clang  5.0.0
MacroArgs.cpp
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1 //===--- MacroArgs.cpp - Formal argument info for Macros ------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the MacroArgs interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Lex/MacroArgs.h"
16 #include "clang/Lex/MacroInfo.h"
17 #include "clang/Lex/Preprocessor.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/Support/SaveAndRestore.h"
20 #include <algorithm>
21 
22 using namespace clang;
23 
24 /// MacroArgs ctor function - This destroys the vector passed in.
26  ArrayRef<Token> UnexpArgTokens,
27  bool VarargsElided, Preprocessor &PP) {
28  assert(MI->isFunctionLike() &&
29  "Can't have args for an object-like macro!");
30  MacroArgs **ResultEnt = nullptr;
31  unsigned ClosestMatch = ~0U;
32 
33  // See if we have an entry with a big enough argument list to reuse on the
34  // free list. If so, reuse it.
35  for (MacroArgs **Entry = &PP.MacroArgCache; *Entry;
36  Entry = &(*Entry)->ArgCache)
37  if ((*Entry)->NumUnexpArgTokens >= UnexpArgTokens.size() &&
38  (*Entry)->NumUnexpArgTokens < ClosestMatch) {
39  ResultEnt = Entry;
40 
41  // If we have an exact match, use it.
42  if ((*Entry)->NumUnexpArgTokens == UnexpArgTokens.size())
43  break;
44  // Otherwise, use the best fit.
45  ClosestMatch = (*Entry)->NumUnexpArgTokens;
46  }
47 
49  if (!ResultEnt) {
50  // Allocate memory for a MacroArgs object with the lexer tokens at the end.
51  Result = (MacroArgs *)malloc(sizeof(MacroArgs) +
52  UnexpArgTokens.size() * sizeof(Token));
53  // Construct the MacroArgs object.
54  new (Result)
55  MacroArgs(UnexpArgTokens.size(), VarargsElided, MI->getNumParams());
56  } else {
57  Result = *ResultEnt;
58  // Unlink this node from the preprocessors singly linked list.
59  *ResultEnt = Result->ArgCache;
60  Result->NumUnexpArgTokens = UnexpArgTokens.size();
61  Result->VarargsElided = VarargsElided;
62  Result->NumMacroArgs = MI->getNumParams();
63  }
64 
65  // Copy the actual unexpanded tokens to immediately after the result ptr.
66  if (!UnexpArgTokens.empty())
67  std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(),
68  const_cast<Token*>(Result->getUnexpArgument(0)));
69 
70  return Result;
71 }
72 
73 /// destroy - Destroy and deallocate the memory for this object.
74 ///
76  StringifiedArgs.clear();
77 
78  // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries
79  // would deallocate the element vectors.
80  for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i)
81  PreExpArgTokens[i].clear();
82 
83  // Add this to the preprocessor's free list.
84  ArgCache = PP.MacroArgCache;
85  PP.MacroArgCache = this;
86 }
87 
88 /// deallocate - This should only be called by the Preprocessor when managing
89 /// its freelist.
91  MacroArgs *Next = ArgCache;
92 
93  // Run the dtor to deallocate the vectors.
94  this->~MacroArgs();
95  // Release the memory for the object.
96  free(this);
97 
98  return Next;
99 }
100 
101 
102 /// getArgLength - Given a pointer to an expanded or unexpanded argument,
103 /// return the number of tokens, not counting the EOF, that make up the
104 /// argument.
105 unsigned MacroArgs::getArgLength(const Token *ArgPtr) {
106  unsigned NumArgTokens = 0;
107  for (; ArgPtr->isNot(tok::eof); ++ArgPtr)
108  ++NumArgTokens;
109  return NumArgTokens;
110 }
111 
112 
113 /// getUnexpArgument - Return the unexpanded tokens for the specified formal.
114 ///
115 const Token *MacroArgs::getUnexpArgument(unsigned Arg) const {
116  // The unexpanded argument tokens start immediately after the MacroArgs object
117  // in memory.
