1 files changed, 376 insertions, 0 deletions
diff --git a/libs/angle/src/compiler/preprocessor/MacroExpander.cpp b/libs/angle/src/compiler/preprocessor/MacroExpander.cpp
new file mode 100644
index 000000000..3c0423e72
--- /dev/null
+++ b/libs/angle/src/compiler/preprocessor/MacroExpander.cpp
@@ -0,0 +1,376 @@
+//
+// Copyright (c) 2011 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "MacroExpander.h"
+
+#include <algorithm>
+#include <sstream>
+
+#include "DiagnosticsBase.h"
+#include "Token.h"
+
+namespace pp
+{
+
+class TokenLexer : public Lexer
+{
+ public:
+    typedef std::vector<Token> TokenVector;
+
+    TokenLexer(TokenVector *tokens)
+    {
+        tokens->swap(mTokens);
+        mIter = mTokens.begin();
+    }
+
+    void lex(Token *token) override
+    {
+        if (mIter == mTokens.end())
+        {
+            token->reset();
+            token->type = Token::LAST;
+        }
+        else
+        {
+            *token = *mIter++;
+        }
+    }
+
+ private:
+    PP_DISALLOW_COPY_AND_ASSIGN(TokenLexer);
+
+    TokenVector mTokens;
+    TokenVector::const_iterator mIter;
+};
+
+MacroExpander::MacroExpander(Lexer *lexer, MacroSet *macroSet, Diagnostics *diagnostics)
+    : mLexer(lexer), mMacroSet(macroSet), mDiagnostics(diagnostics)
+{
+}
+
+MacroExpander::~MacroExpander()
+{
+    for (std::size_t i = 0; i < mContextStack.size(); ++i)
+    {
+        delete mContextStack[i];
+    }
+}
+
+void MacroExpander::lex(Token *token)
+{
+    while (true)
+    {
+        getToken(token);
+
+        if (token->type != Token::IDENTIFIER)
+            break;
+
+        if (token->expansionDisabled())
+            break;
+
+        MacroSet::const_iterator iter = mMacroSet->find(token->text);
+        if (iter == mMacroSet->end())
+            break;
+
+        const Macro& macro = iter->second;
+        if (macro.disabled)
+        {
+            // If a particular token is not expanded, it is never expanded.
+            token->setExpansionDisabled(true);
+            break;
+        }
+        if ((macro.type == Macro::kTypeFunc) && !isNextTokenLeftParen())
+        {
+            // If the token immediately after the macro name is not a '(',
+            // this macro should not be expanded.
+            break;
+        }
+
+        pushMacro(macro, *token);
+    }
+}
+
+void MacroExpander::getToken(Token *token)
+{
+    if (mReserveToken.get())
+    {
+        *token = *mReserveToken;
+        mReserveToken.reset();
+        return;
+    }
+
+    // First pop all empty macro contexts.
+    while (!mContextStack.empty() && mContextStack.back()->empty())
+    {
+        popMacro();
+    }
+
+    if (!mContextStack.empty())
+    {
+        *token = mContextStack.back()->get();
+    }
+    else
+    {
+        mLexer->lex(token);
+    }
+}
+
+void MacroExpander::ungetToken(const Token &token)
+{
+    if (!mContextStack.empty())
+    {
+        MacroContext *context = mContextStack.back();
+        context->unget();
+        assert(context->replacements[context->index] == token);
+    }
+    else
+    {
+        assert(!mReserveToken.get());
+        mReserveToken.reset(new Token(token));
+    }
+}
+
+bool MacroExpander::isNextTokenLeftParen()
+{
+    Token token;
+    getToken(&token);
+
+    bool lparen = token.type == '(';
+    ungetToken(token);
+
+    return lparen;
+}
+
+bool MacroExpander::pushMacro(const Macro &macro, const Token &identifier)
+{
+    assert(!macro.disabled);
+    assert(!identifier.expansionDisabled());
+    assert(identifier.type == Token::IDENTIFIER);
+    assert(identifier.text == macro.name);
+
+    std::vector<Token> replacements;
+    if (!expandMacro(macro, identifier, &replacements))
+        return false;
+
+    // Macro is disabled for expansion until it is popped off the stack.
+    macro.disabled = true;
+
+    MacroContext *context = new MacroContext;
+    context->macro = &macro;
+    context->replacements.swap(replacements);
+    mContextStack.push_back(context);
+    return true;
+}
+
+void MacroExpander::popMacro()
+{
+    assert(!mContextStack.empty());
+
+    MacroContext *context = mContextStack.back();
+    mContextStack.pop_back();
+
+    assert(context->empty());
+    assert(context->macro->disabled);
+    context->macro->disabled = false;
+    delete context;
+}
+
+bool MacroExpander::expandMacro(const Macro &macro,
+                                const Token &identifier,
+                                std::vector<Token> *replacements)
+{
+    replacements->clear();
+
+    // In the case of an object-like macro, the replacement list gets its location
+    // from the identifier, but in the case of a function-like macro, the replacement
+    // list gets its location from the closing parenthesis of the macro invocation.
