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 #31252

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>
diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index 5630e12..86d52f5 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -287,7 +287,7 @@
 			}
 		}
 		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 b0ed019..8e4126d 100644
--- a/src/cmd/compile/internal/gc/pgen.go
+++ b/src/cmd/compile/internal/gc/pgen.go
@@ -266,7 +266,7 @@
 				// 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 0000000..fa43150
--- /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 0000000..9bfc0ff
--- /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 0000000..928c8ee
--- /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 0000000..25a7548
--- /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 0000000..973ae1d
--- /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