cmd/compile: fix missing update source type in storeArgOrLoad

After removing trivial wrapper types, the source needs to be updated
with new type, otherwise, it leads to mismatch between field offset and
the source type for selecting struct/array.

Fixes #49249

Change-Id: I26f9440bcb2e78bcf0617afc21d9d40cdbe4aca6
Reviewed-on: https://go-review.googlesource.com/c/go/+/360057
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/src/cmd/compile/internal/ssa/expand_calls.go b/src/cmd/compile/internal/ssa/expand_calls.go
index 18c9ab696d5d0e011210d669f6c1b30f9fcbf3cc..91ff9f87f93107e81dac562a63898845505b4041 100644 (file)
--- a/src/cmd/compile/internal/ssa/expand_calls.go
+++ b/src/cmd/compile/internal/ssa/expand_calls.go
@@ -954,6 +954,7 @@ func (x *expandState) storeArgOrLoad(pos src.XPos, b *Block, source, mem *Value,
                elt := t.Elem()
                if source.Type != t && t.NumElem() == 1 && elt.Size() == t.Size() && t.Size() == x.regSize {
                        t = removeTrivialWrapperTypes(t)
+                       source.Type = t
                        // it could be a leaf type, but the "leaf" could be complex64 (for example)
                        return x.storeArgOrLoad(pos, b, source, mem, t, storeOffset, loadRegOffset, storeRc)
                }
@@ -987,6 +988,7 @@ func (x *expandState) storeArgOrLoad(pos src.XPos, b *Block, source, mem *Value,
                        // v139 is later stored as an intVal == struct{val *big.Int} which naively requires the fields of
                        // of a *uint8, which does not succeed.
                        t = removeTrivialWrapperTypes(t)
+                       source.Type = t
                        // it could be a leaf type, but the "leaf" could be complex64 (for example)
                        return x.storeArgOrLoad(pos, b, source, mem, t, storeOffset, loadRegOffset, storeRc)
                }

diff --git a/test/fixedbugs/issue49249.go b/test/fixedbugs/issue49249.go
new file mode 100644 (file)
index 0000000..f152a5a
--- /dev/null
+++ b/test/fixedbugs/issue49249.go
@@ -0,0 +1,55 @@
+// compile -l
+
+// 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.
+
+package p
+
+func f() int {
+       var a, b struct {
+               s struct {
+                       s struct {
+                               byte
+                               float32
+                       }
+               }
+       }
+       _ = a
+
+       return func() int {
+               return func() int {
+                       a = struct {
+                               s struct {
+                                       s struct {
+                                               byte
+                                               float32
+                                       }
+                               }
+                       }{b.s}
+                       return 0
+               }()
+       }()
+}
+
+func g() int {
+       var a, b struct {
+               s [1][1]struct {
+                       byte
+                       float32
+               }
+       }
+       _ = a
+
+       return func() int {
+               return func() int {
+                       a = struct {
+                               s [1][1]struct {
+                                       byte
+                                       float32
+                               }
+                       }{b.s}
+                       return 0
+               }()
+       }()
+}