Mercurial > lcfOS
diff python/c3/parser.py @ 149:74241ca312cc
Fixes on parser and semantics
author | Windel Bouwman |
---|---|
date | Fri, 01 Mar 2013 11:43:52 +0100 |
parents | e5263f74b287 |
children | 4ae0e02599de |
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--- a/python/c3/parser.py Fri Mar 01 10:24:01 2013 +0100 +++ b/python/c3/parser.py Fri Mar 01 11:43:52 2013 +0100 @@ -6,11 +6,6 @@ '<': 20, '>': 20, '==': 20, '<=': 20, '>=': 20, '!=': 20, \ '+': 30, '-': 30, '*': 40, '/': 40 } -def getTokenPrecedence(typ): - if typ in binopPrecs: - return binopPrecs[typ] - return -1 - class Parser: """ Parses sourcecode into an abstract syntax tree (AST) """ def __init__(self, sema, diag): @@ -38,7 +33,9 @@ return self.token.typ @property def PeakPrec(self): - return getTokenPrecedence(self.Peak) + if self.Peak in binopPrecs: + return binopPrecs[self.Peak] + return -1 def hasConsumed(self, typ): if self.Peak == typ: self.Consume(typ) @@ -64,16 +61,18 @@ self.Consume('END') def parseTopLevel(self): - is_public = self.hasConsumed('public') if self.Peak == 'function': - self.parseFunctionDefinition(is_public) + self.parseFunctionDefinition() elif self.Peak == 'var': - self.parseVarDef(is_public) + self.parseVarDef() + self.Consume(';') + else: + self.Error('Expected function or variable') def parseDesignator(self): """ A designator designates an object """ name = self.Consume('ID') - return name + return name.val # Type system def parseType(self): @@ -81,19 +80,25 @@ return d # Variable declarations: - def parseVarDef(self, is_public): + def parseVarDef(self): self.Consume('var') - typ = self.parseType() - ID = self.Consume('ID') - self.Consume(';') - v = Variable(i.name, typename, public=is_public) - self.curScope.add(v) + t = self.parseType() + def parseVar(): + name = self.Consume('ID') + ival = None + if self.hasConsumed('='): + ival = self.parseExpression() + self.sema.actOnVarDef(name.val, name.loc, t, ival) + parseVar() + while self.hasConsumed(','): + parseVar() # Procedures - def parseFunctionDefinition(self, is_pub): + def parseFunctionDefinition(self): self.Consume('function') returntype = self.parseType() - procname = self.Consume('ID') + pname = self.Consume('ID') + self.sema.actOnFuncDef1(pname.val, pname.loc) self.Consume('(') parameters = [] if not self.hasConsumed(')'): @@ -105,9 +110,8 @@ name = self.Consume('ID') parameters.append(astnodes.Parameter(name, typ)) self.Consume(')') - proctyp = astnodes.FunctionType(parameters, returntype) body = self.parseCompoundStatement() - return astnodes.Procedure(procname, proctyp, body) + self.sema.actOnFuncDef2(parameters, returntype, body) # Statements: def parseAssignment(self, lval): @@ -125,48 +129,37 @@ self.Consume(')') return ProcedureCall(procedure, args) - def parseLocal(self, t): - name = self.Consume('ID') - if self.hasConsumed('='): - ival = self.parseExpression() - else: - ival = None - self.sema.actOnLocal(t, name, ival) - def parseLocalDeclaration(self): - self.Consume('var') - t = self.parseType() - self.parseLocal(t) - while self.hasConsumed(','): - self.parseLocal(t) - def parseIfStatement(self): self.Consume('if') self.Consume('(') condition = self.parseExpression() self.Consume(')') - truestatement = self.parseStatement() + yes = self.parseCompoundStatement() if self.hasConsumed('else'): - els = self.parseStatement() - return astnodes.IfStatement(condition, truestatement, els) - return astnodes.IfStatement(condition, truestatement) + no = self.parseCompoundStatement() + return astnodes.IfStatement(condition, yes, no) + return astnodes.IfStatement(condition, yes) def parseWhileStatement(self): self.Consume('while') self.Consume('(') condition = self.parseExpression() self.Consume(')') - statements = self.parseStatement() + statements = self.parseCompoundStatement() + return astnodes.WhileStatement(condition, statements) + def parseReturnStatement(self): self.Consume('return') expr = self.parseExpression() + return astnodes.ReturnStatement(expr) def parseCompoundStatement(self): - self.Consume('{') - statements = [self.parseStatement()] - while self.hasConsumed(';'): + self.Consume('{') + statements = [self.parseStatement()] + while self.hasConsumed(';'): statements.append(self.parseStatement()) - self.Consume('}') - return astnodes.CompoundStatement(statements) + self.Consume('}') + return astnodes.CompoundStatement(statements) def parseStatement(self): # Determine statement type based on the pending token: @@ -177,11 +170,10 @@ elif self.Peak == '{': return self.parseCompoundStatement() elif self.Peak == 'var': - return self.parseLocalDeclaration() + return self.parseVarDef() elif self.Peak == 'return': return self.parseReturnStatement() elif self.Peak == 'ID': - # Assignment or procedure call designator = self.parseDesignator() if self.Peak == '(': return self.parseProcedureCall(designator) @@ -199,7 +191,7 @@ return e elif self.Peak == 'NUMBER': val = self.Consume('NUMBER') - return astnodes.Constant(val, val) + return self.sema.actOnNumber(val.val, val.loc) elif self.Peak == 'ID': d = self.parseDesignator() return d @@ -212,6 +204,6 @@ rhs = self.parsePrimary() while self.PeakPrec > op_prec: rhs = self.parseBinopRhs(rhs, self.PeakPrec) - lhs = astnodes.Binop(lhs, op, rhs) + lhs = self.sema.actOnBinop(lhs, op.typ, rhs, op.loc) return lhs