clang 10.0.0git

ModuleDependencyCollector.cpp
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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 public:
30 ModuleDependencyListener(ModuleDependencyCollector &Collector)
31 : Collector(Collector) {}
32 bool needsInputFileVisitation() override { return true; }
33 bool needsSystemInputFileVisitation() override { return true; }
34 bool visitInputFile(StringRef Filename, bool IsSystem, bool IsOverridden,
35 bool IsExplicitModule) override {
36 Collector.addFile(Filename);
37 return true;
38 }
39 };
40
41 struct ModuleDependencyPPCallbacks : public PPCallbacks {
42 ModuleDependencyCollector &Collector;
43 SourceManager &SM;
44 ModuleDependencyPPCallbacks(ModuleDependencyCollector &Collector,
45 SourceManager &SM)
46 : Collector(Collector), SM(SM) {}
47
48 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
49 StringRef FileName, bool IsAngled,
50 CharSourceRange FilenameRange, const FileEntry *File,
51 StringRef SearchPath, StringRef RelativePath,
52 const Module *Imported,
53 SrcMgr::CharacteristicKind FileType) override {
54 if (!File)
55 return;
56 Collector.addFile(File->getName());
57 }
58 };
59
60 struct ModuleDependencyMMCallbacks : public ModuleMapCallbacks {
61 ModuleDependencyCollector &Collector;
62 ModuleDependencyMMCallbacks(ModuleDependencyCollector &Collector)
63 : Collector(Collector) {}
64
65 void moduleMapAddHeader(StringRef HeaderPath) override {
66 if (llvm::sys::path::is_absolute(HeaderPath))
67 Collector.addFile(HeaderPath);
68 }
69 void moduleMapAddUmbrellaHeader(FileManager *FileMgr,
70 const FileEntry *Header) override {
71 StringRef HeaderFilename = Header->getName();
72 moduleMapAddHeader(HeaderFilename);
73 // The FileManager can find and cache the symbolic link for a framework
74 // header before its real path, this means a module can have some of its
75 // headers to use other paths. Although this is usually not a problem, it's
76 // inconsistent, and not collecting the original path header leads to
77 // umbrella clashes while rebuilding modules in the crash reproducer. For
78 // example:
79 // ApplicationServices.framework/Frameworks/ImageIO.framework/ImageIO.h
80 // instead of:
81 // ImageIO.framework/ImageIO.h
82 //
83 // FIXME: this shouldn't be necessary once we have FileName instances
84 // around instead of FileEntry ones. For now, make sure we collect all
85 // that we need for the reproducer to work correctly.
86 StringRef UmbreallDirFromHeader =
87 llvm::sys::path::parent_path(HeaderFilename);
88 StringRef UmbrellaDir = Header->getDir()->getName();
89 if (!UmbrellaDir.equals(UmbreallDirFromHeader)) {
90 SmallString<128> AltHeaderFilename;
91 llvm::sys::path::append(AltHeaderFilename, UmbrellaDir,
92 llvm::sys::path::filename(HeaderFilename));
93 if (FileMgr->getFile(AltHeaderFilename))
94 moduleMapAddHeader(AltHeaderFilename);
95 }
96 }
97 };
98
99 }
100
101 void ModuleDependencyCollector::attachToASTReader(ASTReader &R) {
102 R.addListener(std::make_unique<ModuleDependencyListener>(*this));
103 }
104
105 void ModuleDependencyCollector::attachToPreprocessor(Preprocessor &PP) {
106 PP.addPPCallbacks(std::make_unique<ModuleDependencyPPCallbacks>(
107 *this, PP.getSourceManager()));
108 PP.getHeaderSearchInfo().getModuleMap().addModuleMapCallbacks(
109 std::make_unique<ModuleDependencyMMCallbacks>(*this));
110 }
111
112 static bool isCaseSensitivePath(StringRef Path) {
113 SmallString<256> TmpDest = Path, UpperDest, RealDest;
114 // Remove component traversals, links, etc.
115 if (llvm::sys::fs::real_path(Path, TmpDest))
116 return true; // Current default value in vfs.yaml
117 Path = TmpDest;
118
119 // Change path to all upper case and ask for its real path, if the latter
120 // exists and is equal to Path, it's not case sensitive. Default to case
121 // sensitive in the absence of realpath, since this is what the VFSWriter
122 // already expects when sensitivity isn't setup.
