YouCompleteMe/cpp/llvm/utils/TableGen/StringToOffsetTable.h
2012-07-05 17:51:06 -07:00

83 lines
2.5 KiB
C++

//===- StringToOffsetTable.h - Emit a big concatenated string ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef TBLGEN_STRING_TO_OFFSET_TABLE_H
#define TBLGEN_STRING_TO_OFFSET_TABLE_H
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
/// StringToOffsetTable - This class uniques a bunch of nul-terminated strings
/// and keeps track of their offset in a massive contiguous string allocation.
/// It can then output this string blob and use indexes into the string to
/// reference each piece.
class StringToOffsetTable {
StringMap<unsigned> StringOffset;
std::string AggregateString;
public:
unsigned GetOrAddStringOffset(StringRef Str, bool appendZero = true) {
StringMapEntry<unsigned> &Entry = StringOffset.GetOrCreateValue(Str, -1U);
if (Entry.getValue() == -1U) {
// Add the string to the aggregate if this is the first time found.
Entry.setValue(AggregateString.size());
AggregateString.append(Str.begin(), Str.end());
if (appendZero)
AggregateString += '\0';
}
return Entry.getValue();
}
void EmitString(raw_ostream &O) {
// Escape the string.
SmallString<256> Str;
raw_svector_ostream(Str).write_escaped(AggregateString);
AggregateString = Str.str();
O << " \"";
unsigned CharsPrinted = 0;
for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
if (CharsPrinted > 70) {
O << "\"\n \"";
CharsPrinted = 0;
}
O << AggregateString[i];
++CharsPrinted;
// Print escape sequences all together.
if (AggregateString[i] != '\\')
continue;
assert(i+1 < AggregateString.size() && "Incomplete escape sequence!");
if (isdigit(AggregateString[i+1])) {
assert(isdigit(AggregateString[i+2]) &&
isdigit(AggregateString[i+3]) &&
"Expected 3 digit octal escape!");
O << AggregateString[++i];
O << AggregateString[++i];
O << AggregateString[++i];
CharsPrinted += 3;
} else {
O << AggregateString[++i];
++CharsPrinted;
}
}
O << "\"";
}
};
} // end namespace llvm
#endif