Enable multi-module support for wasm-c-api (#426)

it is allowed that all imported functions and globals can be
linked by multi-module feature automatically or by wasm-c-api manually

samples/wasm-c-api/src/callback.c

@@ -4,6 +4,14 @@
 #include <inttypes.h>
 
 #include "wasm_c_api.h"
+#include "wasm_export.h"
+#include "bh_platform.h"
+
+extern bool
+reader(const char *module_name, uint8 **p_buffer, uint32 *p_size);
+
+extern void
+destroyer(uint8 *buffer, uint32 size);
 
 #define own
 
@@ -61,6 +69,8 @@ own wasm_trap_t* closure_callback(
 
 
 int main(int argc, const char* argv[]) {
+  wasm_runtime_set_module_reader(reader, destroyer);
+
   // Initialize.
   printf("Initializing...\n");
   wasm_engine_t* engine = wasm_engine_new();

samples/wasm-c-api/src/global.c

@@ -4,6 +4,14 @@
 #include <inttypes.h>
 
 #include "wasm_c_api.h"
+#include "wasm_export.h"
+#include "bh_platform.h"
+
+extern bool
+reader(const char *module_name, uint8 **p_buffer, uint32 *p_size);
+
+extern void
+destroyer(uint8 *buffer, uint32 size);
 
 #define own
 
@@ -46,6 +54,8 @@ wasm_func_t* get_export_func(const wasm_extern_vec_t* exports, size_t i) {
 
 
 int main(int argc, const char* argv[]) {
+  wasm_runtime_set_module_reader(reader, destroyer);
+
   // Initialize.
   printf("Initializing...\n");
   wasm_engine_t* engine = wasm_engine_new();

samples/wasm-c-api/src/globalexportimport-0.wat

@@ -0,0 +1,5 @@
+(module
+  (global $mut_f32_export (export "var f32") (mut f32) (f32.const 7))
+  (func (export "get var f32 export") (result f32) (global.get $mut_f32_export))
+  (func (export "set var f32 export") (param f32) (global.set $mut_f32_export (local.get 0)))
+)

samples/wasm-c-api/src/globalexportimport-1.wat

@@ -0,0 +1,7 @@
+(module
+  (global $mut_f32_import (export "var f32") (import "globalexportimport-0" "var f32") (mut f32))
+  (func (export "get var f32 export") (import "globalexportimport-0" "get var f32 export") (result f32))
+  (func (export "set var f32 export") (import "globalexportimport-0" "set var f32 export") (param f32))
+  (func (export "get var f32 import") (result f32) (global.get $mut_f32_import))
+  (func (export "set var f32 import") (param f32) (global.set $mut_f32_import (local.get 0)))
+)

