[release-branch.go1.12] cmd/compile: use correct package name for stack object symbol

Stack object generation code was always using the local package name
for its symbol. Normally that doesn't matter, as we usually only
compile functions in the local package. But for wrappers, the compiler
generates functions which live in other packages. When there are two
other packages with identical functions to wrap, the same name appears
twice, and the compiler goes boom.

Fixes #31396

Change-Id: I7026eebabe562cb159b8b6046cf656afd336ba25
Reviewed-on: https://go-review.googlesource.com/c/go/+/171464
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
(cherry picked from commit 43001a0dc96a29f662f2782c5fb3ca998eadd623)
Reviewed-on: https://go-review.googlesource.com/c/go/+/173317
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

7 files changed, 72 insertions, 2 deletions

diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index 5630e12ace..86d52f5084 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -287,7 +287,7 @@ func addGCLocals() {
 			}
 		}
 		if x := s.Func.StackObjects; x != nil {
-			ggloblsym(x, int32(len(x.P)), obj.RODATA|obj.LOCAL)
+			ggloblsym(x, int32(len(x.P)), obj.RODATA|obj.DUPOK)
 		}
 	}
 }
diff --git a/src/cmd/compile/internal/gc/pgen.go b/src/cmd/compile/internal/gc/pgen.go
index 28143dee29..5636ccd1db 100644
--- a/src/cmd/compile/internal/gc/pgen.go
+++ b/src/cmd/compile/internal/gc/pgen.go
@@ -267,7 +267,7 @@ func compile(fn *Node) {
 					// Also make sure we allocate a linker symbol
 					// for the stack object data, for the same reason.
 					if fn.Func.lsym.Func.StackObjects == nil {
-						fn.Func.lsym.Func.StackObjects = lookup(fmt.Sprintf("%s.stkobj", fn.funcname())).Linksym()
+						fn.Func.lsym.Func.StackObjects = Ctxt.Lookup(fn.Func.lsym.Name + ".stkobj")
 					}
 				}
 			}
diff --git a/test/fixedbugs/issue31252.dir/a.go b/test/fixedbugs/issue31252.dir/a.go
new file mode 100644
index 0000000000..fa431502c0
--- /dev/null
+++ b/test/fixedbugs/issue31252.dir/a.go
@@ -0,0 +1,13 @@
+// Copyright 2019 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 a
+
+import "fmt"
+
+type IndexController struct{}
+
+func (this *IndexController) Index(m *string) {
+	fmt.Println(m)
+}
diff --git a/test/fixedbugs/issue31252.dir/b.go b/test/fixedbugs/issue31252.dir/b.go
new file mode 100644
index 0000000000..9bfc0ff92e
--- /dev/null
+++ b/test/fixedbugs/issue31252.dir/b.go
@@ -0,0 +1,13 @@
+// Copyright 2019 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 b
+
+import "fmt"
+
+type IndexController struct{}
+
+func (this *IndexController) Index(m *string) {
+	fmt.Println(m)
+}
diff --git a/test/fixedbugs/issue31252.dir/c.go b/test/fixedbugs/issue31252.dir/c.go
new file mode 100644
index 0000000000..928c8eee1c
--- /dev/null
+++ b/test/fixedbugs/issue31252.dir/c.go
@@ -0,0 +1,26 @@
+// Copyright 2019 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 c
+
+import (
+	"a"
+	"b"
+)
+
+type HandlerFunc func(*string)
+
+func RouterInit() {
+	//home API
+	homeIndex := &a.IndexController{}
+	GET("/home/index/index", homeIndex.Index)
+	//admin API
+	adminIndex := &b.IndexController{}
+	GET("/admin/index/index", adminIndex.Index)
+	return
+}
+
+func GET(path string, handlers ...HandlerFunc) {
+	return
+}
diff --git a/test/fixedbugs/issue31252.dir/main.go b/test/fixedbugs/issue31252.dir/main.go
new file mode 100644
index 0000000000..25a7548668
--- /dev/null
+++ b/test/fixedbugs/issue31252.dir/main.go
@@ -0,0 +1,11 @@
+// Copyright 2019 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 main
+
+import "c"
+
+func main() {
+	c.RouterInit()
+}
diff --git a/test/fixedbugs/issue31252.go b/test/fixedbugs/issue31252.go
new file mode 100644
index 0000000000..973ae1dcef
--- /dev/null
+++ b/test/fixedbugs/issue31252.go
@@ -0,0 +1,7 @@
+// compiledir
+
+// Copyright 2019 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 ignored