1//===--- DependencyGraph.cpp - Generate dependency file -------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This code generates a header dependency graph in DOT format, for use
10// with, e.g., GraphViz.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Frontend/Utils.h"
15#include "clang/Basic/FileManager.h"
16#include "clang/Basic/SourceManager.h"
17#include "clang/Frontend/FrontendDiagnostic.h"
18#include "clang/Lex/PPCallbacks.h"
19#include "clang/Lex/Preprocessor.h"
20#include "llvm/ADT/SetVector.h"
21#include "llvm/Support/GraphWriter.h"
22#include "llvm/Support/raw_ostream.h"
23
24using namespace clang;
25namespace DOT = llvm::DOT;
26
27namespace {
28class DependencyGraphCallback : public PPCallbacks {
29 const Preprocessor *PP;
30 std::string OutputFile;
31 std::string SysRoot;
32 llvm::SetVector<FileEntryRef> AllFiles;
33 using DependencyMap =
34 llvm::DenseMap<FileEntryRef, SmallVector<FileEntryRef, 2>>;
35
36 DependencyMap Dependencies;
37
38private:
39 raw_ostream &writeNodeReference(raw_ostream &OS,
40 const FileEntry *Node);
41 void OutputGraphFile();
42
43public:
44 DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
45 StringRef SysRoot)
46 : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) {}
47
48 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
49 StringRef FileName, bool IsAngled,
50 CharSourceRange FilenameRange,
51 OptionalFileEntryRef File, StringRef SearchPath,
52 StringRef RelativePath, const Module *SuggestedModule,
53 bool ModuleImported,
54 SrcMgr::CharacteristicKind FileType) override;
55
56 void EmbedDirective(SourceLocation HashLoc, StringRef FileName, bool IsAngled,
57 OptionalFileEntryRef File,
58 const LexEmbedParametersResult &Params) override;
59
60 void EndOfMainFile() override {
61 OutputGraphFile();
62 }
63
64};
65}
66
67void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
68 StringRef SysRoot) {
69 PP.addPPCallbacks(C: std::make_unique<DependencyGraphCallback>(args: &PP, args&: OutputFile,
70 args&: SysRoot));
71}
72
73void DependencyGraphCallback::InclusionDirective(
74 SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
75 bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File,
76 StringRef SearchPath, StringRef RelativePath, const Module *SuggestedModule,
77 bool ModuleImported, SrcMgr::CharacteristicKind FileType) {
78 if (!File)
79 return;
80
81 SourceManager &SM = PP->getSourceManager();
82 OptionalFileEntryRef FromFile =
83 SM.getFileEntryRefForID(FID: SM.getFileID(SpellingLoc: SM.getExpansionLoc(Loc: HashLoc)));
84 if (!FromFile)
85 return;
86
87 Dependencies[*FromFile].push_back(Elt: *File);
88
89 AllFiles.insert(X: *File);
90 AllFiles.insert(X: *FromFile);
91}
92
93void DependencyGraphCallback::EmbedDirective(SourceLocation HashLoc, StringRef,
94 bool, OptionalFileEntryRef File,
95 const LexEmbedParametersResult &) {
96 if (!File)
97 return;
98
99 SourceManager &SM = PP->getSourceManager();
100 OptionalFileEntryRef FromFile =
101 SM.getFileEntryRefForID(FID: SM.getFileID(SpellingLoc: SM.getExpansionLoc(Loc: HashLoc)));
102 if (!FromFile)
103 return;
104
105 Dependencies[*FromFile].push_back(Elt: *File);
106
107 AllFiles.insert(X: *File);
108 AllFiles.insert(X: *FromFile);
109}
110
111raw_ostream &
112DependencyGraphCallback::writeNodeReference(raw_ostream &OS,
113 const FileEntry *Node) {
114 OS << "header_" << Node->getUID();
115 return OS;
116}
117
118void DependencyGraphCallback::OutputGraphFile() {
119 std::error_code EC;
120 llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_TextWithCRLF);
121 if (EC) {
122 PP->getDiagnostics().Report(DiagID: diag::err_fe_error_opening) << OutputFile
123 << EC.message();
124 return;
125 }
126
127 OS << "digraph \"dependencies\" {\n";
128
129 // Write the nodes
130 for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
131 // Write the node itself.
132 OS.indent(NumSpaces: 2);
133 writeNodeReference(OS, Node: AllFiles[I]);
134 OS << " [ shape=\"box\", label=\"";
135 StringRef FileName = AllFiles[I].getName();
136 FileName.consume_front(Prefix: SysRoot);
137
138 OS << DOT::EscapeString(Label: std::string(FileName)) << "\"];\n";
139 }
140
141 // Write the edges
142 for (DependencyMap::iterator F = Dependencies.begin(),
143 FEnd = Dependencies.end();
144 F != FEnd; ++F) {
145 for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
146 OS.indent(NumSpaces: 2);
147 writeNodeReference(OS, Node: F->first);
148 OS << " -> ";
149 writeNodeReference(OS, Node: F->second[I]);
150 OS << ";\n";
151 }
152 }
153 OS << "}\n";
154}
155
156