EVM-C: improve capi.c and compile against ExampleVM

examples/CMakeLists.txt

@@ -1,5 +1,6 @@
-add_library(example-capi STATIC EXCLUDE_FROM_ALL capi.c)
-target_include_directories(example-capi PRIVATE ../include)
-
 add_library(example-vm STATIC EXCLUDE_FROM_ALL examplevm.c)
 target_include_directories(example-vm PRIVATE ../include)
+
+add_executable(example-capi EXCLUDE_FROM_ALL capi.c)
+target_include_directories(example-capi PRIVATE ../include)
+target_link_libraries(example-capi PRIVATE example-vm)

examples/capi.c

@@ -1,11 +1,25 @@
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include "evm.h"
 
-struct evm_uint256 balance(struct evm_env*, struct evm_hash160 address);
+struct evm_uint256 balance(struct evm_env* env, struct evm_hash160 address)
+{
+    struct evm_uint256 ret = { .words = { 1 } };
+    return ret;
+}
+
+struct evm_hash160 address(struct evm_env* env)
+{
+    struct evm_hash160 ret = { .bytes = { 1, 2, 3, 4 } };
+    return ret;
+}
 
 union evm_variant query(struct evm_env* env,
                         enum evm_query_key key,
                         union evm_variant arg) {
     union evm_variant result;
+    printf("EVM-C: QUERY %d\n", key);
     switch (key) {
     case EVM_GAS_LIMIT: result.int64 = 314; break;
 
@@ -13,25 +27,70 @@ union evm_variant query(struct evm_env* env,
         result.uint256 = balance(env, arg.address);
         break;
 
+    case EVM_ADDRESS:
+        result.address = address(env);
+        break;
+
     default: result.int64 = 0; break;
     }
     return result;
 }
 
+void update(struct evm_env* env,
+            enum evm_update_key key,
+            union evm_variant arg1,
+            union evm_variant arg2)
+{
+    printf("EVM-C: UPDATE %d\n", key);
+}
+
+int64_t call(
+    struct evm_env* _opaqueEnv,
+    enum evm_call_kind _kind,
+    int64_t _gas,
+    struct evm_hash160 _address,
+    struct evm_uint256 _value,
+    uint8_t const* _inputData,
+    size_t _inputSize,
+    uint8_t* _outputData,
+    size_t _outputSize
+)
+{
+    printf("EVM-C: CALL %d\n", _kind);
+    return EVM_EXCEPTION;
+}
+
 /// Example how the API is supposed to be used.
-void example() {
-    struct evm_instance* jit = evm_create(query, 0, 0);
+int main(int argc, char *argv[]) {
+    printf("Using VM: %s (%s)\n", evm_get_info(EVM_NAME), evm_get_info(EVM_VERSION));
+
+    struct evm_instance* jit = evm_create(query, update, call);
 
     char const code[] = "exec()";
+    const size_t code_size = sizeof(code);
     struct evm_hash256 code_hash = {.words = {1, 2, 3}};
     char const input[] = "Hello World!";
     struct evm_uint256 value = {{1, 0, 0, 0}};
 
     int64_t gas = 200000;
     struct evm_result result =
-        evm_execute(jit, NULL, code_hash, code, sizeof(code), gas, input,
+        evm_execute(jit, NULL, EVM_HOMESTEAD, code_hash, (const uint8_t *)code, code_size, gas, (const uint8_t *)input,
                     sizeof(input), value);
 
+    printf("Execution result:\n");
+    if (result.gas_left & EVM_EXCEPTION) {
+      printf("  EVM eception\n");
+    }
+    printf("  Gas used: %lld\n", gas - result.gas_left);
+    printf("  Gas left: %lld\n", result.gas_left);
+    printf("  Output size: %zd\n", result.output_size);
+
+    printf("  Output: ");
+    for (int i = 0; i < result.output_size; i++) {
+        printf("%02x ", result.output_data[i]);
+    }
+    printf("\n");
+
     evm_destroy_result(result);
     evm_destroy(jit);
 }