Return bool from evmc_get_code_size_fn()

bindings/go/evmc/host.c

@@ -73,8 +73,8 @@ static inline void go_exported_functions_type_checks()
     bool_flag = getBalance(uint256be, context, address);
 
     evmc_get_code_size_fn get_code_size_fn = NULL;
-    size = get_code_size_fn(context, address);
-    size = getCodeSize(context, address);
+    bool_flag = get_code_size_fn(&size, context, address);
+    bool_flag = getCodeSize(&size, context, address);
 
     evmc_get_code_hash_fn get_code_hash_fn = NULL;
     bool_flag = get_code_hash_fn(uint256be, context, address);

bindings/go/evmc/host.go

@@ -74,7 +74,7 @@ type HostContext interface {
 	GetStorage(addr common.Address, key common.Hash) common.Hash
 	SetStorage(addr common.Address, key common.Hash, value common.Hash) StorageStatus
 	GetBalance(addr common.Address) (common.Hash, error)
-	GetCodeSize(addr common.Address) int
+	GetCodeSize(addr common.Address) (int, error)
 	GetCodeHash(addr common.Address) (common.Hash, error)
 	GetCode(addr common.Address) []byte
 	Selfdestruct(addr common.Address, beneficiary common.Address)
@@ -122,10 +122,15 @@ func getBalance(pResult *C.struct_evmc_uint256be, pCtx unsafe.Pointer, pAddr *C.
 }
 
 //export getCodeSize
-func getCodeSize(pCtx unsafe.Pointer, pAddr *C.struct_evmc_address) C.size_t {
+func getCodeSize(pResult *C.size_t, pCtx unsafe.Pointer, pAddr *C.struct_evmc_address) C.bool {
 	idx := int((*C.struct_extended_context)(pCtx).index)
 	ctx := getHostContext(idx)
-	return C.size_t(ctx.GetCodeSize(goAddress(*pAddr)))
+	codeSize, err := ctx.GetCodeSize(goAddress(*pAddr))
+	if err != nil {
+		return false
+	}
+	*pResult = C.size_t(codeSize)
+	return true
 }
 
 //export getCodeHash

examples/example_host.cpp

@@ -60,11 +60,12 @@ static bool get_balance(evmc_uint256be* result, evmc_context* context, const evm
     return true;
 }
 
-static size_t get_code_size(evmc_context* context, const evmc_address* address)
+static bool get_code_size(size_t* result, evmc_context* context, const evmc_address* address)
 {
+    (void)result;
     (void)context;
     (void)address;
-    return 0;
+    return false;
 }
 
 static bool get_code_hash(evmc_uint256be* result,

include/evmc/evmc.h

@@ -494,11 +494,21 @@ typedef bool (*evmc_get_balance_fn)(struct evmc_uint256be* result,
 /**
  * Get code size callback function.
  *
- *  This callback function is used by an EVM to get the size of the code stored
- *  in the account at the given address. For accounts not having a code, this
- *  function returns 0.
+ * This callback function is used by a VM to get the size of the code stored
+ * in the account at the given address.
+ *
+ * @param[out] result   The pointer to the place where to put the result code size.
+ *                      The pointed memory is only modified when the function returns true.
+ *                      The pointer MUST NOT be null.
+ * @param      context  The pointer to the Host execution context.
+ * @param      address  The address of the account.
+ * @return              If the account exists the size of its code is put at the location
+ *                      pointed by @p result and true is returned.
+ *                      If the account does not exist false is returned without
+ *                      modifying the memory pointed by @p result.
  */
-typedef size_t (*evmc_get_code_size_fn)(struct evmc_context* context,
+typedef bool (*evmc_get_code_size_fn)(size_t* result,
+                                      struct evmc_context* context,
                                       const struct evmc_address* address);
 
 /**