// nextUnit parses a unit.
func (p *Parser) nextUnit() ssa.Node {
p.enter()
var regNode ssa.Node
var reg *ssa.Register
switch p.tok.Type {
case token.IDENT:
nameTok := p.tok
fmt.Println(nameTok)
p.next()
if p.tok.Type == token.LPAREN {
p.next() // '('
if p.tok.Type != token.RPAREN {
paramNode := p.nextExpression()
fmt.Println(paramNode)
for p.tok.Type == token.COMMA {
p.next() // ','
paramTok := p.tok
fmt.Println(paramTok)
p.nextExpression()
}
}
p.nextExpected(token.RPAREN)
} else if p.tok.Type == token.LBRACK {
p.next()
p.nextExpression()
p.nextExpected(token.RBRACK)
}
case token.INT:
reg = p.alloc.Request()
// assembler.emit("li", reg, p.tok.String());
p.next() // int constant
regNode = ssa.NewRegNode(types.Int, reg)
case token.FLOAT:
// p.tok.String()
p.next()
case token.CHAR:
// p.tok.String()
p.next()
case token.STRING:
reg = p.alloc.Request()
// Label label = global.enterString(scanner.getString());
// assembler.emit("la", reg, label);
p.next() // string constant
regNode = ssa.NewRegNode(types.String, reg)
default:
log.Fatalf("term expected, got '%s'", p.tok)
}
p.exit()
return regNode
}
// nextFunctionSignature parses a function signature.
func (p *Parser) nextFunctionSignature() {
p.enter()
// skip 'func'
p.nextExpected(token.FUNC)
// save the func name token
funcNameTok := p.tok
p.nextExpected(token.IDENT) // skip func name
p.nextExpected(token.LPAREN) // skip '('
// create a new func signature type
funcSigType := types.NewFunc()
// look for func parameters
if p.tok.Type != token.RPAREN {
// save the parameter name token
paramNameTok := p.tok
// skip param name
p.nextExpected(token.IDENT)
// get the parameter type
paramType := p.nextType()
// add the parameter type to the func signature type
funcSigType.AddParam(paramType)
// allocate a register and create a new register node
reg := p.alloc.Request()
regNode := ssa.NewRegNode(paramType, reg)
// add the parameter name token and register node to the current scope
p.scope.Add(paramNameTok, regNode)
// look for more parameters
for p.tok.Type == token.COMMA {
p.next() // skip ','
// save the parameter name token
paramNameTok = p.tok
// skip parameter name
p.nextExpected(token.IDENT)
// get the parameter type
paramType = p.nextType()
// add the parameter type to the func signature type
funcSigType.AddParam(paramType)
// allocate a register and create a new register node
reg = p.alloc.Request()
regNode = ssa.NewRegNode(paramType, reg)
// add the parameter name token and register node to the current scope
p.scope.Add(paramNameTok, regNode)
}
}
// skip ')'
p.nextExpected(token.RPAREN)
// look for return value
if p.tok.Type != token.LBRACE {
// get the return value type
paramType := p.nextType()
// add the return value type to the func signature type
funcSigType.AddValue(paramType)
// look for more return types
for p.tok.Type == token.COMMA {
p.next() // skip ','
// get the return value type
paramType = p.nextType()
// add the return value type to the func signature type
funcSigType.AddValue(paramType)
}
}
// create a func signature label and node
label := ssa.NewLabel(funcNameTok.String())
funcSigNode := ssa.NewFuncNode(funcSigType, label)
// check any previous type declarations via TBV
if ok, err := p.tbv.Verify(funcNameTok, funcSigNode); ok && err != nil {
userErr(err, funcNameTok)
}
// set the func signature node to the global scope and check for user error
if err := p.scope.Global(funcNameTok, funcSigNode); err != nil {
userErr(err, funcNameTok)
}
p.exit()
}