aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/clang14/lib/Lex/TokenConcatenation.cpp
blob: f6b005d9e19cf441d024fb316a16b81669a41fa8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
//===--- TokenConcatenation.cpp - Token Concatenation Avoidance -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the TokenConcatenation class.
//
//===----------------------------------------------------------------------===//

#include "clang/Lex/TokenConcatenation.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/Support/ErrorHandling.h"
using namespace clang;


/// IsStringPrefix - Return true if Str is a string prefix.
/// 'L', 'u', 'U', or 'u8'. Including raw versions.
static bool IsStringPrefix(StringRef Str, bool CPlusPlus11) {

  if (Str[0] == 'L' ||
      (CPlusPlus11 && (Str[0] == 'u' || Str[0] == 'U' || Str[0] == 'R'))) {

    if (Str.size() == 1)
      return true; // "L", "u", "U", and "R"

    // Check for raw flavors. Need to make sure the first character wasn't
    // already R. Need CPlusPlus11 check for "LR".
    if (Str[1] == 'R' && Str[0] != 'R' && Str.size() == 2 && CPlusPlus11)
      return true; // "LR", "uR", "UR"

    // Check for "u8" and "u8R"
    if (Str[0] == 'u' && Str[1] == '8') {
      if (Str.size() == 2) return true; // "u8"
      if (Str.size() == 3 && Str[2] == 'R') return true; // "u8R"
    }
  }

  return false;
}

/// IsIdentifierStringPrefix - Return true if the spelling of the token
/// is literally 'L', 'u', 'U', or 'u8'. Including raw versions.
bool TokenConcatenation::IsIdentifierStringPrefix(const Token &Tok) const {
  const LangOptions &LangOpts = PP.getLangOpts();

  if (!Tok.needsCleaning()) {
    if (Tok.getLength() < 1 || Tok.getLength() > 3)
      return false;
    SourceManager &SM = PP.getSourceManager();
    const char *Ptr = SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation()));
    return IsStringPrefix(StringRef(Ptr, Tok.getLength()),
                          LangOpts.CPlusPlus11);
  }

  if (Tok.getLength() < 256) {
    char Buffer[256];
    const char *TokPtr = Buffer;
    unsigned length = PP.getSpelling(Tok, TokPtr);
    return IsStringPrefix(StringRef(TokPtr, length), LangOpts.CPlusPlus11);
  }

  return IsStringPrefix(StringRef(PP.getSpelling(Tok)), LangOpts.CPlusPlus11);
}

TokenConcatenation::TokenConcatenation(const Preprocessor &pp) : PP(pp) {
  memset(TokenInfo, 0, sizeof(TokenInfo));

  // These tokens have custom code in AvoidConcat.
  TokenInfo[tok::identifier      ] |= aci_custom;
  TokenInfo[tok::numeric_constant] |= aci_custom_firstchar;
  TokenInfo[tok::period          ] |= aci_custom_firstchar;
  TokenInfo[tok::amp             ] |= aci_custom_firstchar;
  TokenInfo[tok::plus            ] |= aci_custom_firstchar;
  TokenInfo[tok::minus           ] |= aci_custom_firstchar;
  TokenInfo[tok::slash           ] |= aci_custom_firstchar;
  TokenInfo[tok::less            ] |= aci_custom_firstchar;
  TokenInfo[tok::greater         ] |= aci_custom_firstchar;
  TokenInfo[tok::pipe            ] |= aci_custom_firstchar;
  TokenInfo[tok::percent         ] |= aci_custom_firstchar;
  TokenInfo[tok::colon           ] |= aci_custom_firstchar;
  TokenInfo[tok::hash            ] |= aci_custom_firstchar;
  TokenInfo[tok::arrow           ] |= aci_custom_firstchar;

  // These tokens have custom code in C++11 mode.
  if (PP.getLangOpts().CPlusPlus11) {
    TokenInfo[tok::string_literal      ] |= aci_custom;
    TokenInfo[tok::wide_string_literal ] |= aci_custom;
    TokenInfo[tok::utf8_string_literal ] |= aci_custom;
    TokenInfo[tok::utf16_string_literal] |= aci_custom;
    TokenInfo[tok::utf32_string_literal] |= aci_custom;
    TokenInfo[tok::char_constant       ] |= aci_custom;
    TokenInfo[tok::wide_char_constant  ] |= aci_custom;
    TokenInfo[tok::utf16_char_constant ] |= aci_custom;
    TokenInfo[tok::utf32_char_constant ] |= aci_custom;
  }

