Add setter for enabling multi-memory to the C API.

crates/c-api/include/wasmtime/config.h

@@ -176,6 +176,14 @@ WASMTIME_CONFIG_PROP(void, wasm_bulk_memory, bool)
  */
 WASMTIME_CONFIG_PROP(void, wasm_multi_value, bool)
 
+/**
+ * \brief Configures whether the WebAssembly multi-memory proposal is
+ * enabled.
+ *
+ * This setting is `false` by default.
+ */
+WASMTIME_CONFIG_PROP(void, wasm_multi_memory, bool)
+
 /**
  * \brief Configures whether the WebAssembly module linking proposal is
  * enabled.

crates/c-api/src/config.rs

@@ -90,6 +90,11 @@ pub extern "C" fn wasmtime_config_wasm_multi_value_set(c: &mut wasm_config_t, en
     c.config.wasm_multi_value(enable);
 }
 
+#[no_mangle]
+pub extern "C" fn wasmtime_config_wasm_multi_memory_set(c: &mut wasm_config_t, enable: bool) {
+    c.config.wasm_multi_memory(enable);
+}
+
 #[no_mangle]
 pub extern "C" fn wasmtime_config_wasm_module_linking_set(c: &mut wasm_config_t, enable: bool) {
     c.config.wasm_module_linking(enable);

