1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/angle/src/compiler/preprocessor/MacroExpander.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,370 @@
1.4 +//
1.5 +// Copyright (c) 2011 The ANGLE Project Authors. All rights reserved.
1.6 +// Use of this source code is governed by a BSD-style license that can be
1.7 +// found in the LICENSE file.
1.8 +//
1.9 +
1.10 +#include "MacroExpander.h"
1.11 +
1.12 +#include <algorithm>
1.13 +#include <sstream>
1.14 +
1.15 +#include "DiagnosticsBase.h"
1.16 +#include "Token.h"
1.17 +
1.18 +namespace pp
1.19 +{
1.20 +
1.21 +class TokenLexer : public Lexer
1.22 +{
1.23 + public:
1.24 + typedef std::vector<Token> TokenVector;
1.25 +
1.26 + TokenLexer(TokenVector* tokens)
1.27 + {
1.28 + tokens->swap(mTokens);
1.29 + mIter = mTokens.begin();
1.30 + }
1.31 +
1.32 + virtual void lex(Token* token)
1.33 + {
1.34 + if (mIter == mTokens.end())
1.35 + {
1.36 + token->reset();
1.37 + token->type = Token::LAST;
1.38 + }
1.39 + else
1.40 + {
1.41 + *token = *mIter++;
1.42 + }
1.43 + }
1.44 +
1.45 + private:
1.46 + PP_DISALLOW_COPY_AND_ASSIGN(TokenLexer);
1.47 +
1.48 + TokenVector mTokens;
1.49 + TokenVector::const_iterator mIter;
1.50 +};
1.51 +
1.52 +MacroExpander::MacroExpander(Lexer* lexer,
1.53 + MacroSet* macroSet,
1.54 + Diagnostics* diagnostics) :
1.55 + mLexer(lexer),
1.56 + mMacroSet(macroSet),
1.57 + mDiagnostics(diagnostics)
1.58 +{
1.59 +}
1.60 +
1.61 +MacroExpander::~MacroExpander()
1.62 +{
1.63 + for (std::size_t i = 0; i < mContextStack.size(); ++i)
1.64 + {
1.65 + delete mContextStack[i];
1.66 + }
1.67 +}
1.68 +
1.69 +void MacroExpander::lex(Token* token)
1.70 +{
1.71 + while (true)
1.72 + {
1.73 + getToken(token);
1.74 +
1.75 + if (token->type != Token::IDENTIFIER)
1.76 + break;
1.77 +
1.78 + if (token->expansionDisabled())
1.79 + break;
1.80 +
1.81 + MacroSet::const_iterator iter = mMacroSet->find(token->text);
1.82 + if (iter == mMacroSet->end())
1.83 + break;
1.84 +
1.85 + const Macro& macro = iter->second;
1.86 + if (macro.disabled)
1.87 + {
1.88 + // If a particular token is not expanded, it is never expanded.
1.89 + token->setExpansionDisabled(true);
1.90 + break;
1.91 + }
1.92 + if ((macro.type == Macro::kTypeFunc) && !isNextTokenLeftParen())
1.93 + {
1.94 + // If the token immediately after the macro name is not a '(',
1.95 + // this macro should not be expanded.
1.96 + break;
1.97 + }
1.98 +
1.99 + pushMacro(macro, *token);
1.100 + }
1.101 +}
1.102 +
1.103 +void MacroExpander::getToken(Token* token)
1.104 +{
1.105 + if (mReserveToken.get())
1.106 + {
1.107 + *token = *mReserveToken;
1.108 + mReserveToken.reset();
1.109 + return;
1.110 + }
1.111 +
1.112 + // First pop all empty macro contexts.
