Merge pull request #227 from wasmerio/fix/c-api-fix-imports

Fix C API table/global/memory imports

lib/runtime-c-api/src/lib.rs

@@ -454,12 +454,24 @@ pub unsafe extern "C" fn wasmer_module_instantiate(
             .or_insert_with(|| Namespace::new());
 
         let export = match import.tag {
-            wasmer_import_export_kind::WASM_MEMORY => import.value.memory as *mut Export,
-            wasmer_import_export_kind::WASM_FUNCTION => import.value.func as *mut Export,
-            wasmer_import_export_kind::WASM_GLOBAL => import.value.global as *mut Export,
-            wasmer_import_export_kind::WASM_TABLE => import.value.table as *mut Export,
+            wasmer_import_export_kind::WASM_MEMORY => {
+                let mem = import.value.memory as *mut Memory;
+                Export::Memory((&*mem).clone())
+            }
+            wasmer_import_export_kind::WASM_FUNCTION => {
+                let func_export = import.value.func as *mut Export;
+                (&*func_export).clone()
+            }
+            wasmer_import_export_kind::WASM_GLOBAL => {
+                let global = import.value.global as *mut Global;
+                Export::Global((&*global).clone())
+            }
+            wasmer_import_export_kind::WASM_TABLE => {
+                let table = import.value.table as *mut Table;
+                Export::Table((&*table).clone())
+            }
         };
-        namespace.insert(import_name, unsafe { (&*export).clone() });
+        namespace.insert(import_name, export);
     }
     for (module_name, namespace) in namespaces.into_iter() {
         import_object.register(module_name, namespace);
@@ -806,12 +818,24 @@ pub unsafe extern "C" fn wasmer_instantiate(
             .or_insert_with(|| Namespace::new());
 
         let export = match import.tag {
-            wasmer_import_export_kind::WASM_MEMORY => import.value.memory as *mut Export,
-            wasmer_import_export_kind::WASM_FUNCTION => import.value.func as *mut Export,
-            wasmer_import_export_kind::WASM_GLOBAL => import.value.global as *mut Export,
-            wasmer_import_export_kind::WASM_TABLE => import.value.table as *mut Export,
+            wasmer_import_export_kind::WASM_MEMORY => {
+                let mem = import.value.memory as *mut Memory;
+                Export::Memory((&*mem).clone())
+            }
+            wasmer_import_export_kind::WASM_FUNCTION => {
+                let func_export = import.value.func as *mut Export;
+                (&*func_export).clone()
+            }
+            wasmer_import_export_kind::WASM_GLOBAL => {
+                let global = import.value.global as *mut Global;
+                Export::Global((&*global).clone())
+            }
+            wasmer_import_export_kind::WASM_TABLE => {
+                let table = import.value.table as *mut Table;
+                Export::Table((&*table).clone())
+            }
         };
-        namespace.insert(import_name, unsafe { (&*export).clone() });
+        namespace.insert(import_name, unsafe { export });
     }
     for (module_name, namespace) in namespaces.into_iter() {
         import_object.register(module_name, namespace);

lib/runtime-c-api/tests/.gitignore

@@ -12,6 +12,7 @@ _deps
 test-globals
 test-exports
 test-instantiate
+test-imports
 test-import-function
 test-memory
 test-module-imports

lib/runtime-c-api/tests/CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required (VERSION 2.6)
 project (WasmerCApiTests)
 
+add_executable(test-imports test-imports.c)
 add_executable(test-exports test-exports.c)
 add_executable(test-globals test-globals.c)
 add_executable(test-instantiate test-instantiate.c)
@@ -21,6 +22,8 @@ if(NOT WASMER_LIB)
     message(FATAL_ERROR "wasmer library not found")
 endif()
 
+target_link_libraries(test-imports
+        general ${WASMER_LIB})
 target_link_libraries(test-exports
         general ${WASMER_LIB})
 target_link_libraries(test-globals
@@ -43,6 +46,7 @@ target_link_libraries(test-tables
         general ${WASMER_LIB})
 
 enable_testing()
+add_test(test-imports test-imports)
 add_test(test-exports test-exports)
 add_test(test-globals test-globals)
 add_test(test-instantiate test-instantiate)

