shared_ptr<Statement> Parser::parseWhile()
{
shared_ptr<WhileStmt> whStmt = make_shared<WhileStmt>();
whStmt->value = *it;
currNode = whStmt;
it++;
shared_ptr<Expression> cond = parseExpression();
whStmt->condition = cond;
//it++;
match(DO);
it++;
if (match(BEGIN))
{
shared_ptr<Statement> body = parseStmtList(END);
whStmt->body=body;
match(END);
it++;
match(SEMI);
}
else
{
shared_ptr<Statement> body1 = parseStatement();
whStmt->body = body1;
}
return whStmt;
}
shared_ptr<Statement> Parser::parseIf()
{
shared_ptr<IfStmt> ifstmt = make_shared<IfStmt>();
ifstmt->value = *it;
currNode = ifstmt;
it++;
auto cond = parseExpression();
ifstmt->condition = cond;
match(THEN);
it++;
if (match(BEGIN))
{
currNode = ifstmt;
shared_ptr<Statement> body = parseStmtList(END);
ifstmt->thenBody=body;
match(END);
it++;
match(SEMI);
}
else
{
shared_ptr<Statement> body1 = parseStatement();
ifstmt->thenBody = body1;
}
ifstmt->haveElse = false;
while (advance(ELSE))
{
ifstmt->haveElse = true;
it++;
shared_ptr<ElseStmt> elseStmt = static_pointer_cast<ElseStmt>(parseElse());
ifstmt->elseBody = elseStmt;
}
return ifstmt;
}
shared_ptr<Statement> Parser::parseElse()
{
shared_ptr<ElseStmt> elseStmt = make_shared<ElseStmt>();
elseStmt->value = *it;
it++;
if (match(IF))//match if
{
shared_ptr<IfStmt> elseifnode = static_pointer_cast<IfStmt>(parseIf());
elseStmt->addNode(elseifnode);
}
else if (match(BEGIN))//match begin Compound Statement 复合语句
{
shared_ptr<Statement> body = parseStmtList(END);
elseStmt->body = body;
match(END);
it++;
match(SEMI);
}
else//单行语句
{
shared_ptr<Statement> body1 = parseStatement();
elseStmt->addNode(body1);
}
return elseStmt;
}
/***************************************************************
* Function: CodeParser::parseWhileStmt()
* Purpose : Parse the XML code of a while loop statement
* Initial : Maxime Chevalier-Boisvert on November 8, 2008
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseWhileStmt(const XML::Element* pElement)
{
unsigned loopDepth = ++maxLoopDepth;
// Parse the condition expression
Expression* pCondExpr = parseExpression(pElement->getChildElement(0));
// Parse the loop body
StmtSequence* pLoopBody = parseStmtList(pElement->getChildElement(1));
unsigned annotations = 0;
// reset maxLoopDepth && currentDepth
if (loopDepth == maxLoopDepth) {
// isInnermost loop is true;
annotations |= Statement::INNERMOST;
}
if (loopDepth == 1) {
// isOutermost loop is true;
annotations |= Statement::OUTERMOST;
// reset the loop depth counter
maxLoopDepth = 0;
}
// return the new for statement object
return new WhileStmt(pCondExpr, pLoopBody, annotations);
}
/***************************************************************
* Function: CodeParser::parseForStmt()
* Purpose : Parse the XML code of a for loop statement
* Initial : Maxime Chevalier-Boisvert on November 8, 2008
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseForStmt(const XML::Element* pElement)
{
unsigned loopDepth = ++maxLoopDepth;
// Parse the assignment statement
Statement* pAssignStmt = parseStatement(pElement->getChildElement(0));
// Ensure that this statement really is an assignment statement
if (pAssignStmt->getStmtType() != Statement::ASSIGN)
throw XML::ParseError("Invalid statement type", pElement->getChildElement(0)->getTextPos());
// Parse the loop body
StmtSequence* pLoopBody = parseStmtList(pElement->getChildElement(1));
unsigned annotations = 0;
// reset maxLoopDepth
if (loopDepth == maxLoopDepth) {
// isInnermost loop is true;
annotations |= Statement::INNERMOST;
}
if (loopDepth == 1) {
// isOutermost loop is true;
annotations |= Statement::OUTERMOST;
// reset the counters
maxLoopDepth = 0;
}
// return the new for statement object