1.113 + while (!mContextStack.empty() && mContextStack.back()->empty())
1.114 + {
1.115 + popMacro();
1.116 + }
1.117 +
1.118 + if (!mContextStack.empty())
1.119 + {
1.120 + *token = mContextStack.back()->get();
1.121 + }
1.122 + else
1.123 + {
1.124 + mLexer->lex(token);
1.125 + }
1.126 +}
1.127 +
1.128 +void MacroExpander::ungetToken(const Token& token)
1.129 +{
1.130 + if (!mContextStack.empty())
1.131 + {
1.132 + MacroContext* context = mContextStack.back();
1.133 + context->unget();
1.134 + assert(context->replacements[context->index] == token);
1.135 + }
1.136 + else
1.137 + {
1.138 + assert(!mReserveToken.get());
1.139 + mReserveToken.reset(new Token(token));
1.140 + }
1.141 +}
1.142 +
1.143 +bool MacroExpander::isNextTokenLeftParen()
1.144 +{
1.145 + Token token;
1.146 + getToken(&token);
1.147 +
1.148 + bool lparen = token.type == '(';
1.149 + ungetToken(token);
1.150 +
1.151 + return lparen;
1.152 +}
1.153 +
1.154 +bool MacroExpander::pushMacro(const Macro& macro, const Token& identifier)
1.155 +{
1.156 + assert(!macro.disabled);
1.157 + assert(!identifier.expansionDisabled());
1.158 + assert(identifier.type == Token::IDENTIFIER);
1.159 + assert(identifier.text == macro.name);
1.160 +
1.161 + std::vector<Token> replacements;
1.162 + if (!expandMacro(macro, identifier, &replacements))
1.163 + return false;
1.164 +
1.165 + // Macro is disabled for expansion until it is popped off the stack.
1.166 + macro.disabled = true;
1.167 +
1.168 + MacroContext* context = new MacroContext;
1.169 + context->macro = ¯o;
1.170 + context->replacements.swap(replacements);
1.171 + mContextStack.push_back(context);
1.172 + return true;
1.173 +}
1.174 +
1.175 +void MacroExpander::popMacro()
1.176 +{
1.177 + assert(!mContextStack.empty());
1.178 +
1.179 + MacroContext* context = mContextStack.back();
1.180 + mContextStack.pop_back();
1.181 +
1.182 + assert(context->empty());
1.183 + assert(context->macro->disabled);
1.184 + context->macro->disabled = false;
1.185 + delete context;
1.186 +}
1.187 +
1.188 +bool MacroExpander::expandMacro(const Macro& macro,
1.189 + const Token& identifier,
1.190 + std::vector<Token>* replacements)
1.191 +{
1.192 + replacements->clear();
1.193 + if (macro.type == Macro::kTypeObj)
1.194 + {
1.195 + replacements->assign(macro.replacements.begin(),
1.196 + macro.replacements.end());
1.197 +
1.198 + if (macro.predefined)
1.199 + {
1.200 + static const std::string kLine = "__LINE__";
1.201 + static const std::string kFile = "__FILE__";
1.202 +
1.203 + assert(replacements->size() == 1);
1.204 + Token& repl = replacements->front();
1.205 + if (macro.name == kLine)
1.206 + {
1.207 + std::ostringstream stream;
1.208 + stream << identifier.location.line;
1.209 + repl.text = stream.str();
1.210 + }
1.211 + else if (macro.name == kFile)
1.212 + {
1.213 + std::ostringstream stream;
1.214 + stream << identifier.location.file;
1.215 + repl.text = stream.str();
1.216 + }
1.217 + }
1.218 + }
1.219 + else
1.220 + {
1.221 + assert(macro.type == Macro::kTypeFunc);
1.222 + std::vector<MacroArg> args;
1.223 + args.reserve(macro.parameters.size());
1.224 + if (!collectMacroArgs(macro, identifier, &args))
1.225 + return false;
1.226 +
1.227 + replaceMacroParams(macro, args, replacements);
1.228 + }
1.229 +
1.230 + for (std::size_t i = 0; i < replacements->size(); ++i)
1.231 + {
1.232 + Token& repl = replacements->at(i);
1.233 + if (i == 0)
1.234 + {
1.235 + // The first token in the replacement list inherits the padding
1.236 + // properties of the identifier token.
1.237 + repl.setAtStartOfLine(identifier.atStartOfLine());
1.238 + repl.setHasLeadingSpace(identifier.hasLeadingSpace());
1.239 + }
1.240 + repl.location = identifier.location;
1.241 + }
1.242 + return true;
1.243 +}
1.244 +
1.245 +bool MacroExpander::collectMacroArgs(const Macro& macro,
1.246 + const Token& identifier,
1.247 + std::vector<MacroArg>* args)
1.248 +{
1.249 + Token token;
1.250 + getToken(&token);
1.251 + assert(token.type == '(');
1.252 +
1.253 + args->push_back(MacroArg());
1.254 + for (int openParens = 1; openParens != 0; )
1.255 + {
1.256 + getToken(&token);
1.257 +
1.258 + if (token.type == Token::LAST)
1.259 + {
1.260 + mDiagnostics->report(Diagnostics::MACRO_UNTERMINATED_INVOCATION,
1.261 + identifier.location, identifier.text);
1.262 + // Do not lose EOF token.
