def build_for_statement(self, tree):
if tree.getChildCount() < 6:
raise RuntimeError("invalid FOR statement: '" + tree.getText() +
"'")
token = tree.getChild(0).getPayload()
# for开头
if not isinstance(token, Token) or token.type != CXLexer.FOR:
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
token = tree.getChild(1).getPayload()
if not isinstance(token,
Token) or token.type != CXLexer.LEFTPARENTHESIS:
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
token = tree.getChild(tree.getChildCount() - 2).getPayload()
if not isinstance(token,
Token) or token.type != CXLexer.RIGHTPARENTHESIS:
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
child_index = 2
semicolon_index = 0
init_expression = Expression(None)
check_expression = Expression(None)
update_expression = Expression(None)
while True:
token = tree.getChild(child_index).getPayload()
if isinstance(token, Token):
if token.type == CXLexer.RIGHTPARENTHESIS:
break
# index=2为分号表示初始语句为空
elif token.type == CXLexer.SEMICOLON:
semicolon_index += 1
child_index += 1
if semicolon_index > 2:
raise RuntimeError("Invalid FOR statement: '" +
tree.getText() + "'")
else:
raise RuntimeError("Invalid FOR statement: '" +
tree.getText() + "'")
else:
if semicolon_index == 0:
init_expression = self.build_expression(
tree.getChild(child_index))
elif semicolon_index == 1:
check_expression = self.build_expression(
tree.getChild(child_index))
else:
update_expression = self.build_expression(
tree.getChild(child_index))
child_index += 1
self.symbol_table.open_scope()
statement = self.build_compound_statement(
tree.getChild(tree.getChildCount() - 1))
self.symbol_table.close_scope()
return ForStatement(init_expression, check_expression,
update_expression, statement, self.symbol_table)
def buildForStatement(self, tree):
"""Build For Statement"""
# FOR LPAREN expression? SEMICOLON expression? SEMICOLON expression? RPAREN statement
if (tree.getChildCount() < 6):
raise RuntimeError("invalid FOR statement: `" + tree.getText() +
"`")
# Check if FOR at front
token = tree.getChild(0).getPayload()
if (not isinstance(token, Token) or token.type != CLexer.FOR):
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
# Check if LPAREN at front
token = tree.getChild(1).getPayload()
if (not isinstance(token, Token) or token.type != CLexer.LPAREN):
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
# Check for RPAREN
token = tree.getChild(tree.getChildCount() - 2).getPayload()
if (not isinstance(token, Token) or token.type != CLexer.RPAREN):
raise RuntimeError("Invalid FOR statement: '" + tree.getText() +
"'")
childIndex = 2
semicolonIndex = 0
initExpression = Expression(None)
checkExpression = Expression(None)
updateExpression = Expression(None)
while (True):
token = tree.getChild(childIndex).getPayload()
if (isinstance(token, Token)):
if (token.type == CLexer.RPAREN):
break
elif (token.type == CLexer.SEMICOLON):
semicolonIndex += 1
childIndex += 1
if (semicolonIndex > 2):
raise RuntimeError("Invalid FOR statement: '" +
tree.getText() + "'")
else:
raise RuntimeError("Invalid FOR statement: '" +
tree.getText() + "'")
else:
if (semicolonIndex == 0):
initExpression = self.buildExpression(
tree.getChild(childIndex))
elif (semicolonIndex == 1):
checkExpression = self.buildExpression(
tree.getChild(childIndex))
else:
updateExpression = self.buildExpression(
tree.getChild(childIndex))
childIndex += 1
# build statement
self.sym.openScope()
statement = self.buildStatement(tree.getChild(tree.getChildCount() -
1))
self.sym.closeScope()
return ForStatement(initExpression, checkExpression, updateExpression,
statement, self.sym)