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compiler: refactor BinaryExpr handling

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Reuse code between if conditions and expression context.
This commit is contained in:
Evgenii Stratonikov 2020-08-23 14:52:37 +03:00
parent 4d04c56efb
commit 51f3baf68e
2 changed files with 85 additions and 46 deletions
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125
pkg/compiler/codegen.go
View file

@ -561,8 +561,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
lElseEnd := c.newLabel()
if n.Cond != nil {
ast.Walk(c, n.Cond)
emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOTL, lElse)
c.emitBoolExpr(n.Cond, true, false, lElse)
}
c.setLabel(lIf)
@ -689,50 +688,8 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
return nil
case *ast.BinaryExpr:
// The AST package will try to resolve all basic literals for us.
// If the typeinfo.Value is not nil we know that the expr is resolved
// and needs no further action. e.g. x := 2 + 2 + 2 will be resolved to 6.
// NOTE: Constants will also be automatically resolved be the AST parser.
// example:
// const x = 10
// x + 2 will results into 12
tinfo := c.typeAndValueOf(n)
if tinfo.Value != nil {
c.emitLoadConst(tinfo)
c.emitBinaryExpr(n, false, false, 0)
return nil
}
if arg := c.getCompareWithNilArg(n); arg != nil {
ast.Walk(c, arg)
emit.Opcode(c.prog.BinWriter, opcode.ISNULL)
if n.Op == token.NEQ {
emit.Opcode(c.prog.BinWriter, opcode.NOT)
}
return nil
}
switch n.Op {
case token.LAND, token.LOR:
end := c.newLabel()
ast.Walk(c, n.X)
if n.Op == token.LAND {
emit.Instruction(c.prog.BinWriter, opcode.JMPIF, []byte{2 + 1 + 5})
emit.Opcode(c.prog.BinWriter, opcode.PUSHF)
} else {
emit.Instruction(c.prog.BinWriter, opcode.JMPIFNOT, []byte{2 + 1 + 5})
emit.Opcode(c.prog.BinWriter, opcode.PUSHT)
}
emit.Jmp(c.prog.BinWriter, opcode.JMPL, end)
ast.Walk(c, n.Y)
c.setLabel(end)
return nil
default:
ast.Walk(c, n.X)
ast.Walk(c, n.Y)
c.emitToken(n.Op, c.typeOf(n.X))
return nil
}
case *ast.CallExpr:
var (
@ -1122,6 +1079,84 @@ func (c *codegen) getCompareWithNilArg(n *ast.BinaryExpr) ast.Expr {
return nil
}
func (c *codegen) emitJumpOnCondition(cond bool, jmpLabel uint16) {
if cond {
emit.Jmp(c.prog.BinWriter, opcode.JMPIFL, jmpLabel)
} else {
emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOTL, jmpLabel)
}
}
func (c *codegen) emitBoolExpr(n ast.Expr, needJump bool, cond bool, jmpLabel uint16) {
if be, ok := n.(*ast.BinaryExpr); ok {
c.emitBinaryExpr(be, needJump, cond, jmpLabel)
} else {
ast.Walk(c, n)
if needJump {
c.emitJumpOnCondition(cond, jmpLabel)
}
}
}
func (c *codegen) emitBinaryExpr(n *ast.BinaryExpr, needJump bool, cond bool, jmpLabel uint16) {
// The AST package will try to resolve all basic literals for us.
// If the typeinfo.Value is not nil we know that the expr is resolved
// and needs no further action. e.g. x := 2 + 2 + 2 will be resolved to 6.
// NOTE: Constants will also be automatically resolved be the AST parser.
// example:
// const x = 10
// x + 2 will results into 12
tinfo := c.typeAndValueOf(n)
if tinfo.Value != nil {
c.emitLoadConst(tinfo)
if needJump && isBool(tinfo.Type) {
c.emitJumpOnCondition(cond, jmpLabel)
}
return
} else if arg := c.getCompareWithNilArg(n); arg != nil {
ast.Walk(c, arg)
emit.Opcode(c.prog.BinWriter, opcode.ISNULL)
if needJump {
c.emitJumpOnCondition(cond == (n.Op == token.EQL), jmpLabel)
} else if n.Op == token.NEQ {
emit.Opcode(c.prog.BinWriter, opcode.NOT)
}
return
}
switch n.Op {
case token.LAND, token.LOR:
end := c.newLabel()
// true || .. == true, false && .. == false
condShort := n.Op == token.LOR
if needJump {
l := end
if cond == condShort {
l = jmpLabel
}
c.emitBoolExpr(n.X, true, condShort, l)
c.emitBoolExpr(n.Y, true, cond, jmpLabel)
} else {
push := c.newLabel()
c.emitBoolExpr(n.X, true, condShort, push)
c.emitBoolExpr(n.Y, false, false, 0)
emit.Jmp(c.prog.BinWriter, opcode.JMPL, end)
c.setLabel(push)
emit.Bool(c.prog.BinWriter, condShort)
}
c.setLabel(end)
default:
ast.Walk(c, n.X)
ast.Walk(c, n.Y)
c.emitToken(n.Op, c.typeOf(n.X))
if needJump {
c.emitJumpOnCondition(cond, jmpLabel)
}
}
}
func (c *codegen) pushStackLabel(name string, size int) {
c.labelList = append(c.labelList, labelWithStackSize{
name: name,

4
pkg/compiler/types.go
View file

@ -31,6 +31,10 @@ func isByte(typ types.Type) bool {
return isBasicTypeOfKind(typ, types.Uint8, types.Int8)
}
func isBool(typ types.Type) bool {
return isBasicTypeOfKind(typ, types.Bool, types.UntypedBool)
}
func isNumber(typ types.Type) bool {
t, ok := typ.Underlying().(*types.Basic)
return ok && t.Info()&types.IsNumeric != 0