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

.github/workflows/linux.yml

@@ -84,12 +84,18 @@ jobs:
         cmake .. -DWAMR_BUILD_CUSTOM_NAME_SECTION=1
         make
         cd .. && rm -rf build
-    - name: download wasi-sdk
+    - name: download and install wasi-sdk
       run: |
         cd /opt
         wget https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-8/wasi-sdk-8.0-linux.tar.gz
         tar -xzf wasi-sdk-8.0-linux.tar.gz
         mv wasi-sdk-8.0 wasi-sdk
+    - name: download and install wabt
+      run: |
+        cd /opt
+        wget https://github.com/WebAssembly/wabt/releases/download/1.0.19/wabt-1.0.19-ubuntu.tar.gz
+        tar -xzf wabt-1.0.19-ubuntu.tar.gz
+        mv wabt-1.0.19 wabt
     - name: Build Sample [wasm-c-api]
       run: |
         cd samples/wasm-c-api

.github/workflows/mac.yml

@@ -84,6 +84,12 @@ jobs:
         cmake .. -DWAMR_BUILD_CUSTOM_NAME_SECTION=1
         make
         cd .. && rm -rf build
+    - name: download and install wabt
+      run: |
+        cd /opt
+        sudo wget https://github.com/WebAssembly/wabt/releases/download/1.0.19/wabt-1.0.19-macos.tar.gz
+        sudo tar -xzf wabt-1.0.19-macos.tar.gz
+        sudo mv wabt-1.0.19 wabt
     - name: Build Sample [wasm-c-api]
       run: |
         cd samples/wasm-c-api

core/iwasm/common/wasm_c_api.c

@@ -1696,7 +1696,14 @@ interp_global_set(const WASMModuleInstance *inst_interp,
     const WASMGlobalInstance *global_interp =
       inst_interp->globals + global_idx_rt;
     uint8 val_type_rt = global_interp->type;
+#if WASM_ENABLE_MULTI_MODULE != 0
+    uint8 *data = global_interp->import_global_inst
+                    ? global_interp->import_module_inst->global_data
+                        + global_interp->import_global_inst->data_offset
+                    : inst_interp->global_data + global_interp->data_offset;
+#else
     uint8 *data = inst_interp->global_data + global_interp->data_offset;
+#endif
     bool ret = true;
 
     switch (val_type_rt) {
@@ -1732,7 +1739,14 @@ interp_global_get(const WASMModuleInstance *inst_interp,
 {
     WASMGlobalInstance *global_interp = inst_interp->globals + global_idx_rt;
     uint8 val_type_rt = global_interp->type;
+#if WASM_ENABLE_MULTI_MODULE != 0
+    uint8 *data = global_interp->import_global_inst
+                    ? global_interp->import_module_inst->global_data
+                        + global_interp->import_global_inst->data_offset
+                    : inst_interp->global_data + global_interp->data_offset;
+#else
     uint8 *data = inst_interp->global_data + global_interp->data_offset;
+#endif
     bool ret = true;
 
     switch (val_type_rt) {
@@ -2080,6 +2094,7 @@ interp_link_global(const WASMModule *module_interp,
     }
 
     import->global_idx_rt = global_idx_rt;
+    imported_global_interp->u.global.is_linked = true;
     return true;
 }
 
@@ -2432,35 +2447,44 @@ wasm_instance_new(wasm_store_t *store,
     }
 
     /* link module and imports */
-    if (INTERP_MODE == current_runtime_mode()) {
+    if (imports) {
+        if (INTERP_MODE == current_runtime_mode()) {
 #if WASM_ENABLE_INTERP != 0
-        import_count = ((WASMModule *)*module)->import_count;
-        INIT_VEC(instance->imports, wasm_extern_vec, import_count);
-        if (!instance->imports) {
-            goto failed;
-        }
+            import_count = ((WASMModule *)*module)->import_count;
+            INIT_VEC(instance->imports, wasm_extern_vec, import_count);
+            if (!instance->imports) {
+                goto failed;
+            }
 
