C++ ConstantTablePtr::getValue方法代码示例

bool AnalysisResult::isConstantDeclared(const std::string &constName) const {
  if (m_constants->isPresent(constName)) return true;
  auto const iter = m_constDecs.find(constName);
  if (iter == m_constDecs.end()) return false;
  FileScopePtr fileScope = iter->second;
  ConstantTablePtr constants = fileScope->getConstants();
  ConstructPtr decl = constants->getValue(constName);
  if (decl) return true;
  return false;
}

ExpressionPtr ClassConstantExpression::preOptimize(AnalysisResultPtr ar) {
  if (ar->getPhase() < AnalysisResult::FirstPreOptimize) {
    return ExpressionPtr();
  }
  if (m_redeclared) return ExpressionPtr();
  ClassScopePtr cls = ar->resolveClass(m_className);
  if (!cls || cls->isRedeclaring()) return ExpressionPtr();
  ConstantTablePtr constants = cls->getConstants();
  if (constants->isExplicitlyDeclared(m_varName)) {
    ConstructPtr decl = constants->getValue(m_varName);
    if (decl) {
      ExpressionPtr value = dynamic_pointer_cast<Expression>(decl);
      if (!m_visited) {
        m_visited = true;
        ar->pushScope(cls);
        ExpressionPtr optExp = value->preOptimize(ar);
        ar->popScope();
        m_visited = false;
        if (optExp) value = optExp;
      }
      if (value->isScalar()) {
        // inline the value
        if (value->is(Expression::KindOfScalarExpression)) {
          ScalarExpressionPtr exp =
            dynamic_pointer_cast<ScalarExpression>(Clone(value));
          exp->setComment(getText());
          return exp;
        } else if (value->is(Expression::KindOfConstantExpression)) {
          // inline the value
          ConstantExpressionPtr exp =
            dynamic_pointer_cast<ConstantExpression>(Clone(value));
          exp->setComment(getText());
          return exp;
        }
      }
    }
  }
  return ExpressionPtr();
}

ExpressionPtr SimpleFunctionCall::preOptimize(AnalysisResultPtr ar) {
  ar->preOptimize(m_nameExp);
  ar->preOptimize(m_params);
  if (ar->getPhase() != AnalysisResult::SecondPreOptimize) {
    return ExpressionPtr();
  }
  // optimize away various "exists" functions, this may trigger
  // dead code elimination and improve type-inference.
  if (m_className.empty() &&
      (m_type == DefinedFunction ||
       m_type == FunctionExistsFunction ||
       m_type == ClassExistsFunction ||
       m_type == InterfaceExistsFunction) &&
      m_params && m_params->getCount() == 1) {
    ExpressionPtr value = (*m_params)[0];
    if (value->isScalar()) {
      ScalarExpressionPtr name = dynamic_pointer_cast<ScalarExpression>(value);
      if (name && name->isLiteralString()) {
        string symbol = name->getLiteralString();
        switch (m_type) {
        case DefinedFunction: {
          ConstantTablePtr constants = ar->getConstants();
          // system constant
          if (constants->isPresent(symbol)) {
            return CONSTANT("true");
          }
          // user constant
          BlockScopePtr block = ar->findConstantDeclarer(symbol);
          // not found (i.e., undefined)
          if (!block) {
            if (symbol.find("::") == std::string::npos) {
              return CONSTANT("false");
            } else {
              // e.g., defined("self::ZERO")
              return ExpressionPtr();
            }
          }
          constants = block->getConstants();
          // already set to be dynamic
          if (constants->isDynamic(symbol)) return ExpressionPtr();
          ConstructPtr decl = constants->getValue(symbol);
          ExpressionPtr constValue = dynamic_pointer_cast<Expression>(decl);
          if (constValue->isScalar()) {
            return CONSTANT("true");
          } else {
            return ExpressionPtr();
          }
          break;
        }
        case FunctionExistsFunction: {
          const std::string &lname = Util::toLower(symbol);
          if (Option::DynamicInvokeFunctions.find(lname) ==
              Option::DynamicInvokeFunctions.end()) {
            FunctionScopePtr func = ar->findFunction(lname);
            if (!func) {
              return CONSTANT("false");
            } else if (!func->isVolatile()) {
              return CONSTANT("true");
            }
          }
          break;
        }
        case InterfaceExistsFunction: {
          ClassScopePtr cls = ar->findClass(Util::toLower(symbol));
          if (!cls || !cls->isInterface()) {
            return CONSTANT("false");
          } else if (!cls->isVolatile()) {
            return CONSTANT("true");
          }
          break;
        }
        case ClassExistsFunction: {
          ClassScopePtr cls = ar->findClass(Util::toLower(symbol));
          if (!cls || cls->isInterface()) {
            return CONSTANT("false");
          } else if (!cls->isVolatile()) {
            return CONSTANT("true");
          }
          break;
        }
        default:
          ASSERT(false);
        }
      }
    }
  }
  return ExpressionPtr();
}