#include "llvm/Debugger/SourceFile.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cassert>
using namespace llvm;
static const char EmptyFile = 0;
SourceFile::SourceFile(const std::string &fn, const GlobalVariable *Desc)
: Filename(fn), Descriptor(Desc) {
File.reset(MemoryBuffer::getFileOrSTDIN(fn));
if (File == 0)
File.reset(MemoryBuffer::getMemBuffer(&EmptyFile, &EmptyFile));
}
SourceFile::~SourceFile() {
}
void SourceFile::calculateLineOffsets() const {
assert(LineOffset.empty() && "Line offsets already computed!");
const char *BufPtr = File->getBufferStart();
const char *FileStart = BufPtr;
const char *FileEnd = File->getBufferEnd();
do {
LineOffset.push_back(BufPtr-FileStart);
while (BufPtr != FileEnd && *BufPtr != '\n' && *BufPtr != '\r')
++BufPtr;
if (BufPtr != FileEnd) {
++BufPtr; if (BufPtr[-1] == '\r' && BufPtr != FileEnd && BufPtr[0] == '\n')
++BufPtr; }
} while (BufPtr != FileEnd);
}
void SourceFile::getSourceLine(unsigned LineNo, const char *&LineStart,
const char *&LineEnd) const {
LineStart = LineEnd = 0;
if (LineOffset.empty()) calculateLineOffsets();
if (LineNo >= LineOffset.size()) return;
LineStart = File->getBufferStart()+LineOffset[LineNo];
if (LineNo+1 < LineOffset.size())
LineEnd = File->getBufferStart()+LineOffset[LineNo+1];
else
LineEnd = File->getBufferEnd();
while (LineEnd != LineStart && (LineEnd[-1] == '\n' || LineEnd[-1] == '\r'))
--LineEnd;
assert(LineEnd >= LineStart && "We somehow got our pointers swizzled!");
}