/**
* EVMC: Ethereum Client-VM Connector API
*
* @copyright
* Copyright 2016-2019 The EVMC Authors.
* Licensed under the Apache License, Version 2.0.
*
* @defgroup EVMC EVMC
* @{
*/
#ifndef EVMC_H
#define EVMC_H
#if defined(__clang__) || (defined(__GNUC__) && __GNUC__ >= 6)
/**
* Portable declaration of "deprecated" attribute.
*
* Available for clang and GCC 6+ compilers. The older GCC compilers know
* this attribute, but it cannot be applied to enum elements.
*/
#define EVMC_DEPRECATED __attribute__((deprecated))
#else
#define EVMC_DEPRECATED
#endif
#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. */
#ifdef __cplusplus
extern "C" {
#endif
/* BEGIN Python CFFI declarations */
enum
{
/**
* The EVMC ABI version number of the interface declared in this file.
*
* The EVMC ABI version always equals the major version number of the EVMC project.
* The Host SHOULD check if the ABI versions match when dynamically loading VMs.
*
* @see @ref versioning
*/
EVMC_ABI_VERSION = 7
};
/**
* The fixed size array of 32 bytes.
*
* 32 bytes of data capable of storing e.g. 256-bit hashes.
*/
typedef struct evmc_bytes32
{
/** The 32 bytes. */
uint8_t bytes[32];
} evmc_bytes32;
/**
* The alias for evmc_bytes32 to represent a big-endian 256-bit integer.
*/
typedef struct evmc_bytes32 evmc_uint256be;
/** Big-endian 160-bit hash suitable for keeping an Ethereum address. */
typedef struct evmc_address
{
/** The 20 bytes of the hash. */
uint8_t bytes[20];
} evmc_address;
/** The kind of call-like instruction. */
enum evmc_call_kind
{
EVMC_CALL = 0, /**< Request CALL. */
EVMC_DELEGATECALL = 1, /**< Request DELEGATECALL. Valid since Homestead.
The value param ignored. */
EVMC_CALLCODE = 2, /**< Request CALLCODE. */
EVMC_CREATE = 3, /**< Request CREATE. */
EVMC_CREATE2 = 4 /**< Request CREATE2. Valid since Constantinople.*/
};
/** The flags for ::evmc_message. */
enum evmc_flags
{
EVMC_STATIC = 1 /**< Static call mode. */
};
/**
* The message describing an EVM call,
* including a zero-depth calls from a transaction origin.
*/
struct evmc_message
{
/** The kind of the call. For zero-depth calls ::EVMC_CALL SHOULD be used. */
enum evmc_call_kind kind;
/**
* Additional flags modifying the call execution behavior.
* In the current version the only valid values are ::EVMC_STATIC or 0.
*/
uint32_t flags;
/** The call depth. */
int32_t depth;
/** The amount of gas for message execution. */
int64_t gas;
/** The destination of the message. */
evmc_address destination;
/** The sender of the message. */
evmc_address sender;
/**
* The message input data.
*
* This MAY be NULL.
*/
const uint8_t* input_data;
/**
* The size of the message input data.
*
* If input_data is NULL this MUST be 0.
*/
size_t input_size;
/**
* The amount of Ether transferred with the message.
*/
evmc_uint256be value;
/**
* The optional value used in new contract address construction.
*
* Ignored unless kind is EVMC_CREATE2.
*/
evmc_bytes32 create2_salt;
};
/** The transaction and block data for execution. */
struct evmc_tx_context
{
evmc_uint256be tx_gas_price; /**< The transaction gas price. */
evmc_address tx_origin; /**< The transaction origin account. */
evmc_address block_coinbase; /**< The miner of the block. */
int64_t block_number; /**< The block number. */
int64_t block_timestamp; /**< The block timestamp. */
int64_t block_gas_limit; /**< The block gas limit. */
evmc_uint256be block_difficulty; /**< The block difficulty. */
evmc_uint256be chain_id; /**< The blockchain's ChainID. */
};
/**
* @struct evmc_host_context
* The opaque data type representing the Host execution context.
* @see evmc_execute_fn().
*/
struct evmc_host_context;
/**
* Get transaction context callback function.
*
* This callback function is used by an EVM to retrieve the transaction and
* block context.
*
* @param context The pointer to the Host execution context.
* @return The transaction context.
