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_LTX_" prefix so that the symbol addresses can be fetched from the preloaded symbol list by lt_dlsym(): */ #define get_vtable dyld_LTX_get_vtable LT_BEGIN_C_DECLS LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data); LT_END_C_DECLS /* Boilerplate code to set up the vtable for hooking this loader into libltdl's loader list: */ static int vl_init (lt_user_data loader_data); static int vl_exit (lt_user_data loader_data); static lt_module vm_open (lt_user_data loader_data, const char *filename, lt_dladvise advise); static int vm_close (lt_user_data loader_data, lt_module module); static void * vm_sym (lt_user_data loader_data, lt_module module, const char *symbolname); static lt_dlvtable *vtable = 0; /* Return the vtable for this loader, only the name and sym_prefix attributes (plus the virtual function implementations, obviously) change between loaders. */ lt_dlvtable * get_vtable (lt_user_data loader_data) { if (!vtable) { vtable = lt__zalloc (sizeof *vtable); } if (vtable && !vtable->name) { vtable->name = "lt_dyld"; vtable->sym_prefix = "_"; vtable->dlloader_init = vl_init; vtable->module_open = vm_open; vtable->module_close = vm_close; vtable->find_sym = vm_sym; vtable->dlloader_exit = vl_exit; vtable->dlloader_data = loader_data; vtable->priority = LT_DLLOADER_APPEND; } if (vtable && (vtable->dlloader_data != loader_data)) { LT__SETERROR (INIT_LOADER); return 0; } return vtable; } /* --- IMPLEMENTATION --- */ #if defined(HAVE_MACH_O_DYLD_H) # if !defined(__APPLE_CC__) && !defined(__MWERKS__) && !defined(__private_extern__) /* Is this correct? Does it still function properly? */ # define __private_extern__ extern # endif # include #endif #include /* We have to put some stuff here that isn't in older dyld.h files */ #if !defined(ENUM_DYLD_BOOL) # define ENUM_DYLD_BOOL # undef FALSE # undef TRUE enum DYLD_BOOL { FALSE, TRUE }; #endif #if !defined(LC_REQ_DYLD) # define LC_REQ_DYLD 0x80000000 #endif #if !defined(LC_LOAD_WEAK_DYLIB) # define LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD) #endif #if !defined(NSADDIMAGE_OPTION_NONE) # define NSADDIMAGE_OPTION_NONE 0x0 #endif #if !defined(NSADDIMAGE_OPTION_RETURN_ON_ERROR) # define NSADDIMAGE_OPTION_RETURN_ON_ERROR 0x1 #endif #if !defined(NSADDIMAGE_OPTION_WITH_SEARCHING) # define NSADDIMAGE_OPTION_WITH_SEARCHING 0x2 #endif #if !defined(NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED) # define NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED 0x4 #endif #if !defined(NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME) # define NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME 0x8 #endif #if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND) # define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND 0x0 #endif #if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW) # define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW 0x1 #endif #if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY) # define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY 0x2 #endif #if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR) # define NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR 0x4 #endif #define LT__SYMLOOKUP_OPTS (NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW \ | NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR) #if defined(__BIG_ENDIAN__) # define LT__MAGIC MH_MAGIC #else # define LT__MAGIC MH_CIGAM #endif #define DYLD__SETMYERROR(errmsg) LT__SETERRORSTR (dylderror (errmsg)) #define DYLD__SETERROR(errcode) DYLD__SETMYERROR (LT__STRERROR (errcode)) typedef struct mach_header mach_header; typedef struct