Other)
167      Other->HandleDiagnostic(DiagLevel, Info);
168  }
169
170  DiagnosticConsumer *Other;
171  SmallVector<std::string, 2> UnusedInputs;
172};
173
174// Unary functor for asking "Given a StringRef S1, does there exist a string
175// S2 in Arr where S1 == S2?"
176struct MatchesAny {
177  MatchesAny(ArrayRef<std::string> Arr) : Arr(Arr) {}
178  bool operator() (StringRef S) {
179    for (const std::string *I = Arr.begin(), *E = Arr.end(); I != E; ++I)
180      if (*I == S)
181        return true;
182    return false;
183  }
184private:
185  ArrayRef<std::string> Arr;
186};
187
188/// \brief Strips any positional args and possible argv[0] from a command-line
189/// provided by the user to construct a FixedCompilationDatabase.
190///
191/// FixedCompilationDatabase requires a command line to be in this format as it
192/// constructs the command line for each file by appending the name of the file
193/// to be compiled. FixedCompilationDatabase also adds its own argv[0] to the
194/// start of the command line although its value is not important as it's just
195/// ignored by the Driver invoked by the ClangTool using the
196/// FixedCompilationDatabase.
197///
198/// FIXME: This functionality should probably be made available by
199/// clang::driver::Driver although what the interface should look like is not
200/// clear.
201///
202/// \param[in] Args Args as provided by the user.
203/// \param[out] Resulting stripped command line.
204///
205/// \returns \li true if successful.
206///          \li false if \c Args cannot be used for compilation jobs (e.g.
207///          contains an option like -E or -version).
208bool stripPositionalArgs(std::vector<const char *> Args,
209                         std::vector<std::string> &Result) {
210  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
211  UnusedInputDiagConsumer DiagClient;
212  DiagnosticsEngine Diagnostics(
213      IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
214      &*DiagOpts, &DiagClient, false);
215
216  // Neither clang executable nor default image name are required since the
217  // jobs the driver builds will not be executed.
218  OwningPtr<driver::Driver> NewDriver(new driver::Driver(
219      /* ClangExecutable= */ "", llvm::sys::getDefaultTargetTriple(),
220      /* DefaultImageName= */ "", Diagnostics));
221  NewDriver->setCheckInputsExist(false);
222
223  // This becomes the new argv[0]. The value is actually not important as it
224  // isn't used for invoking Tools.
225  Args.insert(Args.begin(), "clang-tool");
226
227  // By adding -c, we force the driver to treat compilation as the last phase.
228  // It will then issue warnings via Diagnostics about un-used options that
229  // would have been used for linking. If the user provided a compiler name as
230  // the original argv[0], this will be treated as a linker input thanks to
231  // insertng a new argv[0] above. All un-used options get collected by
232  // UnusedInputdiagConsumer and get stripped out later.
233  Args.push_back("-c");
234
235  // Put a dummy C++ file on to ensure there's at least one compile job for the
236  // driver to construct. If the user specified some other argument that
237  // prevents compilation, e.g. -E or something like -version, we may still end
238  // up with no jobs but then this is the user's fault.
239  Args.push_back("placeholder.cpp");
240
241  const OwningPtr<driver::Compilation> Compilation(
242      NewDriver->BuildCompilation(Args));
243
244  const driver::JobList &Jobs = Compilation->getJobs();
245
246  CompileJobAnalyzer CompileAnalyzer;
247
248  for (driver::JobList::const_iterator I = Jobs.begin(), E = Jobs.end(); I != E;
249       ++I) {
250    if ((*I)->getKind() == driver::Job::CommandClass) {
251      const driver::Command *Cmd = cast<driver::Command>(*I);
252      // Collect only for Assemble jobs. If we do all jobs we get duplicates
253      // since Link jobs point to Assemble jobs as inputs.
254      if (Cmd->getSource().getKind() == driver::Action::AssembleJobClass)
255        CompileAnalyzer.run(&Cmd->getSource());
256    }
257  }
258
259  if (CompileAnalyzer.Inputs.empty()) {
260    // No compile jobs found.
261    // FIXME: Emit a warning of some kind?
262    return false;
263  }
264
265  // Remove all compilation input files from the command line. This is
266  // necessary so that getCompileCommands() can construct a command line for
267  // each file.
268  std::vector<const char *>::iterator End = std::remove_if(
269      Args.begin(), Args.end(), MatchesAny(CompileAnalyzer.Inputs));
270
271  // Remove all inputs deemed unused for compilation.
272  End = std::remove_if(Args.begin(), End, MatchesAny(DiagClient.UnusedInputs));
273
274  // Remove the -c add above as well. It will be at the end right now.
275  --End;
276
277  Result = std::vector<std::string>(Args.begin() + 1, End);
278  return true;
279}
280
281FixedCompilationDatabase *
282FixedCompilationDatabase::loadFromCommandLine(int &Argc,
283                                              const char **Argv,
284                                              Twine Directory) {
285  const char **DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
286  if (DoubleDash == Argv + Argc)
287    return NULL;
288  std::vector<const char *> CommandLine(DoubleDash + 1, Argv + Argc);
289  Argc = DoubleDash - Argv;
290
291  std::vector<std::string> StrippedArgs;
292  if (!stripPositionalArgs(CommandLine, StrippedArgs))
293    return 0;
294  return new FixedCompilationDatabase(Directory, StrippedArgs);
295}
296
297FixedCompilationDatabase::
298FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
299  std::vector<std::string> ToolCommandLine(1, "clang-tool");
300  ToolCommandLine.insert(ToolCommandLine.end(),
301                         CommandLine.begin(), CommandLine.end());
302  CompileCommands.push_back(CompileCommand(Directory, ToolCommandLine));
303}
304
305std::vector<CompileCommand>
306FixedCompilationDatabase::getCompileCommands(StringRef FilePath) const {
307  std::vector<CompileCommand> Result(CompileCommands);
308  Result[0].CommandLine.push_back(FilePath);
309  return Result;
310}
311
312std::vector<std::string>
313FixedCompilationDatabase::getAllFiles() const {
314  return std::vector<std::string>();
315}
316
317std::vector<CompileCommand>
318FixedCompilationDatabase::getAllCompileCommands() const {
319  return std::vector<CompileCommand>();
320}
321
322// This anchor is used to force the linker to link in the generated object file
323// and thus register the JSONCompilationDatabasePlugin.
324extern volatile int JSONAnchorSource;
325static int JSONAnchorDest = JSONAnchorSource;
326
327} // end namespace tooling
328} // end namespace clang
329