1 /* 2 Example of using `anyref` values. 3 4 You can build using cmake: 5 6 mkdir build && cd build && cmake .. && \ 7 cmake --build . --target wasmtime-anyref 8 */ 9 10 #include <assert.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <string.h> 14 #include <wasm.h> 15 #include <wasmtime.h> 16 17 static void exit_with_error(const char *message, wasmtime_error_t *error, 18 wasm_trap_t *trap); 19 20 int main() { 21 bool ok = true; 22 // Create a new configuration with Wasm GC enabled. 23 printf("Initializing...\n"); 24 wasm_config_t *config = wasm_config_new(); 25 assert(config != NULL); 26 wasmtime_config_wasm_reference_types_set(config, true); 27 wasmtime_config_wasm_function_references_set(config, true); 28 wasmtime_config_wasm_gc_set(config, true); 29 30 // Create an *engine*, which is a compilation context, with our configured 31 // options. 32 wasm_engine_t *engine = wasm_engine_new_with_config(config); 33 assert(engine != NULL); 34 35 // With an engine we can create a *store* which is a group of wasm instances 36 // that can interact with each other. 37 wasmtime_store_t *store = wasmtime_store_new(engine, NULL, NULL); 38 assert(store != NULL); 39 wasmtime_context_t *context = wasmtime_store_context(store); 40 41 // Read our input file, which in this case is a wasm text file. 42 FILE *file = fopen("examples/anyref.wat", "r"); 43 assert(file != NULL); 44 fseek(file, 0L, SEEK_END); 45 size_t file_size = ftell(file); 46 fseek(file, 0L, SEEK_SET); 47 wasm_byte_vec_t wat; 48 wasm_byte_vec_new_uninitialized(&wat, file_size); 49 if (fread(wat.data, file_size, 1, file) != 1) { 50 printf("> Error loading module!\n"); 51 return 1; 52 } 53 fclose(file); 54 55 // Parse the wat into the binary wasm format 56 wasm_byte_vec_t wasm; 57 wasmtime_error_t *error = wasmtime_wat2wasm(wat.data, wat.size, &wasm); 58 if (error != NULL) 59 exit_with_error("failed to parse wat", error, NULL); 60 wasm_byte_vec_delete(&wat); 61 62 // Now that we've got our binary webassembly we can compile our module. 63 printf("Compiling module...\n"); 64 wasmtime_module_t *module = NULL; 65 error = wasmtime_module_new(engine, (uint8_t *)wasm.data, wasm.size, &module); 66 wasm_byte_vec_delete(&wasm); 67 if (error != NULL) 68 exit_with_error("failed to compile module", error, NULL); 69 70 // Instantiate the module. 71 printf("Instantiating module...\n"); 72 wasm_trap_t *trap = NULL; 73 wasmtime_instance_t instance; 74 error = wasmtime_instance_new(context, module, NULL, 0, &instance, &trap); 75 if (error != NULL || trap != NULL) 76 exit_with_error("failed to instantiate", error, trap); 77 78 printf("Creating new `anyref` from i31...\n"); 79 80 // Create a new `anyref` value from an i31 (`i31ref` is a subtype of 81 // `anyref`). 82 wasmtime_anyref_t anyref; 83 wasmtime_anyref_from_i31(context, 1234, &anyref); 84 assert(!wasmtime_anyref_is_null(&anyref)); 85 86 // The `anyref`'s inner i31 value should be 1234. 87 uint32_t i31val = 0; 88 bool is_i31 = wasmtime_anyref_i31_get_u(context, &anyref, &i31val); 89 assert(is_i31); 90 assert(i31val == 1234); 91 92 printf("Touching `anyref` table...\n"); 93 94 wasmtime_extern_t item; 95 96 // Lookup the `table` export. 97 ok = wasmtime_instance_export_get(context, &instance, "table", 98 strlen("table"), &item); 99 assert(ok); 100 assert(item.kind == WASMTIME_EXTERN_TABLE); 101 102 // Set `table[3]` to our `anyref`. 103 wasmtime_val_t anyref_val; 104 anyref_val.kind = WASMTIME_ANYREF; 105 anyref_val.of.anyref = anyref; 106 error = wasmtime_table_set(context, &item.of.table, 3, &anyref_val); 107 if (error != NULL) 108 exit_with_error("failed to set table", error, NULL); 109 110 // `table[3]` should now be our `anyref`. 