-        import_count = interp_link(instance, (WASMModule *)*module,
-                                   (wasm_extern_t **)imports);
+            if (import_count) {
+                import_count = interp_link(instance, (WASMModule *)*module,
+                                           (wasm_extern_t **)imports);
+                if ((int32)import_count < 0) {
+                    goto failed;
+                }
+            }
 #endif
-    }
-    else {
+        }
+        else {
 #if WASM_ENABLE_AOT != 0
-        import_count = ((AOTModule *)*module)->import_func_count
-                       + ((AOTModule *)*module)->import_global_count
-                       + ((AOTModule *)*module)->import_memory_count
-                       + ((AOTModule *)*module)->import_table_count;
-        INIT_VEC(instance->imports, wasm_extern_vec, import_count);
-        if (!instance->imports) {
-            goto failed;
-        }
+            import_count = ((AOTModule *)*module)->import_func_count
+                           + ((AOTModule *)*module)->import_global_count
+                           + ((AOTModule *)*module)->import_memory_count
+                           + ((AOTModule *)*module)->import_table_count;
+            INIT_VEC(instance->imports, wasm_extern_vec, import_count);
+            if (!instance->imports) {
+                goto failed;
+            }
 
-        import_count =
-          aot_link(instance, (AOTModule *)*module, (wasm_extern_t **)imports);
+            if (import_count) {
+                import_count = aot_link(instance, (AOTModule *)*module,
+                                        (wasm_extern_t **)imports);
+                if ((int32)import_count < 0) {
+                    goto failed;
+                }
+            }
 #endif
-    }
-    if ((int32)import_count < 0) {
-        goto failed;
+        }
     }
 
     instance->inst_comm_rt = wasm_runtime_instantiate(

core/iwasm/common/wasm_runtime_common.c

@@ -539,6 +539,12 @@ wasm_runtime_destroy_loading_module_list()
 }
 #endif /* WASM_ENABLE_MULTI_MODULE */
 
+bool
+wasm_runtime_is_host_module(const char *module_name)
+{
+    return strlen(module_name) == 0;
+}
+
 bool
 wasm_runtime_is_built_in_module(const char *module_name)
 {
@@ -2342,7 +2348,8 @@ wasm_application_execute_func(WASMModuleInstanceCommon *module_inst,
             wasm_runtime_set_exception(module_inst, buf);
             goto fail;
         }
-        type = wasm_func->u.func->func_type;
+        type = wasm_func->is_import_func ? wasm_func->u.func_import->func_type
+                                         : wasm_func->u.func->func_type;
         argc1 = wasm_func->param_cell_num;
         cell_num = argc1 > wasm_func->ret_cell_num ?
                    argc1 : wasm_func->ret_cell_num;

core/iwasm/common/wasm_runtime_common.h

@@ -373,6 +373,9 @@ void
 wasm_runtime_destroy_loading_module_list();
 #endif /* WASM_ENALBE_MULTI_MODULE */
 
+bool
+wasm_runtime_is_host_module(const char *module_name);
+
 bool
 wasm_runtime_is_built_in_module(const char *module_name);
 

core/iwasm/interpreter/wasm.h

@@ -177,6 +177,7 @@ typedef struct WASMGlobalImport {
     bool is_mutable;
     /* global data after linked */
     WASMValue global_data_linked;
+    bool is_linked;
 #if WASM_ENABLE_MULTI_MODULE != 0
     /* imported function pointer after linked */
     /* TODO: remove if not needed */

core/iwasm/interpreter/wasm_interp_classic.c

@@ -1362,12 +1362,8 @@ label_pop_csp_n:
           /* always call module own functions */
           cur_func = module->functions + fidx;
 
