Support if expressions in mk2rbc
Bug: 201700692
Test: go test
Change-Id: Icdf30c4d625d81974db946bd91660a29a0373ac7
diff --git a/mk2rbc/expr.go b/mk2rbc/expr.go
index ec0b279..81b31c7 100644
--- a/mk2rbc/expr.go
+++ b/mk2rbc/expr.go
@@ -85,6 +85,31 @@
s.emit(gctx)
}
+// Boolean literal
+type boolLiteralExpr struct {
+ literal bool
+}
+
+func (b *boolLiteralExpr) eval(_ map[string]starlarkExpr) (res starlarkExpr, same bool) {
+ return b, true
+}
+
+func (b *boolLiteralExpr) emit(gctx *generationContext) {
+ if b.literal {
+ gctx.write("True")
+ } else {
+ gctx.write("False")
+ }
+}
+
+func (_ *boolLiteralExpr) typ() starlarkType {
+ return starlarkTypeBool
+}
+
+func (b *boolLiteralExpr) emitListVarCopy(gctx *generationContext) {
+ b.emit(gctx)
+}
+
// interpolateExpr represents Starlark's interpolation operator <string> % list
// we break <string> into a list of chunks, i.e., "first%second%third" % (X, Y)
// will have chunks = ["first", "second", "third"] and args = [X, Y]
@@ -617,6 +642,55 @@
cx.emit(gctx)
}
+type ifExpr struct {
+ condition starlarkExpr
+ ifTrue starlarkExpr
+ ifFalse starlarkExpr
+}
+
+func (i *ifExpr) eval(valueMap map[string]starlarkExpr) (res starlarkExpr, same bool) {
+ cond, condSame := i.condition.eval(valueMap)
+ t, tSame := i.ifTrue.eval(valueMap)
+ f, fSame := i.ifFalse.eval(valueMap)
+ same = condSame && tSame && fSame
+ if same {
+ return i, same
+ } else {
+ return &ifExpr{
+ condition: cond,
+ ifTrue: t,
+ ifFalse: f,
+ }, same
+ }
+}
+
+func (i *ifExpr) emit(gctx *generationContext) {
+ gctx.write("(")
+ i.ifTrue.emit(gctx)
+ gctx.write(" if ")
+ i.condition.emit(gctx)
+ gctx.write(" else ")
+ i.ifFalse.emit(gctx)
+ gctx.write(")")
+}
+
+func (i *ifExpr) typ() starlarkType {
+ tType := i.ifTrue.typ()
+ fType := i.ifFalse.typ()
+ if tType != fType && tType != starlarkTypeUnknown && fType != starlarkTypeUnknown {
+ panic("Conflicting types in if expression")
+ }
+ if tType != starlarkTypeUnknown {
+ return tType
+ } else {
+ return fType
+ }
+}
+
+func (i *ifExpr) emitListVarCopy(gctx *generationContext) {
+ i.emit(gctx)
+}
+
type badExpr struct {
errorLocation ErrorLocation
message string