From deb6790fcfe943c640a4ef393036690eef5eef5c Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Fri, 14 Mar 2025 13:19:18 -0700 Subject: cmd/compile: remove implicit deref from len(p) where p is ptr-to-array func f() *[4]int { return nil } _ = len(f()) should not panic. We evaluate f, but there isn't a dereference according to the spec (just "arg is evaluated"). Update #72844 Change-Id: Ia32cefc1b7aa091cd1c13016e015842b4d12d5b4 Reviewed-on: https://go-review.googlesource.com/c/go/+/658096 LUCI-TryBot-Result: Go LUCI Reviewed-by: Robert Griesemer Reviewed-by: Keith Randall --- src/cmd/compile/internal/typecheck/expr.go | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/cmd/compile/internal/typecheck/expr.go b/src/cmd/compile/internal/typecheck/expr.go index 2eec8d41ad..44a69f0332 100644 --- a/src/cmd/compile/internal/typecheck/expr.go +++ b/src/cmd/compile/internal/typecheck/expr.go @@ -634,16 +634,16 @@ func tcIndex(n *ir.IndexExpr) ir.Node { func tcLenCap(n *ir.UnaryExpr) ir.Node { n.X = Expr(n.X) n.X = DefaultLit(n.X, nil) - n.X = implicitstar(n.X) l := n.X t := l.Type() if t == nil { n.SetType(nil) return n } - var ok bool - if n.Op() == ir.OLEN { + if t.IsPtr() && t.Elem().IsArray() { + ok = true + } else if n.Op() == ir.OLEN { ok = okforlen[t.Kind()] } else { ok = okforcap[t.Kind()] -- cgit v1.3-5-g9baa