return new ForStmt((AssignStmt*)pAssignStmt, pLoopBody, annotations);
}
shared_ptr<Statement> Parser::parseRepeat()
{
shared_ptr<RepeatStmt> repeatStmt = make_shared<RepeatStmt>();
currNode = repeatStmt;
shared_ptr<Statement> body=parseStmtList(UNTIL);
repeatStmt->body = body;
match(UNTIL);
shared_ptr<Expression> cond = parseExpression();
repeatStmt->untilCond = cond;
return repeatStmt;
}
/***************************************************************
* Function: CodeParser::parseScript()
* Purpose : Parse the XML code of a script
* Initial : Maxime Chevalier-Boisvert on November 4, 2008
****************************************************************
Revisions and bug fixes:
*/
IIRNode* CodeParser::parseScript(const XML::Element* pElement)
{
// Declare a pointer for the sequence statement
StmtSequence* pSequenceStmt = NULL;
// For each child element
for (size_t i = 0; i < pElement->getNumChildren(); ++i)
{
// Get a pointer to this element
XML::Element* pFuncElement = pElement->getChildElement(i);
// If this is a symbol table
if (pFuncElement->getName() == "Symboltable")
{
// Ignore for now
}
// If this is the statement list
else if (pFuncElement->getName() == "StmtList")
{
// If the statement list was already encountered, throw an exception
if (pSequenceStmt != NULL)
throw XML::ParseError("Duplicate statement list", pElement->getTextPos());
// Parse the statement list
pSequenceStmt = parseStmtList(pFuncElement);
}
// Otherwise
else
{
// This is an invalid element type, throw an exception
throw XML::ParseError("Invalid element type in script: \"" + pFuncElement->getName() + "\"", pFuncElement->getTextPos());
}
}
// If the statement list is missing, throw an exception
if (pSequenceStmt == NULL)
throw XML::ParseError("Missing statement list", pElement->getTextPos());
// Create and return a new program function object
return new ProgFunction(
"",
ProgFunction::ParamVector(),
ProgFunction::ParamVector(),
ProgFunction::FuncVector(),
pSequenceStmt,
true
);
}
//lead into the program
void Parser::parseBlock()
{
++it;
switch (it->tag)
{
case CONSTANT:
parseConstant();
parseBlock();
break;
case VAR:
parseVariables();
parseBlock();
break;
case TYPE:
parseType();
parseBlock();
break;
case FUNCTION:
parseFunction();
parseBlock();
break;
case PROCEDURE:
parseProcedure();
parseBlock();
break;
case BEGIN:
{
shared_ptr<Statement> block =
parseStmtList(currNode == root ? FINISH : END);
//root的block与函数的block
if (currNode != root)
{
(static_pointer_cast<FunctionStmt>(currNode))->body=block;
}
else
{
block->value.value = "__Main__";
currNode->addNode(block);
}
bool tmp=it->tag == FINISH || it->tag == END;
if (it->tag == END)
{
it++;
match(SEMI);
}
}
break;
}
}
shared_ptr<Statement> Parser::parseFor()
{
//for k=1 to 10 do
shared_ptr<ForStmt> forStmt = make_shared<ForStmt>();
forStmt->value = *it;
currNode = forStmt;
it++;
shared_ptr<AssignStmt> startVal = static_pointer_cast<AssignStmt>(parseStatement());
forStmt->startStmt = startVal;
Tag direction=it->tag;
forStmt->direction = direction;
bool tmpCheck=find(TO)||find(DOWNTO);
if (!tmpCheck)
{
Error err("syntax error", *it);
errList.push_back(err);
}
it++;
auto endVal = parseExpression();
forStmt->endValue = endVal;
match(DO);
it++;
if (match(BEGIN))
{
shared_ptr<Statement> body = parseStmtList(END);
forStmt->body = body ;
match(END);
it++;
match(SEMI);
}
else
{
shared_ptr<Statement> body1 = parseStatement();
forStmt->body = body1;
}
return forStmt;
}
/***************************************************************
* Function: CodeParser::parseFunction()
* Purpose : Parse the XML code of a function
* Initial : Maxime Chevalier-Boisvert on November 3, 2008
****************************************************************
Revisions and bug fixes:
