# Module `0x1::errors` Module defining error codes used in Move aborts throughout the framework. A u64 error code is constructed from two values: 1. The *error category* which is encoded in the lower 8 bits of the code. Error categories are declared in this module and are globally unique across the Diem framework. There is a limited fixed set of predefined categories, and the framework is guaranteed to use those consistently. 2. The *error reason* which is encoded in the remaining 56 bits of the code. The reason is a unique number relative to the module which raised the error and can be used to obtain more information about the error at hand. It is mostly used for diagnosis purposes. Error reasons may change over time as the framework evolves. >TODO: determine what kind of stability guarantees we give about reasons/associated module. - [Constants](#@Constants_0) - [Function `make`](#0x1_errors_make) - [Function `invalid_state`](#0x1_errors_invalid_state) - [Function `requires_address`](#0x1_errors_requires_address) - [Function `requires_role`](#0x1_errors_requires_role) - [Function `requires_capability`](#0x1_errors_requires_capability) - [Function `not_published`](#0x1_errors_not_published) - [Function `already_published`](#0x1_errors_already_published) - [Function `invalid_argument`](#0x1_errors_invalid_argument) - [Function `limit_exceeded`](#0x1_errors_limit_exceeded) - [Function `internal`](#0x1_errors_internal) - [Function `custom`](#0x1_errors_custom)

## Constants Attempting to publish a resource that is already published. Example: calling an initialization function twice.

const ALREADY_PUBLISHED: u8 = 6;

A custom error category for extension points.

const CUSTOM: u8 = 255;

An internal error (bug) has occurred.

const INTERNAL: u8 = 10;

An argument provided to an operation is invalid. Example: a signing key has the wrong format.

const INVALID_ARGUMENT: u8 = 7;

The system is in a state where the performed operation is not allowed. Example: call to a function only allowed in genesis.

const INVALID_STATE: u8 = 1;

A limit on an amount, e.g. a currency, is exceeded. Example: withdrawal of money after account limits window is exhausted.

const LIMIT_EXCEEDED: u8 = 8;

A resource is required but not published. Example: access to non-existing AccountLimits resource.

const NOT_PUBLISHED: u8 = 5;

The signer of a transaction does not have the expected address for this operation. Example: a call to a function which publishes a resource under a particular address.

const REQUIRES_ADDRESS: u8 = 2;

The signer of a transaction does not have a required capability.

const REQUIRES_CAPABILITY: u8 = 4;

The signer of a transaction does not have the expected role for this operation. Example: a call to a function which requires the signer to have the role of treasury compliance.

const REQUIRES_ROLE: u8 = 3;

## Function `make` A function to create an error from from a category and a reason.

fun make(category: u8, reason: u64): u64

Implementation

fun make(category: u8, reason: u64): u64 {
    (category as u64) + (reason << 8)
}

Specification

pragma opaque = true;
ensures [concrete] result == category + (reason << 8) % (1 << 64);
aborts_if [abstract] false;
ensures [abstract] result == category;

## Function `invalid_state`

public fun invalid_state(reason: u64): u64

Implementation

public fun invalid_state(reason: u64): u64 { make(INVALID_STATE, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == INVALID_STATE;

## Function `requires_address`

public fun requires_address(reason: u64): u64

Implementation

public fun requires_address(reason: u64): u64 { make(REQUIRES_ADDRESS, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == REQUIRES_ADDRESS;

## Function `requires_role`

public fun requires_role(reason: u64): u64

Implementation

public fun requires_role(reason: u64): u64 { make(REQUIRES_ROLE, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == REQUIRES_ROLE;

## Function `requires_capability`

public fun requires_capability(reason: u64): u64

Implementation

public fun requires_capability(reason: u64): u64 { make(REQUIRES_CAPABILITY, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == REQUIRES_CAPABILITY;

## Function `not_published`

public fun not_published(reason: u64): u64

Implementation

public fun not_published(reason: u64): u64 { make(NOT_PUBLISHED, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == NOT_PUBLISHED;

## Function `already_published`

public fun already_published(reason: u64): u64

Implementation

public fun already_published(reason: u64): u64 { make(ALREADY_PUBLISHED, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == ALREADY_PUBLISHED;

## Function `invalid_argument`

public fun invalid_argument(reason: u64): u64

Implementation

public fun invalid_argument(reason: u64): u64 { make(INVALID_ARGUMENT, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == INVALID_ARGUMENT;

## Function `limit_exceeded`

public fun limit_exceeded(reason: u64): u64

Implementation

public fun limit_exceeded(reason: u64): u64 { make(LIMIT_EXCEEDED, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == LIMIT_EXCEEDED;

## Function `internal`

public fun internal(reason: u64): u64

Implementation

public fun internal(reason: u64): u64 { make(INTERNAL, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == INTERNAL;

## Function `custom`

public fun custom(reason: u64): u64

Implementation

public fun custom(reason: u64): u64 { make(CUSTOM, reason) }

Specification

pragma opaque = true;
aborts_if false;
ensures result == CUSTOM;