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Chris Lattnere5c8ffe2008-03-09 02:55:12 +00001//===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
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 TokenLexer interface.
11//
12//===----------------------------------------------------------------------===//
13
14#include "MacroArgs.h"
15#include "clang/Lex/MacroInfo.h"
16#include "clang/Lex/Preprocessor.h"
Chris Lattner500d3292009-01-29 05:15:15 +000017#include "clang/Lex/LexDiagnostic.h"
Chris Lattnere5c8ffe2008-03-09 02:55:12 +000018using namespace clang;
19
20/// MacroArgs ctor function - This destroys the vector passed in.
21MacroArgs *MacroArgs::create(const MacroInfo *MI,
22 const Token *UnexpArgTokens,
23 unsigned NumToks, bool VarargsElided) {
24 assert(MI->isFunctionLike() &&
25 "Can't have args for an object-like macro!");
Chris Lattner7c351222009-01-26 04:33:10 +000026
Chris Lattnere5c8ffe2008-03-09 02:55:12 +000027 // Allocate memory for the MacroArgs object with the lexer tokens at the end.
28 MacroArgs *Result = (MacroArgs*)malloc(sizeof(MacroArgs) +
29 NumToks*sizeof(Token));
30 // Construct the macroargs object.
31 new (Result) MacroArgs(NumToks, VarargsElided);
32
33 // Copy the actual unexpanded tokens to immediately after the result ptr.
34 if (NumToks)
35 memcpy(const_cast<Token*>(Result->getUnexpArgument(0)),
36 UnexpArgTokens, NumToks*sizeof(Token));
37
38 return Result;
39}
40
41/// destroy - Destroy and deallocate the memory for this object.
42///
43void MacroArgs::destroy() {
44 // Run the dtor to deallocate the vectors.
45 this->~MacroArgs();
46 // Release the memory for the object.
47 free(this);
48}
49
50
51/// getArgLength - Given a pointer to an expanded or unexpanded argument,
52/// return the number of tokens, not counting the EOF, that make up the
53/// argument.
54unsigned MacroArgs::getArgLength(const Token *ArgPtr) {
55 unsigned NumArgTokens = 0;
56 for (; ArgPtr->isNot(tok::eof); ++ArgPtr)
57 ++NumArgTokens;
58 return NumArgTokens;
59}
60
61
62/// getUnexpArgument - Return the unexpanded tokens for the specified formal.
63///
64const Token *MacroArgs::getUnexpArgument(unsigned Arg) const {
65 // The unexpanded argument tokens start immediately after the MacroArgs object
66 // in memory.
67 const Token *Start = (const Token *)(this+1);
68 const Token *Result = Start;
69 // Scan to find Arg.
70 for (; Arg; ++Result) {
71 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
72 if (Result->is(tok::eof))
73 --Arg;
74 }
Chris Lattner9fc9e772009-05-13 00:55:26 +000075 assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
Chris Lattnere5c8ffe2008-03-09 02:55:12 +000076 return Result;
77}
78
79
80/// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
81/// by pre-expansion, return false. Otherwise, conservatively return true.
82bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok,
83 Preprocessor &PP) const {
84 // If there are no identifiers in the argument list, or if the identifiers are
85 // known to not be macros, pre-expansion won't modify it.
86 for (; ArgTok->isNot(tok::eof); ++ArgTok)
87 if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) {
88 if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled())
89 // Return true even though the macro could be a function-like macro
90 // without a following '(' token.
91 return true;
92 }
93 return false;
94}
95
96/// getPreExpArgument - Return the pre-expanded form of the specified
97/// argument.
98const std::vector<Token> &
99MacroArgs::getPreExpArgument(unsigned Arg, Preprocessor &PP) {
100 assert(Arg < NumUnexpArgTokens && "Invalid argument number!");
101
102 // If we have already computed this, return it.
103 if (PreExpArgTokens.empty())
104 PreExpArgTokens.resize(NumUnexpArgTokens);
105
106 std::vector<Token> &Result = PreExpArgTokens[Arg];
107 if (!Result.empty()) return Result;
108
109 const Token *AT = getUnexpArgument(Arg);
110 unsigned NumToks = getArgLength(AT)+1; // Include the EOF.
111
112 // Otherwise, we have to pre-expand this argument, populating Result. To do
113 // this, we set up a fake TokenLexer to lex from the unexpanded argument
114 // list. With this installed, we lex expanded tokens until we hit the EOF
115 // token at the end of the unexp list.
Chris Lattner6b884502008-03-10 06:06:04 +0000116 PP.EnterTokenStream(AT, NumToks, false /*disable expand*/,
117 false /*owns tokens*/);
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000118
119 // Lex all of the macro-expanded tokens into Result.
