go/types, types2: refactor Checker.rangeStmt for clarity
Change-Id: I0c2f921389416ab222b84f77699fd4b3246ef0e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/581776
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
diff --git a/src/cmd/compile/internal/types2/stmt.go b/src/cmd/compile/internal/types2/stmt.go
index 7fd7009..1984777 100644
--- a/src/cmd/compile/internal/types2/stmt.go
+++ b/src/cmd/compile/internal/types2/stmt.go
@@ -923,19 +923,26 @@
check.errorf(lhs, InvalidSyntaxTree, "cannot declare %s", lhs)
obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable
}
+ assert(obj.typ == nil)
+
+ // initialize lhs iteration variable, if any
+ typ := rhs[i]
+ if typ == nil {
+ obj.typ = Typ[Invalid]
+ obj.used = true // don't complain about unused variable
+ continue
+ }
// initialize lhs variable
if constIntRange {
check.initVar(obj, &x, "range clause")
- } else if typ := rhs[i]; typ != nil {
+ } else {
x.mode = value
x.expr = lhs // we don't have a better rhs expression to use here
x.typ = typ
check.initVar(obj, &x, "assignment") // error is on variable, use "assignment" not "range clause"
- } else {
- obj.typ = Typ[Invalid]
- obj.used = true // don't complain about unused variable
}
+ assert(obj.typ != nil)
}
// declare variables
@@ -954,9 +961,15 @@
continue
}
+ // assign to lhs iteration variable, if any
+ typ := rhs[i]
+ if typ == nil {
+ continue
+ }
+
if constIntRange {
check.assignVar(lhs, nil, &x, "range clause")
- } else if typ := rhs[i]; typ != nil {
+ } else {
x.mode = value
x.expr = lhs // we don't have a better rhs expression to use here
x.typ = typ
diff --git a/src/go/types/stmt.go b/src/go/types/stmt.go
index 30b4948..bfb51fd 100644
--- a/src/go/types/stmt.go
+++ b/src/go/types/stmt.go
@@ -923,19 +923,26 @@
check.errorf(lhs, InvalidSyntaxTree, "cannot declare %s", lhs)
obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable
}
+ assert(obj.typ == nil)
+
+ // initialize lhs iteration variable, if any
+ typ := rhs[i]
+ if typ == nil {
+ obj.typ = Typ[Invalid]
+ obj.used = true // don't complain about unused variable
+ continue
+ }
// initialize lhs variable
if constIntRange {
check.initVar(obj, &x, "range clause")
- } else if typ := rhs[i]; typ != nil {
+ } else {
x.mode = value
x.expr = lhs // we don't have a better rhs expression to use here
x.typ = typ
check.initVar(obj, &x, "assignment") // error is on variable, use "assignment" not "range clause"
- } else {
- obj.typ = Typ[Invalid]
- obj.used = true // don't complain about unused variable
}
+ assert(obj.typ != nil)
}
// declare variables
@@ -954,9 +961,15 @@
continue
}
+ // assign to lhs iteration variable, if any
+ typ := rhs[i]
+ if typ == nil {
+ continue
+ }
+
if constIntRange {
check.assignVar(lhs, nil, &x, "range clause")
- } else if typ := rhs[i]; typ != nil {
+ } else {
x.mode = value
x.expr = lhs // we don't have a better rhs expression to use here
x.typ = typ
