1 //===--- ModuleDependencyCollector.cpp - Collect module dependencies ------===//
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 // Collect the dependencies of a set of modules.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/Basic/CharInfo.h"
14 #include "clang/Frontend/Utils.h"
15 #include "clang/Lex/Preprocessor.h"
16 #include "clang/Serialization/ASTReader.h"
17 #include "llvm/ADT/iterator_range.h"
18 #include "llvm/Config/llvm-config.h"
19 #include "llvm/Support/FileSystem.h"
20 #include "llvm/Support/Path.h"
21 #include "llvm/Support/raw_ostream.h"
22
23 using namespace clang;
24
25 namespace {
26 /// Private implementations for ModuleDependencyCollector
27 class ModuleDependencyListener : public ASTReaderListener {
28 ModuleDependencyCollector &Collector;
29 FileManager &FileMgr;
30 public:
ModuleDependencyListener(ModuleDependencyCollector & Collector,FileManager & FileMgr)31 ModuleDependencyListener(ModuleDependencyCollector &Collector,
32 FileManager &FileMgr)
33 : Collector(Collector), FileMgr(FileMgr) {}
needsInputFileVisitation()34 bool needsInputFileVisitation() override { return true; }
needsSystemInputFileVisitation()35 bool needsSystemInputFileVisitation() override { return true; }
visitInputFile(StringRef Filename,bool IsSystem,bool IsOverridden,bool IsExplicitModule)36 bool visitInputFile(StringRef Filename, bool IsSystem, bool IsOverridden,
37 bool IsExplicitModule) override {
38 // Run this through the FileManager in order to respect 'use-external-name'
39 // in case we have a VFS overlay.
40 if (auto FE = FileMgr.getOptionalFileRef(Filename))
41 Filename = FE->getName();
42 Collector.addFile(Filename);
43 return true;
44 }
45 };
46
47 struct ModuleDependencyPPCallbacks : public PPCallbacks {
48 ModuleDependencyCollector &Collector;
49 SourceManager &SM;
ModuleDependencyPPCallbacks__anone6f4b26c0111::ModuleDependencyPPCallbacks50 ModuleDependencyPPCallbacks(ModuleDependencyCollector &Collector,
51 SourceManager &SM)
52 : Collector(Collector), SM(SM) {}
53
InclusionDirective__anone6f4b26c0111::ModuleDependencyPPCallbacks54 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
55 StringRef FileName, bool IsAngled,
56 CharSourceRange FilenameRange,
57 OptionalFileEntryRef File, StringRef SearchPath,
58 StringRef RelativePath, const Module *Imported,
59 SrcMgr::CharacteristicKind FileType) override {
60 if (!File)
61 return;
62 Collector.addFile(File->getName());
63 }
64 };
65
66 struct ModuleDependencyMMCallbacks : public ModuleMapCallbacks {
67 ModuleDependencyCollector &Collector;
ModuleDependencyMMCallbacks__anone6f4b26c0111::ModuleDependencyMMCallbacks68 ModuleDependencyMMCallbacks(ModuleDependencyCollector &Collector)
69 : Collector(Collector) {}
70
moduleMapAddHeader__anone6f4b26c0111::ModuleDependencyMMCallbacks71 void moduleMapAddHeader(StringRef HeaderPath) override {
72 if (llvm::sys::path::is_absolute(HeaderPath))
73 Collector.addFile(HeaderPath);
74 }
moduleMapAddUmbrellaHeader__anone6f4b26c0111::ModuleDependencyMMCallbacks75 void moduleMapAddUmbrellaHeader(FileManager *FileMgr,
76 const FileEntry *Header) override {
77 StringRef HeaderFilename = Header->getName();
78 moduleMapAddHeader(HeaderFilename);
79 // The FileManager can find and cache the symbolic link for a framework
80 // header before its real path, this means a module can have some of its
81 // headers to use other paths. Although this is usually not a problem, it's
82 // inconsistent, and not collecting the original path header leads to
83 // umbrella clashes while rebuilding modules in the crash reproducer. For
84 // example:
85 // ApplicationServices.framework/Frameworks/ImageIO.framework/ImageIO.h
86 // instead of:
87 // ImageIO.framework/ImageIO.h
88 //
89 // FIXME: this shouldn't be necessary once we have FileName instances
90 // around instead of FileEntry ones. For now, make sure we collect all
91 // that we need for the reproducer to work correctly.
