llvm-project/llvm/lib/Debugger/SourceFile.cpp

117 lines
3.8 KiB
C++

//===-- SourceFile.cpp - SourceFile implementation for the debugger -------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SourceFile class for the LLVM debugger.
//
//===----------------------------------------------------------------------===//
#include "llvm/Debugger/SourceFile.h"
#include "Support/SlowOperationInformer.h"
#include "Support/FileUtilities.h"
#include <iostream>
#include <cerrno>
#include <fcntl.h>
#include <unistd.h>
using namespace llvm;
/// readFile - Load Filename into FileStart and FileEnd.
///
void SourceFile::readFile() {
ssize_t FileSize = getFileSize(Filename);
if (FileSize != -1) {
FDHandle FD(open(Filename.c_str(), O_RDONLY));
if (FD != -1) {
char *FilePos = new char[FileSize];
FileStart = FilePos;
// If this takes a long time, inform the user what we are doing.
SlowOperationInformer SOI("loading source file '" + Filename + "'");
try {
// Read in the whole buffer.
unsigned Amount = FileSize;
while (Amount) {
unsigned AmountToRead = 512*1024;
if (Amount < AmountToRead) AmountToRead = Amount;
ssize_t ReadAmount = read(FD, FilePos, AmountToRead);
if (ReadAmount < 0 && errno == EINTR)
continue;
else if (ReadAmount <= 0) {
// Couldn't read whole file just free memory and continue.
throw "Error reading file '" + Filename + "'!";
}
Amount -= ReadAmount;
FilePos += ReadAmount;
SOI.progress(FileSize-Amount, FileSize);
}
} catch (const std::string &Msg) {
std::cout << Msg << "\n";
// If the user cancels the operation, clean up after ourselves.
delete [] FileStart;
FileStart = 0;
return;
}
FileEnd = FileStart+FileSize;
}
}
}
/// calculateLineOffsets - Compute the LineOffset vector for the current file.
///
void SourceFile::calculateLineOffsets() const {
assert(LineOffset.empty() && "Line offsets already computed!");
const char *BufPtr = FileStart;
do {
LineOffset.push_back(BufPtr-FileStart);
// Scan until we get to a newline.
while (BufPtr != FileEnd && *BufPtr != '\n' && *BufPtr != '\r')
++BufPtr;
if (BufPtr != FileEnd) {
++BufPtr; // Skip over the \n or \r
if (BufPtr[-1] == '\r' && BufPtr != FileEnd && BufPtr[0] == '\n')
++BufPtr; // Skip over dos/windows style \r\n's
}
} while (BufPtr != FileEnd);
}
/// getSourceLine - Given a line number, return the start and end of the line
/// in the file. If the line number is invalid, or if the file could not be
/// loaded, null pointers are returned for the start and end of the file. Note
/// that line numbers start with 0, not 1.
void SourceFile::getSourceLine(unsigned LineNo, const char *&LineStart,
const char *&LineEnd) const {
LineStart = LineEnd = 0;
if (FileStart == 0) return; // Couldn't load file, return null pointers
if (LineOffset.empty()) calculateLineOffsets();
// Asking for an out-of-range line number?
if (LineNo >= LineOffset.size()) return;
// Otherwise, they are asking for a valid line, which we can fulfill.
LineStart = FileStart+LineOffset[LineNo];
if (LineNo+1 < LineOffset.size())
LineEnd = FileStart+LineOffset[LineNo+1];
else
LineEnd = FileEnd;
// If the line ended with a newline, strip it off.
while (LineEnd != LineStart && (LineEnd[-1] == '\n' || LineEnd[-1] == '\r'))
--LineEnd;
assert(LineEnd >= LineStart && "We somehow got our pointers swizzled!");
}