+    // This is tested by dEQP-GLES3.functional.shaders.preprocessor.predefined_macros.*
+    SourceLocation replacementLocation = identifier.location;
+    if (macro.type == Macro::kTypeObj)
+    {
+        replacements->assign(macro.replacements.begin(),
+                             macro.replacements.end());
+
+        if (macro.predefined)
+        {
+            const char kLine[] = "__LINE__";
+            const char kFile[] = "__FILE__";
+
+            assert(replacements->size() == 1);
+            Token& repl = replacements->front();
+            if (macro.name == kLine)
+            {
+                std::ostringstream stream;
+                stream << identifier.location.line;
+                repl.text = stream.str();
+            }
+            else if (macro.name == kFile)
+            {
+                std::ostringstream stream;
+                stream << identifier.location.file;
+                repl.text = stream.str();
+            }
+        }
+    }
+    else
+    {
+        assert(macro.type == Macro::kTypeFunc);
+        std::vector<MacroArg> args;
+        args.reserve(macro.parameters.size());
+        if (!collectMacroArgs(macro, identifier, &args, &replacementLocation))
+            return false;
+
+        replaceMacroParams(macro, args, replacements);
+    }
+
+    for (std::size_t i = 0; i < replacements->size(); ++i)
+    {
+        Token& repl = replacements->at(i);
+        if (i == 0)
+        {
+            // The first token in the replacement list inherits the padding
+            // properties of the identifier token.
+            repl.setAtStartOfLine(identifier.atStartOfLine());
+            repl.setHasLeadingSpace(identifier.hasLeadingSpace());
+        }
+        repl.location = replacementLocation;
+    }
+    return true;
+}
+
+bool MacroExpander::collectMacroArgs(const Macro &macro,
+                                     const Token &identifier,
+                                     std::vector<MacroArg> *args,
+                                     SourceLocation *closingParenthesisLocation)
+{
+    Token token;
+    getToken(&token);
+    assert(token.type == '(');
+
+    args->push_back(MacroArg());
+    for (int openParens = 1; openParens != 0; )
+    {
+        getToken(&token);
+
+        if (token.type == Token::LAST)
+        {
+            mDiagnostics->report(Diagnostics::PP_MACRO_UNTERMINATED_INVOCATION,
+                                 identifier.location, identifier.text);
+            // Do not lose EOF token.
+            ungetToken(token);
+            return false;
+        }
+
+        bool isArg = false; // True if token is part of the current argument.
+        switch (token.type)
+        {
+          case '(':
+            ++openParens;
+            isArg = true;
+            break;
+          case ')':
+            --openParens;
+            isArg = openParens != 0;
+            *closingParenthesisLocation = token.location;
+            break;
+          case ',':
+            // The individual arguments are separated by comma tokens, but
+            // the comma tokens between matching inner parentheses do not
+            // seperate arguments.
+            if (openParens == 1)
+                args->push_back(MacroArg());
+            isArg = openParens != 1;
+            break;
+          default:
+            isArg = true;
+            break;
+        }
+        if (isArg)
+        {
+            MacroArg &arg = args->back();
+            // Initial whitespace is not part of the argument.
+            if (arg.empty())
+                token.setHasLeadingSpace(false);
+            arg.push_back(token);
+        }
+    }
+
+    const Macro::Parameters &params = macro.parameters;
+    // If there is only one empty argument, it is equivalent to no argument.
+    if (params.empty() && (args->size() == 1) && args->front().empty())
+    {
+        args->clear();
+    }
+    // Validate the number of arguments.
+    if (args->size() != params.size())
+    {
+        Diagnostics::ID id = args->size() < macro.parameters.size() ?
+            Diagnostics::PP_MACRO_TOO_FEW_ARGS :
+            Diagnostics::PP_MACRO_TOO_MANY_ARGS;
+        mDiagnostics->report(id, identifier.location, identifier.text);
+        return false;
+    }
+
+    // Pre-expand each argument before substitution.
+    // This step expands each argument individually before they are
+    // inserted into the macro body.
+    for (std::size_t i = 0; i < args->size(); ++i)
+    {
+        MacroArg &arg = args->at(i);
+        TokenLexer lexer(&arg);
+        MacroExpander expander(&lexer, mMacroSet, mDiagnostics);
+
+        arg.clear();
+        expander.lex(&token);
+        while (token.type != Token::LAST)
+        {
+            arg.push_back(token);
+            expander.lex(&token);
+        }
+    }
+    return true;
+}
+
+void MacroExpander::replaceMacroParams(const Macro &macro,
+                                       const std::vector<MacroArg> &args,
+                                       std::vector<Token> *replacements)
+{
+    for (std::size_t i = 0; i < macro.replacements.size(); ++i)
+    {
+        const Token &repl = macro.replacements[i];
+        if (repl.type != Token::IDENTIFIER)
+        {
+            replacements->push_back(repl);
+            continue;
+        }
+
+        // TODO(alokp): Optimize this.
+        // There is no need to search for macro params every time.
+        // The param index can be cached with the replacement token.
+        Macro::Parameters::const_iterator iter = std::find(
+            macro.parameters.begin(), macro.parameters.end(), repl.text);
+        if (iter == macro.parameters.end())
+        {
+            replacements->push_back(repl);
+            continue;
+        }
+
+        std::size_t iArg = std::distance(macro.parameters.begin(), iter);
+        const MacroArg &arg = args[iArg];
+        if (arg.empty())
+        {
+            continue;
+        }
+        std::size_t iRepl = replacements->size();
+        replacements->insert(replacements->end(), arg.begin(), arg.end());
+        // The replacement token inherits padding properties from
+        // macro replacement token.
+        replacements->at(iRepl).setHasLeadingSpace(repl.hasLeadingSpace());
+    }
+}
+
+}  // namespace pp
+