examples/multimemory.c

@@ -0,0 +1,327 @@
+/*
+An example of how to interact with multiple memories.
+
+You can compile and run this example on Linux with:
+
+   cargo build --release -p wasmtime-c-api
+   cc examples/multimemory.c \
+       -I crates/c-api/include \
+       -I crates/c-api/wasm-c-api/include \
+       target/release/libwasmtime.a \
+       -lpthread -ldl -lm \
+       -o multimemory
+   ./multimemory
+
+Note that on Windows and macOS the command will be similar, but you'll need
+to tweak the `-lpthread` and such annotations.
+*/
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wasm.h>
+#include <wasmtime.h>
+
+static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap);
+
+void check(bool success) {
+  if (!success) {
+    printf("> Error, expected success\n");
+    exit(1);
+  }
+}
+
+void check_call(wasmtime_context_t *store,
+                wasmtime_func_t *func,
+                const wasmtime_val_t* args,
+                size_t nargs,
+                int32_t expected) {
+  wasmtime_val_t results[1];
+  wasm_trap_t *trap = NULL;
+  wasmtime_error_t *error = wasmtime_func_call(
+      store, func, args, nargs, results, 1, &trap
+  );
+  if (error != NULL || trap != NULL)
+    exit_with_error("failed to call function", error, trap);
+  if (results[0].of.i32 != expected) {
+    printf("> Error on result\n");
+    exit(1);
+  }
+}
+
+void check_call0(wasmtime_context_t *store, wasmtime_func_t *func, int32_t expected) {
+  check_call(store, func, NULL, 0, expected);
+}
+
+void check_call1(wasmtime_context_t *store, wasmtime_func_t *func, int32_t arg, int32_t expected) {
+  wasmtime_val_t args[1];
+  args[0].kind = WASMTIME_I32;
+  args[0].of.i32 = arg;
+  check_call(store, func, args, 1, expected);
+}
+
+void check_call2(wasmtime_context_t *store, wasmtime_func_t *func, int32_t arg1, int32_t arg2, int32_t expected) {
+  wasmtime_val_t args[2];
+  args[0].kind = WASMTIME_I32;
+  args[0].of.i32 = arg1;
+  args[1].kind = WASMTIME_I32;
+  args[1].of.i32 = arg2;
+  check_call(store, func, args, 2, expected);
+}
+
+void check_ok(wasmtime_context_t *store, wasmtime_func_t *func, const wasmtime_val_t* args, size_t nargs) {
+  wasm_trap_t *trap = NULL;
+  wasmtime_error_t *error = wasmtime_func_call(store, func, args, nargs, NULL, 0, &trap);
+  if (error != NULL || trap != NULL)
+    exit_with_error("failed to call function", error, trap);
+}
+
+void check_ok2(wasmtime_context_t *store, wasmtime_func_t *func, int32_t arg1, int32_t arg2) {
+  wasmtime_val_t args[2];
+  args[0].kind = WASMTIME_I32;
+  args[0].of.i32 = arg1;
+  args[1].kind = WASMTIME_I32;
+  args[1].of.i32 = arg2;
+  check_ok(store, func, args, 2);
+}
+
+void check_trap(wasmtime_context_t *store,
+                wasmtime_func_t *func,
+                const wasmtime_val_t *args,
+                size_t nargs,
+                size_t num_results) {
+  assert(num_results <= 1);
+  wasmtime_val_t results[1];
+  wasm_trap_t *trap = NULL;
+  wasmtime_error_t *error = wasmtime_func_call(store, func, args, nargs, results, num_results, &trap);
+  if (error != NULL)
+    exit_with_error("failed to call function", error, NULL);
+  if (trap == NULL) {
+    printf("> Error on result, expected trap\n");
+    exit(1);
+  }
+  wasm_trap_delete(trap);
+}
+
+void check_trap1(wasmtime_context_t *store, wasmtime_func_t *func, int32_t arg) {
+  wasmtime_val_t args[1];
+  args[0].kind = WASMTIME_I32;
+  args[0].of.i32 = arg;
+  check_trap(store, func, args, 1, 1);
+}
+
+void check_trap2(wasmtime_context_t *store, wasmtime_func_t *func, int32_t arg1, int32_t arg2) {
+  wasmtime_val_t args[2];
+  args[0].kind = WASMTIME_I32;
+  args[0].of.i32 = arg1;
+  args[1].kind = WASMTIME_I32;
+  args[1].of.i32 = arg2;
+  check_trap(store, func, args, 2, 0);
+}
+
+int main(int argc, const char* argv[]) {
+  // Initialize.
+  printf("Initializing...\n");
+
+  wasm_config_t *config = wasm_config_new();
+  assert(config != NULL);
+  wasmtime_config_wasm_multi_memory_set(config, true);
+
+  wasm_engine_t *engine = wasm_engine_new_with_config(config);
+  assert(engine != NULL);
+
+  wasmtime_store_t* store = wasmtime_store_new(engine, NULL, NULL);
+  wasmtime_context_t *context = wasmtime_store_context(store);
+
+  // Load our input file to parse it next
+  FILE* file = fopen("examples/multimemory.wat", "r");
+  if (!file) {
+    printf("> Error loading file!\n");
+    return 1;
+  }
+  fseek(file, 0L, SEEK_END);
+  size_t file_size = ftell(file);
+  fseek(file, 0L, SEEK_SET);
+  wasm_byte_vec_t wat;
+  wasm_byte_vec_new_uninitialized(&wat, file_size);
+  if (fread(wat.data, file_size, 1, file) != 1) {
+    printf("> Error loading module!\n");
+    return 1;
+  }
+  fclose(file);
+
+  // Parse the wat into the binary wasm format
+  wasm_byte_vec_t binary;
+  wasmtime_error_t *error = wasmtime_wat2wasm(wat.data, wat.size, &binary);
+  if (error != NULL)
+    exit_with_error("failed to parse wat", error, NULL);
+  wasm_byte_vec_delete(&wat);
+
+  // Compile.
+  printf("Compiling module...\n");
+  wasmtime_module_t* module = NULL;
+  error = wasmtime_module_new(engine, (uint8_t*) binary.data, binary.size, &module);
+  if (error)
+    exit_with_error("failed to compile module", error, NULL);
+  wasm_byte_vec_delete(&binary);
+
+  // Instantiate.
+  printf("Instantiating module...\n");
+  wasmtime_instance_t instance;
+  wasm_trap_t *trap = NULL;
+  error = wasmtime_instance_new(context, module, NULL, 0, &instance, &trap);
+  if (error != NULL || trap != NULL)
+    exit_with_error("failed to instantiate", error, trap);
+  wasmtime_module_delete(module);
+
+  // Extract export.
+  printf("Extracting exports...\n");
+  wasmtime_memory_t memory0, memory1;
+  wasmtime_func_t size0, load0, store0, size1, load1, store1;
+  wasmtime_extern_t item;
+  bool ok;
