EVM-C: Fix constness, extend examples

Author: chfast

examples/capi.c

@@ -17,6 +17,13 @@ struct evm_uint160be address(struct evm_env* env)
     return ret;
 }
 
+static void print_address(const struct evm_uint160be* address)
+{
+    int i = 0;
+    for (i = 0; i < sizeof(address->bytes); ++i)
+        printf("%x", address->bytes[i] & 0xff);
+}
+
 static void query(union evm_variant* result,
                   struct evm_env* env,
                   enum evm_query_key key,
@@ -43,11 +50,24 @@ static void query(union evm_variant* result,
 }
 
 static void set_storage(struct evm_env* env,
-                        const struct evm_uint160be* addr,
+                        const struct evm_uint160be* address,
                         const struct evm_uint256be* key,
                         const struct evm_uint256be* value)
 {
-    printf("EVM-C: SSTORE");
+    printf("EVM-C: SSTORE @");
+    print_address(address);
+    printf("\n");
+}
+
+static void selfdestruct(struct evm_env* env,
+                         const struct evm_uint160be* address,
+                         const struct evm_uint160be* beneficiary)
+{
+    printf("EVM-C: SELFDESTRUCT ");
+    print_address(address);
+    printf(" -> ");
+    print_address(beneficiary);
+    printf("\n");
 }
 
 static void call(struct evm_result* result,
@@ -69,15 +89,26 @@ static void get_block_hash(struct evm_uint256be* result, struct evm_env* env,
 
 }
 
+/// EVM log callback.
+///
+/// @note The `evm_log` name is used to avoid conflict with `log()` C function.
+static void evm_log(struct evm_env* env, const struct evm_uint160be* address,
+                    const uint8_t* data, size_t data_size,
+                    const struct evm_uint256be topics[], size_t topics_count)
+{
+    printf("EVM-C: LOG%d\n", (int)topics_count);
+}
+
 /// Example how the API is supposed to be used.
 int main(int argc, char *argv[]) {
     struct evm_factory factory = examplevm_get_factory();
     if (factory.abi_version != EVM_ABI_VERSION)
         return 1;  // Incompatible ABI version.
 
-    struct evm_instance* jit = factory.create(query, set_storage, NULL, call,
+    struct evm_instance* jit = factory.create(query, set_storage, selfdestruct,
+                                              call,
                                               get_tx_context, get_block_hash,
-                                              NULL);
+                                              evm_log);
 
     uint8_t const code[] = "Place some EVM bytecode here";
     const size_t code_size = sizeof(code);

examples/examplevm.c

@@ -9,9 +9,11 @@ struct examplevm
     struct evm_instance instance;
     evm_query_state_fn query_fn;
     evm_set_storage_fn set_storage_fn;
+    evm_selfdestruct_fn selfdestruct_fn;
     evm_call_fn call_fn;
     evm_get_tx_context_fn get_tx_context_fn;
     evm_get_block_hash_fn get_block_hash_fn;
+    evm_log_fn log_fn;
 
     int example_option;
 };
@@ -115,7 +117,7 @@ static struct evm_result execute(struct evm_instance* instance,
 }
 
 static struct evm_instance* evm_create(evm_query_state_fn query_fn,
-                                       evm_set_storage_fn update_fn,
+                                       evm_set_storage_fn set_storage_fn,
                                        evm_selfdestruct_fn selfdestruct_fn,
                                        evm_call_fn call_fn,
                                        evm_get_tx_context_fn get_tx_context_fn,
@@ -128,10 +130,12 @@ static struct evm_instance* evm_create(evm_query_state_fn query_fn,
     interface->execute = execute;
     interface->set_option = evm_set_option;
     vm->query_fn = query_fn;
-    vm->set_storage_fn = update_fn;
+    vm->set_storage_fn = set_storage_fn;
+    vm->selfdestruct_fn = selfdestruct_fn;
     vm->call_fn = call_fn;
     vm->get_tx_context_fn = get_tx_context_fn;
     vm->get_block_hash_fn = get_block_hash_fn;
+    vm->log_fn = log_fn;
     return interface;
 }
 

include/evm.h

@@ -282,7 +282,7 @@ typedef void (*evm_set_storage_fn)(struct evm_env* env,
 ///                     the host application.
 /// @param address      The address of the contract to be selfdestructed.
 /// @param beneficiary  The address where the remaining ETH is going to be
-///                     transfer.
+///                     transferred.
 typedef void (*evm_selfdestruct_fn)(struct evm_env* env,
                                     const struct evm_uint160be* address,
                                     const struct evm_uint160be* beneficiary);
@@ -291,19 +291,20 @@ typedef void (*evm_selfdestruct_fn)(struct evm_env* env,
 ///
 /// This callback function is used by an EVM to inform about a LOG that happened
 /// during an EVM bytecode execution.
-/// @param env         The pointer to execution environment managed by the host
-///                    application.
-/// @param address     The address of the contract that generated the log.
-/// @param data        The pointer to unindexed data attached to the log.
-/// @param data_size   The length of the data.
-/// @param topics      The pointer to the array of topics attached to the log.
-/// @param topics_num  The number of the topics. Valid values 0 - 4.
+/// @param env           The pointer to execution environment managed by
+///                      the host application.
+/// @param address       The address of the contract that generated the log.
+/// @param data          The pointer to unindexed data attached to the log.
+/// @param data_size     The length of the data.
+/// @param topics        The pointer to the array of topics attached to the log.
+/// @param topics_count  The number of the topics. Valid values are between
+///                      0 and 4 inclusively.
 typedef void (*evm_log_fn)(struct evm_env* env,
                            const struct evm_uint160be* address,
                            const uint8_t* data,
                            size_t data_size,
-                           struct evm_uint256be topics[],
-                           size_t topics_num);
+                           const struct evm_uint256be topics[],
+                           size_t topics_count);
 
 /// Pointer to the callback function supporting EVM calls.
 ///
@@ -331,7 +332,7 @@ struct evm_instance;  ///< Forward declaration.
 /// @param get_block_hash_fn  Pointer to get block hash function. Nonnull.
 /// @return           Pointer to the created EVM instance.
 typedef struct evm_instance* (*evm_create_fn)(evm_query_state_fn query_fn,
-                                              evm_set_storage_fn update_fn,
+                                              evm_set_storage_fn set_storage_fn,
                                               evm_selfdestruct_fn selfdestruct_fn,
                                               evm_call_fn call_fn,
                                               evm_get_tx_context_fn get_tx_context_fn,