-          if (cur_func->is_import_func
-#if WASM_ENABLE_MULTI_MODULE != 0
-              && !cur_func->import_func_inst
-#endif
-          )
-              cur_func_type = cur_func->u.func_import->func_type;
+          if (cur_func->is_import_func)
+            cur_func_type = cur_func->u.func_import->func_type;
           else
             cur_func_type = cur_func->u.func->func_type;
           if (!wasm_type_equal(cur_type, cur_func_type)) {

core/iwasm/interpreter/wasm_interp_fast.c

@@ -1270,11 +1270,7 @@ recover_br_info:
           WASMType *func_type;
           uint32 off, ret_offset;
           uint8 *ret_types;
-          if (cur_func->is_import_func
-#if WASM_ENABLE_MULTI_MODULE != 0
-              && !cur_func->import_func_inst
-#endif
-          )
+          if (cur_func->is_import_func)
             func_type = cur_func->u.func_import->func_type;
           else
             func_type = cur_func->u.func->func_type;
@@ -1354,11 +1350,7 @@ recover_br_info:
           /* always call module own functions */
           cur_func = module->functions + fidx;
 
-          if (cur_func->is_import_func
-#if WASM_ENABLE_MULTI_MODULE != 0
-              && !cur_func->import_func_inst
-#endif
-          )
+          if (cur_func->is_import_func)
             cur_func_type = cur_func->u.func_import->func_type;
           else
             cur_func_type = cur_func->u.func->func_type;
@@ -3253,11 +3245,7 @@ recover_br_info:
          * values' offset so we must skip remain return values' offsets.
          */
         WASMType *func_type;
-        if (cur_func->is_import_func
-#if WASM_ENABLE_MULTI_MODULE != 0
-            && !cur_func->import_func_inst
-#endif
-        )
+        if (cur_func->is_import_func)
           func_type = cur_func->u.func_import->func_type;
         else
           func_type = cur_func->u.func->func_type;

core/iwasm/interpreter/wasm_loader.c

@@ -796,10 +796,11 @@ load_function_import(const WASMModule *parent_module, WASMModule *sub_module,
 
     declare_func_type = parent_module->types[declare_type_index];
 
-    is_built_in_module = wasm_runtime_is_built_in_module(sub_module_name);
-    if (is_built_in_module) {
-        LOG_DEBUG("%s is a function of a built-in module %s",
-                  function_name, sub_module_name);
+    if (wasm_runtime_is_host_module(sub_module_name)) {
+        /* do nothing, wait for injecting host created fuctions */
+    }
+    else if ((is_built_in_module =
+                wasm_runtime_is_built_in_module(sub_module_name))) {
         /* check built-in modules */
         linked_func = wasm_native_resolve_symbol(sub_module_name,
                                                  function_name,
@@ -810,8 +811,6 @@ load_function_import(const WASMModule *parent_module, WASMModule *sub_module,
     }
 #if WASM_ENABLE_MULTI_MODULE != 0
     else {
-        LOG_DEBUG("%s is a function of a sub-module %s",
-                  function_name, sub_module_name);
         linked_func = wasm_loader_resolve_function(sub_module_name,
                                                    function_name,
                                                    declare_func_type,
@@ -820,19 +819,6 @@ load_function_import(const WASMModule *parent_module, WASMModule *sub_module,
     }
 #endif
 
-    if (!linked_func) {
-#if WASM_ENABLE_SPEC_TEST != 0
-        set_error_buf(error_buf, error_buf_size,
-                      "unknown import or incompatible import type");
-        return false;
-#else
-#if WASM_ENABLE_WAMR_COMPILER == 0
-        LOG_WARNING("warning: fail to link import function (%s, %s)",
-                    sub_module_name, function_name);
-#endif
-#endif
-    }
-
     function->module_name = sub_module_name;
     function->field_name = function_name;
     function->func_type = declare_func_type;
@@ -1096,8 +1082,6 @@ load_global_import(const WASMModule *parent_module,
     const uint8 *p = *p_buf, *p_end = buf_end;
     uint8 declare_type = 0;
     uint8 declare_mutable = 0;
-    bool is_mutable = false;
-    bool ret = false;
 
     CHECK_BUF(p, p_end, 2);
     declare_type = read_uint8(p);
@@ -1109,50 +1093,33 @@ load_global_import(const WASMModule *parent_module,
         return false;
     }
 