120 do {
121 Result.push_back(Token());
Chris Lattner7c351222009-01-26 04:33:10 +0000122 Token &Tok = Result.back();
123 PP.Lex(Tok);
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000124 } while (Result.back().isNot(tok::eof));
125
126 // Pop the token stream off the top of the stack. We know that the internal
127 // pointer inside of it is to the "end" of the token stream, but the stack
128 // will not otherwise be popped until the next token is lexed. The problem is
129 // that the token may be lexed sometime after the vector of tokens itself is
130 // destroyed, which would be badness.
131 PP.RemoveTopOfLexerStack();
132 return Result;
133}
134
135
136/// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
137/// tokens into the literal string token that should be produced by the C #
138/// preprocessor operator. If Charify is true, then it should be turned into
139/// a character literal for the Microsoft charize (#@) extension.
140///
141Token MacroArgs::StringifyArgument(const Token *ArgToks,
142 Preprocessor &PP, bool Charify) {
143 Token Tok;
144 Tok.startToken();
145 Tok.setKind(tok::string_literal);
146
147 const Token *ArgTokStart = ArgToks;
148
149 // Stringify all the tokens.
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000150 llvm::SmallString<128> Result;
151 Result += "\"";
152
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000153 bool isFirst = true;
154 for (; ArgToks->isNot(tok::eof); ++ArgToks) {
155 const Token &Tok = *ArgToks;
156 if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()))
157 Result += ' ';
158 isFirst = false;
159
160 // If this is a string or character constant, escape the token as specified
161 // by 6.10.3.2p2.
162 if (Tok.is(tok::string_literal) || // "foo"
163 Tok.is(tok::wide_string_literal) || // L"foo"
164 Tok.is(tok::char_constant)) { // 'x' and L'x'.
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000165 std::string Str = Lexer::Stringify(PP.getSpelling(Tok));
166 Result.append(Str.begin(), Str.end());
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000167 } else {
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000168 // Otherwise, just append the token. Do some gymnastics to get the token
169 // in place and avoid copies where possible.
170 unsigned CurStrLen = Result.size();
171 Result.resize(CurStrLen+Tok.getLength());
172 const char *BufPtr = &Result[CurStrLen];
173 unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr);
174
175 // If getSpelling returned a pointer to an already uniqued version of the
176 // string instead of filling in BufPtr, memcpy it onto our string.
177 if (BufPtr != &Result[CurStrLen])
178 memcpy(&Result[CurStrLen], BufPtr, ActualTokLen);
179
180 // If the token was dirty, the spelling may be shorter than the token.
181 if (ActualTokLen != Tok.getLength())
182 Result.resize(CurStrLen+ActualTokLen);
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000183 }
184 }
185
186 // If the last character of the string is a \, and if it isn't escaped, this
187 // is an invalid string literal, diagnose it as specified in C99.
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000188 if (Result.back() == '\\') {
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000189 // Count the number of consequtive \ characters. If even, then they are
190 // just escaped backslashes, otherwise it's an error.
191 unsigned FirstNonSlash = Result.size()-2;
192 // Guaranteed to find the starting " if nothing else.
193 while (Result[FirstNonSlash] == '\\')
194 --FirstNonSlash;
195 if ((Result.size()-1-FirstNonSlash) & 1) {
196 // Diagnose errors for things like: #define F(X) #X / F(\)
197 PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal);
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000198 Result.pop_back(); // remove one of the \'s.
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000199 }
200 }
201 Result += '"';
202
203 // If this is the charify operation and the result is not a legal character
204 // constant, diagnose it.
205 if (Charify) {
206 // First step, turn double quotes into single quotes:
207 Result[0] = '\'';
208 Result[Result.size()-1] = '\'';
209
210 // Check for bogus character.
211 bool isBad = false;
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000212 if (Result.size() == 3)
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000213 isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above.
Chris Lattnerc19e8a22009-01-05 23:04:18 +0000214 else
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000215 isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x'
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000216
217 if (isBad) {
218 PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify);
219 Result = "' '"; // Use something arbitrary, but legal.
220 }
221 }
222
Chris Lattner47246be2009-01-26 19:29:26 +0000223 PP.CreateString(&Result[0], Result.size(), Tok);
Chris Lattnere5c8ffe2008-03-09 02:55:12 +0000224 return Tok;
225}
226
227/// getStringifiedArgument - Compute, cache, and return the specified argument
228/// that has been 'stringified' as required by the # operator.
229const Token &MacroArgs::getStringifiedArgument(unsigned ArgNo,
230 Preprocessor &PP) {
231 assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!");
232 if (StringifiedArgs.empty()) {
233 StringifiedArgs.resize(getNumArguments());
234 memset(&StringifiedArgs[0], 0,
235 sizeof(StringifiedArgs[0])*getNumArguments());
236 }
237 if (StringifiedArgs[ArgNo].isNot(tok::string_literal))
238 StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP);
239 return StringifiedArgs[ArgNo];
240}