*/
typedef struct evmc_tx_context (*evmc_get_tx_context_fn)(struct evmc_host_context* context);
/**
* Get block hash callback function.
*
* This callback function is used by a VM to query the hash of the header of the given block.
* If the information about the requested block is not available, then this is signalled by
* returning null bytes.
*
* @param context The pointer to the Host execution context.
* @param number The block number.
* @return The block hash or null bytes
* if the information about the block is not available.
*/
typedef evmc_bytes32 (*evmc_get_block_hash_fn)(struct evmc_host_context* context, int64_t number);
/**
* The execution status code.
*
* Successful execution is represented by ::EVMC_SUCCESS having value 0.
*
* Positive values represent failures defined by VM specifications with generic
* ::EVMC_FAILURE code of value 1.
*
* Status codes with negative values represent VM internal errors
* not provided by EVM specifications. These errors MUST not be passed back
* to the caller. They MAY be handled by the Client in predefined manner
* (see e.g. ::EVMC_REJECTED), otherwise internal errors are not recoverable.
* The generic representant of errors is ::EVMC_INTERNAL_ERROR but
* an EVM implementation MAY return negative status codes that are not defined
* in the EVMC documentation.
*
* @note
* In case new status codes are needed, please create an issue or pull request
* in the EVMC repository (https://github.com/ethereum/evmc).
*/
enum evmc_status_code
{
/** Execution finished with success. */
EVMC_SUCCESS = 0,
/** Generic execution failure. */
EVMC_FAILURE = 1,
/**
* Execution terminated with REVERT opcode.
*
* In this case the amount of gas left MAY be non-zero and additional output
* data MAY be provided in ::evmc_result.
*/
EVMC_REVERT = 2,
/** The execution has run out of gas. */
EVMC_OUT_OF_GAS = 3,
/**
* The designated INVALID instruction has been hit during execution.
*
* The EIP-141 (https://github.com/ethereum/EIPs/blob/master/EIPS/eip-141.md)
* defines the instruction 0xfe as INVALID instruction to indicate execution
* abortion coming from high-level languages. This status code is reported
* in case this INVALID instruction has been encountered.
*/
EVMC_INVALID_INSTRUCTION = 4,
/** An undefined instruction has been encountered. */
EVMC_UNDEFINED_INSTRUCTION = 5,
/**
* The execution has attempted to put more items on the EVM stack
* than the specified limit.
*/
EVMC_STACK_OVERFLOW = 6,
/** Execution of an opcode has required more items on the EVM stack. */
EVMC_STACK_UNDERFLOW = 7,
/** Execution has violated the jump destination restrictions. */
EVMC_BAD_JUMP_DESTINATION = 8,
/**
* Tried to read outside memory bounds.
*
* An example is RETURNDATACOPY reading past the available buffer.
*/
EVMC_INVALID_MEMORY_ACCESS = 9,
/** Call depth has exceeded the limit (if any) */
EVMC_CALL_DEPTH_EXCEEDED = 10,
/** Tried to execute an operation which is restricted in static mode. */
EVMC_STATIC_MODE_VIOLATION = 11,
/**
* A call to a precompiled or system contract has ended with a failure.
*
* An example: elliptic curve functions handed invalid EC points.
*/
EVMC_PRECOMPILE_FAILURE = 12,
/**
* Contract validation has failed (e.g. due to EVM 1.5 jump validity,
* Casper's purity checker or ewasm contract rules).
*/
EVMC_CONTRACT_VALIDATION_FAILURE = 13,
/**
* An argument to a state accessing method has a value outside of the
* accepted range of values.
*/
EVMC_ARGUMENT_OUT_OF_RANGE = 14,
/**
* A WebAssembly `unreachable` instruction has been hit during execution.
*/
EVMC_WASM_UNREACHABLE_INSTRUCTION = 15,
/**
* A WebAssembly trap has been hit during execution. This can be for many
* reasons, including division by zero, validation errors, etc.
*/
EVMC_WASM_TRAP = 16,
/** The caller does not have enough funds for value transfer. */
EVMC_INSUFFICIENT_BALANCE = 17,
/** EVM implementation generic internal error. */
EVMC_INTERNAL_ERROR = -1,
/**
* The execution of the given code and/or message has been rejected
* by the EVM implementation.
*
* This error SHOULD be used to signal that the EVM is not able to or
* willing to execute the given code type or message.
