The symbols are a static array of NativeSymbol
typedef struct NativeSymbol {
const char *symbol;
void *func_ptr;
const char *signature;
/* attachment which can be retrieved in native API by
calling wasm_runtime_get_function_attachment(exec_env) */
void *attachment;
} NativeSymbol;
wasm_native_init
bool
wasm_native_init()
{
NativeSymbol *native_symbols;
uint32 n_native_symbols;
#if WASM_ENABLE_LIBC_BUILTIN != 0
n_native_symbols = get_libc_builtin_export_apis(&native_symbols);
if (!wasm_native_register_natives("env",
native_symbols, n_native_symbols))
return false;
#endif /* WASM_ENABLE_LIBC_BUILTIN */
#if WASM_ENABLE_SPEC_TEST
n_native_symbols = get_spectest_export_apis(&native_symbols);
if (!wasm_native_register_natives("spectest",
native_symbols, n_native_symbols))
return false;
#endif /* WASM_ENABLE_SPEC_TEST */
#if WASM_ENABLE_LIBC_WASI != 0
n_native_symbols = get_libc_wasi_export_apis(&native_symbols);
if (!wasm_native_register_natives("wasi_unstable",
native_symbols, n_native_symbols))
return false;
if (!wasm_native_register_natives("wasi_snapshot_preview1",
native_symbols, n_native_symbols))
return false;
#endif
#if WASM_ENABLE_BASE_LIB != 0
n_native_symbols = get_base_lib_export_apis(&native_symbols);
if (n_native_symbols > 0
&& !wasm_native_register_natives("env",
native_symbols, n_native_symbols))
return false;
#endif
#if WASM_ENABLE_APP_FRAMEWORK != 0
n_native_symbols = get_ext_lib_export_apis(&native_symbols);
if (n_native_symbols > 0
&& !wasm_native_register_natives("env",
native_symbols, n_native_symbols))
return false;
#endif
#if WASM_ENABLE_LIB_PTHREAD != 0
if (!lib_pthread_init())
return false;
n_native_symbols = get_lib_pthread_export_apis(&native_symbols);
if (n_native_symbols > 0
&& !wasm_native_register_natives("env",
native_symbols, n_native_symbols))
return false;
#endif
#if WASM_ENABLE_LIBC_EMCC != 0
n_native_symbols = get_libc_emcc_export_apis(&native_symbols);
if (n_native_symbols > 0
&& !wasm_native_register_natives("env",
native_symbols, n_native_symbols))
return false;
#endif /* WASM_ENABLE_LIBC_EMCC */
return true;
}
register_natives
Regestered functions are organized as a linked list, each module holds several functions imported from a specific library:
typedef struct NativeSymbolsNode {
struct NativeSymbolsNode *next;
const char *module_name;
NativeSymbol *native_symbols;
uint32 n_native_symbols;
bool call_conv_raw;
} NativeSymbolsNode, *NativeSymbolsList;
static bool
register_natives(const char *module_name,
NativeSymbol *native_symbols,
uint32 n_native_symbols,
bool call_conv_raw)
{
NativeSymbolsNode *node;
#if ENABLE_SORT_DEBUG != 0
struct timeval start;
struct timeval end;
unsigned long timer;
#endif
if (!(node = wasm_runtime_malloc(sizeof(NativeSymbolsNode))))
return false;
#if WASM_ENABLE_MEMORY_TRACING != 0
os_printf("Register native, size: %u\n", sizeof(NativeSymbolsNode));
#endif
node->module_name = module_name;
node->native_symbols = native_symbols;
node->n_native_symbols = n_native_symbols;
node->call_conv_raw = call_conv_raw;
/* Add to list head */
node->next = g_native_symbols_list;
g_native_symbols_list = node;
#if ENABLE_SORT_DEBUG != 0
gettimeofday(&start, NULL);
#endif
#if ENABLE_QUICKSORT == 0
sort_symbol_ptr(native_symbols, n_native_symbols);
#else
quick_sort_symbols(native_symbols, 0, (int)(n_native_symbols - 1));
#endif
#if ENABLE_SORT_DEBUG != 0
gettimeofday(&end, NULL);
timer = 1000000 * (end.tv_sec - start.tv_sec)
+ (end.tv_usec - start.tv_usec);
LOG_ERROR("module_name: %s, nums: %d, sorted used: %ld us",
module_name, n_native_symbols, timer);
#endif
return true;
}