Add explicit error type for operations on Memory

lib/c-api/src/import/wasi.rs

@@ -213,7 +213,7 @@ pub unsafe extern "C" fn wasmer_wasi_generate_default_import_object() -> *mut wa
     let mut wasi_env = wasi::WasiEnv::new(wasi_state);
     // this API will now leak a `Memory`
     let memory_type = MemoryType::new(0, None, false);
-    let memory = Memory::new(store, memory_type);
+    let memory = Memory::new(store, memory_type).expect("create memory");
     wasi_env.set_memory(&memory);
     // TODO(mark): review lifetime of `Memory` here
     let import_object = Box::new(wasi::generate_import_object_from_env(

lib/c-api/src/memory.rs

@@ -69,9 +69,18 @@ pub unsafe extern "C" fn wasmer_memory_new(
     };
     let store = crate::get_global_store();
     let desc = MemoryType::new(Pages(limits.min), max, false);
-    let new_memory = Memory::new(store, desc);
-    *memory = Box::into_raw(Box::new(new_memory)) as *mut wasmer_memory_t;
-    wasmer_result_t::WASMER_OK
+    match Memory::new(store, desc) {
+        Ok(new_memory) => {
+            *memory = Box::into_raw(Box::new(new_memory)) as *mut wasmer_memory_t;
+            wasmer_result_t::WASMER_OK
+        }
+        Err(err) => {
+            update_last_error(CApiError {
+                msg: err.to_string(),
+            });
+            wasmer_result_t::WASMER_ERROR
+        }
+    }
 }
 
 /// Grows a memory by the given number of pages (of 65Kb each).
@@ -105,8 +114,13 @@ pub extern "C" fn wasmer_memory_grow(memory: *mut wasmer_memory_t, delta: u32) -
     let grow_result = memory.grow(Pages(delta));
 
     match grow_result {
-        Some(_) => wasmer_result_t::WASMER_OK,
-        _ => wasmer_result_t::WASMER_ERROR,
+        Ok(_) => wasmer_result_t::WASMER_OK,
+        Err(err) => {
+            update_last_error(CApiError {
+                msg: err.to_string(),
+            });
+            wasmer_result_t::WASMER_ERROR
+        }
     }
 }
 

lib/c-api/tests/test-memory.c

@@ -40,7 +40,7 @@ int main()
     char *error_str = malloc(error_len);
     wasmer_last_error_message(error_str, error_len);
     printf("Error str: `%s`\n", error_str);
-    assert(0 == strcmp(error_str, "Failed to add pages because would exceed maximum number of pages for the memory. Left: 22, Added: 15"));
+    assert(0 == strcmp(error_str, "Memory could not grow 10 more pages (12 pages currently) without exceeding the maximum of 15 pages"));
     free(error_str);
 
     wasmer_memory_t *bad_memory = NULL;
@@ -58,7 +58,7 @@ int main()
     char *error_str2 = malloc(error_len2);
     wasmer_last_error_message(error_str2, error_len2);
     printf("Error str 2: `%s`\n", error_str2);
-    assert(0 == strcmp(error_str2, "Unable to create because the supplied descriptor is invalid: \"Max number of memory pages is less than the minimum number of pages\""));
+    assert(0 == strcmp(error_str2, "The given memory plan was invalid because the maximum allowed memory (10 pages) is less than the minimum required memory (15 pages)"));
     free(error_str2);
 
     printf("Destroy memory\n");