118  const Token *Start = (const Token *)(this+1);
119  const Token *Result = Start;
120  // Scan to find Arg.
121  for (; Arg; ++Result) {
122  assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
123  if (Result->is(tok::eof))
124  --Arg;
125  }
126  assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
127  return Result;
128 }
129 
130 
131 /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
132 /// by pre-expansion, return false. Otherwise, conservatively return true.
134  Preprocessor &PP) const {
135  // If there are no identifiers in the argument list, or if the identifiers are
136  // known to not be macros, pre-expansion won't modify it.
137  for (; ArgTok->isNot(tok::eof); ++ArgTok)
138  if (IdentifierInfo *II = ArgTok->getIdentifierInfo())
139  if (II->hasMacroDefinition())
140  // Return true even though the macro could be a function-like macro
141  // without a following '(' token, or could be disabled, or not visible.
142  return true;
143  return false;
144 }
145 
146 /// getPreExpArgument - Return the pre-expanded form of the specified
147 /// argument.
148 const std::vector<Token> &
149 MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI,
150  Preprocessor &PP) {
151  assert(Arg < MI->getNumParams() && "Invalid argument number!");
152 
153  // If we have already computed this, return it.
154  if (PreExpArgTokens.size() < MI->getNumParams())
155  PreExpArgTokens.resize(MI->getNumParams());
156 
157  std::vector<Token> &Result = PreExpArgTokens[Arg];
158  if (!Result.empty()) return Result;
159 
160  SaveAndRestore<bool> PreExpandingMacroArgs(PP.InMacroArgPreExpansion, true);
161 
162  const Token *AT = getUnexpArgument(Arg);
163  unsigned NumToks = getArgLength(AT)+1; // Include the EOF.
164 
165  // Otherwise, we have to pre-expand this argument, populating Result. To do
166  // this, we set up a fake TokenLexer to lex from the unexpanded argument
167  // list. With this installed, we lex expanded tokens until we hit the EOF
168  // token at the end of the unexp list.
169  PP.EnterTokenStream(AT, NumToks, false /*disable expand*/,
170  false /*owns tokens*/);
171 
172  // Lex all of the macro-expanded tokens into Result.
173  do {
174  Result.push_back(Token());
175  Token &Tok = Result.back();
176  PP.Lex(Tok);
177  } while (Result.back().isNot(tok::eof));
178 
179  // Pop the token stream off the top of the stack. We know that the internal
180  // pointer inside of it is to the "end" of the token stream, but the stack
181  // will not otherwise be popped until the next token is lexed. The problem is
182  // that the token may be lexed sometime after the vector of tokens itself is
183  // destroyed, which would be badness.
184  if (PP.InCachingLexMode())
185  PP.ExitCachingLexMode();
187  return Result;
188 }
189 
190 
191 /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
192 /// tokens into the literal string token that should be produced by the C #
193 /// preprocessor operator. If Charify is true, then it should be turned into
194 /// a character literal for the Microsoft charize (#@) extension.
195 ///
197  Preprocessor &PP, bool Charify,
198  SourceLocation ExpansionLocStart,
199  SourceLocation ExpansionLocEnd) {
200  Token Tok;
201  Tok.startToken();
202  Tok.setKind(Charify ? tok::char_constant : tok::string_literal);
203 
204  const Token *ArgTokStart = ArgToks;
205 
206  // Stringify all the tokens.
208  Result += "\"";
209 
210  bool isFirst = true;
211  for (; ArgToks->isNot(tok::eof); ++ArgToks) {
212  const Token &Tok = *ArgToks;
213  if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()))
214  Result += ' ';
215  isFirst = false;
216 
217  // If this is a string or character constant, escape the token as specified
218  // by 6.10.3.2p2.
219  if (tok::isStringLiteral(Tok.getKind()) || // "foo", u8R"x(foo)x"_bar, etc.