92 StringRef UmbreallDirFromHeader =
93 llvm::sys::path::parent_path(HeaderFilename);
94 StringRef UmbrellaDir = Header->getDir()->getName();
95 if (!UmbrellaDir.equals(UmbreallDirFromHeader)) {
96 SmallString<128> AltHeaderFilename;
97 llvm::sys::path::append(AltHeaderFilename, UmbrellaDir,
98 llvm::sys::path::filename(HeaderFilename));
99 if (FileMgr->getFile(AltHeaderFilename))
100 moduleMapAddHeader(AltHeaderFilename);
101 }
102 }
103 };
104
105 }
106
attachToASTReader(ASTReader & R)107 void ModuleDependencyCollector::attachToASTReader(ASTReader &R) {
108 R.addListener(
109 std::make_unique<ModuleDependencyListener>(*this, R.getFileManager()));
110 }
111
attachToPreprocessor(Preprocessor & PP)112 void ModuleDependencyCollector::attachToPreprocessor(Preprocessor &PP) {
113 PP.addPPCallbacks(std::make_unique<ModuleDependencyPPCallbacks>(
114 *this, PP.getSourceManager()));
115 PP.getHeaderSearchInfo().getModuleMap().addModuleMapCallbacks(
116 std::make_unique<ModuleDependencyMMCallbacks>(*this));
117 }
118
isCaseSensitivePath(StringRef Path)119 static bool isCaseSensitivePath(StringRef Path) {
120 SmallString<256> TmpDest = Path, UpperDest, RealDest;
121 // Remove component traversals, links, etc.
122 if (llvm::sys::fs::real_path(Path, TmpDest))
123 return true; // Current default value in vfs.yaml
124 Path = TmpDest;
125
126 // Change path to all upper case and ask for its real path, if the latter
127 // exists and is equal to Path, it's not case sensitive. Default to case
128 // sensitive in the absence of realpath, since this is what the VFSWriter
129 // already expects when sensitivity isn't setup.
130 for (auto &C : Path)
131 UpperDest.push_back(toUppercase(C));
132 if (!llvm::sys::fs::real_path(UpperDest, RealDest) && Path.equals(RealDest))
133 return false;
134 return true;
135 }
136
writeFileMap()137 void ModuleDependencyCollector::writeFileMap() {
138 if (Seen.empty())
139 return;
140
141 StringRef VFSDir = getDest();
142
143 // Default to use relative overlay directories in the VFS yaml file. This
144 // allows crash reproducer scripts to work across machines.
145 VFSWriter.setOverlayDir(VFSDir);
146
147 // Explicitly set case sensitivity for the YAML writer. For that, find out
148 // the sensitivity at the path where the headers all collected to.
149 VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));
150
151 // Do not rely on real path names when executing the crash reproducer scripts
152 // since we only want to actually use the files we have on the VFS cache.
153 VFSWriter.setUseExternalNames(false);
154
155 std::error_code EC;
156 SmallString<256> YAMLPath = VFSDir;
157 llvm::sys::path::append(YAMLPath, "vfs.yaml");
158 llvm::raw_fd_ostream OS(YAMLPath, EC, llvm::sys::fs::OF_TextWithCRLF);
159 if (EC) {
160 HasErrors = true;
161 return;
162 }
163 VFSWriter.write(OS);
164 }
165
copyToRoot(StringRef Src,StringRef Dst)166 std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src,
167 StringRef Dst) {
168 using namespace llvm::sys;
169 llvm::FileCollector::PathCanonicalizer::PathStorage Paths =
170 Canonicalizer.canonicalize(Src);
171
172 SmallString<256> CacheDst = getDest();
173
174 if (Dst.empty()) {
175 // The common case is to map the virtual path to the same path inside the
176 // cache.
177 path::append(CacheDst, path::relative_path(Paths.CopyFrom));
178 } else {
179 // When collecting entries from input vfsoverlays, copy the external
180 // contents into the cache but still map from the source.
181 if (!fs::exists(Dst))
182 return std::error_code();
183 path::append(CacheDst, Dst);
184 Paths.CopyFrom = Dst;
185 }
186
187 // Copy the file into place.
188 if (std::error_code EC = fs::create_directories(path::parent_path(CacheDst),
189 /*IgnoreExisting=*/true))
190 return EC;
191 if (std::error_code EC = fs::copy_file(Paths.CopyFrom, CacheDst))
192 return EC;
193
194 // Always map a canonical src path to its real path into the YAML, by doing
195 // this we map different virtual src paths to the same entry in the VFS
196 // overlay, which is a way to emulate symlink inside the VFS; this is also
197 // needed for correctness, not doing that can lead to module redefinition
198 // errors.
199 addFileMapping(Paths.VirtualPath, CacheDst);
200 return std::error_code();
201 }
202
addFile(StringRef Filename,StringRef FileDst)203 void ModuleDependencyCollector::addFile(StringRef Filename, StringRef FileDst) {
204 if (insertSeen(Filename))
205 if (copyToRoot(Filename, FileDst))
206 HasErrors = true;
207 }
208