@ -182,7 +182,14 @@ Things to note about the call tracer:
- In case a frame reverts, the field `output` will contain the raw return data
- In case the top level frame reverts, its `revertReason` field will contain the parsed reason of revert as returned by the Solidity contract
`callTracer` has an option to only trace the main (top-level) call and none of the sub-calls. This avoids extra processing for each call frame if only the top-level call info are required. Here's how it can be configured:
#### Config
`callTracer` accepts two options:
- `onlyTopCall: true` instructs the tracer to only process the main (top-level) call and none of the sub-calls. This avoids extra processing for each call frame if only the top-level call info are required.
- `withLog: true` instructs the tracer to also collect the logs emitted during each call.
This page showed how to use the tracers that come bundled with Geth. There are a set written in Go and a set written in Javascript. They are invoked by passing their names when calling an API method. State overrides can be used in combination with tracers to examine precisely what the EVM will do in some hypothetical scenario.
This page showed how to use the tracers that come bundled with Geth. There are a set written in Go and a set written in Javascript. They are invoked by passing their names when calling an API method. State overrides can be used in combination with tracers to examine precisely what the EVM will do in some hypothetical scenarios.
@ -5,312 +5,9 @@ description: Introduction to writing custom tracers for Geth
In addition to the default opcode tracer and the built-in tracers, Geth offers the possibility to write custom code that hook to events in the EVM to process and return the data in a consumable format. Custom tracers can be written either in Javascript or Go. JS tracers are good for quick prototyping and experimentation as well as for less intensive applications. Go tracers are performant but require the tracer to be compiled together with the Geth source code.
## Custom Javascript tracing {#custom-js-tracing}
## Custom Go tracing
Transaction traces include the complete status of the EVM at every point during the transaction execution, which can be a very large amount of data. Often, users are only interested in a small subset of that data. Javascript trace filters are available to isolate the useful information. Detailed information about `debug_traceTransaction` and its component parts is available in the [reference documentation](/docs/rpc/ns-debug#debug_tracetransaction).
### A simple filter {#simple-filter}
Filters are Javascript functions that select information from the trace to persist and discard based on some conditions. The following Javascript function returns only the sequence of opcodes executed by the transaction as a comma-separated list. The function could be written directly in the Javascript console, but it is cleaner to write it in a separate re-usable file and load it into the console.
1. Create a file, `filterTrace_1.js`, with this content:
More information about the `JSON.stringify` function is available [here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify).
The commands above worked by calling the same `debug.traceTransaction` function that was previously explained in [basic traces](https://geth.ethereum.org/docs/dapp/tracing), but with a new parameter, `tracer`. This parameter takes the JavaScript object formated as a string. In the case of the trace above, it is:
- `fault`, called if there is a problem in the execution.
- `result`, called to produce the results that are returned by `debug.traceTransaction`
- after the execution is done.
In this case, `retVal` is used to store the list of strings to return in `result`.
The `step` function adds to `retVal` the program counter and the name of the opcode there. Then, in `result`, this list is returned to be sent to the caller.
### Filtering with conditions {#filtering-with-conditions}
For actual filtered tracing we need an `if` statement to only log relevant information. For example, to isolate the transaction's interaction with storage, the following tracer could be used:
The `step` function here looks at the opcode number of the op, and only pushes an entry if the opcode is `SLOAD` or `SSTORE` ([here is a list of EVM opcodes and their numbers](https://github.com/wolflo/evm-opcodes)). We could have used `log.op.toString()` instead, but it is faster to compare numbers rather than strings.
The output looks similar to this:
```javascript
[
"5921: SLOAD",
.
.
.
"2413: SSTORE",
"2420: SLOAD",
"2475: SSTORE",
"6094: SSTORE"
]
```
### Stack Information {#stack-information}
The trace above reports the program counter (PC) and whether the program read from storage or wrote to it. That alone isn't particularly useful. To know more, the `log.stack.peek` function can be used to peek into the stack. `log.stack.peek(0)` is the stack top, `log.stack.peek(1)` the entry below it, etc.
The values returned by `log.stack.peek` are Go `big.Int` objects. By default they are converted to JavaScript floating point numbers, so you need `toString(16)` to get them as hexadecimals, which is how 256-bit values such as storage cells and their content are normally represented.
#### Storage Information {#storage-information}
The function below provides a trace of all the storage operations and their parameters. This gives a more complete picture of the program's interaction with storage.
One piece of information missing from the function above is the result on an `SLOAD` operation. The state we get inside `log` is the state prior to the execution of the opcode, so that value is not known yet. For more operations we can figure it out for ourselves, but we don't have access to the
storage, so here we can't.
The solution is to have a flag, `afterSload`, which is only true in the opcode right after an `SLOAD`, when we can see the result at the top of the stack.
