clang  3.9.0
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) MacroArgs(UnexpArgTokens.size(), VarargsElided);
55  } else {
56  Result = *ResultEnt;
57  // Unlink this node from the preprocessors singly linked list.
58  *ResultEnt = Result->ArgCache;
59  Result->NumUnexpArgTokens = UnexpArgTokens.size();
60  Result->VarargsElided = VarargsElided;
61  }
62 
63  // Copy the actual unexpanded tokens to immediately after the result ptr.
64  if (!UnexpArgTokens.empty())
65  std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(),
66  const_cast<Token*>(Result->getUnexpArgument(0)));
67 
68  return Result;
69 }
70 
71 /// destroy - Destroy and deallocate the memory for this object.
72 ///
74  StringifiedArgs.clear();
75 
76  // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries
77  // would deallocate the element vectors.
78  for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i)
79  PreExpArgTokens[i].clear();
80 
81  // Add this to the preprocessor's free list.
82  ArgCache = PP.MacroArgCache;
83  PP.MacroArgCache = this;
84 }
85 
86 /// deallocate - This should only be called by the Preprocessor when managing
87 /// its freelist.
89  MacroArgs *Next = ArgCache;
90 
91  // Run the dtor to deallocate the vectors.
92  this->~MacroArgs();
93  // Release the memory for the object.
94  free(this);
95 
96  return Next;
97 }
98 
99 
100 /// getArgLength - Given a pointer to an expanded or unexpanded argument,
101 /// return the number of tokens, not counting the EOF, that make up the
102 /// argument.
103 unsigned MacroArgs::getArgLength(const Token *ArgPtr) {
104  unsigned NumArgTokens = 0;
105  for (; ArgPtr->isNot(tok::eof); ++ArgPtr)
106  ++NumArgTokens;
107  return NumArgTokens;
108 }
109 
110 
111 /// getUnexpArgument - Return the unexpanded tokens for the specified formal.
112 ///
113 const Token *MacroArgs::getUnexpArgument(unsigned Arg) const {
114  // The unexpanded argument tokens start immediately after the MacroArgs object
115  // in memory.
116  const Token *Start = (const Token *)(this+1);
117  const Token *Result = Start;
118  // Scan to find Arg.
119  for (; Arg; ++Result) {
120  assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
121  if (Result->is(tok::eof))
122  --Arg;
123  }
124  assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
125  return Result;
126 }
127 
128 
129 /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
130 /// by pre-expansion, return false. Otherwise, conservatively return true.
132  Preprocessor &PP) const {
133  // If there are no identifiers in the argument list, or if the identifiers are
134  // known to not be macros, pre-expansion won't modify it.
135  for (; ArgTok->isNot(tok::eof); ++ArgTok)
136  if (IdentifierInfo *II = ArgTok->getIdentifierInfo())
137  if (II->hasMacroDefinition())
138  // Return true even though the macro could be a function-like macro
139  // without a following '(' token, or could be disabled, or not visible.
140  return true;
141  return false;
142 }
143 
144 /// getPreExpArgument - Return the pre-expanded form of the specified
145 /// argument.
146 const std::vector<Token> &
147 MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI,
148  Preprocessor &PP) {
149  assert(Arg < MI->getNumArgs() && "Invalid argument number!");
150 
151  // If we have already computed this, return it.
152  if (PreExpArgTokens.size() < MI->getNumArgs())
153  PreExpArgTokens.resize(MI->getNumArgs());
154 
155  std::vector<Token> &Result = PreExpArgTokens[Arg];
156  if (!Result.empty()) return Result;
157 
158  SaveAndRestore<bool> PreExpandingMacroArgs(PP.InMacroArgPreExpansion, true);
159 
160  const Token *AT = getUnexpArgument(Arg);
161  unsigned NumToks = getArgLength(AT)+1; // Include the EOF.
162 
163  // Otherwise, we have to pre-expand this argument, populating Result. To do
164  // this, we set up a fake TokenLexer to lex from the unexpanded argument
165  // list. With this installed, we lex expanded tokens until we hit the EOF
166  // token at the end of the unexp list.
167  PP.EnterTokenStream(AT, NumToks, false /*disable expand*/,
168  false /*owns tokens*/);
169 
170  // Lex all of the macro-expanded tokens into Result.
171  do {
172  Result.push_back(Token());
173  Token &Tok = Result.back();
174  PP.Lex(Tok);
175  } while (Result.back().isNot(tok::eof));
176 
177  // Pop the token stream off the top of the stack. We know that the internal
178  // pointer inside of it is to the "end" of the token stream, but the stack
179  // will not otherwise be popped until the next token is lexed. The problem is
180  // that the token may be lexed sometime after the vector of tokens itself is
181  // destroyed, which would be badness.
182  if (PP.InCachingLexMode())
183  PP.ExitCachingLexMode();
185  return Result;
186 }
187 
188 
189 /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
190 /// tokens into the literal string token that should be produced by the C #
191 /// preprocessor operator. If Charify is true, then it should be turned into
192 /// a character literal for the Microsoft charize (#@) extension.
193 ///
195  Preprocessor &PP, bool Charify,
196  SourceLocation ExpansionLocStart,
197  SourceLocation ExpansionLocEnd) {
198  Token Tok;
199  Tok.startToken();
200  Tok.setKind(Charify ? tok::char_constant : tok::string_literal);
201 
202  const Token *ArgTokStart = ArgToks;
203 
204  // Stringify all the tokens.