+  ok = wasmtime_instance_export_get(context, &instance, "memory0", strlen("memory0"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_MEMORY);
+  memory0 = item.of.memory;
+  ok = wasmtime_instance_export_get(context, &instance, "size0", strlen("size0"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  size0 = item.of.func;
+  ok = wasmtime_instance_export_get(context, &instance, "load0", strlen("load0"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  load0 = item.of.func;
+  ok = wasmtime_instance_export_get(context, &instance, "store0", strlen("store0"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  store0 = item.of.func;
+  ok = wasmtime_instance_export_get(context, &instance, "memory1", strlen("memory1"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_MEMORY);
+  memory1 = item.of.memory;
+  ok = wasmtime_instance_export_get(context, &instance, "size1", strlen("size1"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  size1 = item.of.func;
+  ok = wasmtime_instance_export_get(context, &instance, "load1", strlen("load1"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  load1 = item.of.func;
+  ok = wasmtime_instance_export_get(context, &instance, "store1", strlen("store1"), &item);
+  assert(ok && item.kind == WASMTIME_EXTERN_FUNC);
+  store1 = item.of.func;
+
+  // Check initial memory.
+  printf("Checking memory...\n");
+  check(wasmtime_memory_size(context, &memory0) == 2);
+  check(wasmtime_memory_data_size(context, &memory0) == 0x20000);
+  check(wasmtime_memory_data(context, &memory0)[0] == 0);
+  check(wasmtime_memory_data(context, &memory0)[0x1000] == 1);
+  check(wasmtime_memory_data(context, &memory0)[0x1001] == 2);
+  check(wasmtime_memory_data(context, &memory0)[0x1002] == 3);
+  check(wasmtime_memory_data(context, &memory0)[0x1003] == 4);
+
+  check_call0(context, &size0, 2);
+  check_call1(context, &load0, 0, 0);
+  check_call1(context, &load0, 0x1000, 1);
+  check_call1(context, &load0, 0x1001, 2);
+  check_call1(context, &load0, 0x1002, 3);
+  check_call1(context, &load0, 0x1003, 4);
+  check_call1(context, &load0, 0x1ffff, 0);
+  check_trap1(context, &load0, 0x20000);
+
+  check(wasmtime_memory_size(context, &memory1) == 2);
+  check(wasmtime_memory_data_size(context, &memory1) == 0x20000);
+  check(wasmtime_memory_data(context, &memory1)[0] == 0);
+  check(wasmtime_memory_data(context, &memory1)[0x1000] == 4);
+  check(wasmtime_memory_data(context, &memory1)[0x1001] == 3);
+  check(wasmtime_memory_data(context, &memory1)[0x1002] == 2);
+  check(wasmtime_memory_data(context, &memory1)[0x1003] == 1);
+
+  check_call0(context, &size1, 2);
+  check_call1(context, &load1, 0, 0);
+  check_call1(context, &load1, 0x1000, 4);
+  check_call1(context, &load1, 0x1001, 3);
+  check_call1(context, &load1, 0x1002, 2);
+  check_call1(context, &load1, 0x1003, 1);
+  check_call1(context, &load1, 0x1ffff, 0);
+  check_trap1(context, &load1, 0x20000);
+
+  // Mutate memory.
+  printf("Mutating memory...\n");
+  wasmtime_memory_data(context, &memory0)[0x1003] = 5;
+  check_ok2(context, &store0, 0x1002, 6);
+  check_trap2(context, &store0, 0x20000, 0);
+
+  check(wasmtime_memory_data(context, &memory0)[0x1002] == 6);
+  check(wasmtime_memory_data(context, &memory0)[0x1003] == 5);
+  check_call1(context, &load0, 0x1002, 6);
+  check_call1(context, &load0, 0x1003, 5);
+
+  wasmtime_memory_data(context, &memory1)[0x1003] = 7;
+  check_ok2(context, &store1, 0x1002, 8);
+  check_trap2(context, &store1, 0x20000, 0);
+
+  check(wasmtime_memory_data(context, &memory1)[0x1002] == 8);
+  check(wasmtime_memory_data(context, &memory1)[0x1003] == 7);
+  check_call1(context, &load1, 0x1002, 8);
+  check_call1(context, &load1, 0x1003, 7);
+
+  // Grow memory.
+  printf("Growing memory...\n");
+  uint32_t old_size;
+  error = wasmtime_memory_grow(context, &memory0, 1, &old_size);
+  if (error != NULL)
+    exit_with_error("failed to grow memory", error, trap);
+  check(wasmtime_memory_size(context, &memory0) == 3);
+  check(wasmtime_memory_data_size(context, &memory0) == 0x30000);
+
+  check_call1(context, &load0, 0x20000, 0);
+  check_ok2(context, &store0, 0x20000, 0);
+  check_trap1(context, &load0, 0x30000);
+  check_trap2(context, &store0, 0x30000, 0);
+
+  error = wasmtime_memory_grow(context, &memory0, 1, &old_size);
+  assert(error != NULL);
+  wasmtime_error_delete(error);
+  error = wasmtime_memory_grow(context, &memory0, 0, &old_size);
+  if (error != NULL)
+    exit_with_error("failed to grow memory", error, trap);
+
+  error = wasmtime_memory_grow(context, &memory1, 2, &old_size);
+  if (error != NULL)
+    exit_with_error("failed to grow memory", error, trap);
+  check(wasmtime_memory_size(context, &memory1) == 4);
+  check(wasmtime_memory_data_size(context, &memory1) == 0x40000);
+
+  check_call1(context, &load1, 0x30000, 0);
+  check_ok2(context, &store1, 0x30000, 0);
+  check_trap1(context, &load1, 0x40000);
+  check_trap2(context, &store1, 0x40000, 0);
+
+  error = wasmtime_memory_grow(context, &memory1, 1, &old_size);
+  assert(error != NULL);
+  wasmtime_error_delete(error);
+  error = wasmtime_memory_grow(context, &memory1, 0, &old_size);
+  if (error != NULL)
+    exit_with_error("failed to grow memory", error, trap);
+
+  // Shut down.
+  printf("Shutting down...\n");
+  wasmtime_store_delete(store);
+  wasm_engine_delete(engine);
+
+  // All done.
+  printf("Done.\n");
+  return 0;
+}
+
+static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap) {
+  fprintf(stderr, "error: %s\n", message);
+  wasm_byte_vec_t error_message;
+  if (error != NULL) {
+    wasmtime_error_message(error, &error_message);
+    wasmtime_error_delete(error);
+  } else {
+    wasm_trap_message(trap, &error_message);
+    wasm_trap_delete(trap);
+  }
+  fprintf(stderr, "%.*s\n", (int) error_message.size, error_message.data);
+  wasm_byte_vec_delete(&error_message);
+  exit(1);
+}