* If an EVM returns the ::EVMC_REJECTED status code,
* the Client MAY try to execute it in other EVM implementation.
* For example, the Client tries running a code in the EVM 1.5. If the
* code is not supported there, the execution falls back to the EVM 1.0.
*/
EVMC_REJECTED = -2,
/** The VM failed to allocate the amount of memory needed for execution. */
EVMC_OUT_OF_MEMORY = -3
};
/* Forward declaration. */
struct evmc_result;
/**
* Releases resources assigned to an execution result.
*
* This function releases memory (and other resources, if any) assigned to the
* specified execution result making the result object invalid.
*
* @param result The execution result which resources are to be released. The
* result itself it not modified by this function, but becomes
* invalid and user MUST discard it as well.
* This MUST NOT be NULL.
*
* @note
* The result is passed by pointer to avoid (shallow) copy of the ::evmc_result
* struct. Think of this as the best possible C language approximation to
* passing objects by reference.
*/
typedef void (*evmc_release_result_fn)(const struct evmc_result* result);
/** The EVM code execution result. */
struct evmc_result
{
/** The execution status code. */
enum evmc_status_code status_code;
/**
* The amount of gas left after the execution.
*
* If evmc_result::status_code is neither ::EVMC_SUCCESS nor ::EVMC_REVERT
* the value MUST be 0.
*/
int64_t gas_left;
/**
* The reference to output data.
*
* The output contains data coming from RETURN opcode (iff evmc_result::code
* field is ::EVMC_SUCCESS) or from REVERT opcode.
*
* The memory containing the output data is owned by EVM and has to be
* freed with evmc_result::release().
*
* This MAY be NULL.
*/
const uint8_t* output_data;
/**
* The size of the output data.
*
* If output_data is NULL this MUST be 0.
*/
size_t output_size;
/**
* The method releasing all resources associated with the result object.
*
* This method (function pointer) is optional (MAY be NULL) and MAY be set
* by the VM implementation. If set it MUST be called by the user once to
* release memory and other resources associated with the result object.
* Once the resources are released the result object MUST NOT be used again.
*
* The suggested code pattern for releasing execution results:
* @code
* struct evmc_result result = ...;
* if (result.release)
* result.release(&result);
* @endcode
*
* @note
* It works similarly to C++ virtual destructor. Attaching the release
* function to the result itself allows VM composition.
*/
evmc_release_result_fn release;
/**
* The address of the contract created by create instructions.
*
* This field has valid value only if:
* - it is a result of the Host method evmc_host_interface::call
* - and the result describes successful contract creation
* (evmc_result::status_code is ::EVMC_SUCCESS).
* In all other cases the address MUST be null bytes.
*/
evmc_address create_address;
/**
* Reserved data that MAY be used by a evmc_result object creator.
*
* This reserved 4 bytes together with 20 bytes from create_address form
* 24 bytes of memory called "optional data" within evmc_result struct
* to be optionally used by the evmc_result object creator.
*
* @see evmc_result_optional_data, evmc_get_optional_data().
*
* Also extends the size of the evmc_result to 64 bytes (full cache line).
*/
uint8_t padding[4];
};
/**
* Check account existence callback function.
*
* 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 bool (*evmc_account_exists_fn)(struct evmc_host_context* context,
const evmc_address* address);
/**
* Get storage callback function.
*
* This callback function is used by a VM to query the given account storage entry.
*
* @param context The Host execution context.
* @param address The address of the account.
* @param key The index of the account's storage entry.
* @return The storage value at the given storage key or null bytes
* if the account does not exist.
*/
typedef evmc_bytes32 (*evmc_get_storage_fn)(struct evmc_host_context* context,
const evmc_address* address,
const evmc_bytes32* key);
/**
* The effect of an attempt to modify a contract storage item.
*
* For the purpose of explaining the meaning of each element, the following
* notation is used:
* - 0 is zero value,
* - X != 0 (X is any value other than 0),
* - Y != X, Y != 0 (Y is any value other than X and 0),
* - Z != Y (Z is any value other than Y),
* - the "->" means the change from one value to another.
*/
enum evmc_storage_status
{
/**
* The value of a storage item has been left unchanged: 0 -> 0 and X -> X.
*/
EVMC_STORAGE_UNCHANGED = 0,
/**
* The value of a storage item has been modified: X -> Y.
