1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <inttypes.h>
5
6 #include "wasm.h"
7
8 #define own
9
10 // A function to be called from Wasm code.
hello_callback( const wasm_val_t args[], wasm_val_t results[] )11 own wasm_trap_t* hello_callback(
12 const wasm_val_t args[], wasm_val_t results[]
13 ) {
14 printf("Calling back...\n");
15 printf("> Hello World!\n");
16 return NULL;
17 }
18
19
main(int argc, const char* argv[])20 int main(int argc, const char* argv[]) {
21 // Initialize.
22 printf("Initializing...\n");
23 wasm_engine_t* engine = wasm_engine_new();
24 wasm_store_t* store = wasm_store_new(engine);
25
26 // Load binary.
27 printf("Loading binary...\n");
28 FILE* file = fopen("hello.wasm", "r");
29 if (!file) {
30 printf("> Error loading module!\n");
31 return 1;
32 }
33 fseek(file, 0L, SEEK_END);
34 size_t file_size = ftell(file);
35 fseek(file, 0L, SEEK_SET);
36 wasm_byte_vec_t binary;
37 wasm_byte_vec_new_uninitialized(&binary, file_size);
38 if (fread(binary.data, file_size, 1, file) != 1) {
39 printf("> Error loading module!\n");
40 return 1;
41 }
42 fclose(file);
43
44 // Compile.
45 printf("Compiling module...\n");
46 own wasm_module_t* module = wasm_module_new(store, &binary);
47 if (!module) {
48 printf("> Error compiling module!\n");
49 return 1;
50 }
51
52 wasm_byte_vec_delete(&binary);
53
54 // Create external print functions.
55 printf("Creating callback...\n");
56 own wasm_functype_t* hello_type = wasm_functype_new_0_0();
57 own wasm_func_t* hello_func =
58 wasm_func_new(store, hello_type, hello_callback);
59
60 wasm_functype_delete(hello_type);
61
62 // Instantiate.
63 printf("Instantiating module...\n");
64 const wasm_extern_t* imports[] = { wasm_func_as_extern(hello_func) };
65 own wasm_instance_t* instance =
66 wasm_instance_new(store, module, imports, NULL);
67 if (!instance) {
68 printf("> Error instantiating module!\n");
69 return 1;
70 }
71
72 wasm_func_delete(hello_func);
73
74 // Extract export.
75 printf("Extracting export...\n");
76 own wasm_extern_vec_t exports;
77 wasm_instance_exports(instance, &exports);
78 if (exports.size == 0) {
79 printf("> Error accessing exports!\n");
80 return 1;
81 }
82 const wasm_func_t* run_func = wasm_extern_as_func(exports.data[0]);
83 if (run_func == NULL) {
84 printf("> Error accessing export!\n");
85 return 1;
86 }
87
88 wasm_module_delete(module);
89 wasm_instance_delete(instance);
90
91 // Call.
92 printf("Calling export...\n");
93 if (wasm_func_call(run_func, NULL, NULL)) {
94 printf("> Error calling function!\n");
95 return 1;
96 }
97
98 wasm_extern_vec_delete(&exports);
99
100 // Shut down.
101 printf("Shutting down...\n");
102 wasm_store_delete(store);
103 wasm_engine_delete(engine);
104
105 // All done.
106 printf("Done.\n");
107 return 0;
108 }
109