123 for (auto &C : Path)
124 UpperDest.push_back(toUppercase(C));
125 if (!llvm::sys::fs::real_path(UpperDest, RealDest) && Path.equals(RealDest))
126 return false;
127 return true;
128 }
129
130 void ModuleDependencyCollector::writeFileMap() {
131 if (Seen.empty())
132 return;
133
134 StringRef VFSDir = getDest();
135
136 // Default to use relative overlay directories in the VFS yaml file. This
137 // allows crash reproducer scripts to work across machines.
138 VFSWriter.setOverlayDir(VFSDir);
139
140 // Explicitly set case sensitivity for the YAML writer. For that, find out
141 // the sensitivity at the path where the headers all collected to.
142 VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));
143
144 // Do not rely on real path names when executing the crash reproducer scripts
145 // since we only want to actually use the files we have on the VFS cache.
146 VFSWriter.setUseExternalNames(false);
147
148 std::error_code EC;
149 SmallString<256> YAMLPath = VFSDir;
150 llvm::sys::path::append(YAMLPath, "vfs.yaml");
151 llvm::raw_fd_ostream OS(YAMLPath, EC, llvm::sys::fs::OF_Text);
152 if (EC) {
153 HasErrors = true;
154 return;
155 }
156 VFSWriter.write(OS);
157 }
158
159 bool ModuleDependencyCollector::getRealPath(StringRef SrcPath,
160 SmallVectorImpl<char> &Result) {
161 using namespace llvm::sys;
162 SmallString<256> RealPath;
163 StringRef FileName = path::filename(SrcPath);
164 std::string Dir = path::parent_path(SrcPath).str();
165 auto DirWithSymLink = SymLinkMap.find(Dir);
166
167 // Use real_path to fix any symbolic link component present in a path.
168 // Computing the real path is expensive, cache the search through the
169 // parent path directory.
170 if (DirWithSymLink == SymLinkMap.end()) {
171 if (llvm::sys::fs::real_path(Dir, RealPath))
172 return false;
173 SymLinkMap[Dir] = RealPath.str();
174 } else {
175 RealPath = DirWithSymLink->second;
176 }
177
178 path::append(RealPath, FileName);
179 Result.swap(RealPath);
180 return true;
181 }
182
183 std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src,
184 StringRef Dst) {
185 using namespace llvm::sys;
186
187 // We need an absolute src path to append to the root.
188 SmallString<256> AbsoluteSrc = Src;
189 fs::make_absolute(AbsoluteSrc);
190 // Canonicalize src to a native path to avoid mixed separator styles.
191 path::native(AbsoluteSrc);
192 // Remove redundant leading "./" pieces and consecutive separators.
193 AbsoluteSrc = path::remove_leading_dotslash(AbsoluteSrc);
194
195 // Canonicalize the source path by removing "..", "." components.
196 SmallString<256> VirtualPath = AbsoluteSrc;
197 path::remove_dots(VirtualPath, /*remove_dot_dot=*/true);
198
199 // If a ".." component is present after a symlink component, remove_dots may
200 // lead to the wrong real destination path. Let the source be canonicalized
201 // like that but make sure we always use the real path for the destination.
202 SmallString<256> CopyFrom;
203 if (!getRealPath(AbsoluteSrc, CopyFrom))
204 CopyFrom = VirtualPath;
205 SmallString<256> CacheDst = getDest();
206
207 if (Dst.empty()) {
208 // The common case is to map the virtual path to the same path inside the
209 // cache.
210 path::append(CacheDst, path::relative_path(CopyFrom));
211 } else {
212 // When collecting entries from input vfsoverlays, copy the external
213 // contents into the cache but still map from the source.
214 if (!fs::exists(Dst))
215 return std::error_code();
216 path::append(CacheDst, Dst);
217 CopyFrom = Dst;
218 }
219
220 // Copy the file into place.
221 if (std::error_code EC = fs::create_directories(path::parent_path(CacheDst),
222 /*IgnoreExisting=*/true))
223 return EC;
224 if (std::error_code EC = fs::copy_file(CopyFrom, CacheDst))
225 return EC;
226
227 // Always map a canonical src path to its real path into the YAML, by doing
228 // this we map different virtual src paths to the same entry in the VFS
229 // overlay, which is a way to emulate symlink inside the VFS; this is also
230 // needed for correctness, not doing that can lead to module redefinition
231 // errors.
