// EVMC: Ethereum Client-VM Connector API.
// Copyright 2018 The EVMC Authors.
// Licensed under the Apache License, Version 2.0.
/**
* EVMC Helpers
*
* A collection of C helper functions for invoking a VM instance methods.
* These are convenient for languages where invoking function pointers
* is "ugly" or impossible (such as Go).
*
* @defgroup helpers EVMC Helpers
* @{
*/
#pragma once
#include <evmc/evmc.h>
#include <stdlib.h>
#include <string.h>
#ifdef __cplusplus
extern "C" {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
#endif
/**
* Returns true if the VM has a compatible ABI version.
*/
static inline bool evmc_is_abi_compatible(struct evmc_vm* vm)
{
return vm->abi_version == EVMC_ABI_VERSION;
}
/**
* Returns the name of the VM.
*/
static inline const char* evmc_vm_name(struct evmc_vm* vm)
{
return vm->name;
}
/**
* Returns the version of the VM.
*/
static inline const char* evmc_vm_version(struct evmc_vm* vm)
{
return vm->version;
}
/**
* Checks if the VM has the given capability.
*
* @see evmc_get_capabilities_fn
*/
static inline bool evmc_vm_has_capability(struct evmc_vm* vm, enum evmc_capabilities capability)
{
return (vm->get_capabilities(vm) & (evmc_capabilities_flagset)capability) != 0;
}
/**
* Destroys the VM instance.
*
* @see evmc_destroy_fn
*/
static inline void evmc_destroy(struct evmc_vm* vm)
{
vm->destroy(vm);
}
/**
* Sets the option for the VM, if the feature is supported by the VM.
*
* @see evmc_set_option_fn
*/
static inline enum evmc_set_option_result evmc_set_option(struct evmc_vm* vm,
char const* name,
char const* value)
{
if (vm->set_option)
return vm->set_option(vm, name, value);
return EVMC_SET_OPTION_INVALID_NAME;
}
/**
* Executes code in the VM instance.
*
* @see evmc_execute_fn.
*/
static inline struct evmc_result evmc_execute(struct evmc_vm* vm,
const struct evmc_host_interface* host,
struct evmc_host_context* context,
enum evmc_revision rev,
const struct evmc_message* msg,
uint8_t const* code,
size_t code_size)
{
return vm->execute(vm, host, context, rev, msg, code, code_size);
}
/// The evmc_result release function using free() for releasing the memory.
///
/// This function is used in the evmc_make_result(),
/// but may be also used in other case if convenient.
///
/// @param result The result object.
static void evmc_free_result_memory(const struct evmc_result* result)
{
free((uint8_t*)result->output_data);
}
/// Creates the result from the provided arguments.
///
/// The provided output is copied to memory allocated with malloc()
/// and the evmc_result::release function is set to one invoking free().
///
/// In case of memory allocation failure, the result has all fields zeroed
/// and only evmc_result::status_code is set to ::EVMC_OUT_OF_MEMORY internal error.
///
/// @param status_code The status code.
/// @param gas_left The amount of gas left.
/// @param gas_refund The amount of refunded gas.
/// @param output_data The pointer to the output.
/// @param output_size The output size.
static inline struct evmc_result evmc_make_result(enum evmc_status_code status_code,
int64_t gas_left,
int64_t gas_refund,
const uint8_t* output_data,
size_t output_size)
{
struct evmc_result result;
memset(&result, 0, sizeof(result));
if (output_size != 0)
{
uint8_t* buffer = (uint8_t*)malloc(output_size);
if (!buffer)
{
result.status_code = EVMC_OUT_OF_MEMORY;
return result;
}
memcpy(buffer, output_data, output_size);
result.output_data = buffer;
result.output_size = output_size;
result.release = evmc_free_result_memory;
}
result.status_code = status_code;
result.gas_left = gas_left;
result.gas_refund = gas_refund;
return result;
}
/**
* Releases the resources allocated to the execution result.
*
* @param result The result object to be released. MUST NOT be NULL.
*
* @see evmc_result::release() evmc_release_result_fn
*/
static inline void evmc_release_result(struct evmc_result* result)
{
if (result->release)
result->release(result);
}
/**
* Helpers for optional storage of evmc_result.
