//===--- DependencyGraph.cpp - Generate dependency file -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This code generates a header dependency graph in DOT format, for use
// with, e.g., GraphViz.
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/Utils.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
namespace DOT = llvm::DOT;
namespace {
class DependencyGraphCallback : public PPCallbacks {
const Preprocessor *PP;
std::string OutputFile;
std::string SysRoot;
llvm::SetVector<const FileEntry *> AllFiles;
typedef llvm::DenseMap<const FileEntry *,
SmallVector<const FileEntry *, 2> > DependencyMap;
DependencyMap Dependencies;
private:
raw_ostream &writeNodeReference(raw_ostream &OS,
const FileEntry *Node);
void OutputGraphFile();
public:
DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
StringRef SysRoot)
: PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
StringRef FileName, bool IsAngled,
CharSourceRange FilenameRange, const FileEntry *File,
StringRef SearchPath, StringRef RelativePath,
const Module *Imported,
SrcMgr::CharacteristicKind FileType) override;
void EndOfMainFile() override {
OutputGraphFile();
}
};
}
void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
StringRef SysRoot) {
PP.addPPCallbacks(std::make_unique<DependencyGraphCallback>(&PP, OutputFile,
SysRoot));
}
void DependencyGraphCallback::InclusionDirective(
SourceLocation HashLoc,
const Token &IncludeTok,
StringRef FileName,
bool IsAngled,
CharSourceRange FilenameRange,
const FileEntry *File,
StringRef SearchPath,
StringRef RelativePath,
const Module *Imported,
SrcMgr::CharacteristicKind FileType) {
if (!File)
return;
SourceManager &SM = PP->getSourceManager();
const FileEntry *FromFile
= SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
if (!FromFile)
return;
Dependencies[FromFile].push_back(File);
AllFiles.insert(File);
AllFiles.insert(FromFile);
}
raw_ostream &
DependencyGraphCallback::writeNodeReference(raw_ostream &OS,
const FileEntry *Node) {
OS << "header_" << Node->getUID();
return OS;
}
void DependencyGraphCallback::OutputGraphFile() {
std::error_code EC;
llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF);
if (EC) {
PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
<< EC.message();
return;
}
OS << "digraph \"dependencies\" {\n";
// Write the nodes
for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
// Write the node itself.
OS.indent(2);
writeNodeReference(OS, AllFiles[I]);
OS << " [ shape=\"box\", label=\"";
StringRef FileName = AllFiles[I]->getName();
if (FileName.startswith(SysRoot))
FileName = FileName.substr(SysRoot.size());
OS << DOT::EscapeString(std::string(FileName)) << "\"];\n";
}
// Write the edges
for (DependencyMap::iterator F = Dependencies.begin(),
FEnd = Dependencies.end();
F != FEnd; ++F) {
for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
OS.indent(2);
writeNodeReference(OS, F->first);
OS << " -> ";
writeNodeReference(OS, F->second[I]);
OS << ";\n";
}
}
OS << "}\n";
}