232 addFileMapping(VirtualPath, CacheDst);
233 return std::error_code();
234 }
235
236 void ModuleDependencyCollector::addFile(StringRef Filename, StringRef FileDst) {
237 if (insertSeen(Filename))
238 if (copyToRoot(Filename, FileDst))
239 HasErrors = true;
240 }
clang::FileManager
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:171
clang::ModuleDependencyCollector::attachToASTReader
void attachToASTReader(ASTReader &R) override
Definition: ModuleDependencyCollector.cpp:101
ASTReader.h
sys
clang::SrcMgr::CharacteristicKind
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:77
clang::HeaderSearch::getModuleMap
ModuleMap & getModuleMap()
Retrieve the module map.
Definition: HeaderSearch.h:652
clang::PPCallbacks
This interface provides a way to observe the actions of the preprocessor as it does its thing...
Definition: PPCallbacks.h:35
clang::Token
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
clang::Module
Describes a module or submodule.
Definition: Module.h:64
llvm::SmallVectorImpl< char >
clang::Preprocessor::getHeaderSearchInfo
HeaderSearch & getHeaderSearchInfo() const
Definition: Preprocessor.h:912
clang::ModuleDependencyCollector::attachToPreprocessor
void attachToPreprocessor(Preprocessor &PP) override
Definition: ModuleDependencyCollector.cpp:105
clang::ModuleMap::addModuleMapCallbacks
void addModuleMapCallbacks(std::unique_ptr< ModuleMapCallbacks > Callback)
Add a module map callback.
Definition: ModuleMap.h:418
Utils.h
llvm::SmallString< 128 >
CharInfo.h
Filename
StringRef Filename
Definition: Format.cpp:1825
clang::CharSourceRange
Represents a character-granular source range.
Definition: SourceLocation.h:250
Preprocessor.h
Defines the clang::Preprocessor interface.
clang::ModuleMapCallbacks
A mechanism to observe the actions of the module map parser as it reads module map files...
Definition: ModuleMap.h:47
clang::InclusionDirective
Record the location of an inclusion directive, such as an #include or #import statement.
Definition: PreprocessingRecord.h:208
clang::ModuleDependencyCollector
Collects the dependencies for imported modules into a directory.
Definition: Utils.h:149
clang::ObjCSubstitutionContext::Result
The result type of a method or function.
SM
const SourceManager & SM
Definition: Format.cpp:1685
clang::Preprocessor::getSourceManager
SourceManager & getSourceManager() const
Definition: Preprocessor.h:911
clang::FileEntry::getDir
const DirectoryEntry * getDir() const
Return the directory the file lives in.
Definition: FileManager.h:111
clang::ModuleDependencyCollector::writeFileMap
virtual void writeFileMap()
Definition: ModuleDependencyCollector.cpp:130
clang::ASTReader::addListener
void addListener(std::unique_ptr< ASTReaderListener > L)
Add an AST callback listener.
Definition: ASTReader.h:1576
clang::SourceLocation
Encodes a location in the source.
Definition: SourceLocation.h:86
clang::FileEntry::getName
StringRef getName() const
Definition: FileManager.h:102
clang::FileEntry
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:78
clang::ModuleDependencyCollector::addFile
virtual void addFile(StringRef Filename, StringRef FileDst={})
Definition: ModuleDependencyCollector.cpp:236
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:21
isCaseSensitivePath
static bool isCaseSensitivePath(StringRef Path)
Definition: ModuleDependencyCollector.cpp:112
clang::ASTReader
Reads an AST files chain containing the contents of a translation unit.
Definition: ASTReader.h:340
clang::FileManager::getFile
llvm::ErrorOr< const FileEntry * > getFile(StringRef Filename, bool OpenFile=false, bool CacheFailure=true)
Lookup, cache, and verify the specified file (real or virtual).
Definition: FileManager.cpp:195
clang::ASTReaderListener
Abstract interface for callback invocations by the ASTReader.
Definition: ASTReader.h:112
clang::AttrSyntax::C
clang::toUppercase
LLVM_READONLY char toUppercase(char c)
Converts the given ASCII character to its uppercase equivalent.
Definition: CharInfo.h:173
clang::Preprocessor::addPPCallbacks
void addPPCallbacks(std::unique_ptr< PPCallbacks > C)
Definition: Preprocessor.h:1005
clang::SourceManager
This class handles loading and caching of source files into memory.
Definition: SourceManager.h:596
clang::Preprocessor
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:128
clang::DirectoryEntry::getName
StringRef getName() const
Definition: FileManager.h:52