misc/cgo/test: add cgo build constraints

We're about to move this package to cmd/cgo/internal, where it will
get caught up in the "CGO_ENABLED=0 go install cmd" done by make.bash.
Currently, building this package with CGO_ENABLED=0 fails because it
contains several source files that don't themselves import "C", but do
import a subdirectory where that package imports "C" and thus has no
exported API.

Fix the CGO_ENABLED=0 build of this package by adding the necessary
cgo build tags. Not all source files need it, but this CL makes
"CGO_ENABLED=0 go test -c" work in this package.

For #37486.

Change-Id: Id137cdfbdd950eea802413536d990ab642ebcd7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/493215
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Austin Clements <austin@google.com>

misc/cgo/test/cgo_linux_test.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 import (

misc/cgo/test/cgo_test.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 import "testing"

misc/cgo/test/cgo_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
+//go:build cgo && !windows
 
 package cgotest
 

misc/cgo/test/gcc68255.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 import (

misc/cgo/test/issue18146.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
+//go:build cgo && !windows
 
 // Issue 18146: pthread_create failure during syscall.Exec.
 

misc/cgo/test/issue23555.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Test that we can have two identical cgo packages in a single binary.
 // No runtime test; just make sure it compiles.
 

misc/cgo/test/issue24161_darwin_test.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 import (

misc/cgo/test/issue26430.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Issue 26430: incomplete typedef leads to inconsistent typedefs error.
 // No runtime test; just make sure it compiles.
 

misc/cgo/test/issue26743.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Issue 26743: typedef of uint leads to inconsistent typedefs error.
 // No runtime test; just make sure it compiles.
 

misc/cgo/test/issue27340.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Failed to resolve typedefs consistently.
 // No runtime test; just make sure it compiles.
 

misc/cgo/test/issue29563.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
+//go:build cgo && !windows
 
 // Issue 29563: internal linker fails on duplicate weak symbols.
 // No runtime test; just make sure it compiles.

misc/cgo/test/issue30527.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Issue 30527: function call rewriting casts untyped
 // constants to int because of ":=" usage.
 

misc/cgo/test/issue43639.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 // Issue 43639: No runtime test needed, make sure package misc/cgo/test/issue43639 compiles well.

misc/cgo/test/issue52611.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Issue 52611: inconsistent compiler behaviour when compiling a C.struct.
 // No runtime test; just make sure it compiles.
 

misc/cgo/test/issue8828.go

@@ -1,9 +1,9 @@
-// compile
-
 // Copyright 2014 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.
 
+//go:build cgo
+
 // Issue 8828: compiling a file with -compiler=gccgo fails if a .c file
 // has the same name as compiled directory.
 

misc/cgo/test/issue9026.go

@@ -1,3 +1,9 @@
+// Copyright 2023 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.
+
+//go:build cgo
+
 package cgotest
 
 import (

misc/cgo/test/issue9400/stubs.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build gc
+//go:build linux && gc
 
 package issue9400
 

misc/cgo/test/issue9510.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 // Test that we can link together two different cgo packages that both
 // use the same libgcc function.
 

misc/cgo/test/test26213.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build cgo
+
 package cgotest
 
 import (

misc/cgo/test/test_unix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
+//go:build unix
 
 package cgotest