reland: Fix issue 189 (#197)

Use the standard Cgo import mechanism when CGO_ENABLED=1. This fixes an issue where sometimes the external linker would fail to add the dlfcn symbols causing a linker error.

Closes #189

commit: 11c42be97b82c25f97b7c45c230f2a670c2fc91f
author: TotallyGamerJet · 2y ago · 2024-01-17 15:43 UTC
committer: Hajime Hoshi · 2y ago · 2024-01-18 03:34 UTC
parent: 603bc82
signature: unsigned

13 files · +71 -26

M cgo.go +5 -1


@@ -12,4 +12,8 @@ package purego
12	12		// which will import this package automatically. Normally this isn't an issue since it
13	13		// usually isn't possible to call into C without using that import. However, with purego
14	14		// it is since we don't use `import "C"`!
15		-	import _ "runtime/cgo"
	15	+	import (
	16	+	_ "runtime/cgo"
	17	+
	18	+	_ "github.com/ebitengine/purego/internal/cgo"
	19	+	)


@@ -12,4 +12,8 @@ package purego
12		// which will import this package automatically. Normally this isn't an issue since it	12		// which will import this package automatically. Normally this isn't an issue since it
13		// usually isn't possible to call into C without using that import. However, with purego	13		// usually isn't possible to call into C without using that import. However, with purego
14		// it is since we don't use `import "C"`!	14		// it is since we don't use `import "C"`!
15	-	import _ "runtime/cgo"	15	+	import (
			16	+	_ "runtime/cgo"
			17	+
			18	+	_ "github.com/ebitengine/purego/internal/cgo"
			19	+	)

M dlfcn_darwin.go +0 -5


@@ -12,8 +12,3 @@ const (
12	12		RTLD_LOCAL = 0x4 // All symbols are not made available for relocation processing by other modules.
13	13		RTLD_GLOBAL = 0x8 // All symbols are available for relocation processing of other modules.
14	14		)
15		-
16		-	//go:cgo_import_dynamic purego_dlopen dlopen "/usr/lib/libSystem.B.dylib"
17		-	//go:cgo_import_dynamic purego_dlsym dlsym "/usr/lib/libSystem.B.dylib"
18		-	//go:cgo_import_dynamic purego_dlerror dlerror "/usr/lib/libSystem.B.dylib"
19		-	//go:cgo_import_dynamic purego_dlclose dlclose "/usr/lib/libSystem.B.dylib"


@@ -12,8 +12,3 @@ const (
12		RTLD_LOCAL = 0x4 // All symbols are not made available for relocation processing by other modules.	12	RTLD_LOCAL = 0x4 // All symbols are not made available for relocation processing by other modules.
13		RTLD_GLOBAL = 0x8 // All symbols are available for relocation processing of other modules.	13	RTLD_GLOBAL = 0x8 // All symbols are available for relocation processing of other modules.
14		)	14	)
15	-
16	-	//go:cgo_import_dynamic purego_dlopen dlopen "/usr/lib/libSystem.B.dylib"
17	-	//go:cgo_import_dynamic purego_dlsym dlsym "/usr/lib/libSystem.B.dylib"
18	-	//go:cgo_import_dynamic purego_dlerror dlerror "/usr/lib/libSystem.B.dylib"
19	-	//go:cgo_import_dynamic purego_dlclose dlclose "/usr/lib/libSystem.B.dylib"

M dlfcn_freebsd.go +0 -5


@@ -11,8 +11,3 @@ const (
11	11		RTLD_LOCAL = 0x00000 // All symbols are not made available for relocation processing by other modules.
12	12		RTLD_GLOBAL = 0x00100 // All symbols are available for relocation processing of other modules.
13	13		)
14		-
15		-	//go:cgo_import_dynamic purego_dlopen dlopen "libc.so.7"
16		-	//go:cgo_import_dynamic purego_dlsym dlsym "libc.so.7"
17		-	//go:cgo_import_dynamic purego_dlerror dlerror "libc.so.7"
18		-	//go:cgo_import_dynamic purego_dlclose dlclose "libc.so.7"


@@ -11,8 +11,3 @@ const (
11		RTLD_LOCAL = 0x00000 // All symbols are not made available for relocation processing by other modules.	11	RTLD_LOCAL = 0x00000 // All symbols are not made available for relocation processing by other modules.
12		RTLD_GLOBAL = 0x00100 // All symbols are available for relocation processing of other modules.	12	RTLD_GLOBAL = 0x00100 // All symbols are available for relocation processing of other modules.
13		)	13	)
14	-
15	-	//go:cgo_import_dynamic purego_dlopen dlopen "libc.so.7"
16	-	//go:cgo_import_dynamic purego_dlsym dlsym "libc.so.7"
17	-	//go:cgo_import_dynamic purego_dlerror dlerror "libc.so.7"
18	-	//go:cgo_import_dynamic purego_dlclose dlclose "libc.so.7"

