1 //===- StringToOffsetTable.h - Emit a big concatenated string ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef TBLGEN_STRING_TO_OFFSET_TABLE_H
11 #define TBLGEN_STRING_TO_OFFSET_TABLE_H
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/StringMap.h"
15 #include "llvm/ADT/StringExtras.h"
16 #include "llvm/Support/raw_ostream.h"
20 /// StringToOffsetTable - This class uniques a bunch of nul-terminated strings
21 /// and keeps track of their offset in a massive contiguous string allocation.
22 /// It can then output this string blob and use indexes into the string to
23 /// reference each piece.
24 class StringToOffsetTable {
25 StringMap<unsigned> StringOffset;
26 std::string AggregateString;
29 unsigned GetOrAddStringOffset(StringRef Str, bool appendZero = true) {
30 StringMapEntry<unsigned> &Entry = StringOffset.GetOrCreateValue(Str, -1U);
31 if (Entry.getValue() == -1U) {
32 // Add the string to the aggregate if this is the first time found.
33 Entry.setValue(AggregateString.size());
34 AggregateString.append(Str.begin(), Str.end());
36 AggregateString += '\0';
39 return Entry.getValue();
42 void EmitString(raw_ostream &O) {
45 raw_svector_ostream(Str).write_escaped(AggregateString);
46 AggregateString = Str.str();
49 unsigned CharsPrinted = 0;
50 for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
51 if (CharsPrinted > 70) {
55 O << AggregateString[i];
58 // Print escape sequences all together.
59 if (AggregateString[i] != '\\')
62 assert(i+1 < AggregateString.size() && "Incomplete escape sequence!");
63 if (isdigit(AggregateString[i+1])) {
64 assert(isdigit(AggregateString[i+2]) &&
65 isdigit(AggregateString[i+3]) &&
66 "Expected 3 digit octal escape!");
67 O << AggregateString[++i];
68 O << AggregateString[++i];
69 O << AggregateString[++i];
72 O << AggregateString[++i];
80 } // end namespace llvm