1 //===- StringToOffsetTable.h - Emit a big concatenated string ---*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #ifndef LLVM_TABLEGEN_STRINGTOOFFSETTABLE_H
10 #define LLVM_TABLEGEN_STRINGTOOFFSETTABLE_H
12 #include "llvm/ADT/SmallString.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/ADT/StringMap.h"
15 #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 bool Empty() const { return StringOffset.empty(); }
31 unsigned GetOrAddStringOffset(StringRef Str, bool appendZero = true) {
33 StringOffset.insert(std::make_pair(Str, AggregateString.size()));
34 if (IterBool.second) {
35 // Add the string to the aggregate if this is the first time found.
36 AggregateString.append(Str.begin(), Str.end());
38 AggregateString += '\0';
41 return IterBool.first->second;
44 void EmitString(raw_ostream &O) {
47 raw_svector_ostream(Str).write_escaped(AggregateString);
48 AggregateString = Str.str();
51 unsigned CharsPrinted = 0;
52 for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
53 if (CharsPrinted > 70) {
57 O << AggregateString[i];
60 // Print escape sequences all together.
61 if (AggregateString[i] != '\\')
64 assert(i + 1 < AggregateString.size() && "Incomplete escape sequence!");
65 if (isdigit(AggregateString[i + 1])) {
66 assert(isdigit(AggregateString[i + 2]) &&
67 isdigit(AggregateString[i + 3]) &&
68 "Expected 3 digit octal escape!");
69 O << AggregateString[++i];
70 O << AggregateString[++i];
71 O << AggregateString[++i];
74 O << AggregateString[++i];
81 /// Emit the string using character literals. MSVC has a limitation that
82 /// string literals cannot be longer than 64K.
83 void EmitCharArray(raw_ostream &O) {
84 assert(AggregateString.find(')') == std::string::npos &&
85 "can't emit raw string with closing parens");
88 for (char C : AggregateString) {
90 O.write_escaped(StringRef(&C, 1));
102 } // end namespace llvm