Refactor cgen's writeStatementAssign
diff --git a/internal/cgen/statement.go b/internal/cgen/statement.go
index a5e9e25..a16e66a 100644
--- a/internal/cgen/statement.go
+++ b/internal/cgen/statement.go
@@ -95,22 +95,23 @@
}
}
- couldSuspend := false
- if err := g.writeBuiltinQuestionCall(b, rhs, 0); err == nil {
- // No-op.
- } else if err != errNoSuchBuiltin {
- return err
- } else {
- if err := g.writeStatementAssign0(b, op, lhs, rhs); err != nil {
+ couldSuspend, skipRHS := false, false
+ if rhs.Effect().Coroutine() {
+ if err := g.writeBuiltinQuestionCall(b, rhs, 0); err == nil {
+ skipRHS = true
+ } else if err != errNoSuchBuiltin {
return err
+ } else if op != t.IDEqQuestion {
+ if err := g.writeCoroSuspPoint(b, false); err != nil {
+ return err
+ }
+ b.writes("status = ")
+ couldSuspend = true
}
- couldSuspend = (op != t.IDEqQuestion) && rhs.Effect().Coroutine()
}
- if lhs != nil {
- if err := g.writeStatementAssign1(b, op, lhs, rhs); err != nil {
- return err
- }
+ if err := g.writeStatementAssign1(b, op, lhs, rhs, skipRHS); err != nil {
+ return err
}
if needWriteLoadExprDerivedVars {
if err := g.writeLoadExprDerivedVars(b, rhs); err != nil {
@@ -123,69 +124,61 @@
return nil
}
-func (g *gen) writeStatementAssign0(b *buffer, op t.ID, lhs *a.Expr, rhs *a.Expr) error {
- if (lhs == nil) || rhs.Effect().Coroutine() {
- if op == t.IDEqQuestion {
- if g.currFunk.tempW > maxTemp {
- return fmt.Errorf("too many temporary variables required")
- }
- temp := g.currFunk.tempW
- g.currFunk.tempW++
+func (g *gen) writeStatementAssign1(b *buffer, op t.ID, lhs *a.Expr, rhs *a.Expr, skipRHS bool) error {
+ lhsBuf := buffer(nil)
+ opName, closer, disableWconversion := "", "", false
- b.printf("wuffs_base__status %s%d = ", tPrefix, temp)
- } else if rhs.Effect().Coroutine() {
- if err := g.writeCoroSuspPoint(b, false); err != nil {
- return err
- }
- b.writes("status = ")
- }
-
- if err := g.writeExpr(b, rhs, 0); err != nil {
+ if lhs != nil {
+ if err := g.writeExpr(&lhsBuf, lhs, 0); err != nil {
return err
}
- b.writes(";\n")
- }
- return nil
-}
+ if lTyp := lhs.MType(); lTyp.IsArrayType() {
+ b.writes("memcpy(")
+ opName, closer = ",", fmt.Sprintf(", sizeof(%s))", lhsBuf)
-func (g *gen) writeStatementAssign1(b *buffer, op t.ID, lhs *a.Expr, rhs *a.Expr) error {
- lhsBuf := buffer(nil)
- if err := g.writeExpr(&lhsBuf, lhs, 0); err != nil {
- return err
- }
-
- opName, closer, disableWconversion := "", "", false
- if lTyp := lhs.MType(); lTyp.IsArrayType() {
- b.writes("memcpy(")
- opName, closer = ",", fmt.Sprintf(", sizeof(%s))", lhsBuf)
-
- } else {
- switch op {
- case t.IDTildeSatPlusEq, t.IDTildeSatMinusEq:
- uBits := uintBits(lTyp.QID())
- if uBits == 0 {
- return fmt.Errorf("unsupported tilde-operator type %q", lTyp.Str(g.tm))
- }
- uOp := "add"
- if op != t.IDTildeSatPlusEq {
- uOp = "sub"
- }
- b.printf("wuffs_base__u%d__sat_%s_indirect(&", uBits, uOp)
- opName, closer = ", ", ")"
-
- case t.IDPlusEq, t.IDMinusEq:
- if lTyp.IsNumType() {
- if u := lTyp.QID()[1]; u == t.IDU8 || u == t.IDU16 {
- disableWconversion = true
+ } else {
+ switch op {
+ case t.IDEqQuestion:
+ opName = cOpName(t.IDEqQuestion)
+ if g.currFunk.tempW > maxTemp {
+ return fmt.Errorf("too many temporary variables required")
}
- }
- fallthrough
+ temp := g.currFunk.tempW
+ g.currFunk.tempW++
- default:
- opName = cOpName(op)
- if opName == "" {
- return fmt.Errorf("unrecognized operator %q", op.AmbiguousForm().Str(g.tm))
+ b.printf("wuffs_base__status %s%d = ", tPrefix, temp)
+
+ if err := g.writeExpr(b, rhs, 0); err != nil {
+ return err
+ }
+ b.writes(";\n")
+
+ case t.IDTildeSatPlusEq, t.IDTildeSatMinusEq:
+ uBits := uintBits(lTyp.QID())
+ if uBits == 0 {
+ return fmt.Errorf("unsupported tilde-operator type %q", lTyp.Str(g.tm))
+ }
+ uOp := "add"
+ if op != t.IDTildeSatPlusEq {
+ uOp = "sub"
+ }
+ b.printf("wuffs_base__u%d__sat_%s_indirect(&", uBits, uOp)
+ opName, closer = ", ", ")"
+
+ case t.IDPlusEq, t.IDMinusEq:
+ if lTyp.IsNumType() {
+ if u := lTyp.QID()[1]; u == t.IDU8 || u == t.IDU16 {
+ disableWconversion = true
+ }
+ }
+ fallthrough
+
+ default:
+ opName = cOpName(op)
+ if opName == "" {
+ return fmt.Errorf("unrecognized operator %q", op.AmbiguousForm().Str(g.tm))
+ }
}
}
}
@@ -200,19 +193,24 @@
b.writes("#endif\n")
}
+ n := len(*b)
b.writex(lhsBuf)
b.writes(opName)
- if rhs.Effect().Coroutine() {
+ if g.currFunk.tempR != g.currFunk.tempW {
if g.currFunk.tempR != (g.currFunk.tempW - 1) {
return fmt.Errorf("internal error: temporary variable count out of sync")
}
b.printf("%s%d", tPrefix, g.currFunk.tempR)
g.currFunk.tempR++
+ } else if skipRHS {
+ // No-op.
} else if err := g.writeExpr(b, rhs, 0); err != nil {
return err
}
b.writes(closer)
- b.writes(";\n")
+ if n != len(*b) {
+ b.writes(";\n")
+ }
if disableWconversion {
b.writes("#if defined(__GNUC__)\n")