samples/wasm-c-api/src/globalexportimport.c

@@ -0,0 +1,166 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "wasm_c_api.h"
+#include "wasm_export.h"
+#include "bh_platform.h"
+
+extern bool
+reader(const char *module_name, uint8 **p_buffer, uint32 *p_size);
+
+extern void
+destroyer(uint8 *buffer, uint32 size);
+
+#define own
+
+wasm_global_t* get_export_global(const wasm_extern_vec_t* exports, size_t i) {
+  if (exports->size <= i || !wasm_extern_as_global(exports->data[i])) {
+    printf("> Error accessing global export %zu!\n", i);
+    exit(1);
+  }
+  return wasm_extern_as_global(exports->data[i]);
+}
+
+wasm_func_t* get_export_func(const wasm_extern_vec_t* exports, size_t i) {
+  if (exports->size <= i || !wasm_extern_as_func(exports->data[i])) {
+    printf("> Error accessing function export %zu!\n", i);
+    exit(1);
+  }
+  return wasm_extern_as_func(exports->data[i]);
+}
+
+
+#define check(val, type, expected) \
+  if (val.of.type != expected) { \
+    printf("> Expected reading value %f or %d \n", expected, expected); \
+    printf("> Error reading value %f or %d\n", val.of.type, val.of.type); \
+  }
+
+#define check_global(global, type, expected) \
+  { \
+    wasm_val_t val; \
+    wasm_global_get(global, &val); \
+    check(val, type, expected); \
+  }
+
+#define check_call(func, type, expected) \
+  { \
+    wasm_val_t results[1]; \
+    wasm_func_call(func, NULL, results); \
+    check(results[0], type, expected); \
+  }
+
+wasm_module_t * create_module_from_file(wasm_store_t* store, const char * filename)
+{
+  FILE* file = fopen(filename, "rb");
+  fseek(file, 0L, SEEK_END);
+  size_t file_size = ftell(file);
+  fseek(file, 0L, SEEK_SET);
+  wasm_byte_vec_t binary;
+  wasm_byte_vec_new_uninitialized(&binary, file_size);
+  if (fread(binary.data, file_size, 1, file) != 1) {
+    printf("> Error loading module!\n");
+    return 1;
+  }
+  // Compile.
+  printf("Compiling module...\n");
+  own wasm_module_t* module = wasm_module_new(store, &binary);
+  if (!module) {
+    printf("> Error compiling module!\n");
+    return 1;
+  }
+  wasm_byte_vec_delete(&binary);
+  fclose(file);
+  return module;
+}
+
+
+int main(int argc, const char* argv[]) {
+  wasm_runtime_set_module_reader(reader, destroyer);
+
+  // Initialize.
+  printf("Initializing...\n");
+  wasm_engine_t* engine = wasm_engine_new();
+  wasm_store_t* store = wasm_store_new(engine);
+
+  // Load binary.
+  printf("Loading binary...\n");
+#if WASM_ENABLE_AOT != 0 && WASM_ENABLE_INTERP == 0
+  wasm_module_t* moduleimport =  create_module_from_file(store, "globalimport.aot");
+#else
+  wasm_module_t* moduleimport =  create_module_from_file(store, "globalexportimport-1.wasm");
+#endif
+
+  // Instantiate.
+  printf("Instantiating Import module...\n");
+  own wasm_instance_t* instance_import =
+    wasm_instance_new(store, moduleimport, NULL, NULL); //after this var_f32_export->inst_comm_rt is module_import
+  if (!instance_import) {
+    printf("> Error instantiating Import module!\n");
+    return 1;
+  }
+  wasm_module_delete(moduleimport);
+
+  // Extract export.
+  printf("Extracting exports from Import module...\n");
+  own wasm_extern_vec_t exports_of_import;
+  wasm_instance_exports(instance_import, &exports_of_import);
+  int i = 0;
+  wasm_global_t *var_f32_export = get_export_global(&exports_of_import, i++);
+  wasm_func_t *get_var_f32_export = get_export_func(&exports_of_import, i++);
+  wasm_func_t* set_var_f32_export = get_export_func(&exports_of_import, i++);
+  wasm_func_t* get_var_f32_import = get_export_func(&exports_of_import, i++);
+  wasm_func_t* set_var_f32_import = get_export_func(&exports_of_import, i++);
+
+  // Interact.
+
+  // Check initial values.
+  printf("Check initial values...\n");
+  check_global(var_f32_export, f32, 7.0);
+  check_call(get_var_f32_export, f32, 7.0); //Call to module export
+  check_call(get_var_f32_import, f32, 7.0); //Call to module import
+
+
+  // Modify variables through API and check again.
+  printf("Modify the variable to 37.0...\n");
+  wasm_val_t val37 = {.kind = WASM_F32, .of = {.f32 = 37.0}};
+  wasm_global_set(var_f32_export, &val37);  //  var_f32_export->inst_comm_rt is module_import now
+
+  check_global(var_f32_export, f32, 37.0);
+  check_call(get_var_f32_export, f32, 37.0); //Call to module export  Failed here, still 7
+  check_call(get_var_f32_import, f32, 37.0); //Call to module import
+
+  // Modify variables through calls and check again.
+  printf("Modify the variable to 77.0...\n");
+  wasm_val_t args77[] = { {.kind = WASM_F32, .of = {.f32 = 77.}} };
+  wasm_func_call(set_var_f32_export, args77, NULL); //Call to module export
+  check_call(get_var_f32_export, f32, 77.0);          //Call to module export
+  check_global(var_f32_export, f32, 77.0);    //Failed here, still 37
+  check_call(get_var_f32_import, f32, 77.0); //Call to module import  Failed here, still 37
+
+
+  printf("Modify the variable to 78.0...\n");
+  wasm_val_t args78[] = { {.kind = WASM_F32, .of = {.f32 = 78.0}} };
+  wasm_func_call(set_var_f32_import, args78, NULL);
+  check_global(var_f32_export, f32, 78.0);
+  check_call(get_var_f32_export, f32, 78.0); //Call to module export Failed here, still 77
+  check_call(get_var_f32_import, f32, 78.0); //Call to module import
+
+
+  // wasm_extern_vec_delete(&exports_of_export);
+  //wasm_instance_delete(instance_export);
+  wasm_extern_vec_delete(&exports_of_import);
+  //wasm_instance_delete(instance_import);
+
+  // Shut down.
+  printf("Shutting down...\n");
+  wasm_store_delete(store);
+  wasm_engine_delete(engine);
+
+  // All done.
+  printf("Done.\n");
+  return 0;
+
+}

samples/wasm-c-api/src/hello.c

@@ -4,6 +4,14 @@
 #include <inttypes.h>
 
 #include "wasm_c_api.h"
+#include "wasm_export.h"
+#include "bh_platform.h"
+
+extern bool
+reader(const char *module_name, uint8 **p_buffer, uint32 *p_size);
+
+extern void
+destroyer(uint8 *buffer, uint32 size);
 
 #define own
 
@@ -18,6 +26,8 @@ own wasm_trap_t* hello_callback(
 
 
 int main(int argc, const char* argv[]) {
+  wasm_runtime_set_module_reader(reader, destroyer);
+
   // Initialize.
   printf("Initializing...\n");
   wasm_engine_t* engine = wasm_engine_new();

samples/wasm-c-api/src/utils/multi_module_utils.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "bh_read_file.h"
+#include "wasm_export.h"
+
+static char *
+build_module_path(const char *module_name)
+{
+    const char *module_search_path = ".";
+    const char *format = "%s/%s.wasm";
+    int sz = strlen(module_search_path) + strlen("/") + strlen(module_name)
+             + strlen(".wasm") + 1;
+    char *wasm_file_name = BH_MALLOC(sz);
+    if (!wasm_file_name) {
+        return NULL;
+    }
+
+    snprintf(wasm_file_name, sz, format, module_search_path, module_name);
+    return wasm_file_name;
+}
+
+bool
+reader(const char *module_name, uint8 **p_buffer, uint32 *p_size)
+{
+    char *wasm_file_path = build_module_path(module_name);
+    if (!wasm_file_path) {
+        return false;
+    }
+
+    *p_buffer = (uint8_t *)bh_read_file_to_buffer(wasm_file_path, p_size);
+    BH_FREE(wasm_file_path);
+    return *p_buffer != NULL;
+}
+
+void
+destroyer(uint8 *buffer, uint32 size)
+{
+    if (!buffer) {
+        return;
+    }
+
+    BH_FREE(buffer);
+    buffer = NULL;
+}