FLEX/Classes/Utility/Runtime/flex_fishhook.h

// Copyright (c) 2013, Facebook, Inc.
// All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
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//     this list of conditions and the following disclaimer.
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//     this list of conditions and the following disclaimer in the documentation
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#ifndef fishhook_h
#define fishhook_h

#include <stddef.h>
#include <stdint.h>

#if !defined(FISHHOOK_EXPORT)
#define FISHHOOK_VISIBILITY __attribute__((visibility("hidden")))
#else
#define FISHHOOK_VISIBILITY __attribute__((visibility("default")))
#endif

#ifdef __cplusplus
extern "C" {
#endif //__cplusplus

/**
 * A structure representing a particular intended rebinding from a symbol
 * name to its replacement
 */
struct rebinding {
    const char *name;
    void *replacement;
    void **replaced;
};

/**
 * For each rebinding in rebindings, rebinds references to external, indirect
 * symbols with the specified name to instead point at replacement for each
 * image in the calling process as well as for all future images that are loaded
 * by the process. If rebind_functions is called more than once, the symbols to
 * rebind are added to the existing list of rebindings, and if a given symbol
 * is rebound more than once, the later rebinding will take precedence.
 * @return 0 on success
 */
FISHHOOK_VISIBILITY
int flex_rebind_symbols(struct rebinding rebindings[], size_t rebindings_nel);

/**
 * Rebinds as above, but only in the specified image. The header should point
 * to the mach-o header, the slide should be the slide offset. Others as above.
 * @return 0 on success
 */
FISHHOOK_VISIBILITY
int flex_rebind_symbols_image(void *header,
                              intptr_t slide,
                              struct rebinding rebindings[],
                              size_t rebindings_nel);

#ifdef __cplusplus
}
#endif //__cplusplus

#endif //fishhook_h