  // These tokens have custom code in C++17 mode.
  if (PP.getLangOpts().CPlusPlus17)
    TokenInfo[tok::utf8_char_constant] |= aci_custom;

  // These tokens have custom code in C++2a mode.
  if (PP.getLangOpts().CPlusPlus20)
    TokenInfo[tok::lessequal ] |= aci_custom_firstchar;

  // These tokens change behavior if followed by an '='.
  TokenInfo[tok::amp         ] |= aci_avoid_equal;           // &=
  TokenInfo[tok::plus        ] |= aci_avoid_equal;           // +=
  TokenInfo[tok::minus       ] |= aci_avoid_equal;           // -=
  TokenInfo[tok::slash       ] |= aci_avoid_equal;           // /=
  TokenInfo[tok::less        ] |= aci_avoid_equal;           // <=
  TokenInfo[tok::greater     ] |= aci_avoid_equal;           // >=
  TokenInfo[tok::pipe        ] |= aci_avoid_equal;           // |=
  TokenInfo[tok::percent     ] |= aci_avoid_equal;           // %=
  TokenInfo[tok::star        ] |= aci_avoid_equal;           // *=
  TokenInfo[tok::exclaim     ] |= aci_avoid_equal;           // !=
  TokenInfo[tok::lessless    ] |= aci_avoid_equal;           // <<=
  TokenInfo[tok::greatergreater] |= aci_avoid_equal;         // >>=
  TokenInfo[tok::caret       ] |= aci_avoid_equal;           // ^=
  TokenInfo[tok::equal       ] |= aci_avoid_equal;           // ==
}

/// GetFirstChar - Get the first character of the token \arg Tok,
/// avoiding calls to getSpelling where possible.
static char GetFirstChar(const Preprocessor &PP, const Token &Tok) {
  if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
    // Avoid spelling identifiers, the most common form of token.
    return II->getNameStart()[0];
  } else if (!Tok.needsCleaning()) {
    if (Tok.isLiteral() && Tok.getLiteralData()) {
      return *Tok.getLiteralData();
    } else {
      SourceManager &SM = PP.getSourceManager();
      return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation()));
    }
  } else if (Tok.getLength() < 256) {
    char Buffer[256];
    const char *TokPtr = Buffer;
    PP.getSpelling(Tok, TokPtr);
    return TokPtr[0];
  } else {
    return PP.getSpelling(Tok)[0];
  }
}

/// AvoidConcat - If printing PrevTok immediately followed by Tok would cause
/// the two individual tokens to be lexed as a single token, return true
/// (which causes a space to be printed between them).  This allows the output
/// of -E mode to be lexed to the same token stream as lexing the input
/// directly would.
///
/// This code must conservatively return true if it doesn't want to be 100%
/// accurate.  This will cause the output to include extra space characters,
/// but the resulting output won't have incorrect concatenations going on.
/// Examples include "..", which we print with a space between, because we
/// don't want to track enough to tell "x.." from "...".
bool TokenConcatenation::AvoidConcat(const Token &PrevPrevTok,
                                     const Token &PrevTok,
                                     const Token &Tok) const {
  // Conservatively assume that every annotation token that has a printable
  // form requires whitespace.
  if (PrevTok.isAnnotation())
    return true;

  // First, check to see if the tokens were directly adjacent in the original
  // source.  If they were, it must be okay to stick them together: if there
  // were an issue, the tokens would have been lexed differently.
  SourceManager &SM = PP.getSourceManager();
  SourceLocation PrevSpellLoc = SM.getSpellingLoc(PrevTok.getLocation());
  SourceLocation SpellLoc = SM.getSpellingLoc(Tok.getLocation());
  if (PrevSpellLoc.getLocWithOffset(PrevTok.getLength()) == SpellLoc)
    return false;

  tok::TokenKind PrevKind = PrevTok.getKind();
  if (!PrevTok.isAnnotation() && PrevTok.getIdentifierInfo())
    PrevKind = tok::identifier; // Language keyword or named operator.