111 wasmtime_val_t elem; 112 ok = wasmtime_table_get(context, &item.of.table, 3, &elem); 113 assert(ok); 114 assert(elem.kind == WASMTIME_ANYREF); 115 is_i31 = false; 116 i31val = 0; 117 is_i31 = wasmtime_anyref_i31_get_u(context, &elem.of.anyref, &i31val); 118 assert(is_i31); 119 assert(i31val == 1234); 120 wasmtime_val_unroot(&elem); 121 122 printf("Touching `anyref` global...\n"); 123 124 // Lookup the `global` export. 125 ok = wasmtime_instance_export_get(context, &instance, "global", 126 strlen("global"), &item); 127 assert(ok); 128 assert(item.kind == WASMTIME_EXTERN_GLOBAL); 129 130 // Set the global to our `anyref`. 131 error = wasmtime_global_set(context, &item.of.global, &anyref_val); 132 if (error != NULL) 133 exit_with_error("failed to set global", error, NULL); 134 135 // Get the global, and it should return our `anyref` again. 136 wasmtime_val_t global_val; 137 wasmtime_global_get(context, &item.of.global, &global_val); 138 assert(global_val.kind == WASMTIME_ANYREF); 139 is_i31 = false; 140 i31val = 0; 141 is_i31 = wasmtime_anyref_i31_get_u(context, &global_val.of.anyref, &i31val); 142 assert(is_i31); 143 assert(i31val == 1234); 144 wasmtime_val_unroot(&global_val); 145 146 printf("Passing `anyref` into func...\n"); 147 148 // Lookup the `take_anyref` export. 149 ok = wasmtime_instance_export_get(context, &instance, "take_anyref", 150 strlen("take_anyref"), &item); 151 assert(ok); 152 assert(item.kind == WASMTIME_EXTERN_FUNC); 153 154 // And call it! 155 error = wasmtime_func_call(context, &item.of.func, &anyref_val, 1, NULL, 0, 156 &trap); 157 if (error != NULL || trap != NULL) 158 exit_with_error("failed to call function", error, trap); 159 160 printf("Getting `anyref` from func...\n"); 161 162 // Lookup the `return_anyref` export. 163 ok = wasmtime_instance_export_get(context, &instance, "return_anyref", 164 strlen("return_anyref"), &item); 165 assert(ok); 166 assert(item.kind == WASMTIME_EXTERN_FUNC); 167 168 // And call it! 169 wasmtime_val_t results[1]; 170 error = 171 wasmtime_func_call(context, &item.of.func, NULL, 0, results, 1, &trap); 172 if (error != NULL || trap != NULL) 173 exit_with_error("failed to call function", error, trap); 174 175 // `return_anyfunc` returns an `i31ref` that wraps `42`. 176 assert(results[0].kind == WASMTIME_ANYREF); 177 is_i31 = false; 178 i31val = 0; 179 is_i31 = wasmtime_anyref_i31_get_u(context, &results[0].of.anyref, &i31val); 180 assert(is_i31); 181 assert(i31val == 42); 182 wasmtime_val_unroot(&results[0]); 183 wasmtime_val_unroot(&anyref_val); 184 185 // We can GC any now-unused references to our anyref that the store is 186 // holding. 187 printf("GCing within the store...\n"); 188 wasmtime_context_gc(context); 189 190 // Clean up after ourselves at this point 191 printf("All finished!\n"); 192 193 wasmtime_store_delete(store); 194 wasmtime_module_delete(module); 195 wasm_engine_delete(engine); 196 return 0; 197 } 198 199 static void exit_with_error(const char *message, wasmtime_error_t *error, 200 wasm_trap_t *trap) { 201 fprintf(stderr, "error: %s\n", message); 202 wasm_byte_vec_t error_message; 203 if (error != NULL) { 204 wasmtime_error_message(error, &error_message); 205 wasmtime_error_delete(error); 206 } else { 207 wasm_trap_message(trap, &error_message); 208 wasm_trap_delete(trap); 209 } 210 fprintf(stderr, "%.*s\n", (int)error_message.size, error_message.data); 211 wasm_byte_vec_delete(&error_message); 212 exit(1); 213 } 214