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::string Error;
58 llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
59 OutputPath.str().c_str(), Error,
60 llvm::sys::fs::F_Append | llvm::sys::fs::F_Text);
61 if (!Error.empty()) {
62 PP.getDiagnostics().Report(
63 clang::diag::warn_fe_cc_print_header_failure) << Error;
64 delete OS;
65 } else {
66 OS->SetUnbuffered();
67 OS->SetUseAtomicWrites(true);
68 OutputFile = OS;
69 OwnsOutputFile = true;
70 }
71 }
72
73 PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders,
74 OutputFile, OwnsOutputFile,
75 ShowDepth, MSStyle));
76 }
77
FileChanged(SourceLocation Loc,FileChangeReason Reason,SrcMgr::CharacteristicKind NewFileType,FileID PrevFID)78 void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
79 FileChangeReason Reason,
80 SrcMgr::CharacteristicKind NewFileType,
81 FileID PrevFID) {
82 // Unless we are exiting a #include, make sure to skip ahead to the line the
83 // #include directive was at.
84 PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
85 if (UserLoc.isInvalid())
86 return;
87
88 // Adjust the current include depth.
89 if (Reason == PPCallbacks::EnterFile) {
90 ++CurrentIncludeDepth;
91 } else if (Reason == PPCallbacks::ExitFile) {
92 if (CurrentIncludeDepth)
93 --CurrentIncludeDepth;
94
95 // We track when we are done with the predefines by watching for the first
96 // place where we drop back to a nesting depth of 1.
97 if (CurrentIncludeDepth == 1 && !HasProcessedPredefines)
98 HasProcessedPredefines = true;
99
100 return;
101 } else
102 return;
103
104 // Show the header if we are (a) past the predefines, or (b) showing all
105 // headers and in the predefines at a depth past the initial file and command
106 // line buffers.
107 bool ShowHeader = (HasProcessedPredefines ||
108 (ShowAllHeaders && CurrentIncludeDepth > 2));
109
110 // Dump the header include information we are past the predefines buffer or
111 // are showing all headers.
112 if (ShowHeader && Reason == PPCallbacks::EnterFile) {
113 // Write to a temporary string to avoid unnecessary flushing on errs().
114 SmallString<512> Filename(UserLoc.getFilename());
115 if (!MSStyle)
116 Lexer::Stringify(Filename);
117
118 SmallString<256> Msg;
119 if (MSStyle)
120 Msg += "Note: including file:";
121
122 if (ShowDepth) {
123 // The main source file is at depth 1, so skip one dot.
124 for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
125 Msg += MSStyle ? ' ' : '.';
126
127 if (!MSStyle)
128 Msg += ' ';
129 }
130 Msg += Filename;
131 Msg += '\n';
132
133 OutputFile->write(Msg.data(), Msg.size());
134 }
135 }
136