### Dealing With Calls Between Contracts {#calls-between-contracts}
So the storage has been treated as if there are only 2<sup>256</sup> cells. However, that is not true. Contracts can call other contracts, and then the storage involved is the storage of the other contract. We can see the address of the current contract in `log.contract.getAddress()`. This value is the execution context - the contract whose storage we are using - even when code from another contract is executed (by using
[`CALLCODE` or `DELEGATECALL`](https://docs.soliditylang.org/en/v0.8.14/introduction-to-smart-contracts.html#delegatecall-callcode-and-libraries)).
However, `log.contract.getAddress()` returns an array of bytes. To convert this to the familiar hexadecimal representation of Ethereum addresses, `this.byteHex()` and `array2Hex()` can be used.
This tutorial has focused on `debug_traceTransaction()` which reports information about individual transactions. There are also RPC endpoints that provide different information, including tracing the EVM execution within a block, between two blocks, for specific `eth_call`s or rejected blocks. The full list of trace functions can be explored in the [reference documentation](/content/docs/interacting_with_geth/RPC/ns-debug.md).
## Custom Go tracing {#custom-go-tracing}
Custom tracers can also be made more performant by writing them in Go. The gain in performance mostly comes from the fact that Geth doesn't need
to interpret JS code and can execute native functions. Geth comes with several built-in [native tracers](https://github.com/ethereum/go-ethereum/tree/master/eth/tracers/native) which can serve as examples. Please note that unlike JS tracers, Go tracing scripts cannot be simply passed as an argument to the API. They will need to be added to and compiled with the rest of the Geth source code.
Custom tracers can also be made more performant by writing them in Go. The gain in performance mostly comes from the fact that Geth doesn't need to interpret JS code and can execute native functions. Geth comes with several built-in [native tracers](https://github.com/ethereum/go-ethereum/tree/master/eth/tracers/native) which can serve as examples. Please note that unlike JS tracers, Go tracing scripts cannot be simply passed as an argument to the API. They will need to be added to and compiled with the rest of the Geth source code.
In this section a simple native tracer that counts the number of opcodes will be covered. First follow the instructions to [clone and build](/content/docs/getting_started/Installing-Geth.md) Geth from source code. Next save the following snippet as a `.go` file and add it to `eth/tracers/native`:
@ -402,7 +99,7 @@ Every method of the [EVMLogger interface](https://pkg.go.dev/github.com/ethereum
To test out this tracer the source is first compiled with `make geth`. Then in the console it can be invoked through the usual API methods by passing in the name it was registered under:
@ -412,6 +109,167 @@ To test out this tracer the source is first compiled with `make geth`. Then in t
}
```
## Summary {#summary}
## Custom Javascript tracing
Transaction traces include the complete status of the EVM at every point during the transaction execution, which can be a very large amount of data. Often, users are only interested in a small subset of that data. Javascript trace filters are available to isolate the useful information.
Specifying the `tracer` option in one of the tracing methods (see list in [reference](/docs/rpc/ns-debug)) enables JavaScript-based tracing. In this mode, `tracer` is interpreted as a JavaScript expression that is expected to evaluate to an object which must expose the `result` and `fault` methods. There exist 4 additional methods, namely: `setup`, `step`, `enter`, and `exit`. `enter` and `exit` must be present or omitted together.
### Setup
`setup` is invoked once, in the beginning when the tracer is being constructed by Geth for a given transaction. It takes in one argument `config`. `config` is tracer-specific and allows users to pass in options to the tracer. `config` is to be JSON-decoded for usage and its default value is `"{}"`.
The `config` in the following example is the `onlyTopCall` option available in the `callTracer`:
`step` is a function that takes two arguments, `log` and `db`, and is called for each step of the EVM, or when an error occurs, as the specified transaction is traced.
`log` has the following fields:
- `op`: Object, an OpCode object representing the current opcode
- `stack`: Object, a structure representing the EVM execution stack
- `memory`: Object, a structure representing the contract's memory space
- `contract`: Object, an object representing the account executing the current operation
and the following methods:
- `getPC()` - returns a Number with the current program counter
- `getGas()` - returns a Number with the amount of gas remaining
- `getCost()` - returns the cost of the opcode as a Number
- `getDepth()` - returns the execution depth as a Number
- `getRefund()` - returns the amount to be refunded as a Number
- `getError()` - returns information about the error if one occured, otherwise returns `undefined`
If error is non-empty, all other fields should be ignored.
For efficiency, the same `log` object is reused on each execution step, updated with current values; make sure to copy values you want to preserve beyond the current call. For instance, this step function will not work:
- `isPush()` - returns true if the opcode is a PUSHn
- `toString()` - returns the string representation of the opcode
- `toNumber()` - returns the opcode's number
`log.memory` has the following methods:
- `slice(start, stop)` - returns the specified segment of memory as a byte slice
- `getUint(offset)` - returns the 32 bytes at the given offset
- `length()` - returns the memory size
`log.stack` has the following methods:
- `peek(idx)` - returns the idx-th element from the top of the stack (0 is the topmost element) as a big.Int
- `length()` - returns the number of elements in the stack
`log.contract` has the following methods:
- `getCaller()` - returns the address of the caller
- `getAddress()` - returns the address of the current contract
- `getValue()` - returns the amount of value sent from caller to contract as a big.Int
- `getInput()` - returns the input data passed to the contract
`db` has the following methods:
- `getBalance(address)` - returns a `big.Int` with the specified account's balance
- `getNonce(address)` - returns a Number with the specified account's nonce
- `getCode(address)` - returns a byte slice with the code for the specified account
- `getState(address, hash)` - returns the state value for the specified account and the specified hash
- `exists(address)` - returns true if the specified address exists
If the step function throws an exception or executes an illegal operation at any point, it will not be called on any further VM steps, and the error will be returned to the caller.