dylib_command dylib_command; static const char *dylderror (const char *errmsg); static const mach_header *lt__nsmodule_get_header (NSModule module); static const char *lt__header_get_instnam (const mach_header *mh); static const mach_header *lt__match_loadedlib (const char *name); static NSSymbol lt__linkedlib_symbol (const char *symname, const mach_header *mh); static const mach_header *(*lt__addimage) (const char *image_name, unsigned long options) = 0; static NSSymbol (*lt__image_symbol) (const mach_header *image, const char *symbolName, unsigned long options) = 0; static enum DYLD_BOOL (*lt__image_symbol_p) (const mach_header *image, const char *symbolName) = 0; static enum DYLD_BOOL (*lt__module_export) (NSModule module) = 0; static int dyld_cannot_close = 0; /* A function called through the vtable when this loader is no longer needed by the application. */ static int vl_exit (lt_user_data LT__UNUSED loader_data) { vtable = NULL; return 0; } /* A function called through the vtable to initialise this loader. */ static int vl_init (lt_user_data loader_data) { int errors = 0; if (! dyld_cannot_close) { if (!_dyld_present ()) { ++errors; } else { (void) _dyld_func_lookup ("__dyld_NSAddImage", (unsigned long*) <__addimage); (void) _dyld_func_lookup ("__dyld_NSLookupSymbolInImage", (unsigned long*)<__image_symbol); (void) _dyld_func_lookup ("__dyld_NSIsSymbolNameDefinedInImage", (unsigned long*) <__image_symbol_p); (void) _dyld_func_lookup ("__dyld_NSMakePrivateModulePublic", (unsigned long*) <__module_export); dyld_cannot_close = lt_dladderror ("can't close a dylib"); } } return errors; } /* A function called through the vtable to open a module with this loader. Returns an opaque representation of the newly opened module for processing with this loader's other vtable functions. */ static lt_module vm_open (lt_user_data loader_data, const char *filename, lt_dladvise LT__UNUSED advise) { lt_module module = 0; NSObjectFileImage ofi = 0; if (!filename) { return (lt_module) -1; } switch (NSCreateObjectFileImageFromFile (filename, &ofi)) { case NSObjectFileImageSuccess: module = NSLinkModule (ofi, filename, NSLINKMODULE_OPTION_RETURN_ON_ERROR | NSLINKMODULE_OPTION_PRIVATE | NSLINKMODULE_OPTION_BINDNOW); NSDestroyObjectFileImage (ofi); if (module) { lt__module_export (module); } break; case NSObjectFileImageInappropriateFile: if (lt__image_symbol_p && lt__image_symbol) { module = (lt_module) lt__addimage(filename, NSADDIMAGE_OPTION_RETURN_ON_ERROR); } break; case NSObjectFileImageFailure: case NSObjectFileImageArch: case NSObjectFileImageFormat: case NSObjectFileImageAccess: /*NOWORK*/ break; } if (!module) { DYLD__SETERROR (CANNOT_OPEN); } return module; } /* A function called through the vtable when a particular module should be unloaded. */ static int vm_close (lt_user_data loader_data, lt_module module) { int errors = 0; if (module != (lt_module) -1) { const mach_header *mh = (const mach_header *) module; int flags = 0; if (mh->magic == LT__MAGIC) { lt_dlseterror (dyld_cannot_close); ++errors; } else { /* Currently, if a module contains c++ static destructors and it is unloaded, we get a segfault in atexit(), due to compiler and dynamic loader differences of opinion, this works around that. */ if ((const struct section *) NULL != getsectbynamefromheader (lt__nsmodule_get_header (module), "__DATA", "__mod_term_func")) { flags |= NSUNLINKMODULE_OPTION_KEEP_MEMORY_MAPPED; } #if defined(__ppc__) flags |= NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES; #endif if (!NSUnLinkModule (module, flags)) { DYLD__SETERROR (CANNOT_CLOSE); ++errors; } } } return errors; } /* A function called