206  Result += "\"";
207 
208  bool isFirst = true;
209  for (; ArgToks->isNot(tok::eof); ++ArgToks) {
210  const Token &Tok = *ArgToks;
211  if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()))
212  Result += ' ';
213  isFirst = false;
214 
215  // If this is a string or character constant, escape the token as specified
216  // by 6.10.3.2p2.
217  if (tok::isStringLiteral(Tok.getKind()) || // "foo", u8R"x(foo)x"_bar, etc.
218  Tok.is(tok::char_constant) || // 'x'
219  Tok.is(tok::wide_char_constant) || // L'x'.
220  Tok.is(tok::utf8_char_constant) || // u8'x'.
221  Tok.is(tok::utf16_char_constant) || // u'x'.
222  Tok.is(tok::utf32_char_constant)) { // U'x'.
223  bool Invalid = false;
224  std::string TokStr = PP.getSpelling(Tok, &Invalid);
225  if (!Invalid) {
226  std::string Str = Lexer::Stringify(TokStr);
227  Result.append(Str.begin(), Str.end());
228  }
229  } else if (Tok.is(tok::code_completion)) {
231  } else {
232  // Otherwise, just append the token. Do some gymnastics to get the token
233  // in place and avoid copies where possible.
234  unsigned CurStrLen = Result.size();
235  Result.resize(CurStrLen+Tok.getLength());
236  const char *BufPtr = Result.data() + CurStrLen;
237  bool Invalid = false;
238  unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid);
239 
240  if (!Invalid) {
241  // If getSpelling returned a pointer to an already uniqued version of
242  // the string instead of filling in BufPtr, memcpy it onto our string.
243  if (ActualTokLen && BufPtr != &Result[CurStrLen])
244  memcpy(&Result[CurStrLen], BufPtr, ActualTokLen);
245 
246  // If the token was dirty, the spelling may be shorter than the token.
247  if (ActualTokLen != Tok.getLength())
248  Result.resize(CurStrLen+ActualTokLen);
249  }
250  }
251  }
252 
253  // If the last character of the string is a \, and if it isn't escaped, this
254  // is an invalid string literal, diagnose it as specified in C99.
255  if (Result.back() == '\\') {
256  // Count the number of consequtive \ characters. If even, then they are
257  // just escaped backslashes, otherwise it's an error.
258  unsigned FirstNonSlash = Result.size()-2;
259  // Guaranteed to find the starting " if nothing else.
260  while (Result[FirstNonSlash] == '\\')
261  --FirstNonSlash;
262  if ((Result.size()-1-FirstNonSlash) & 1) {
263  // Diagnose errors for things like: #define F(X) #X / F(\)
264  PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal);
265  Result.pop_back(); // remove one of the \'s.
266  }
267  }
268  Result += '"';
269 
270  // If this is the charify operation and the result is not a legal character
271  // constant, diagnose it.
272  if (Charify) {
273  // First step, turn double quotes into single quotes:
274  Result[0] = '\'';
275  Result[Result.size()-1] = '\'';
276 
277  // Check for bogus character.
278  bool isBad = false;
279  if (Result.size() == 3)
280  isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above.
281  else
282  isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x'
283 
284  if (isBad) {
285  PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify);
286  Result = "' '"; // Use something arbitrary, but legal.
287  }
288  }
289 
290  PP.CreateString(Result, Tok,
291  ExpansionLocStart, ExpansionLocEnd);
292  return Tok;
293 }
294 
295 /// getStringifiedArgument - Compute, cache, and return the specified argument
296 /// that has been 'stringified' as required by the # operator.
298  Preprocessor &PP,
299  SourceLocation ExpansionLocStart,
300  SourceLocation ExpansionLocEnd) {
301  assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!");
302  if (StringifiedArgs.empty()) {
303  StringifiedArgs.resize(getNumArguments());
304  memset((void*)&StringifiedArgs[0], 0,
305  sizeof(StringifiedArgs[0])*getNumArguments());
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:265
Defines the clang::MacroInfo and clang::MacroDirective classes.
bool hasLeadingSpace() const
Return true if this token has whitespace before it.
Definition: Token.h:269
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:90
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:147
void destroy(Preprocessor &PP)
destroy - Destroy and deallocate the memory for this object.
Definition: MacroArgs.cpp:73
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:113
tok::TokenKind getKind() const
Definition: Token.h:89
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:297
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:194
MacroArgs - An instance of this class captures information about the formal arguments specified to a ...
Definition: MacroArgs.h:29
unsigned getNumArgs() const
Definition: MacroInfo.h:179
Defines the clang::Preprocessor interface.
FormatToken * Token
bool isNot(tok::TokenKind K) const
Definition: Token.h:95
The result type of a method or function.
unsigned getNumArguments() const
getNumArguments - Return the number of arguments passed into this macro invocation.
Definition: MacroArgs.h:99
MacroArgs * deallocate()
deallocate - This should only be called by the Preprocessor when managing its freelist.
Definition: MacroArgs.cpp:88
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:131
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:94
static unsigned getArgLength(const Token *ArgPtr)
getArgLength - Given a pointer to an expanded or unexpanded argument, return the number of tokens...
Definition: MacroArgs.cpp:103
void CodeCompleteNaturalLanguage()
Hook used by the lexer to invoke the "natural language" code completion point.
bool isFunctionLike() const
Definition: MacroInfo.h:196
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:126
unsigned getNumArgs() const
Retrieve the number of template arguments.
Definition: Type.h:4247
void startToken()
Reset all flags to cleared.
Definition: Token.h:168
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:202
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:97
IdentifierInfo * getIdentifierInfo() const
Definition: Token.h:176