clang  8.0.0svn
HeaderIncludeGen.cpp
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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 
11 #include "clang/Frontend/Utils.h"
14 #include "clang/Lex/Preprocessor.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/Support/raw_ostream.h"
17 using namespace clang;
18 
19 namespace {
20 class HeaderIncludesCallback : public PPCallbacks {
22  raw_ostream *OutputFile;
23  const DependencyOutputOptions &DepOpts;
24  unsigned CurrentIncludeDepth;
25  bool HasProcessedPredefines;
26  bool OwnsOutputFile;
27  bool ShowAllHeaders;
28  bool ShowDepth;
29  bool MSStyle;
30 
31 public:
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_) {}
40 
41  ~HeaderIncludesCallback() override {
42  if (OwnsOutputFile)
43  delete OutputFile;
44  }
45 
46  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
48  FileID PrevFID) override;
49 };
50 }
51 
52 static void PrintHeaderInfo(raw_ostream *OutputFile, StringRef Filename,
53  bool ShowDepth, unsigned CurrentIncludeDepth,
54  bool MSStyle) {
55  // Write to a temporary string to avoid unnecessary flushing on errs().
56  SmallString<512> Pathname(Filename);
57  if (!MSStyle)
58  Lexer::Stringify(Pathname);
59 
60  SmallString<256> Msg;
61  if (MSStyle)
62  Msg += "Note: including file:";
63 
64  if (ShowDepth) {
65  // The main source file is at depth 1, so skip one dot.
66  for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
67  Msg += MSStyle ? ' ' : '.';
68 
69  if (!MSStyle)
70  Msg += ' ';
71  }
72  Msg += Pathname;
73  Msg += '\n';
74 
75  *OutputFile << Msg;
76  OutputFile->flush();
77 }
78 
80  const DependencyOutputOptions &DepOpts,
81  bool ShowAllHeaders, StringRef OutputPath,
82  bool ShowDepth, bool MSStyle) {
83  raw_ostream *OutputFile = &llvm::errs();
84  bool OwnsOutputFile = false;
85 
86  // Choose output stream, when printing in cl.exe /showIncludes style.
87  if (MSStyle) {
88  switch (DepOpts.ShowIncludesDest) {
89  default:
90  llvm_unreachable("Invalid destination for /showIncludes output!");
92  OutputFile = &llvm::errs();
93  break;
95  OutputFile = &llvm::outs();
96  break;
97  }
98  }
99 
100  // Open the output file, if used.
101  if (!OutputPath.empty()) {
102  std::error_code EC;
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);
105  if (EC) {
106  PP.getDiagnostics().Report(clang::diag::warn_fe_cc_print_header_failure)
107  << EC.message();
108  delete OS;
109  } else {
110  OS->SetUnbuffered();
111  OutputFile = OS;
112  OwnsOutputFile = true;
113  }
114  }
115 
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,
125  MSStyle));
126 }
127 
128 void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
129  FileChangeReason Reason,
130  SrcMgr::CharacteristicKind NewFileType,
131  FileID PrevFID) {
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())
136  return;
137 
138  // Adjust the current include depth.
139  if (Reason == PPCallbacks::EnterFile) {
140  ++CurrentIncludeDepth;
141  } else if (Reason == PPCallbacks::ExitFile) {
142  if (CurrentIncludeDepth)
143  --CurrentIncludeDepth;
144 
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);
151  }
152  HasProcessedPredefines = true;
153  }
154 
155  return;
156  } else
157  return;
158 
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
161  // line buffers.
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.
169 
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>
172  // header.
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,
178  MSStyle);
179  }
180 }
Defines the SourceManager interface.
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1292
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:78
This interface provides a way to observe the actions of the preprocessor as it does its thing...
Definition: PPCallbacks.h:36
ShowIncludesDestination ShowIncludesDest
Destination of cl.exe style /showIncludes info.
StringRef Filename
Definition: Format.cpp:1629
bool isInvalid() const
Return true if this object is invalid or uninitialized.
static void PrintHeaderInfo(raw_ostream *OutputFile, StringRef Filename, bool ShowDepth, unsigned CurrentIncludeDepth, bool MSStyle)
Defines the clang::Preprocessor interface.
void AttachHeaderIncludeGen(Preprocessor &PP, const DependencyOutputOptions &DepOpts, bool ShowAllHeaders=false, StringRef OutputPath={}, bool ShowDepth=true, bool MSStyle=false)
AttachHeaderIncludeGen - Create a header include list generator, and attach it to the given preproces...
Represents an unpacked "presumed" location which can be presented to the user.
const SourceManager & SM
Definition: Format.cpp:1490
const char * getFilename() const
Return the presumed filename of this location.
#define false
Definition: stdbool.h:33
Encodes a location in the source.
DependencyOutputOptions - Options for controlling the compiler dependency file generation.
std::vector< std::string > ExtraDeps
A list of filenames to be used as extra dependencies for every target.
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
Dataflow Directional Tag Classes.
PresumedLoc getPresumedLoc(SourceLocation Loc, bool UseLineDirectives=true) const
Returns the "presumed" location of a SourceLocation specifies.
DiagnosticsEngine & getDiagnostics() const
Definition: Preprocessor.h:812
void addPPCallbacks(std::unique_ptr< PPCallbacks > C)
Definition: Preprocessor.h:908
This class handles loading and caching of source files into memory.
static std::string Stringify(StringRef Str, bool Charify=false)
Stringify - Convert the specified string into a C string by i) escaping &#39;\&#39; and " characters and ii) ...
Definition: Lexer.cpp:247
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:125