220  Tok.is(tok::char_constant) || // 'x'
221  Tok.is(tok::wide_char_constant) || // L'x'.
222  Tok.is(tok::utf8_char_constant) || // u8'x'.
223  Tok.is(tok::utf16_char_constant) || // u'x'.
224  Tok.is(tok::utf32_char_constant)) { // U'x'.
225  bool Invalid = false;
226  std::string TokStr = PP.getSpelling(Tok, &Invalid);
227  if (!Invalid) {
228  std::string Str = Lexer::Stringify(TokStr);
229  Result.append(Str.begin(), Str.end());
230  }
231  } else if (Tok.is(tok::code_completion)) {
233  } else {
234  // Otherwise, just append the token. Do some gymnastics to get the token
235  // in place and avoid copies where possible.
236  unsigned CurStrLen = Result.size();
237  Result.resize(CurStrLen+Tok.getLength());
238  const char *BufPtr = Result.data() + CurStrLen;
239  bool Invalid = false;
240  unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid);
241 
242  if (!Invalid) {
243  // If getSpelling returned a pointer to an already uniqued version of
244  // the string instead of filling in BufPtr, memcpy it onto our string.
245  if (ActualTokLen && BufPtr != &Result[CurStrLen])
246  memcpy(&Result[CurStrLen], BufPtr, ActualTokLen);
247 
248  // If the token was dirty, the spelling may be shorter than the token.
249  if (ActualTokLen != Tok.getLength())
250  Result.resize(CurStrLen+ActualTokLen);
251  }
252  }
253  }
254 
255  // If the last character of the string is a \, and if it isn't escaped, this
256  // is an invalid string literal, diagnose it as specified in C99.
257  if (Result.back() == '\\') {
258  // Count the number of consequtive \ characters. If even, then they are
259  // just escaped backslashes, otherwise it's an error.
260  unsigned FirstNonSlash = Result.size()-2;
261  // Guaranteed to find the starting " if nothing else.
262  while (Result[FirstNonSlash] == '\\')
263  --FirstNonSlash;
264  if ((Result.size()-1-FirstNonSlash) & 1) {
265  // Diagnose errors for things like: #define F(X) #X / F(\)
266  PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal);
267  Result.pop_back(); // remove one of the \'s.
268  }
269  }
270  Result += '"';
271 
272  // If this is the charify operation and the result is not a legal character
273  // constant, diagnose it.
274  if (Charify) {
275  // First step, turn double quotes into single quotes:
276  Result[0] = '\'';
277  Result[Result.size()-1] = '\'';
278 
279  // Check for bogus character.
280  bool isBad = false;
281  if (Result.size() == 3)
282  isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above.
283  else
284  isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x'
285 
286  if (isBad) {
287  PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify);
288  Result = "' '"; // Use something arbitrary, but legal.
289  }
290  }
291 
292  PP.CreateString(Result, Tok,
293  ExpansionLocStart, ExpansionLocEnd);
294  return Tok;
295 }
296 
297 /// getStringifiedArgument - Compute, cache, and return the specified argument
298 /// that has been 'stringified' as required by the # operator.
300  Preprocessor &PP,
301  SourceLocation ExpansionLocStart,
302  SourceLocation ExpansionLocEnd) {
303  assert(ArgNo < getNumMacroArguments() && "Invalid argument number!");
304  if (StringifiedArgs.empty())
305  StringifiedArgs.resize(getNumMacroArguments(), {});
306 
307  if (StringifiedArgs[ArgNo].isNot(tok::string_literal))
308  StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP,
309  /*Charify=*/false,
310  ExpansionLocStart,
311  ExpansionLocEnd);
312  return StringifiedArgs[ArgNo];
313 }
bool isAtStartOfLine() const
isAtStartOfLine - Return true if this token is at the start of a line.
Definition: Token.h:266
unsigned getNumMacroArguments() const
getNumMacroArguments - Return the number of arguments the invoked macro expects.
Definition: MacroArgs.h:102
Defines the clang::MacroInfo and clang::MacroDirective classes.
bool hasLeadingSpace() const
Return true if this token has whitespace before it.