  // Look up information on when we should avoid concatenation with prevtok.
  unsigned ConcatInfo = TokenInfo[PrevKind];

  // If prevtok never causes a problem for anything after it, return quickly.
  if (ConcatInfo == 0) return false;

  if (ConcatInfo & aci_avoid_equal) {
    // If the next token is '=' or '==', avoid concatenation.
    if (Tok.isOneOf(tok::equal, tok::equalequal))
      return true;
    ConcatInfo &= ~aci_avoid_equal;
  }
  if (Tok.isAnnotation()) {
    // Modules annotation can show up when generated automatically for includes.
    assert(Tok.isOneOf(tok::annot_module_include, tok::annot_module_begin,
                       tok::annot_module_end) &&
           "unexpected annotation in AvoidConcat");
    ConcatInfo = 0;
  }

  if (ConcatInfo == 0)
    return false;

  // Basic algorithm: we look at the first character of the second token, and
  // determine whether it, if appended to the first token, would form (or
  // would contribute) to a larger token if concatenated.
  char FirstChar = 0;
  if (ConcatInfo & aci_custom) {
    // If the token does not need to know the first character, don't get it.
  } else {
    FirstChar = GetFirstChar(PP, Tok);
  }

  switch (PrevKind) {
  default:
    llvm_unreachable("InitAvoidConcatTokenInfo built wrong");

  case tok::raw_identifier:
    llvm_unreachable("tok::raw_identifier in non-raw lexing mode!");

  case tok::string_literal:
  case tok::wide_string_literal:
  case tok::utf8_string_literal:
  case tok::utf16_string_literal:
  case tok::utf32_string_literal:
  case tok::char_constant:
  case tok::wide_char_constant:
  case tok::utf8_char_constant:
  case tok::utf16_char_constant:
  case tok::utf32_char_constant:
    if (!PP.getLangOpts().CPlusPlus11)
      return false;

    // In C++11, a string or character literal followed by an identifier is a
    // single token.
    if (Tok.getIdentifierInfo())
      return true;

    // A ud-suffix is an identifier. If the previous token ends with one, treat
    // it as an identifier.
    if (!PrevTok.hasUDSuffix())
      return false;
    LLVM_FALLTHROUGH;
  case tok::identifier:   // id+id or id+number or id+L"foo".
    // id+'.'... will not append.
    if (Tok.is(tok::numeric_constant))
      return GetFirstChar(PP, Tok) != '.';

    if (Tok.getIdentifierInfo() ||
        Tok.isOneOf(tok::wide_string_literal, tok::utf8_string_literal,
                    tok::utf16_string_literal, tok::utf32_string_literal,
                    tok::wide_char_constant, tok::utf8_char_constant,
                    tok::utf16_char_constant, tok::utf32_char_constant))
      return true;

    // If this isn't identifier + string, we're done.
    if (Tok.isNot(tok::char_constant) && Tok.isNot(tok::string_literal))
      return false;

    // Otherwise, this is a narrow character or string.  If the *identifier*
    // is a literal 'L', 'u8', 'u' or 'U', avoid pasting L "foo" -> L"foo".
    return IsIdentifierStringPrefix(PrevTok);

  case tok::numeric_constant:
    return isPreprocessingNumberBody(FirstChar) ||
           FirstChar == '+' || FirstChar == '-';
  case tok::period:          // ..., .*, .1234
    return (FirstChar == '.' && PrevPrevTok.is(tok::period)) ||
           isDigit(FirstChar) ||
           (PP.getLangOpts().CPlusPlus && FirstChar == '*');
  case tok::amp:             // &&
    return FirstChar == '&';
  case tok::plus:            // ++
    return FirstChar == '+';
  case tok::minus:           // --, ->, ->*
    return FirstChar == '-' || FirstChar == '>';
  case tok::slash:           //, /*, //
    return FirstChar == '*' || FirstChar == '/';
  case tok::less:            // <<, <<=, <:, <%
    return FirstChar == '<' || FirstChar == ':' || FirstChar == '%';
  case tok::greater:         // >>, >>=
    return FirstChar == '>';
  case tok::pipe:            // ||
    return FirstChar == '|';
  case tok::percent:         // %>, %:
    return FirstChar == '>' || FirstChar == ':';
  case tok::colon:           // ::, :>
    return FirstChar == '>' ||
    (PP.getLangOpts().CPlusPlus && FirstChar == ':');
  case tok::hash:            // ##, #@, %:%:
    return FirstChar == '#' || FirstChar == '@' || FirstChar == '%';
  case tok::arrow:           // ->*
    return PP.getLangOpts().CPlusPlus && FirstChar == '*';
  case tok::lessequal:       // <=> (C++2a)
    return PP.getLangOpts().CPlusPlus20 && FirstChar == '>';
  }
}