-    is_mutable = declare_mutable & 1 ? true : false;
-
-#if WASM_ENABLE_LIBC_BUILTIN != 0
-    ret = wasm_runtime_is_built_in_module(sub_module_name);
-    if (ret) {
-        /* check built-in modules */
-        ret = wasm_native_lookup_libc_builtin_global(sub_module_name,
-                                                     global_name, global);
-        if (ret) {
-            LOG_DEBUG("(%s, %s) is a global of a built-in module",
-                      sub_module_name, global_name);
-        }
+    if (wasm_runtime_is_host_module(sub_module_name)) {
+        /* do nothing, let host injects the symbol */
+    }
+    else if (wasm_runtime_is_built_in_module(sub_module_name)) {
+        /* check built-in modules */
+        global->is_linked = wasm_native_lookup_libc_builtin_global(
+              sub_module_name, global_name, global);
     }
-#endif /* WASM_ENABLE_LIBC_BUILTIN */
-
 #if WASM_ENABLE_MULTI_MODULE != 0
-    if (!ret) {
+    else {
         /* check sub modules */
         WASMGlobal *linked_global =
             wasm_loader_resolve_global(sub_module_name, global_name,
                                        declare_type, declare_mutable,
                                        error_buf, error_buf_size);
         if (linked_global) {
-            LOG_DEBUG("(%s, %s) is a global of external module",
-                      sub_module_name, global_name);
             global->import_module = sub_module;
             global->import_global_linked = linked_global;
-            ret = true;
+            global->is_linked = true;
         }
     }
 #endif
 
-    if (!ret) {
-#if WASM_ENABLE_SPEC_TEST != 0
-        set_error_buf(error_buf, error_buf_size,
-                      "unknown import or incompatible import type");
-        return false;
-#endif
-    }
-
     global->module_name = sub_module_name;
     global->field_name = global_name;
     global->type = declare_type;
-    global->is_mutable = is_mutable;
+    global->is_mutable = (declare_mutable == 1);
     return true;
 fail:
     return false;
@@ -1363,8 +1330,7 @@ load_depended_module(const WASMModule *parent_module,
     ret = reader(sub_module_name, &buffer, &buffer_size);
     if (!ret) {
         LOG_DEBUG("read the file of %s failed", sub_module_name);
-        set_error_buf_v(error_buf, error_buf_size,
-                        "failed to read module file of %s",
+        set_error_buf_v(error_buf, error_buf_size, "unknown import",
                         sub_module_name);
         goto DELETE_FROM_LOADING_LIST;
     }
@@ -1568,7 +1534,8 @@ load_import_section(const uint8 *buf, const uint8 *buf_end, WASMModule *module,
             LOG_DEBUG("import #%d: (%s, %s)", i, sub_module_name, field_name);
 #if WASM_ENABLE_MULTI_MODULE != 0
             /* assume built-in modules have been loaded */
-            if (!wasm_runtime_is_built_in_module(sub_module_name)) {
+            if (!wasm_runtime_is_host_module(sub_module_name)
+                && !wasm_runtime_is_built_in_module(sub_module_name)) {
                 LOG_DEBUG("%s is an exported field of a %s", field_name,
                           sub_module_name);
                 /*

core/iwasm/interpreter/wasm_mini_loader.c

@@ -527,19 +527,10 @@ load_global_import(const WASMModule *parent_module,
         /* check built-in modules */
         ret = wasm_native_lookup_libc_builtin_global(sub_module_name,
                                                      global_name, global);
-        if (ret) {
-            LOG_DEBUG("(%s, %s) is a global of a built-in module",
-                      sub_module_name, global_name);
-        }
     }
 #endif /* WASM_ENABLE_LIBC_BUILTIN */
 
-    if (!ret) {
-        set_error_buf(error_buf, error_buf_size,
-                      "unknown import or incompatible import type");
-        return false;
-    }
-
+    global->is_linked = ret;
     global->module_name = sub_module_name;
     global->field_name = global_name;
     global->type = declare_type;

core/iwasm/interpreter/wasm_runtime.c

@@ -550,56 +550,27 @@ functions_instantiate(const WASMModule *module,
 
 #if WASM_ENABLE_MULTI_MODULE != 0
         if (import->u.function.import_module) {
-            LOG_DEBUG("(%s, %s) is a function of a sub-module",
-                      import->u.function.module_name,
-                      import->u.function.field_name);
-
             function->import_module_inst =
               get_sub_module_inst(module_inst,
                                   import->u.function.import_module);
-            bh_assert(function->import_module_inst);
 