A dlfcn_nocgo_darwin.go +11 -0

@@ -0,0 +1,11 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build !cgo
	5	+
	6	+	package purego
	7	+
	8	+	//go:cgo_import_dynamic purego_dlopen dlopen "/usr/lib/libSystem.B.dylib"
	9	+	//go:cgo_import_dynamic purego_dlsym dlsym "/usr/lib/libSystem.B.dylib"
	10	+	//go:cgo_import_dynamic purego_dlerror dlerror "/usr/lib/libSystem.B.dylib"
	11	+	//go:cgo_import_dynamic purego_dlclose dlclose "/usr/lib/libSystem.B.dylib"

@@ -0,0 +1,11 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build !cgo
	5	+
	6	+	package purego
	7	+
	8	+	//go:cgo_import_dynamic purego_dlopen dlopen "/usr/lib/libSystem.B.dylib"
	9	+	//go:cgo_import_dynamic purego_dlsym dlsym "/usr/lib/libSystem.B.dylib"
	10	+	//go:cgo_import_dynamic purego_dlerror dlerror "/usr/lib/libSystem.B.dylib"
	11	+	//go:cgo_import_dynamic purego_dlclose dlclose "/usr/lib/libSystem.B.dylib"

A dlfcn_nocgo_freebsd.go +11 -0

@@ -0,0 +1,11 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
	3	+
	4	+	//go:build !cgo
	5	+
	6	+	package purego
	7	+
	8	+	//go:cgo_import_dynamic purego_dlopen dlopen "libc.so.7"
	9	+	//go:cgo_import_dynamic purego_dlsym dlsym "libc.so.7"
	10	+	//go:cgo_import_dynamic purego_dlerror dlerror "libc.so.7"
	11	+	//go:cgo_import_dynamic purego_dlclose dlclose "libc.so.7"

@@ -0,0 +1,11 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
	3	+
	4	+	//go:build !cgo
	5	+
	6	+	package purego
	7	+
	8	+	//go:cgo_import_dynamic purego_dlopen dlopen "libc.so.7"
	9	+	//go:cgo_import_dynamic purego_dlsym dlsym "libc.so.7"
	10	+	//go:cgo_import_dynamic purego_dlerror dlerror "libc.so.7"
	11	+	//go:cgo_import_dynamic purego_dlclose dlclose "libc.so.7"

M dlfcn_stubs.s +1 -1

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build darwin \|\| freebsd \|\| (linux && !cgo)
	4	+	//go:build !cgo && (darwin \|\| freebsd \|\| linux)
5	5
6	6		#include "textflag.h"
7	7

@@ -1,7 +1,7 @@
1		// SPDX-License-Identifier: Apache-2.0	1		// SPDX-License-Identifier: Apache-2.0
2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3			3
4	-	//go:build darwin \|\| freebsd \|\| (linux && !cgo)	4	+	//go:build !cgo && (darwin \|\| freebsd \|\| linux)
5			5
6		#include "textflag.h"	6		#include "textflag.h"
7			7

A internal/buildtest/main.go +16 -0

@@ -0,0 +1,16 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build !windows
	5	+
	6	+	package main
	7	+
	8	+	import (
	9	+	_ "github.com/ebitengine/purego"
	10	+	)
	11	+
	12	+	import "C"
	13	+
	14	+	// This file tests that build Cgo and purego at the same time succeeds to build (#189).
	15	+	func main() {
	16	+	}

@@ -0,0 +1,16 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build !windows
	5	+
	6	+	package main
	7	+
	8	+	import (
	9	+	_ "github.com/ebitengine/purego"
	10	+	)
	11	+
	12	+	import "C"
	13	+
	14	+	// This file tests that build Cgo and purego at the same time succeeds to build (#189).
	15	+	func main() {
	16	+	}

A internal/cgo/dlfcn_cgo_unix.go +22 -0

@@ -0,0 +1,22 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build darwin \|\| freebsd \|\| linux
	5	+
	6	+	package cgo
	7	+
	8	+	/*
	9	+	#cgo LDFLAGS: -ldl
	10	+
	11	+	#include <dlfcn.h>
	12	+	*/
	13	+	import "C"
	14	+
	15	+	// all that is needed is to assign each dl function because then its
	16	+	// symbol will then be made available to the linker and linked to inside dlfcn.go
	17	+	var (
	18	+	_ = C.dlopen
	19	+	_ = C.dlsym
	20	+	_ = C.dlerror
	21	+	_ = C.dlclose
	22	+	)

@@ -0,0 +1,22 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
	3	+
	4	+	//go:build darwin \|\| freebsd \|\| linux
	5	+
	6	+	package cgo
	7	+
	8	+	/*
	9	+	#cgo LDFLAGS: -ldl
	10	+
	11	+	#include <dlfcn.h>
	12	+	*/
	13	+	import "C"
	14	+
	15	+	// all that is needed is to assign each dl function because then its
	16	+	// symbol will then be made available to the linker and linked to inside dlfcn.go
	17	+	var (
	18	+	_ = C.dlopen
	19	+	_ = C.dlsym
	20	+	_ = C.dlerror
	21	+	_ = C.dlclose
	22	+	)

