From bd3f44e4ffe54e9cf841ebc8356e403bb38436bd Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Tue, 2 May 2023 17:37:00 +0000 Subject: cmd/compile: constant-fold loads from constant dictionaries and types Retrying the original CL with a small modification. The original CL did not handle the case of reading an itab out of a dictionary correctly. When we read an itab out of a dictionary, we must treat the type inside that itab as maybe being put in an interface. Original CL: 486895 Revert CL: 490156 Change-Id: Id2dc1699d184cd8c63dac83986a70b60b4e6cbd7 Reviewed-on: https://go-review.googlesource.com/c/go/+/491495 Reviewed-by: Matthew Dempsky Reviewed-by: Cuong Manh Le Run-TryBot: Keith Randall Reviewed-by: Keith Randall TryBot-Result: Gopher Robot --- src/cmd/link/internal/ld/deadcode.go | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'src/cmd/link/internal/ld/deadcode.go') diff --git a/src/cmd/link/internal/ld/deadcode.go b/src/cmd/link/internal/ld/deadcode.go index c0969b25b0..c687565878 100644 --- a/src/cmd/link/internal/ld/deadcode.go +++ b/src/cmd/link/internal/ld/deadcode.go @@ -180,6 +180,14 @@ func (d *deadcodePass) flood() { // converted to an interface, i.e. should have UsedInIface set. See the // comment below for why we need to unset the Reachable bit and re-mark it. rs := r.Sym() + if d.ldr.IsItab(rs) { + // This relocation can also point at an itab, in which case it + // means "the _type field of that itab". + rs = decodeItabType(d.ldr, d.ctxt.Arch, rs) + } + if !d.ldr.IsGoType(rs) && !d.ctxt.linkShared { + panic(fmt.Sprintf("R_USEIFACE in %s references %s which is not a type or itab", d.ldr.SymName(symIdx), d.ldr.SymName(rs))) + } if !d.ldr.AttrUsedInIface(rs) { d.ldr.SetAttrUsedInIface(rs, true) if d.ldr.AttrReachable(rs) { -- cgit v1.3