llvm-project/clang/lib/Frontend/HeaderIncludeGen.cpp

114 lines
3.8 KiB
C++

//===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/Utils.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
namespace {
class HeaderIncludesCallback : public PPCallbacks {
SourceManager &SM;
llvm::raw_ostream *OutputFile;
unsigned CurrentIncludeDepth;
bool HasProcessedPredefines;
bool OwnsOutputFile;
bool ShowAllHeaders;
public:
HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
llvm::raw_ostream *OutputFile_, bool OwnsOutputFile_)
: SM(PP->getSourceManager()), OutputFile(OutputFile_),
CurrentIncludeDepth(0), HasProcessedPredefines(false),
OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_) {}
~HeaderIncludesCallback() {
if (OwnsOutputFile)
delete OutputFile;
}
virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
SrcMgr::CharacteristicKind FileType);
};
}
void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders,
llvm::StringRef OutputPath) {
llvm::raw_ostream *OutputFile = &llvm::errs();
bool OwnsOutputFile = false;
// Open the output file, if used.
if (!OutputPath.empty()) {
std::string Error;
llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
OutputPath.str().c_str(), Error, llvm::raw_fd_ostream::F_Append);
if (!Error.empty()) {
PP.getDiagnostics().Report(
clang::diag::warn_fe_cc_print_header_failure) << Error;
delete OS;
} else {
OS->SetUnbuffered();
OS->SetUseAtomicWrites(true);
OutputFile = OS;
OwnsOutputFile = true;
}
}
PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders,
OutputFile, OwnsOutputFile));
}
void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
FileChangeReason Reason,
SrcMgr::CharacteristicKind NewFileType) {
// Unless we are exiting a #include, make sure to skip ahead to the line the
// #include directive was at.
PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
if (UserLoc.isInvalid())
return;
// Adjust the current include depth.
if (Reason == PPCallbacks::EnterFile) {
++CurrentIncludeDepth;
} else {
if (CurrentIncludeDepth)
--CurrentIncludeDepth;
// We track when we are done with the predefines by watching for the first
// place where we drop back to a nesting depth of 0.
if (CurrentIncludeDepth == 0 && !HasProcessedPredefines)
HasProcessedPredefines = true;
}
// Show the header if we are (a) past the predefines, or (b) showing all
// headers and in the predefines at a depth past the initial file and command
// line buffers.
bool ShowHeader = (HasProcessedPredefines ||
(ShowAllHeaders && CurrentIncludeDepth > 2));
// Dump the header include information we are past the predefines buffer or
// are showing all headers.
if (ShowHeader && Reason == PPCallbacks::EnterFile) {
// Write to a temporary string to avoid unnecessary flushing on errs().
llvm::SmallString<512> Filename(UserLoc.getFilename());
Lexer::Stringify(Filename);
llvm::SmallString<256> Msg;
for (unsigned i = 0; i != CurrentIncludeDepth; ++i)
Msg += '.';
Msg += ' ';
Msg += Filename;
Msg += '\n';
OutputFile->write(Msg.data(), Msg.size());
}
}