95 lines
3.1 KiB
Go
95 lines
3.1 KiB
Go
|
// SPDX-License-Identifier: Apache-2.0
|
||
|
|
// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
|
||
|
|
|
||
|
|
//go:build darwin || freebsd || linux
|
||
|
|
|
||
|
|
package purego
|
||
|
|
|
||
|
|
import (
|
||
|
|
"unsafe"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Unix Specification for dlfcn.h: https://pubs.opengroup.org/onlinepubs/7908799/xsh/dlfcn.h.html
|
||
|
|
|
||
|
|
var (
|
||
|
|
fnDlopen func(path string, mode int) uintptr
|
||
|
|
fnDlsym func(handle uintptr, name string) uintptr
|
||
|
|
fnDlerror func() string
|
||
|
|
fnDlclose func(handle uintptr) bool
|
||
|
|
)
|
||
|
|
|
||
|
|
func init() {
|
||
|
|
RegisterFunc(&fnDlopen, dlopenABI0)
|
||
|
|
RegisterFunc(&fnDlsym, dlsymABI0)
|
||
|
|
RegisterFunc(&fnDlerror, dlerrorABI0)
|
||
|
|
RegisterFunc(&fnDlclose, dlcloseABI0)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Dlopen examines the dynamic library or bundle file specified by path. If the file is compatible
|
||
|
|
// with the current process and has not already been loaded into the
|
||
|
|
// current process, it is loaded and linked. After being linked, if it contains
|
||
|
|
// any initializer functions, they are called, before Dlopen
|
||
|
|
// returns. It returns a handle that can be used with Dlsym and Dlclose.
|
||
|
|
// A second call to Dlopen with the same path will return the same handle, but the internal
|
||
|
|
// reference count for the handle will be incremented. Therefore, all
|
||
|
|
// Dlopen calls should be balanced with a Dlclose call.
|
||
|
|
func Dlopen(path string, mode int) (uintptr, error) {
|
||
|
|
u := fnDlopen(path, mode)
|
||
|
|
if u == 0 {
|
||
|
|
return 0, Dlerror{fnDlerror()}
|
||
|
|
}
|
||
|
|
return u, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Dlsym takes a "handle" of a dynamic library returned by Dlopen and the symbol name.
|
||
|
|
// It returns the address where that symbol is loaded into memory. If the symbol is not found,
|
||
|
|
// in the specified library or any of the libraries that were automatically loaded by Dlopen
|
||
|
|
// when that library was loaded, Dlsym returns zero.
|
||
|
|
func Dlsym(handle uintptr, name string) (uintptr, error) {
|
||
|
|
u := fnDlsym(handle, name)
|
||
|
|
if u == 0 {
|
||
|
|
return 0, Dlerror{fnDlerror()}
|
||
|
|
}
|
||
|
|
return u, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Dlclose decrements the reference count on the dynamic library handle.
|
||
|
|
// If the reference count drops to zero and no other loaded libraries
|
||
|
|
// use symbols in it, then the dynamic library is unloaded.
|
||
|
|
func Dlclose(handle uintptr) error {
|
||
|
|
if fnDlclose(handle) {
|
||
|
|
return Dlerror{fnDlerror()}
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
//go:linkname openLibrary openLibrary
|
||
|
|
func openLibrary(name string) (uintptr, error) {
|
||
|
|
return Dlopen(name, RTLD_NOW|RTLD_GLOBAL)
|
||
|
|
}
|
||
|
|
|
||
|
|
func loadSymbol(handle uintptr, name string) (uintptr, error) {
|
||
|
|
return Dlsym(handle, name)
|
||
|
|
}
|
||
|
|
|
||
|
|
// these functions exist in dlfcn_stubs.s and are calling C functions linked to in dlfcn_GOOS.go
|
||
|
|
// the indirection is necessary because a function is actually a pointer to the pointer to the code.
|
||
|
|
// sadly, I do not know of anyway to remove the assembly stubs entirely because //go:linkname doesn't
|
||
|
|
// appear to work if you link directly to the C function on darwin arm64.
|
||
|
|
|
||
|
|
//go:linkname dlopen dlopen
|
||
|
|
var dlopen uintptr
|
||
|
|
var dlopenABI0 = uintptr(unsafe.Pointer(&dlopen))
|
||
|
|
|
||
|
|
//go:linkname dlsym dlsym
|
||
|
|
var dlsym uintptr
|
||
|
|
var dlsymABI0 = uintptr(unsafe.Pointer(&dlsym))
|
||
|
|
|
||
|
|
//go:linkname dlclose dlclose
|
||
|
|
var dlclose uintptr
|
||
|
|
var dlcloseABI0 = uintptr(unsafe.Pointer(&dlclose))
|
||
|
|
|
||
|
|
//go:linkname dlerror dlerror
|
||
|
|
var dlerror uintptr
|
||
|
|
var dlerrorABI0 = uintptr(unsafe.Pointer(&dlerror))
|