*/
EVMC_STORAGE_MODIFIED = 1,
/**
* A storage item has been modified after being modified before: X -> Y -> Z.
*/
EVMC_STORAGE_MODIFIED_AGAIN = 2,
/**
* A new storage item has been added: 0 -> X.
*/
EVMC_STORAGE_ADDED = 3,
/**
* A storage item has been deleted: X -> 0.
*/
EVMC_STORAGE_DELETED = 4
};
/**
* Set storage callback function.
*
* This callback function is used by a VM to update the given account storage entry.
* The VM MUST make sure that the account exists. This requirement is only a formality because
* VM implementations only modify storage of the account of the current execution context
* (i.e. referenced by evmc_message::destination).
*
* @param context The pointer to the Host execution context.
* @param address The address of the account.
* @param key The index of the storage entry.
* @param value The value to be stored.
* @return The effect on the storage item.
*/
typedef enum evmc_storage_status (*evmc_set_storage_fn)(struct evmc_host_context* context,
const evmc_address* address,
const evmc_bytes32* key,
const evmc_bytes32* value);
/**
* Get balance callback function.
*
* This callback function is used by a VM to query the balance of the given account.
*
* @param context The pointer to the Host execution context.
* @param address The address of the account.
* @return The balance of the given account or 0 if the account does not exist.
*/
typedef evmc_uint256be (*evmc_get_balance_fn)(struct evmc_host_context* context,
const evmc_address* address);
/**
* Get code size callback function.
*
* This callback function is used by a VM to get the size of the code stored
* in the account at the given address.
*
* @param context The pointer to the Host execution context.
* @param address The address of the account.
* @return The size of the code in the account or 0 if the account does not exist.
*/
typedef size_t (*evmc_get_code_size_fn)(struct evmc_host_context* context,
const evmc_address* address);
/**
* Get code hash callback function.
*
* This callback function is used by a VM to get the keccak256 hash of the code stored
* in the account at the given address. For existing accounts not having a code, this
* function returns keccak256 hash of empty data.
*
* @param context The pointer to the Host execution context.
* @param address The address of the account.
* @return The hash of the code in the account or null bytes if the account does not exist.
*/
typedef evmc_bytes32 (*evmc_get_code_hash_fn)(struct evmc_host_context* context,
const evmc_address* address);
/**
* Copy code callback function.
*
* This callback function is used by an EVM to request a copy of the code
* of the given account to the memory buffer provided by the EVM.
* The Client MUST copy the requested code, starting with the given offset,
* to the provided memory buffer up to the size of the buffer or the size of
* the code, whichever is smaller.
*
* @param context The pointer to the Host execution context. See ::evmc_host_context.
* @param address The address of the account.
* @param code_offset The offset of the code to copy.
* @param buffer_data The pointer to the memory buffer allocated by the EVM
* to store a copy of the requested code.
* @param buffer_size The size of the memory buffer.
* @return The number of bytes copied to the buffer by the Client.
*/
typedef size_t (*evmc_copy_code_fn)(struct evmc_host_context* context,
const evmc_address* address,
size_t code_offset,
uint8_t* buffer_data,
size_t buffer_size);
/**
* Selfdestruct callback function.
*
* This callback function is used by an EVM to SELFDESTRUCT given contract.
* The execution of the contract will not be stopped, that is up to the EVM.
*
* @param context The pointer to the Host execution context. See ::evmc_host_context.
* @param address The address of the contract to be selfdestructed.
* @param beneficiary The address where the remaining ETH is going to be transferred.
*/
typedef void (*evmc_selfdestruct_fn)(struct evmc_host_context* context,
const evmc_address* address,
const evmc_address* beneficiary);
/**
* Log callback function.
*
* This callback function is used by an EVM to inform about a LOG that happened
* during an EVM bytecode execution.
*
* @param context The pointer to the Host execution context. See ::evmc_host_context.
* @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 (*evmc_emit_log_fn)(struct evmc_host_context* context,
const evmc_address* address,
const uint8_t* data,
size_t data_size,
const evmc_bytes32 topics[],
size_t topics_count);
/**
* Pointer to the callback function supporting EVM calls.
*
* @param context The pointer to the Host execution context.
* @param msg The call parameters.
* @return The result of the call.
*/
typedef struct evmc_result (*evmc_call_fn)(struct evmc_host_context* context,
const struct evmc_message* msg);
/**
* The Host interface.
