1 //===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "clang/Frontend/Utils.h"
11 #include "clang/Basic/SourceManager.h"
12 #include "clang/Frontend/FrontendDiagnostic.h"
13 #include "clang/Lex/Preprocessor.h"
14 #include "llvm/ADT/SmallString.h"
15 #include "llvm/Support/raw_ostream.h"
16 using namespace clang;
17
18 namespace {
19 class HeaderIncludesCallback : public PPCallbacks {
20 SourceManager &SM;
21 raw_ostream *OutputFile;
22 unsigned CurrentIncludeDepth;
23 bool HasProcessedPredefines;
24 bool OwnsOutputFile;
25 bool ShowAllHeaders;
26 bool ShowDepth;
27 bool MSStyle;
28
29 public:
HeaderIncludesCallback(const Preprocessor * PP,bool ShowAllHeaders_,raw_ostream * OutputFile_,bool OwnsOutputFile_,bool ShowDepth_,bool MSStyle_)30 HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
31 raw_ostream *OutputFile_, bool OwnsOutputFile_,
32 bool ShowDepth_, bool MSStyle_)
33 : SM(PP->getSourceManager()), OutputFile(OutputFile_),
34 CurrentIncludeDepth(0), HasProcessedPredefines(false),
35 OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_),
36 ShowDepth(ShowDepth_), MSStyle(MSStyle_) {}
37
~HeaderIncludesCallback()38 ~HeaderIncludesCallback() {
39 if (OwnsOutputFile)
40 delete OutputFile;
41 }
42
43 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
44 SrcMgr::CharacteristicKind FileType,
45 FileID PrevFID) override;
46 };
47 }
48
AttachHeaderIncludeGen(Preprocessor & PP,bool ShowAllHeaders,StringRef OutputPath,bool ShowDepth,bool MSStyle)49 void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders,
50 StringRef OutputPath, bool ShowDepth,
51 bool MSStyle) {
52 raw_ostream *OutputFile = MSStyle ? &llvm::outs() : &llvm::errs();
53 bool OwnsOutputFile = false;
54
55 // Open the output file, if used.
56 if (!OutputPath.empty()) {
57 std::error_code EC;
58 llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
59 OutputPath.str(), EC, llvm::sys::fs::F_Append | llvm::sys::fs::F_Text);
60 if (EC) {
61 PP.getDiagnostics().Report(clang::diag::warn_fe_cc_print_header_failure)
62 << EC.message();
63 delete OS;
64 } else {
65 OS->SetUnbuffered();
66 OS->SetUseAtomicWrites(true);
67 OutputFile = OS;
68 OwnsOutputFile = true;
69 }
70 }
71
72 PP.addPPCallbacks(llvm::make_unique<HeaderIncludesCallback>(&PP,
73 ShowAllHeaders,
74 OutputFile,
75 OwnsOutputFile,
76 ShowDepth,
77 MSStyle));
78 }
79
FileChanged(SourceLocation Loc,FileChangeReason Reason,SrcMgr::CharacteristicKind NewFileType,FileID PrevFID)80 void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
81 FileChangeReason Reason,
82 SrcMgr::CharacteristicKind NewFileType,
83 FileID PrevFID) {
84 // Unless we are exiting a #include, make sure to skip ahead to the line the
85 // #include directive was at.
86 PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
87 if (UserLoc.isInvalid())
88 return;
89
90 // Adjust the current include depth.
91 if (Reason == PPCallbacks::EnterFile) {
92 ++CurrentIncludeDepth;
93 } else if (Reason == PPCallbacks::ExitFile) {
94 if (CurrentIncludeDepth)
95 --CurrentIncludeDepth;
96
97 // We track when we are done with the predefines by watching for the first
98 // place where we drop back to a nesting depth of 1.
99 if (CurrentIncludeDepth == 1 && !HasProcessedPredefines)
100 HasProcessedPredefines = true;
101
102 return;
103 } else
104 return;
105
106 // Show the header if we are (a) past the predefines, or (b) showing all
107 // headers and in the predefines at a depth past the initial file and command
108 // line buffers.
109 bool ShowHeader = (HasProcessedPredefines ||
110 (ShowAllHeaders && CurrentIncludeDepth > 2));
111
112 // Dump the header include information we are past the predefines buffer or
113 // are showing all headers.
114 if (ShowHeader && Reason == PPCallbacks::EnterFile) {
115 // Write to a temporary string to avoid unnecessary flushing on errs().
116 SmallString<512> Filename(UserLoc.getFilename());
117 if (!MSStyle)
118 Lexer::Stringify(Filename);
119
120 SmallString<256> Msg;
121 if (MSStyle)
122 Msg += "Note: including file:";
123
124 if (ShowDepth) {
125 // The main source file is at depth 1, so skip one dot.
126 for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
127 Msg += MSStyle ? ' ' : '.';
128
129 if (!MSStyle)
130 Msg += ' ';
131 }
132 Msg += Filename;
133 Msg += '\n';
134
135 OutputFile->write(Msg.data(), Msg.size());
136 OutputFile->flush();
137 }
138 }
139