Merge pull request #138 from ethereum/bool

Use bool type instead of int with 1 and 0

bindings/go/evmc/host.c

@@ -53,12 +53,12 @@ static inline void go_exported_functions_type_checks()
     (void)result;
     enum evmc_storage_status storage_status;
     (void)storage_status;
-    int status;
-    (void)status;
+    bool bool_flag;
+    (void)bool_flag;
 
     evmc_account_exists_fn account_exists_fn = NULL;
-    status = account_exists_fn(context, address);
-    status = accountExists(context, address);
+    bool_flag = account_exists_fn(context, address);
+    bool_flag = accountExists(context, address);
 
     evmc_get_storage_fn get_storage_fn = NULL;
     get_storage_fn(uint256be, context, address, uint256be);
@@ -97,8 +97,8 @@ static inline void go_exported_functions_type_checks()
     tx_context = getTxContext(context);
 
     evmc_get_block_hash_fn get_block_hash_fn = NULL;
-    status = get_block_hash_fn(uint256be, context, number);
-    status = getBlockHash(uint256be, context, number);
+    bool_flag = get_block_hash_fn(uint256be, context, number);
+    bool_flag = getBlockHash(uint256be, context, number);
 
     evmc_emit_log_fn emit_log_fn = NULL;
     emit_log_fn(context, address, data, size, uint256be, size);

bindings/go/evmc/host.go

@@ -88,15 +88,10 @@ type HostContext interface {
 }
 
 //export accountExists
-func accountExists(pCtx unsafe.Pointer, pAddr *C.struct_evmc_address) C.int {
+func accountExists(pCtx unsafe.Pointer, pAddr *C.struct_evmc_address) C.bool {
 	idx := int((*C.struct_extended_context)(pCtx).index)
 	ctx := getHostContext(idx)
-	exists := ctx.AccountExists(goAddress(*pAddr))
-	r := C.int(0)
-	if exists {
-		r = 1
-	}
-	return r
+	return C.bool(ctx.AccountExists(goAddress(*pAddr)))
 }
 
 //export getStorage
@@ -183,17 +178,17 @@ func getTxContext(pCtx unsafe.Pointer) C.struct_evmc_tx_context {
 }
 
 //export getBlockHash
-func getBlockHash(pResult *C.struct_evmc_uint256be, pCtx unsafe.Pointer, number int64) C.int {
+func getBlockHash(pResult *C.struct_evmc_uint256be, pCtx unsafe.Pointer, number int64) C.bool {
 	idx := int((*C.struct_extended_context)(pCtx).index)
 	ctx := getHostContext(idx)
 
 	blockhash, err := ctx.GetBlockHash(number)
 	if err != nil {
-		return C.int(0)
+		return false
 	}
 
 	*pResult = evmcUint256be(blockhash)
-	return C.int(1)
+	return true
 }
 
 //export emitLog

examples/example_host.cpp

@@ -24,11 +24,11 @@ static evmc_uint256be balance(evmc_context* context, const evmc_address* address
     return ret;
 }
 
-static int account_exists(evmc_context* context, const evmc_address* address)
+static bool account_exists(evmc_context* context, const evmc_address* address)
 {
     (void)context;
     (void)address;
-    return 0;
+    return false;
 }
 
 static void get_storage(evmc_uint256be* result,
@@ -114,17 +114,17 @@ static evmc_tx_context get_tx_context(evmc_context* context)
     return result;
 }
 
-static int get_block_hash(evmc_uint256be* result, evmc_context* context, int64_t number)
+static bool get_block_hash(evmc_uint256be* result, evmc_context* context, int64_t number)
 {
     example_host_context* host = static_cast<example_host_context*>(context);
     int64_t current_block_number = host->tx_context.block_number;
 
     if (number >= current_block_number || number < current_block_number - 256)
-        return 0;
+        return false;
 
     evmc_uint256be example_block_hash{};
     *result = example_block_hash;
-    return 1;
+    return true;
 }
 
 static void emit_log(evmc_context* context,

include/evmc/evmc.h

@@ -11,8 +11,9 @@
 #ifndef EVMC_H
 #define EVMC_H
 
-#include <stddef.h> /* Definition of size_t. */
-#include <stdint.h> /* Definition of int64_t, uint64_t. */
+#include <stdbool.h> /* Definition of bool, true and false. */
+#include <stddef.h>  /* Definition of size_t. */
+#include <stdint.h>  /* Definition of int64_t, uint64_t. */
 
 #if __cplusplus
 extern "C" {
@@ -147,19 +148,19 @@ typedef struct evmc_tx_context (*evmc_get_tx_context_fn)(struct evmc_context* co
 /**
  * Get block hash callback function.
  *
- *  This callback function is used by an VM to query the block hash of
- *  a given block. If the requested block is not found, then an appropriate
- *  result code is returned.
+ * This callback function is used by an VM to query the block hash of
+ * a given block. If the requested block is not found, then an appropriate
+ * result code is returned.
  *
- *  @param[out] result   The returned block hash value. Only written to
- *                       if the return value is 1 (information is avialable).
- *  @param      context  The pointer to the Host execution context.
- *  @param      number   The block number.
- *  @return              1 if the information is available, 0 otherwise.
+ * @param[out] result   The returned block hash value. Only written to
+ *                      if the return value is 1 (information is avialable).
+ * @param      context  The pointer to the Host execution context.
+ * @param      number   The block number.
+ * @return              true if the information is available, false otherwise.
  */
-typedef int (*evmc_get_block_hash_fn)(struct evmc_uint256be* result,
-                                      struct evmc_context* context,
-                                      int64_t number);
+typedef bool (*evmc_get_block_hash_fn)(struct evmc_uint256be* result,
+                                       struct evmc_context* context,
+                                       int64_t number);
 
 /**
  * The execution status code.
@@ -387,17 +388,16 @@ struct evmc_result
 
 
 /**
- * Check account existence callback function
+ * Check account existence callback function.
  *
- *  This callback function is used by the EVM to check if
- *  there exists an account at given address.
- *  @param      context  The pointer to the Host execution context.
- *                       @see ::evmc_context.
- *  @param      address  The address of the account the query is about.
- *  @return              1 if exists, 0 otherwise.
+ * This callback function is used by the VM to check if
+ * there exists an account at given address.
+ * @param context  The pointer to the Host execution context.
+ * @param address  The address of the account the query is about.
+ * @return         true if exists, false otherwise.
  */
-typedef int (*evmc_account_exists_fn)(struct evmc_context* context,
-                                      const struct evmc_address* address);
+typedef bool (*evmc_account_exists_fn)(struct evmc_context* context,
+                                       const struct evmc_address* address);
 
 /**
  * Get storage callback function.