*/
ProgFunction* CodeParser::parseFunction(const XML::Element* pElement)
{
// Get the function name
std::string funcName = pElement->getStringAttrib("name");
// Declare a pointer for the sequence statement
StmtSequence* pSequenceStmt = NULL;
// Declare vectors for the input and output parameters
ProgFunction::ParamVector inParams;
ProgFunction::ParamVector outParams;
// Declare a vector for the nested function list
ProgFunction::FuncVector nestedFuncs;
// For each child element
for (size_t i = 0; i < pElement->getNumChildren(); ++i)
{
// Get a pointer to this element
XML::Element* pFuncElement = pElement->getChildElement(i);
// If this is a symbol table
if (pFuncElement->getName() == "Symboltable")
{
// Ignore for now
}
// If this is a parameter declaration list
else if (pFuncElement->getName() == "ParamDeclList")
{
// Ignore for now
}
// If this is an input parameter list
else if (pFuncElement->getName() == "InputParamList")
{
// For each child element
for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
{
// Get the parameter name
const std::string& paramName = pFuncElement->getChildElement(i)->getStringAttrib("nameId");
// Add the parameter to the list
inParams.push_back(SymbolExpr::getSymbol(paramName));
}
}
// If this is an output parameter list
else if (pFuncElement->getName() == "OutputParamList")
{
// For each child element
for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
{
// Get the parameter name
const std::string& paramName = pFuncElement->getChildElement(i)->getStringAttrib("nameId");
// Add the parameter to the list
outParams.push_back(SymbolExpr::getSymbol(paramName));
}
}
// If this is a nested function list
else if (pFuncElement->getName() == "NestedFunctionList")
{
// For each child element
for (size_t i = 0; i < pFuncElement->getNumChildren(); ++i)
{
// Parse this function declaration
ProgFunction* pFunction = parseFunction(pFuncElement->getChildElement(i));
// Add the nested function to the list
nestedFuncs.push_back(pFunction);
}
}
// If this is the statement list
else if (pFuncElement->getName() == "StmtList")
{
// If the statement list was already encountered, throw an exception
if (pSequenceStmt != NULL)
throw XML::ParseError("Duplicate statement list", pElement->getTextPos());
// Parse the statement list
pSequenceStmt = parseStmtList(pFuncElement);
}
// Otherwise
else
{
// This is an invalid element type, throw an exception
throw XML::ParseError("Invalid element type in script: \"" + pFuncElement->getName() + "\"", pFuncElement->getTextPos());
}
}
// If the statement list is missing, throw an exception
if (pSequenceStmt == NULL)
throw XML::ParseError("Missing statement list", pElement->getTextPos());
// Create a new program function object
ProgFunction* pNewFunc = new ProgFunction(
funcName,
inParams,
outParams,
nestedFuncs,
pSequenceStmt
);
// For each nested function
for (ProgFunction::FuncVector::iterator nestItr = nestedFuncs.begin(); nestItr != nestedFuncs.end(); ++nestItr)
{
// Set the parent pointer to the newly created function object
(*nestItr)->setParent(pNewFunc);
}
// Return the new program function object
return pNewFunc;
}
/***************************************************************
* Function: CodeParser::parseSwitchStmt()
* Purpose : Parse the XML code of a switch statement
* Initial : Maxime Chevalier-Boisvert on February 23, 2009
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseSwitchStmt(const XML::Element* pElement)
{
// Parse the switch expression
Expression* pSwitchExpr = parseExpression(pElement->getChildElement(0));
// Declare a case list for the switch cases
SwitchStmt::CaseList caseList;
// Declare a statement sequence pointer for the default case
