Check in LLVM r95781.
diff --git a/lib/Frontend/DependencyFile.cpp b/lib/Frontend/DependencyFile.cpp
new file mode 100644
index 0000000..478c339
--- /dev/null
+++ b/lib/Frontend/DependencyFile.cpp
@@ -0,0 +1,174 @@
+//===--- DependencyFile.cpp - Generate dependency file --------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code generates dependency files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DependencyOutputOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/DirectoryLookup.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+
+using namespace clang;
+
+namespace {
+class DependencyFileCallback : public PPCallbacks {
+ std::vector<std::string> Files;
+ llvm::StringSet<> FilesSet;
+ const Preprocessor *PP;
+ std::vector<std::string> Targets;
+ llvm::raw_ostream *OS;
+ bool IncludeSystemHeaders;
+ bool PhonyTarget;
+private:
+ bool FileMatchesDepCriteria(const char *Filename,
+ SrcMgr::CharacteristicKind FileType);
+ void OutputDependencyFile();
+
+public:
+ DependencyFileCallback(const Preprocessor *_PP,
+ llvm::raw_ostream *_OS,
+ const DependencyOutputOptions &Opts)
+ : PP(_PP), Targets(Opts.Targets), OS(_OS),
+ IncludeSystemHeaders(Opts.IncludeSystemHeaders),
+ PhonyTarget(Opts.UsePhonyTargets) {}
+
+ ~DependencyFileCallback() {
+ OutputDependencyFile();
+ OS->flush();
+ delete OS;
+ }
+
+ virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+ SrcMgr::CharacteristicKind FileType);
+};
+}
+
+void clang::AttachDependencyFileGen(Preprocessor &PP,
+ const DependencyOutputOptions &Opts) {
+ if (Opts.Targets.empty()) {
+ PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
+ return;
+ }
+
+ std::string Err;
+ llvm::raw_ostream *OS(new llvm::raw_fd_ostream(Opts.OutputFile.c_str(), Err));
+ if (!Err.empty()) {
+ PP.getDiagnostics().Report(diag::err_fe_error_opening)
+ << Opts.OutputFile << Err;
+ return;
+ }
+
+ assert(!PP.getPPCallbacks() && "Preprocessor callbacks already registered!");
+ PP.setPPCallbacks(new DependencyFileCallback(&PP, OS, Opts));
+}
+
+/// FileMatchesDepCriteria - Determine whether the given Filename should be
+/// considered as a dependency.
+bool DependencyFileCallback::FileMatchesDepCriteria(const char *Filename,
+ SrcMgr::CharacteristicKind FileType) {
+ if (strcmp("<built-in>", Filename) == 0)
+ return false;
+
+ if (IncludeSystemHeaders)
+ return true;
+
+ return FileType == SrcMgr::C_User;
+}
+
+void DependencyFileCallback::FileChanged(SourceLocation Loc,
+ FileChangeReason Reason,
+ SrcMgr::CharacteristicKind FileType) {
+ if (Reason != PPCallbacks::EnterFile)
+ return;
+
+ // Dependency generation really does want to go all the way to the
+ // file entry for a source location to find out what is depended on.
+ // We do not want #line markers to affect dependency generation!
+ SourceManager &SM = PP->getSourceManager();
+
+ const FileEntry *FE =
+ SM.getFileEntryForID(SM.getFileID(SM.getInstantiationLoc(Loc)));
+ if (FE == 0) return;
+
+ const char *Filename = FE->getName();
+ if (!FileMatchesDepCriteria(Filename, FileType))
+ return;
+
+ // Remove leading "./"
+ if (Filename[0] == '.' && Filename[1] == '/')
+ Filename = &Filename[2];
+
+ if (FilesSet.insert(Filename))
+ Files.push_back(Filename);
+}
+
+void DependencyFileCallback::OutputDependencyFile() {
+ // Write out the dependency targets, trying to avoid overly long
+ // lines when possible. We try our best to emit exactly the same
+ // dependency file as GCC (4.2), assuming the included files are the
+ // same.
+ const unsigned MaxColumns = 75;
+ unsigned Columns = 0;
+
+ for (std::vector<std::string>::iterator
+ I = Targets.begin(), E = Targets.end(); I != E; ++I) {
+ unsigned N = I->length();
+ if (Columns == 0) {
+ Columns += N;
+ *OS << *I;
+ } else if (Columns + N + 2 > MaxColumns) {
+ Columns = N + 2;
+ *OS << " \\\n " << *I;
+ } else {
+ Columns += N + 1;
+ *OS << ' ' << *I;
+ }
+ }
+
+ *OS << ':';
+ Columns += 1;
+
+ // Now add each dependency in the order it was seen, but avoiding
+ // duplicates.
+ for (std::vector<std::string>::iterator I = Files.begin(),
+ E = Files.end(); I != E; ++I) {
+ // Start a new line if this would exceed the column limit. Make
+ // sure to leave space for a trailing " \" in case we need to
+ // break the line on the next iteration.
+ unsigned N = I->length();
+ if (Columns + (N + 1) + 2 > MaxColumns) {
+ *OS << " \\\n ";
+ Columns = 2;
+ }
+ *OS << ' ' << *I;
+ Columns += N + 1;
+ }
+ *OS << '\n';
+
+ // Create phony targets if requested.
+ if (PhonyTarget) {
+ // Skip the first entry, this is always the input file itself.
+ for (std::vector<std::string>::iterator I = Files.begin() + 1,
+ E = Files.end(); I != E; ++I) {
+ *OS << '\n';
+ *OS << *I << ":\n";
+ }
+ }
+}
+