*
* In some contexts (i.e. evmc_result::create_address is unused) objects of
* type evmc_result contains a memory storage that MAY be used by the object
* owner. This group defines helper types and functions for accessing
* the optional storage.
*
* @defgroup result_optional_storage Result Optional Storage
* @{
*/
/**
* The union representing evmc_result "optional storage".
*
* The evmc_result struct contains 24 bytes of optional storage that can be
* reused by the object creator if the object does not contain
* evmc_result::create_address.
*
* A VM implementation MAY use this memory to keep additional data
* when returning result from evmc_execute_fn().
* The host application MAY use this memory to keep additional data
* when returning result of performed calls from evmc_call_fn().
*
* @see evmc_get_optional_storage(), evmc_get_const_optional_storage().
*/
union evmc_result_optional_storage
{
uint8_t bytes[24]; /**< 24 bytes of optional storage. */
void* pointer; /**< Optional pointer. */
};
/** Provides read-write access to evmc_result "optional storage". */
static inline union evmc_result_optional_storage* evmc_get_optional_storage(
struct evmc_result* result)
{
return (union evmc_result_optional_storage*)&result->create_address;
}
/** Provides read-only access to evmc_result "optional storage". */
static inline const union evmc_result_optional_storage* evmc_get_const_optional_storage(
const struct evmc_result* result)
{
return (const union evmc_result_optional_storage*)&result->create_address;
}
/** @} */
/** Returns text representation of the ::evmc_status_code. */
static inline const char* evmc_status_code_to_string(enum evmc_status_code status_code)
{
switch (status_code)
{
case EVMC_SUCCESS:
return "success";
case EVMC_FAILURE:
return "failure";
case EVMC_REVERT:
return "revert";
case EVMC_OUT_OF_GAS:
return "out of gas";
case EVMC_INVALID_INSTRUCTION:
return "invalid instruction";
case EVMC_UNDEFINED_INSTRUCTION:
return "undefined instruction";
case EVMC_STACK_OVERFLOW:
return "stack overflow";
case EVMC_STACK_UNDERFLOW:
return "stack underflow";
case EVMC_BAD_JUMP_DESTINATION:
return "bad jump destination";
case EVMC_INVALID_MEMORY_ACCESS:
return "invalid memory access";
case EVMC_CALL_DEPTH_EXCEEDED:
return "call depth exceeded";
case EVMC_STATIC_MODE_VIOLATION:
return "static mode violation";
case EVMC_PRECOMPILE_FAILURE:
return "precompile failure";
case EVMC_CONTRACT_VALIDATION_FAILURE:
return "contract validation failure";
case EVMC_ARGUMENT_OUT_OF_RANGE:
return "argument out of range";
case EVMC_WASM_UNREACHABLE_INSTRUCTION:
return "wasm unreachable instruction";
case EVMC_WASM_TRAP:
return "wasm trap";
case EVMC_INSUFFICIENT_BALANCE:
return "insufficient balance";
case EVMC_INTERNAL_ERROR:
return "internal error";
case EVMC_REJECTED:
return "rejected";
case EVMC_OUT_OF_MEMORY:
return "out of memory";
}
return "<unknown>";
}
/** Returns the name of the ::evmc_revision. */
static inline const char* evmc_revision_to_string(enum evmc_revision rev)
{
switch (rev)
{
case EVMC_FRONTIER:
return "Frontier";
case EVMC_HOMESTEAD:
return "Homestead";
case EVMC_TANGERINE_WHISTLE:
return "Tangerine Whistle";
case EVMC_SPURIOUS_DRAGON:
return "Spurious Dragon";
case EVMC_BYZANTIUM:
return "Byzantium";
case EVMC_CONSTANTINOPLE:
return "Constantinople";
case EVMC_PETERSBURG:
return "Petersburg";
case EVMC_ISTANBUL:
return "Istanbul";
case EVMC_BERLIN:
return "Berlin";
case EVMC_LONDON:
return "London";
case EVMC_PARIS:
return "Paris";
case EVMC_SHANGHAI:
return "Shanghai";
case EVMC_CANCUN:
return "Cancun";
}
return "<unknown>";
}
/** @} */
#ifdef __cplusplus
#pragma GCC diagnostic pop
} // extern "C"
#endif