StmtSequence* pDefaultCase = NULL;
// For each remaining child element
for (size_t i = 1; i < pElement->getNumChildren(); ++i)
{
// Get a pointer to this child element
XML::Element* pChildElem = pElement->getChildElement(i);
// If this is a switch case block
if (pChildElem->getName() == "SwitchCaseBlock")
{
// Parse the switch case contents and add the case to the list
caseList.push_back(
SwitchStmt::SwitchCase(
parseExpression(pChildElem->getChildElement(0)),
parseStmtList(pChildElem->getChildElement(1))
)
);
}
// If this is a default case block
else if (pChildElem->getName() == "DefaultCaseBlock")
{
// If a default case was already parsed
if (pDefaultCase != NULL)
{
// Throw an exception
throw XML::ParseError("Duplicate default case in switch statement", pChildElem->getTextPos());
}
// Parse the statement list
pDefaultCase = parseStmtList(pChildElem->getChildElement(0));
}
// Otherwise
else
{
// This is an invalid element type, throw an exception
throw XML::ParseError("Invalid element in switch statement: \"" + pChildElem->getName() + "\"", pChildElem->getTextPos());
}
}
// If there is no default case, create an empty one
if (pDefaultCase == NULL)
pDefaultCase = new StmtSequence();
// Create and return the switch statement object
return new SwitchStmt(
pSwitchExpr,
caseList,
pDefaultCase
);
}
/***************************************************************
* Function: CodeParser::parseIfStmt()
* Purpose : Parse the XML code of an if statement
* Initial : Maxime Chevalier-Boisvert on November 5, 2008
****************************************************************
Revisions and bug fixes:
*/
Statement* CodeParser::parseIfStmt(const XML::Element* pElement)
{
// Declare a vector to store the if blocks
std::vector<XML::Element*> ifBlocks;
// Declare a pointer for the else block
XML::Element* pElseBlock = NULL;
// For each child element
for (size_t i = 0; i < pElement->getNumChildren(); ++i)
{
// Get a pointer to this element
XML::Element* pIfElement = pElement->getChildElement(i);
// If this is an if block
if (pIfElement->getName() == "IfBlock")
{
// Add it to the list
ifBlocks.push_back(pIfElement);
}
// If this is an else block
else if (pIfElement->getName() == "ElseBlock")
{
// If there is more than one else block, throw an exception
if (pElseBlock)
throw XML::ParseError("Duplicate else block", pIfElement->getTextPos());
// Store a pointer to the else block
pElseBlock = pIfElement;
}
// Otherwise
else
{
// This is an invalid element type, throw an exception
throw XML::ParseError("Invalid element in if statement: \"" + pIfElement->getName() + "\"", pIfElement->getTextPos());
}
}
// If are are no if blocks, throw an exception
if (ifBlocks.size() == 0)
throw XML::ParseError("Missing if block", pElement->getTextPos());
// Get a pointer to the last if block
XML::Element* pLastIfBlock = ifBlocks.back();
// remove the last if block from the list
ifBlocks.pop_back();
// Create the first if-else statement from the last if and else blocks
IfElseStmt* pIfStmt = new IfElseStmt(
parseExpression(pLastIfBlock->getChildElement(0)),
parseStmtList(pLastIfBlock->getChildElement(1)),
pElseBlock? parseStmtList(pElseBlock->getChildElement(0)):(new StmtSequence())
);
// For each if block, in reverse order
for (std::vector<XML::Element*>::reverse_iterator itr = ifBlocks.rbegin(); itr != ifBlocks.rend(); ++itr)
{
// Get a pointer to this if block element
XML::Element* pIfBlock = *itr;
// Add this if block to the recursive structure
pIfStmt = new IfElseStmt(
parseExpression(pIfBlock->getChildElement(0)),
parseStmtList(pIfBlock->getChildElement(1)),
new StmtSequence(pIfStmt)
);
}
// Return a pointer to the if-else statement
return pIfStmt;
}