cmd/compile: fix open defer of method call

Code generation for open defers failed to account for
presence of method receiver and thus was OFF BY ONE.

Fixes #45062.
Updates #44816.
Updates #40724.

Change-Id: Ia90ea8fd0f7d823e1f757c406f9127136c2ffdd2
Reviewed-on: https://go-review.googlesource.com/c/go/+/302249
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 6a3c0d28cbd854a8e660455d5d9ce1f189cd4577..45e39478fa2d586c68e724c1df38e4343c3453f4 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -353,10 +353,12 @@ func (s *state) emitOpenDeferInfo() {
                        numArgs++
                }
                off = dvarint(x, off, int64(numArgs))
+               argAdjust := 0 // presence of receiver offsets the parameter count.
                if r.rcvrNode != nil {
                        off = dvarint(x, off, -okOffset(r.rcvrNode.FrameOffset()))
                        off = dvarint(x, off, s.config.PtrSize)
                        off = dvarint(x, off, 0) // This is okay because defer records use ABI0 (for now)
+                       argAdjust++
                }
 
                // TODO(register args) assume abi0 for this?
@@ -366,7 +368,7 @@ func (s *state) emitOpenDeferInfo() {
                        f := getParam(r.n, j)
                        off = dvarint(x, off, -okOffset(arg.FrameOffset()))
                        off = dvarint(x, off, f.Type.Size())
-                       off = dvarint(x, off, okOffset(pri.InParam(j).FrameOffset(pri))-ab.LocalsOffset()) // defer does not want the fixed frame adjustment
+                       off = dvarint(x, off, okOffset(pri.InParam(j+argAdjust).FrameOffset(pri))-ab.LocalsOffset()) // defer does not want the fixed frame adjustment
                }
        }
 }
@@ -4925,7 +4927,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
                callABI = s.f.ABI0
        }
 
-       params := callABI.ABIAnalyze(n.X.Type(), false /* Do not set (register) nNames from caller side -- can cause races. */ )
+       params := callABI.ABIAnalyze(n.X.Type(), false /* Do not set (register) nNames from caller side -- can cause races. */)
        types.CalcSize(fn.Type())
        stksize := params.ArgWidth() // includes receiver, args, and results
 

diff --git a/test/abi/open_defer_1.go b/test/abi/open_defer_1.go
new file mode 100644 (file)
index 0000000..0a0ace3
--- /dev/null
+++ b/test/abi/open_defer_1.go
@@ -0,0 +1,36 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// For #45062, miscompilation of open defer of method invocation
+
+package main
+
+func main() {
+       var x, y, z int = -1, -2, -3
+       F(x, y, z)
+}
+
+//go:noinline
+func F(x, y, z int) {
+       defer i.M(x, y, z)
+       defer func() { recover() }()
+       panic("XXX")
+}
+
+type T int
+
+func (t *T) M(x, y, z int) {
+       if x == -1 && y == -2 && z == -3 {
+               return
+       }
+       println("FAIL: Expected -1, -2, -3, but x, y, z =", x, y, z)
+}
+
+var t T = 42
+
+type I interface{ M(x, y, z int) }
+
+var i I = &t