-            WASMFunction *function_linked =
-              import->u.function.import_func_linked;
-
-            function->u.func = function_linked;
-            function->import_func_inst =
-              wasm_lookup_function(function->import_module_inst,
-                                   import->u.function.field_name,
-                                   NULL);
-            bh_assert(function->import_func_inst);
-
-            function->param_cell_num = function->u.func->param_cell_num;
-            function->ret_cell_num = function->u.func->ret_cell_num;
-            function->local_cell_num = function->u.func->local_cell_num;
-            function->param_count =
-              (uint16)function->u.func->func_type->param_count;
-            function->local_count = (uint16)function->u.func->local_count;
-            function->param_types = function->u.func->func_type->types;
-            function->local_types = function->u.func->local_types;
-            function->local_offsets = function->u.func->local_offsets;
-#if WASM_ENABLE_FAST_INTERP != 0
-            function->const_cell_num = function->u.func->const_cell_num;
-#endif
+            if (function->import_module_inst) {
+                function->import_func_inst =
+                  wasm_lookup_function(function->import_module_inst,
+                                       import->u.function.field_name, NULL);
+            }
         }
-        else
 #endif /* WASM_ENABLE_MULTI_MODULE */
-        {
-            LOG_DEBUG("(%s, %s) is a function of native",
-                      import->u.function.module_name,
-                      import->u.function.field_name);
-            function->u.func_import = &import->u.function;
-            function->param_cell_num =
-              import->u.function.func_type->param_cell_num;
-            function->ret_cell_num =
-              import->u.function.func_type->ret_cell_num;
-            function->param_count =
-              (uint16)function->u.func_import->func_type->param_count;
-            function->param_types = function->u.func_import->func_type->types;
-            function->local_cell_num = 0;
-            function->local_count = 0;
-            function->local_types = NULL;
-        }
+        function->u.func_import = &import->u.function;
+        function->param_cell_num =
+          import->u.function.func_type->param_cell_num;
+        function->ret_cell_num = import->u.function.func_type->ret_cell_num;
+        function->param_count =
+          (uint16)function->u.func_import->func_type->param_count;
+        function->param_types = function->u.func_import->func_type->types;
+        function->local_cell_num = 0;
+        function->local_count = 0;
+        function->local_types = NULL;
 
         function++;
     }
@@ -1069,6 +1040,57 @@ sub_module_deinstantiate(WASMModuleInstance *module_inst)
 }
 #endif
 
+static bool
+check_linked_symbol(WASMModuleInstance *module_inst, char *error_buf,
+                    uint32 error_buf_size)
+{
+    WASMModule *module = module_inst->module;
+    uint32 i;
+
+    for (i = 0; i < module->import_function_count; i++) {
+        WASMFunctionImport *func =
+          &((module->import_functions + i)->u.function);
+        if (!func->func_ptr_linked
+#if WASM_ENABLE_MULTI_MODULE != 0
+            && !func->import_func_linked
+#endif
+        ) {
+#if WASM_ENABLE_SPEC_TEST != 0
+            set_error_buf(error_buf, error_buf_size,
+                          "unknown import or incompatible import type");
+            return false;
+#else
+#if WASM_ENABLE_WAMR_COMPILER == 0
+            LOG_WARNING("warning: fail to link import function (%s, %s)",
+                        func->module_name, func->field_name);
+#else
+            /* do nothing to avoid confused message */
+#endif /* WASM_ENABLE_WAMR_COMPILER == 0 */
+#endif /* WASM_ENABLE_SPEC_TEST != 0 */
+        }
+    }
+
+    for (i = 0; i < module->import_global_count; i++) {
+        WASMGlobalImport *global = &((module->import_globals + i)->u.global);
+        if (!global->is_linked) {
+#if WASM_ENABLE_SPEC_TEST != 0
+            set_error_buf(error_buf, error_buf_size,
+                          "unknown import or incompatible import type");
+            return false;
+#else
+#if WASM_ENABLE_WAMR_COMPILER == 0
+            LOG_DEBUG("warning: fail to link import global (%s, %s)",
+                      global->module_name, global->field_name);
+#else
+            /* do nothing to avoid confused message */
+#endif /* WASM_ENABLE_WAMR_COMPILER == 0 */
+#endif /* WASM_ENABLE_SPEC_TEST != 0 */
+        }
+    }
+
+    return true;
+}
+
 /**
  * Instantiate module
  */
@@ -1215,6 +1237,11 @@ wasm_instantiate(WASMModule *module, bool is_sub_inst,
         bh_assert(global_data == global_data_end);
     }
 