Definition: Token.h:270
virtual void clear()
bool isStringLiteral(TokenKind K)
Return true if this is a C or C++ string-literal (or C++11 user-defined-string-literal) token...
Definition: TokenKinds.h:79
StringRef getSpelling(SourceLocation loc, SmallVectorImpl< char > &buffer, bool *invalid=nullptr) const
Return the 'spelling' of the token at the given location; does not go up to the spelling location or ...
One of these records is kept for each identifier that is lexed.
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
void setKind(tok::TokenKind K)
Definition: Token.h:91
const std::vector< Token > & getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP)
getPreExpArgument - Return the pre-expanded form of the specified argument.
Definition: MacroArgs.cpp:149
void destroy(Preprocessor &PP)
destroy - Destroy and deallocate the memory for this object.
Definition: MacroArgs.cpp:75
const Token * getUnexpArgument(unsigned Arg) const
getUnexpArgument - Return a pointer to the first token of the unexpanded token list for the specified...
Definition: MacroArgs.cpp:115
tok::TokenKind getKind() const
Definition: Token.h:90
unsigned getNumParams() const
Definition: MacroInfo.h:176
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const
Forwarding function for diagnostics.
const Token & getStringifiedArgument(unsigned ArgNo, Preprocessor &PP, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd)
getStringifiedArgument - Compute, cache, and return the specified argument that has been 'stringified...
Definition: MacroArgs.cpp:299
static Token StringifyArgument(const Token *ArgToks, Preprocessor &PP, bool Charify, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd)
StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of tokens into the literal string...
Definition: MacroArgs.cpp:196
MacroArgs - An instance of this class captures information about the formal arguments specified to a ...
Definition: MacroArgs.h:29
Defines the clang::Preprocessor interface.
FormatToken * Token
bool isNot(tok::TokenKind K) const
Definition: Token.h:96
The result type of a method or function.
MacroArgs * deallocate()
deallocate - This should only be called by the Preprocessor when managing its freelist.
Definition: MacroArgs.cpp:90
SmallVectorImpl< AnnotatedLine * >::const_iterator Next
Encodes a location in the source.
void Lex(Token &Result)
Lex the next token for this preprocessor.
bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const
ArgNeedsPreexpansion - If we can prove that the argument won't be affected by pre-expansion, return false.
Definition: MacroArgs.cpp:133
bool is(tok::TokenKind K) const
is/isNot - Predicates to check if this token is a specific kind, as in "if (Tok.is(tok::l_brace)) {...
Definition: Token.h:95
static unsigned getArgLength(const Token *ArgPtr)
getArgLength - Given a pointer to an expanded or unexpanded argument, return the number of tokens...
Definition: MacroArgs.cpp:105
void CodeCompleteNaturalLanguage()
Hook used by the lexer to invoke the "natural language" code completion point.
bool isFunctionLike() const
Definition: MacroInfo.h:193
Encapsulates the data about a macro definition (e.g.
Definition: MacroInfo.h:34
void CreateString(StringRef Str, Token &Tok, SourceLocation ExpansionLocStart=SourceLocation(), SourceLocation ExpansionLocEnd=SourceLocation())
Plop the specified string into a scratch buffer and set the specified token's location and length to ...
static MacroArgs * create(const MacroInfo *MI, ArrayRef< Token > UnexpArgTokens, bool VarargsElided, Preprocessor &PP)
MacroArgs ctor function - Create a new MacroArgs object with the specified macro and argument info...
Definition: MacroArgs.cpp:25
void RemoveTopOfLexerStack()
Pop the current lexer/macro exp off the top of the lexer stack.
unsigned getLength() const
Definition: Token.h:127
void startToken()
Reset all flags to cleared.
Definition: Token.h:169
static std::string Stringify(StringRef Str, bool Charify=false)
Stringify - Convert the specified string into a C string by escaping '\' and " characters. This does not add surrounding ""'s to the string.
Definition: Lexer.cpp:214
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:98
IdentifierInfo * getIdentifierInfo() const
Definition: Token.h:177