*
* The set of all callback functions expected by VM instances. This is C
* realisation of vtable for OOP interface (only virtual methods, no data).
* Host implementations SHOULD create constant singletons of this (similarly
* to vtables) to lower the maintenance and memory management cost.
*/
struct evmc_host_interface
{
/** Check account existence callback function. */
evmc_account_exists_fn account_exists;
/** Get storage callback function. */
evmc_get_storage_fn get_storage;
/** Set storage callback function. */
evmc_set_storage_fn set_storage;
/** Get balance callback function. */
evmc_get_balance_fn get_balance;
/** Get code size callback function. */
evmc_get_code_size_fn get_code_size;
/** Get code hash callback function. */
evmc_get_code_hash_fn get_code_hash;
/** Copy code callback function. */
evmc_copy_code_fn copy_code;
/** Selfdestruct callback function. */
evmc_selfdestruct_fn selfdestruct;
/** Call callback function. */
evmc_call_fn call;
/** Get transaction context callback function. */
evmc_get_tx_context_fn get_tx_context;
/** Get block hash callback function. */
evmc_get_block_hash_fn get_block_hash;
/** Emit log callback function. */
evmc_emit_log_fn emit_log;
};
/* Forward declaration. */
struct evmc_vm;
/**
* Destroys the VM instance.
*
* @param vm The VM instance to be destroyed.
*/
typedef void (*evmc_destroy_fn)(struct evmc_vm* vm);
/**
* Possible outcomes of evmc_set_option.
*/
enum evmc_set_option_result
{
EVMC_SET_OPTION_SUCCESS = 0,
EVMC_SET_OPTION_INVALID_NAME = 1,
EVMC_SET_OPTION_INVALID_VALUE = 2
};
/**
* Configures the VM instance.
*
* Allows modifying options of the VM instance.
* Options:
* - code cache behavior: on, off, read-only, ...
* - optimizations,
*
* @param vm The VM instance to be configured.
* @param name The option name. NULL-terminated string. Cannot be NULL.
* @param value The new option value. NULL-terminated string. Cannot be NULL.
* @return The outcome of the operation.
*/
typedef enum evmc_set_option_result (*evmc_set_option_fn)(struct evmc_vm* vm,
char const* name,
char const* value);
/**
* EVM revision.
*
* The revision of the EVM specification based on the Ethereum
* upgrade / hard fork codenames.
*/
enum evmc_revision
{
/**
* The Frontier revision.
*
* The one Ethereum launched with.
*/
EVMC_FRONTIER = 0,
/**
* The Homestead revision.
*
* https://eips.ethereum.org/EIPS/eip-606
*/
EVMC_HOMESTEAD = 1,
/**
* The Tangerine Whistle revision.
*
* https://eips.ethereum.org/EIPS/eip-608
*/
EVMC_TANGERINE_WHISTLE = 2,
/**
* The Spurious Dragon revision.
*
* https://eips.ethereum.org/EIPS/eip-607
*/
EVMC_SPURIOUS_DRAGON = 3,
/**
* The Byzantium revision.
*
* https://eips.ethereum.org/EIPS/eip-609
*/
EVMC_BYZANTIUM = 4,
/**
* The Constantinople revision.
*
* https://eips.ethereum.org/EIPS/eip-1013
*/
EVMC_CONSTANTINOPLE = 5,
/**
* The Petersburg revision.
*
* Other names: Constantinople2, ConstantinopleFix.
*
* https://eips.ethereum.org/EIPS/eip-1716
*/
EVMC_PETERSBURG = 6,
/**
* The Istanbul revision.
*
* The spec draft: https://eips.ethereum.org/EIPS/eip-1679.
*/
EVMC_ISTANBUL = 7,
/**
* The Berlin revision.
*
* The spec draft: https://eips.ethereum.org/EIPS/eip-2070.
*/
EVMC_BERLIN = 8,
/** The maximum EVM revision supported. */
EVMC_MAX_REVISION = EVMC_BERLIN
};
/**
* Executes the given code using the input from the message.
*
* This function MAY be invoked multiple times for a single VM instance.
*
* @param vm The VM instance. This argument MUST NOT be NULL.
* @param host The Host interface. This argument MUST NOT be NULL unless
* the @p vm has the ::EVMC_CAPABILITY_PRECOMPILES capability.
* @param context The opaque pointer to the Host execution context.