+    if (!check_linked_symbol(module_inst, error_buf, error_buf_size)) {
+        wasm_deinstantiate(module_inst, false);
+        return NULL;
+    }
+
     /* Initialize the memory data with data segment section */
     module_inst->default_memory =
       module_inst->memory_count ? module_inst->memories[0] : NULL;

core/shared/mem-alloc/tlsf

@@ -0,0 +1 @@
+Subproject commit a1f743ffac0305408b39e791e0ffb45f6d9bc777

doc/release_ack.md

@@ -0,0 +1,61 @@
+Major feature releases and contributors
+=========================================
+
+
+**May 07, 2019: WAMR first GitHub release**
+
+- Contributors: Wenyong Huang, Weining Lu, Lei Shi, Li Tian, Jizhao Zhang, Yi Zhang, Daoming Qiu, Xin Wang (Intel)
+
+**May 17, 2019: Application manager, WASM APP API, samples and test tools**
+
+- Contributors: Wenyong Huang, Weining Lu, Lei Shi, Li Tian, Jizhao Zhang, Yi Zhang, Daoming Qiu, Xin Wang (Intel)
+
+
+**May 23, 2019: Support AliOS Things**
+
+- Contributor: JinZhou Zhu (Alibaba)
+
+**May 24, 2019: Support memory usage profiler**
+
+- Contributors Wenyong Huang (Intel)
+
+**Jun 11, 2019: Add WASM APP API connection**
+
+
+- Contributor: Weining Lu (Intel)
+
+**Jun 10, 2019: Support VxWorks**
+
+- Contributor: Yiting Wang (WindRiver)
+
+**Aug 1, 2019: Add WGL graphic user interface API**
+
+- Contributor: Weining Lu
+
+**Aug 14, 2019: Add Docker support**
+
+
+- Contributor: beriberikix
+
+
+**Aug 14, 2019: WASM IoT app store demo**
+
+
+- Contributor: Luhanzhi Li, Jun Xu (Intel)
+
+
+**Aug 28, 2019: SGX support**
+
+
+- Contributor: Mic Bowman (Intel)
+
+
+**Sep 6, 2019: Mac platform support**
+
+
+- Contributor: Jonathan Dong (Alibaba)
+
+**Nov 2019: WASI support** (Intel)
+
+**Jan 2020: Ahead of time and Just-in-Time compilation support** (Intel)
+

doc/roadmap.md

@@ -0,0 +1,23 @@
+
+# WebAssembly Micro Runtime Roadmap
+
+
+
+## Data serialization
+Evaluating using cbor as the default data serialization
+
+No plan yet.
+
+
+
+## Threading
+Plan: 2020 Q1
+
+
+
+## AssemblyScript Support and API
+
+Currently under evaluation
+
+
+

samples/wasm-c-api/CMakeLists.txt

@@ -40,6 +40,7 @@ endif()
 
 set(WAMR_BUILD_LIBC_BUILTIN 1)
 set(WAMR_BUILD_LIBC_WASI 0)
+set(WAMR_BUILD_MULTI_MODULE 1)
 
 if(NOT DEFINED WAMR_BUILD_FAST_INTERP)
   set(WAMR_BUILD_FAST_INTERP 0)
@@ -70,47 +71,44 @@ endif()
 ################################################
 