1.263 + ungetToken(token);
1.264 + return false;
1.265 + }
1.266 +
1.267 + bool isArg = false; // True if token is part of the current argument.
1.268 + switch (token.type)
1.269 + {
1.270 + case '(':
1.271 + ++openParens;
1.272 + isArg = true;
1.273 + break;
1.274 + case ')':
1.275 + --openParens;
1.276 + isArg = openParens != 0;
1.277 + break;
1.278 + case ',':
1.279 + // The individual arguments are separated by comma tokens, but
1.280 + // the comma tokens between matching inner parentheses do not
1.281 + // seperate arguments.
1.282 + if (openParens == 1) args->push_back(MacroArg());
1.283 + isArg = openParens != 1;
1.284 + break;
1.285 + default:
1.286 + isArg = true;
1.287 + break;
1.288 + }
1.289 + if (isArg)
1.290 + {
1.291 + MacroArg& arg = args->back();
1.292 + // Initial whitespace is not part of the argument.
1.293 + if (arg.empty()) token.setHasLeadingSpace(false);
1.294 + arg.push_back(token);
1.295 + }
1.296 + }
1.297 +
1.298 + const Macro::Parameters& params = macro.parameters;
1.299 + // If there is only one empty argument, it is equivalent to no argument.
1.300 + if (params.empty() && (args->size() == 1) && args->front().empty())
1.301 + {
1.302 + args->clear();
1.303 + }
1.304 + // Validate the number of arguments.
1.305 + if (args->size() != params.size())
1.306 + {
1.307 + Diagnostics::ID id = args->size() < macro.parameters.size() ?
1.308 + Diagnostics::MACRO_TOO_FEW_ARGS :
1.309 + Diagnostics::MACRO_TOO_MANY_ARGS;
1.310 + mDiagnostics->report(id, identifier.location, identifier.text);
1.311 + return false;
1.312 + }
1.313 +
1.314 + // Pre-expand each argument before substitution.
1.315 + // This step expands each argument individually before they are
1.316 + // inserted into the macro body.
1.317 + for (std::size_t i = 0; i < args->size(); ++i)
1.318 + {
1.319 + MacroArg& arg = args->at(i);
1.320 + TokenLexer lexer(&arg);
1.321 + MacroExpander expander(&lexer, mMacroSet, mDiagnostics);
1.322 +
1.323 + arg.clear();
1.324 + expander.lex(&token);
1.325 + while (token.type != Token::LAST)
1.326 + {
1.327 + arg.push_back(token);
1.328 + expander.lex(&token);
1.329 + }
1.330 + }
1.331 + return true;
1.332 +}
1.333 +
1.334 +void MacroExpander::replaceMacroParams(const Macro& macro,
1.335 + const std::vector<MacroArg>& args,
1.336 + std::vector<Token>* replacements)
1.337 +{
1.338 + for (std::size_t i = 0; i < macro.replacements.size(); ++i)
1.339 + {
1.340 + const Token& repl = macro.replacements[i];
1.341 + if (repl.type != Token::IDENTIFIER)
1.342 + {
1.343 + replacements->push_back(repl);
1.344 + continue;
1.345 + }
1.346 +
1.347 + // TODO(alokp): Optimize this.
1.348 + // There is no need to search for macro params every time.
1.349 + // The param index can be cached with the replacement token.
1.350 + Macro::Parameters::const_iterator iter = std::find(
1.351 + macro.parameters.begin(), macro.parameters.end(), repl.text);
1.352 + if (iter == macro.parameters.end())
1.353 + {
1.354 + replacements->push_back(repl);
1.355 + continue;
1.356 + }
1.357 +
1.358 + std::size_t iArg = std::distance(macro.parameters.begin(), iter);
1.359 + const MacroArg& arg = args[iArg];
1.360 + if (arg.empty())
1.361 + {
1.362 + continue;
1.363 + }
1.364 + std::size_t iRepl = replacements->size();
1.365 + replacements->insert(replacements->end(), arg.begin(), arg.end());
1.366 + // The replacement token inherits padding properties from
1.367 + // macro replacement token.
1.368 + replacements->at(iRepl).setHasLeadingSpace(repl.hasLeadingSpace());
1.369 + }
1.370 +}
1.371 +
1.372 +} // namespace pp
1.373 +