* This argument MAY be NULL. The VM MUST pass the same
* pointer to the methods of the @p host interface.
* The VM MUST NOT dereference the pointer.
* @param rev The requested EVM specification revision.
* @param msg The call parameters. See ::evmc_message. This argument MUST NOT be NULL.
* @param code The reference to the code to be executed. This argument MAY be NULL.
* @param code_size The length of the code. If @p code is NULL this argument MUST be 0.
* @return The execution result.
*/
typedef struct evmc_result (*evmc_execute_fn)(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);
/**
* Possible capabilities of a VM.
*/
enum evmc_capabilities
{
/**
* The VM is capable of executing EVM1 bytecode.
*/
EVMC_CAPABILITY_EVM1 = (1u << 0),
/**
* The VM is capable of executing ewasm bytecode.
*/
EVMC_CAPABILITY_EWASM = (1u << 1),
/**
* The VM is capable of executing the precompiled contracts
* defined for the range of destination addresses.
*
* The EIP-1352 (https://eips.ethereum.org/EIPS/eip-1352) specifies
* the range 0x000...0000 - 0x000...ffff of addresses
* reserved for precompiled and system contracts.
*
* This capability is **experimental** and MAY be removed without notice.
*/
EVMC_CAPABILITY_PRECOMPILES = (1u << 2)
};
/**
* Alias for unsigned integer representing a set of bit flags of EVMC capabilities.
*
* @see evmc_capabilities
*/
typedef uint32_t evmc_capabilities_flagset;
/**
* Return the supported capabilities of the VM instance.
*
* This function MAY be invoked multiple times for a single VM instance,
* and its value MAY be influenced by calls to evmc_vm::set_option.
*
* @param vm The VM instance.
* @return The supported capabilities of the VM. @see evmc_capabilities.
*/
typedef evmc_capabilities_flagset (*evmc_get_capabilities_fn)(struct evmc_vm* vm);
/**
* The VM instance.
*
* Defines the base struct of the VM implementation.
*/
struct evmc_vm
{
/**
* EVMC ABI version implemented by the VM instance.
*
* Can be used to detect ABI incompatibilities.
* The EVMC ABI version represented by this file is in ::EVMC_ABI_VERSION.
*/
const int abi_version;
/**
* The name of the EVMC VM implementation.
*
* It MUST be a NULL-terminated not empty string.
* The content MUST be UTF-8 encoded (this implies ASCII encoding is also allowed).
*/
const char* name;
/**
* The version of the EVMC VM implementation, e.g. "1.2.3b4".
*
* It MUST be a NULL-terminated not empty string.
* The content MUST be UTF-8 encoded (this implies ASCII encoding is also allowed).
*/
const char* version;
/**
* Pointer to function destroying the VM instance.
*
* This is a mandatory method and MUST NOT be set to NULL.
*/
evmc_destroy_fn destroy;
/**
* Pointer to function executing a code by the VM instance.
*
* This is a mandatory method and MUST NOT be set to NULL.
*/
evmc_execute_fn execute;
/**
* A method returning capabilities supported by the VM instance.
*
* The value returned MAY change when different options are set via the set_option() method.
*
* A Client SHOULD only rely on the value returned if it has queried it after
* it has called the set_option().
*
* This is a mandatory method and MUST NOT be set to NULL.
*/
evmc_get_capabilities_fn get_capabilities;
/**
* Optional pointer to function modifying VM's options.
*
* If the VM does not support this feature the pointer can be NULL.
*/
evmc_set_option_fn set_option;
};
/* END Python CFFI declarations */
#ifdef EVMC_DOCUMENTATION
/**
* Example of a function creating an instance of an example EVM implementation.
*
* Each EVM implementation MUST provide a function returning an EVM instance.
* The function SHOULD be named `evmc_create_<vm-name>(void)`. If the VM name contains hyphens
* replaces them with underscores in the function names.
*
* @par Binaries naming convention
* For VMs distributed as shared libraries, the name of the library SHOULD match the VM name.
* The convetional library filename prefixes and extensions SHOULD be ignored by the Client.
* For example, the shared library with the "beta-interpreter" implementation may be named
* `libbeta-interpreter.so`.
*
* @return The VM instance or NULL indicating instance creation failure.
*/
struct evmc_vm* evmc_create_example_vm(void);
#endif
#ifdef __cplusplus
}
#endif
#endif
/** @} */