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