int dlclose(void * handle)
{
struct dlstatus * dls = handle;
if (!isValidStatus(dls))
return 1;
if (dls->module == MAGIC_DYLIB_MOD)
{
warning("trying to close a .dylib!");
error("dynamic libraries cannot be closed");
// Code inside the PAL expects to be able to dlclose anything that
// could be dlopen'd, so we return success here. It doesn't matter
// that we don't do anything; the PAL doesn't require any action
// as a result of this dlclose. Clients of the PAL can't call
// dlclose() directly, so this isn't a concern.
return 0;
}
if (!dls->module)
{
error("module already closed");
return 1;
}
dls->refs--;
if (!dls->refs)
{
unsigned long options = 0;
void (*fini)(void);
if ((fini = dlsymIntern(dls, "__fini",0)))
{
debug("calling _fini()");
fini();
}
if (isFlagSet(dls->mode, RTLD_NODELETE))
options |= NSUNLINKMODULE_OPTION_KEEP_MEMORY_MAPPED;
if (!NSUnLinkModule(dls->module, options))
{
error("unable to unlink module");
return 1;
}
dls->module = 0;
/* Note: the dlstatus struct dls is neither removed from the list
* nor is the memory it occupies freed. This shouldn't pose a
* problem in mostly all cases, though.
*/
}
return 0;
}
void *dlsym(void * handle, const char *symbol)
{
struct dlstatus * dls = handle;
char *mangledSymbol;
void *addr = 0;
if (!isValidStatus(dls))
return NULL;
// We need to "mangle" the symbol name because dyld only deals
// with symbol names as the linker constructs them. The linker
// adds a leading underscore.
mangledSymbol = alloca(strlen(symbol) + 2);
mangledSymbol[0] = '_';
mangledSymbol[1] = '\0';
strcat(mangledSymbol, symbol);
addr = dlsymIntern(dls, mangledSymbol, 1);
return addr;
}
static void *dlsymIntern(struct dlstatus *dls, const char *symbol, int canSetError)
{
NSSymbol *nssym = 0;
#ifdef __GCC__
void *caller = __builtin_return_address(1); /* Be *very* careful about inlining */
#else
void *caller = NULL;
#endif
const struct mach_header *caller_mh = 0;
const char* savedErrorStr = NULL;
resetdlerror();
#ifndef RTLD_SELF
#define RTLD_SELF ((void *) -3)
#endif
if (NULL == dls)
dls = RTLD_SELF;
if ((RTLD_NEXT == dls) || (RTLD_SELF == dls))
{
if (dyld_NSIsSymbolNameDefinedInImage && dyld_NSLookupSymbolInImage)
{
caller_mh = image_for_address(caller);
if (RTLD_SELF == dls)
{
/* FIXME: We should be using the NSModule api, if SELF is an MH_BUNDLE
* But it appears to work anyway, and looking at the code in dyld_libfuncs.c
* this is acceptable.
*/
if (dyld_NSIsSymbolNameDefinedInImage(caller_mh, symbol))
{
nssym = dyld_NSLookupSymbolInImage(caller_mh,
symbol,
NSLOOKUPSYMBOLINIMAGE_OPTION_BIND |
NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR);
}
}
if (!nssym)
{
if (RTLD_SELF == dls)
savedErrorStr = dyld_error_str();
nssym = search_linked_libs(caller_mh, symbol);
}
}
else
{
if (canSetError)
error("RTLD_SELF and RTLD_NEXT are not supported");
return NULL;
}
}
if (!nssym)
{
if (RTLD_DEFAULT == dls)
{
dls = &mainStatus;
}
if (!isValidStatus(dls))
return NULL;
if (dls->module != MAGIC_DYLIB_MOD)
{
nssym = NSLookupSymbolInModule(dls->module, symbol);
if (!nssym && NSIsSymbolNameDefined(symbol))
{
debug("Searching dependencies");
savedErrorStr = dyld_error_str();
nssym = search_linked_libs(get_mach_header_from_NSModule(dls->module), symbol);
}
}
else if (dls->lib && dyld_NSIsSymbolNameDefinedInImage && dyld_NSLookupSymbolInImage)
{
if (dyld_NSIsSymbolNameDefinedInImage(dls->lib, symbol))
{
nssym = dyld_NSLookupSymbolInImage(dls->lib,
symbol,
NSLOOKUPSYMBOLINIMAGE_OPTION_BIND |
NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR);
}
else if (NSIsSymbolNameDefined(symbol))
{
debug("Searching dependencies");
savedErrorStr = dyld_error_str();
nssym = search_linked_libs(dls->lib, symbol);
}
}
else if (dls->module == MAGIC_DYLIB_MOD)
{
/* Global context, use NSLookupAndBindSymbol */
if (NSIsSymbolNameDefined(symbol))
{
/* There doesn't seem to be a return on error option for this call???
this is potentially broken, if binding fails, it will improperly
exit the application. */
nssym = NSLookupAndBindSymbol(symbol);
}
else
{
if (savedErrorStr)
free((char*)savedErrorStr);
savedErrorStr = malloc(256);
snprintf((char*)savedErrorStr, 256, "Symbol \"%s\" not in global context",symbol);
}
}
}
/* Error reporting */
if (!nssym)
{
if (!savedErrorStr || !strlen(savedErrorStr))
{
if (savedErrorStr)
free((char*)savedErrorStr);
savedErrorStr = malloc(256);
snprintf((char*)savedErrorStr, 256,"Symbol \"%s\" not found",symbol);
}
if (canSetError)
{
error(savedErrorStr);
}
else
{
debug(savedErrorStr);
}
if (savedErrorStr)
free((char*)savedErrorStr);
return NULL;
}
return NSAddressOfSymbol(nssym);
}
