mirror of https://github.com/ceph/go-ceph
42 lines
1.0 KiB
Go
42 lines
1.0 KiB
Go
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package dlsym
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// #cgo LDFLAGS: -ldl
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//
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// #include <stdlib.h>
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// #include <dlfcn.h>
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//
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// #ifndef RTLD_DEFAULT /* from dlfcn.h */
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// #define RTLD_DEFAULT ((void *) 0)
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// #endif
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import "C"
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import (
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"errors"
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"fmt"
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"unsafe"
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)
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// ErrUndefinedSymbol is returned by LookupSymbol when the requested symbol
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// could not be found.
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var ErrUndefinedSymbol = errors.New("symbol not found")
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// LookupSymbol resolves the named symbol from the already dynamically loaded
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// libraries. If the symbol is found, a pointer to it is returned, in case of a
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// failure, the message provided by dlerror() is included in the error message.
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func LookupSymbol(symbol string) (unsafe.Pointer, error) {
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cSymName := C.CString(symbol)
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defer C.free(unsafe.Pointer(cSymName))
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// clear dlerror before looking up the symbol
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C.dlerror()
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// resolve the address of the symbol
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sym := C.dlsym(C.RTLD_DEFAULT, cSymName)
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e := C.dlerror()
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dlerr := C.GoString(e)
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if dlerr != "" {
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return nil, fmt.Errorf("%w: %s", ErrUndefinedSymbol, dlerr)
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}
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return sym, nil
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}
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