M internal/cgo/syscall_cgo_unix.go +1 -10

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build freebsd \|\| linux
	4	+	//go:build freebsd \|\| (linux && !(arm64 \|\| amd64))
5	5
6	6		package cgo
7	7

@@ -39,15 +39,6 @@ import "unsafe"
39	39		// assign purego.syscall9XABI0 to the C version of this function.
40	40		var Syscall9XABI0 = unsafe.Pointer(C.syscall9)
41	41
42		-	// all that is needed is to assign each dl function because then its
43		-	// symbol will then be made available to the linker and linked to inside dlfcn.go
44		-	var (
45		-	_ = C.dlopen
46		-	_ = C.dlsym
47		-	_ = C.dlerror
48		-	_ = C.dlclose
49		-	)
50		-
51	42		//go:nosplit
52	43		func Syscall9X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2, err uintptr) {
53	44		args := C.syscall9Args{C.uintptr_t(fn), C.uintptr_t(a1), C.uintptr_t(a2), C.uintptr_t(a3),

 // SPDX-License-Identifier: Apache-2.0
 // SPDX-FileCopyrightText: 2022 The Ebitengine Authors
-//go:build freebsd || linux
+//go:build freebsd || (linux && !(arm64 || amd64))
 package cgo
 // assign purego.syscall9XABI0 to the C version of this function.
 var Syscall9XABI0 = unsafe.Pointer(C.syscall9)
-// all that is needed is to assign each dl function because then its
-// symbol will then be made available to the linker and linked to inside dlfcn.go
-var (
-	_ = C.dlopen
-	_ = C.dlsym
-	_ = C.dlerror
-	_ = C.dlclose
-)
 //go:nosplit
 func Syscall9X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2, err uintptr) {
 	args := C.syscall9Args{C.uintptr_t(fn), C.uintptr_t(a1), C.uintptr_t(a2), C.uintptr_t(a3),

M sys_amd64.s +1 -1

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build darwin \|\| freebsd \|\| (!cgo && linux)
	4	+	//go:build darwin \|\| freebsd \|\| linux
5	5
6	6		#include "textflag.h"
7	7		#include "abi_amd64.h"

@@ -1,7 +1,7 @@
1		// SPDX-License-Identifier: Apache-2.0	1		// SPDX-License-Identifier: Apache-2.0
2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3			3
4	-	//go:build darwin \|\| freebsd \|\| (!cgo && linux)	4	+	//go:build darwin \|\| freebsd \|\| linux
5			5
6		#include "textflag.h"	6		#include "textflag.h"
7		#include "abi_amd64.h"	7		#include "abi_amd64.h"

M sys_arm64.s +1 -1

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build darwin \|\| freebsd \|\| (!cgo && linux) \|\| windows
	4	+	//go:build darwin \|\| freebsd \|\| linux \|\| windows
5	5
6	6		#include "textflag.h"
7	7		#include "go_asm.h"

@@ -1,7 +1,7 @@
1		// SPDX-License-Identifier: Apache-2.0	1		// SPDX-License-Identifier: Apache-2.0
2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3			3
4	-	//go:build darwin \|\| freebsd \|\| (!cgo && linux) \|\| windows	4	+	//go:build darwin \|\| freebsd \|\| linux \|\| windows
5			5
6		#include "textflag.h"	6		#include "textflag.h"
7		#include "go_asm.h"	7		#include "go_asm.h"

M syscall_cgo_linux.go +1 -1

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build cgo
	4	+	//go:build cgo && !(amd64 \|\| arm64)
5	5
6	6		package purego
7	7

@@ -1,7 +1,7 @@
1		// SPDX-License-Identifier: Apache-2.0	1		// SPDX-License-Identifier: Apache-2.0
2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3			3
4	-	//go:build cgo	4	+	//go:build cgo && !(amd64 \|\| arm64)
5			5
6		package purego	6		package purego
7			7

M syscall_sysv.go +1 -1

@@ -1,7 +1,7 @@
1	1		// SPDX-License-Identifier: Apache-2.0
2	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3	3
4		-	//go:build darwin \|\| freebsd \|\| (!cgo && linux && (amd64 \|\| arm64))
	4	+	//go:build darwin \|\| freebsd \|\| (linux && (amd64 \|\| arm64))
5	5
6	6		package purego
7	7

@@ -1,7 +1,7 @@
1		// SPDX-License-Identifier: Apache-2.0	1		// SPDX-License-Identifier: Apache-2.0
2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3			3
4	-	//go:build darwin \|\| freebsd \|\| (!cgo && linux && (amd64 \|\| arm64))	4	+	//go:build darwin \|\| freebsd \|\| (linux && (amd64 \|\| arm64))
5			5
6		package purego	6		package purego
7			7