lib/runtime-c-api/tests/test-imports.c

@@ -0,0 +1,154 @@
+#include <stdio.h>
+#include "../wasmer.h"
+#include <assert.h>
+#include <stdint.h>
+
+static print_str_called = false;
+
+// Host function that will be imported into the Web Assembly Instance
+void print_str(wasmer_instance_context_t *ctx, int32_t ptr, int32_t len)
+{
+    print_str_called = true;
+    wasmer_memory_t *memory = wasmer_instance_context_memory(ctx, 0);
+    uint32_t mem_len = wasmer_memory_length(memory);
+    uint8_t *mem_bytes = wasmer_memory_data(memory);
+    printf("%.*s", len, mem_bytes + ptr);
+}
+
+// Use the last_error API to retrieve error messages
+void print_wasmer_error()
+{
+    int error_len = wasmer_last_error_length();
+    printf("Error len: `%d`\n", error_len);
+    char *error_str = malloc(error_len);
+    wasmer_last_error_message(error_str, error_len);
+    printf("Error str: `%s`\n", error_str);
+}
+
+int main()
+{
+    // Create a new func to hold the parameter and signature
+    // of our `print_str` host function
+    wasmer_value_tag params_sig[] = {WASM_I32, WASM_I32};
+    wasmer_value_tag returns_sig[] = {};
+    wasmer_import_func_t *func = wasmer_import_func_new(print_str, params_sig, 2, returns_sig, 0);
+
+    // Create module name for our imports
+    // represented in bytes for UTF-8 compatability
+    char *module_name = "env";
+    wasmer_byte_array module_name_bytes;
+    module_name_bytes.bytes = module_name;
+    module_name_bytes.bytes_len = strlen(module_name);
+
+    // Define a function import
+    char *import_name = "_print_str";
+    wasmer_byte_array import_name_bytes;
+    import_name_bytes.bytes = import_name;
+    import_name_bytes.bytes_len = strlen(import_name);
+    wasmer_import_t func_import;
+    func_import.module_name = module_name_bytes;
+    func_import.import_name = import_name_bytes;
+    func_import.tag = WASM_FUNCTION;
+    func_import.value.func = func;
+
+    // Define a memory import
+    char *import_memory_name = "memory";
+    wasmer_byte_array import_memory_name_bytes;
+    import_memory_name_bytes.bytes = import_memory_name;
+    import_memory_name_bytes.bytes_len = strlen(import_memory_name);
+    wasmer_import_t memory_import;
+    memory_import.module_name = module_name_bytes;
+    memory_import.import_name = import_memory_name_bytes;
+    memory_import.tag = WASM_MEMORY;
+    wasmer_memory_t *memory = NULL;
+    wasmer_limits_t descriptor;
+    descriptor.min = 256;
+    wasmer_limit_option_t max;
+    max.has_some = true;
+    max.some = 256;
+    descriptor.max = max;
+    wasmer_result_t memory_result = wasmer_memory_new(&memory, descriptor);
+    if (memory_result != WASMER_OK)
+    {
+        print_wasmer_error();
+    }
+    memory_import.value.memory = memory;
+
+    // Define a global import
+    char *import_global_name = "__memory_base";
+    wasmer_byte_array import_global_name_bytes;
+    import_global_name_bytes.bytes = import_global_name;
+    import_global_name_bytes.bytes_len = strlen(import_global_name);
+    wasmer_import_t global_import;
+    global_import.module_name = module_name_bytes;
+    global_import.import_name = import_global_name_bytes;
+    global_import.tag = WASM_GLOBAL;
+    wasmer_value_t val;
+    val.tag = WASM_I32;
+    val.value.I32 = 1024;
+    wasmer_global_t *global = wasmer_global_new(val, false);
+    global_import.value.global = global;
+
+    // Define a table import
+    char *import_table_name = "table";
+    wasmer_byte_array import_table_name_bytes;
+    import_table_name_bytes.bytes = import_table_name;
+    import_table_name_bytes.bytes_len = strlen(import_table_name);
+    wasmer_import_t table_import;
+    table_import.module_name = module_name_bytes;
+    table_import.import_name = import_table_name_bytes;
+    table_import.tag = WASM_TABLE;
+    wasmer_table_t *table = NULL;
+    wasmer_limits_t table_descriptor;
+    table_descriptor.min = 256;
+    wasmer_limit_option_t table_max;
+    table_max.has_some = true;
+    table_max.some = 256;
+    table_descriptor.max = table_max;
+    wasmer_result_t table_result = wasmer_table_new(&table, table_descriptor);
+    if (table_result != WASMER_OK)
+    {
+        print_wasmer_error();
+    }
+    table_import.value.table = table;
+
+    // Define an array containing our imports
+    wasmer_import_t imports[] = {func_import, global_import, memory_import, table_import};
+
+    // Read the wasm file bytes
+    FILE *file = fopen("hello_wasm.wasm", "r");
+    fseek(file, 0, SEEK_END);
+    long len = ftell(file);
+    uint8_t *bytes = malloc(len);
+    fseek(file, 0, SEEK_SET);
+    fread(bytes, 1, len, file);
+    fclose(file);
+
+    // Creates a WebAssembly Instance from wasm bytes and imports
+    wasmer_instance_t *instance = NULL;
+    wasmer_result_t compile_result = wasmer_instantiate(&instance, bytes, len, imports, 3);
+    printf("Compile result:  %d\n", compile_result);
+    if (compile_result != WASMER_OK)
+    {
+        print_wasmer_error();
+    }
+    assert(compile_result == WASMER_OK);
+
+    // Call the exported "hello_wasm" function of our instance
+    wasmer_value_t params[] = {};
+    wasmer_value_t result_one;
+    wasmer_value_t results[] = {result_one};
+    wasmer_result_t call_result = wasmer_instance_call(instance, "_hello_wasm", params, 0, results, 1);
+    printf("Call result:  %d\n", call_result);
+    assert(call_result == WASMER_OK);
+    assert(print_str_called);
+
+    // Use *_destroy methods to cleanup as specified in the header documentation
+    wasmer_import_func_destroy(func);
+    wasmer_global_destroy(global);
+    wasmer_memory_destroy(memory);
+    wasmer_table_destroy(table);
+    wasmer_instance_destroy(instance);
+
+    return 0;
+}