1 //===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "clang/Frontend/DependencyOutputOptions.h"
11 #include "clang/Frontend/Utils.h"
12 #include "clang/Basic/SourceManager.h"
13 #include "clang/Frontend/FrontendDiagnostic.h"
14 #include "clang/Lex/Preprocessor.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/Support/raw_ostream.h"
17 using namespace clang;
20 class HeaderIncludesCallback : public PPCallbacks {
22 raw_ostream *OutputFile;
23 const DependencyOutputOptions &DepOpts;
24 unsigned CurrentIncludeDepth;
25 bool HasProcessedPredefines;
32 HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
33 raw_ostream *OutputFile_,
34 const DependencyOutputOptions &DepOpts,
35 bool OwnsOutputFile_, bool ShowDepth_, bool MSStyle_)
36 : SM(PP->getSourceManager()), OutputFile(OutputFile_), DepOpts(DepOpts),
37 CurrentIncludeDepth(0), HasProcessedPredefines(false),
38 OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_),
39 ShowDepth(ShowDepth_), MSStyle(MSStyle_) {}
41 ~HeaderIncludesCallback() override {
46 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
47 SrcMgr::CharacteristicKind FileType,
48 FileID PrevFID) override;
52 static void PrintHeaderInfo(raw_ostream *OutputFile, StringRef Filename,
53 bool ShowDepth, unsigned CurrentIncludeDepth,
55 // Write to a temporary string to avoid unnecessary flushing on errs().
56 SmallString<512> Pathname(Filename);
58 Lexer::Stringify(Pathname);
62 Msg += "Note: including file:";
65 // The main source file is at depth 1, so skip one dot.
66 for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
67 Msg += MSStyle ? ' ' : '.';
79 void clang::AttachHeaderIncludeGen(Preprocessor &PP,
80 const DependencyOutputOptions &DepOpts,
81 bool ShowAllHeaders, StringRef OutputPath,
82 bool ShowDepth, bool MSStyle) {
83 raw_ostream *OutputFile = &llvm::errs();
84 bool OwnsOutputFile = false;
86 // Choose output stream, when printing in cl.exe /showIncludes style.
88 switch (DepOpts.ShowIncludesDest) {
90 llvm_unreachable("Invalid destination for /showIncludes output!");
91 case ShowIncludesDestination::Stderr:
92 OutputFile = &llvm::errs();
94 case ShowIncludesDestination::Stdout:
95 OutputFile = &llvm::outs();
100 // Open the output file, if used.
101 if (!OutputPath.empty()) {
103 llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
104 OutputPath.str(), EC, llvm::sys::fs::F_Append | llvm::sys::fs::F_Text);
106 PP.getDiagnostics().Report(clang::diag::warn_fe_cc_print_header_failure)
112 OwnsOutputFile = true;
116 // Print header info for extra headers, pretending they were discovered by
117 // the regular preprocessor. The primary use case is to support proper
118 // generation of Make / Ninja file dependencies for implicit includes, such
119 // as sanitizer blacklists. It's only important for cl.exe compatibility,
120 // the GNU way to generate rules is -M / -MM / -MD / -MMD.
121 for (const auto &Header : DepOpts.ExtraDeps)
122 PrintHeaderInfo(OutputFile, Header, ShowDepth, 2, MSStyle);
123 PP.addPPCallbacks(llvm::make_unique<HeaderIncludesCallback>(
124 &PP, ShowAllHeaders, OutputFile, DepOpts, OwnsOutputFile, ShowDepth,
128 void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
129 FileChangeReason Reason,
130 SrcMgr::CharacteristicKind NewFileType,
132 // Unless we are exiting a #include, make sure to skip ahead to the line the
133 // #include directive was at.
134 PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
135 if (UserLoc.isInvalid())
138 // Adjust the current include depth.
139 if (Reason == PPCallbacks::EnterFile) {
140 ++CurrentIncludeDepth;
141 } else if (Reason == PPCallbacks::ExitFile) {
142 if (CurrentIncludeDepth)
143 --CurrentIncludeDepth;
145 // We track when we are done with the predefines by watching for the first
146 // place where we drop back to a nesting depth of 1.
147 if (CurrentIncludeDepth == 1 && !HasProcessedPredefines) {
148 if (!DepOpts.ShowIncludesPretendHeader.empty()) {
149 PrintHeaderInfo(OutputFile, DepOpts.ShowIncludesPretendHeader,
150 ShowDepth, 2, MSStyle);
152 HasProcessedPredefines = true;
159 // Show the header if we are (a) past the predefines, or (b) showing all
160 // headers and in the predefines at a depth past the initial file and command
162 bool ShowHeader = (HasProcessedPredefines ||
163 (ShowAllHeaders && CurrentIncludeDepth > 2));
164 unsigned IncludeDepth = CurrentIncludeDepth;
165 if (!HasProcessedPredefines)
166 --IncludeDepth; // Ignore indent from <built-in>.
167 else if (!DepOpts.ShowIncludesPretendHeader.empty())
168 ++IncludeDepth; // Pretend inclusion by ShowIncludesPretendHeader.
170 // Dump the header include information we are past the predefines buffer or
171 // are showing all headers and this isn't the magic implicit <command line>
173 // FIXME: Identify headers in a more robust way than comparing their name to
174 // "<command line>" and "<built-in>" in a bunch of places.
175 if (ShowHeader && Reason == PPCallbacks::EnterFile &&
176 UserLoc.getFilename() != StringRef("<command line>")) {
177 PrintHeaderInfo(OutputFile, UserLoc.getFilename(), ShowDepth, IncludeDepth,