 ################  application related  ################
-file(GLOB SOURCES src/*.c)
-add_library(c-api ${SOURCES})
-target_include_directories(c-api
-  PRIVATE ${C_API_PATH}/include
+## locate wat2wasm
+find_program(WAT2WASM
+  wat2wasm
+  PATHS /opt/wabt/bin /opt/wabt-1.0.18/bin
+  REQUIRED
 )
-target_link_libraries(c-api PRIVATE vmlib -lpthread -lm)
-if (MSVC)
-  target_compile_definitions(c-api PRIVATE WASM_API_EXTERN=)
+
+if(NOT WAT2WASM)
+  message(SEND_ERROR "can not find wat2wasm")
 endif()
 
+include (${SHARED_DIR}/utils/uncommon/shared_uncommon.cmake)
+
+set(MM_UTIL src/utils/multi_module_utils.c)
+# build executable for each .c
+file(GLOB SOURCES src/*.c)
 foreach(SRC ${SOURCES})
   get_filename_component(APPNAME ${SRC} NAME_WE)
 
-  # build executable for each .c
-  add_executable(${APPNAME} ${SRC})
-  message("create executable about ${APPNAME}")
-  target_link_libraries(${APPNAME} c-api)
+  add_executable(${APPNAME} ${SRC} ${UNCOMMON_SHARED_SOURCE} ${MM_UTIL})
+  target_include_directories(${APPNAME} PRIVATE ${UNCOMMON_SHARED_DIR})
+  target_link_libraries(${APPNAME} vmlib -lpthread -lm)
   if (MSVC)
     target_compile_definitions(${APPNAME} PRIVATE WASM_API_EXTERN=)
   endif()
+endforeach()
 
-  # copy .wasm
-  add_custom_command(TARGET ${APPNAME} POST_BUILD
-      COMMAND ${CMAKE_COMMAND} -E copy
-                  ${CMAKE_CURRENT_SOURCE_DIR}/src/${APPNAME}.wasm
-                  ${PROJECT_BINARY_DIR}/
-      BYPRODUCTS ${APPNAME}.wasm
-      COMMENT "Copy ${SRC} to the output directory"
+# wat to wasm
+file(GLOB WAT_FILES src/*.wat)
+foreach(WAT_FILE ${WAT_FILES})
+  get_filename_component(WATNAME ${WAT_FILE} NAME_WE)
+
+  add_custom_target(${WATNAME}_WASM ALL
+    COMMAND ${WAT2WASM} ${WAT_FILE} -o ${PROJECT_BINARY_DIR}/${WATNAME}.wasm
+    DEPENDS ${WAT_FILE}
+    BYPRODUCTS ${PROJECT_BINARY_DIR}/${WATNAME}.wasm
+    VERBATIM
+    SOURCES ${WAT_FILE}
   )
-
-  # generate .aot file
-  if(${WAMR_BUILD_AOT} EQUAL 1)
-    if(EXISTS ${WAMRC})
-      add_custom_command(TARGET ${APPNAME} POST_BUILD
-          COMMAND ${WAMRC} -o ${APPNAME}.aot
-              ${CMAKE_CURRENT_SOURCE_DIR}/src/${APPNAME}.wasm
-          BYPRODUCTS ${APPNAME}.aot
-          COMMENT "generate a aot file ${APPNAME}.aot"
-      )
-    endif()
-  endif()
-
-endforeach(SRC ${SOURCES})
+endforeach()
 ################################################

samples/wasm-c-api/README.md

@@ -1,5 +1,16 @@
-WAMR supports *wasm-c-api* in both *interpreter* mode and *aot* mode. By default,
-all samples are compiled and run in "interpreter" mode.
+WAMR supports *wasm-c-api* in both *interpreter* mode and *aot* mode.
+
+Before staring, we need to download and intall [WABT](https://github.com/WebAssembly/wabt/releases/latest).
+
+``` shell
+$ cd /opt
+$ wget https://github.com/WebAssembly/wabt/releases/download/1.0.19/wabt-1.0.19-ubuntu.tar.gz
+$ tar -xzf wabt-1.0.19-ubuntu.tar.gz
+$ mv wabt-1.0.19 wabt
+```
+
+By default, all samples are compiled and run in "interpreter" mode.
+
 
 ``` shell
 $ mkdir build

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;
+}