through the vtable to get the address of a symbol loaded from a particular module. */ static void * vm_sym (lt_user_data loader_data, lt_module module, const char *name) { NSSymbol *nssym = 0; const mach_header *mh = (const mach_header *) module; char saveError[256] = "Symbol not found"; if (module == (lt_module) -1) { void *address, *unused; _dyld_lookup_and_bind (name, (unsigned long*) &address, &unused); return address; } if (mh->magic == LT__MAGIC) { if (lt__image_symbol_p && lt__image_symbol) { if (lt__image_symbol_p (mh, name)) { nssym = lt__image_symbol (mh, name, LT__SYMLOOKUP_OPTS); } } } else { nssym = NSLookupSymbolInModule (module, name); } if (!nssym) { strncpy (saveError, dylderror (LT__STRERROR (SYMBOL_NOT_FOUND)), 255); saveError[255] = 0; if (!mh) { mh = (mach_header *)lt__nsmodule_get_header (module); } nssym = lt__linkedlib_symbol (name, mh); } if (!nssym) { LT__SETERRORSTR (saveError); } return nssym ? NSAddressOfSymbol (nssym) : 0; } /* --- HELPER FUNCTIONS --- */ /* Return the dyld error string, or the passed in error string if none. */ static const char * dylderror (const char *errmsg) { NSLinkEditErrors ler; int lerno; const char *file; const char *errstr; NSLinkEditError (&ler, &lerno, &file, &errstr); if (! (errstr && *errstr)) { errstr = errmsg; } return errstr; } /* There should probably be an apple dyld api for this. */ static const mach_header * lt__nsmodule_get_header (NSModule module) { int i = _dyld_image_count(); const char *modname = NSNameOfModule (module); const mach_header *mh = 0; if (!modname) return NULL; while (i > 0) { --i; if (strneq (_dyld_get_image_name (i), modname)) { mh = _dyld_get_image_header (i); break; } } return mh; } /* NSAddImage is also used to get the loaded image, but it only works if the lib is installed, for uninstalled libs we need to check the install_names against each other. Note that this is still broken if DYLD_IMAGE_SUFFIX is set and a different lib was loaded as a result. */ static const char * lt__header_get_instnam (const mach_header *mh) { unsigned long offset = sizeof(mach_header); const char* result = 0; int j; for (j = 0; j < mh->ncmds; j++) { struct load_command *lc; lc = (struct load_command*) (((unsigned long) mh) + offset); if (LC_ID_DYLIB == lc->cmd) { result=(char*)(((dylib_command*) lc)->dylib.name.offset + (unsigned long) lc); } offset += lc->cmdsize; } return result; } static const mach_header * lt__match_loadedlib (const char *name) { const mach_header *mh = 0; int i = _dyld_image_count(); while (i > 0) { const char *id; --i; id = lt__header_get_instnam (_dyld_get_image_header (i)); if (id && strneq (id, name)) { mh = _dyld_get_image_header (i); break; } } return mh; } /* Safe to assume our mh is good. */ static NSSymbol lt__linkedlib_symbol (const char *symname, const mach_header *mh) { NSSymbol symbol = 0; if (lt__image_symbol && NSIsSymbolNameDefined (symname)) { unsigned long offset = sizeof(mach_header); struct load_command *lc; int j; for (j = 0; j < mh->ncmds; j++) { lc = (struct load_command*) (((unsigned long) mh) + offset); if ((LC_LOAD_DYLIB == lc->cmd) || (LC_LOAD_WEAK_DYLIB == lc->cmd)) { unsigned long base = ((dylib_command *) lc)->dylib.name.offset; char *name = (char *) (base + (unsigned long) lc); const mach_header *mh1 = lt__match_loadedlib (name); if (!mh1) { /* Maybe NSAddImage can find it */ mh1 = lt__addimage (name, NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED | NSADDIMAGE_OPTION_WITH_SEARCHING | NSADDIMAGE_OPTION_RETURN_ON_ERROR); } if (mh1) { symbol = lt__image_symbol (mh1, symname, LT__SYMLOOKUP_OPTS); if (symbol) break; } } offset += lc->cmdsize; } } return symbol; }