### Result
`result` is a function that takes two arguments `ctx` and `db`, and is expected to return a JSON-serializable value to return to the RPC caller.
`ctx` is the context in which the transaction is executing and has the following fields:
- `type` - String, one of the two values `CALL` and `CREATE`
- `from` - Address, sender of the transaction
- `to` - Address, target of the transaction
- `input` - Buffer, input transaction data
- `gas` - Number, gas budget of the transaction
- `gasUsed` - Number, amount of gas used in executing the transaction (excludes txdata costs)
- `gasPrice` - Number, gas price configured in the transaction being executed
- `intrinsicGas` - Number, intrinsic gas for the transaction being executed
- `value` - big.Int, amount to be transferred in wei
- `block` - Number, block number
- `output` - Buffer, value returned from EVM
- `time` - String, execution runtime
And these fields are only available for tracing mined transactions (i.e. not available when doing `debug_traceCall`):
- `blockHash` - Buffer, hash of the block that holds the transaction being executed
- `txIndex` - Number, index of the transaction being executed in the block
- `txHash` - Buffer, hash of the transaction being executed
### Fault
`fault` is a function that takes two arguments, `log` and `db`, just like `step` and is invoked when an error happens during the execution of an opcode which wasn't reported in `step`. The method `log.getError()` has information about the error.
### Enter & Exit
`enter` and `exit` are respectively invoked on stepping in and out of an internal call. More specifically they are invoked on the `CALL` variants, `CREATE` variants and also for the transfer implied by a `SELFDESTRUCT`.
`enter` takes a `callFrame` object as argument which has the following methods:
- `getType()` - returns a string which has the type of the call frame
- `getFrom()` - returns the address of the call frame sender
- `getTo()` - returns the address of the call frame target
- `getInput()` - returns the input as a buffer
- `getGas()` - returns a Number which has the amount of gas provided for the frame
- `getValue()` - returns a `big.Int` with the amount to be transferred only if available, otherwise `undefined`
`exit` takes in a `frameResult` object which has the following methods:
- `getGasUsed()` - returns amount of gas used throughout the frame as a Number
- `getOutput()` - returns the output as a buffer
` -getError()` - returns an error if one occured during execution and `undefined` otherwise
### Usage
Note that several values are Golang big.Int objects, not JavaScript numbers or JS bigints. As such, they have the same interface as described in the godocs. Their default serialization to JSON is as a Javascript number; to serialize large numbers accurately call `.String()` on them. For convenience, `big.NewInt(x)` is provided, and will convert a uint to a Go BigInt.
Usage example, returns the top element of the stack at each CALL opcode only:
Geth supports tracing via [custom Javascript tracers](/docs/evm-tracing/custom-tracer#custom-javascript-tracing). This document provides a tutorial with examples on how to achieve this.
### A simple filter
Filters are Javascript functions that select information from the trace to persist and discard based on some conditions. The following Javascript function returns only the sequence of opcodes executed by the transaction as a comma-separated list. The function could be written directly in the Javascript console, but it is cleaner to write it in a separate re-usable file and load it into the console.
1. Create a file, `filterTrace_1.js`, with this content:
More information about the `JSON.stringify` function is available [here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify).
The commands above worked by calling the same `debug.traceTransaction` function that was previously explained in [basic traces](https://geth.ethereum.org/docs/dapp/tracing), but with a new parameter, `tracer`. This parameter takes the JavaScript object formated as a string. In the case of the trace above, it is:
- `fault`, called if there is a problem in the execution.
- `result`, called to produce the results that are returned by `debug.traceTransaction`
- after the execution is done.
In this case, `retVal` is used to store the list of strings to return in `result`.
The `step` function adds to `retVal` the program counter and the name of the opcode there. Then, in `result`, this list is returned to be sent to the caller.
### Filtering with conditions
For actual filtered tracing we need an `if` statement to only log relevant information. For example, to isolate the transaction's interaction with storage, the following tracer could be used:
The `step` function here looks at the opcode number of the op, and only pushes an entry if the opcode is `SLOAD` or `SSTORE` ([here is a list of EVM opcodes and their numbers](https://github.com/wolflo/evm-opcodes)). We could have used `log.op.toString()` instead, but it is faster to compare numbers rather than strings.
The output looks similar to this:
```js
[
"5921: SLOAD",
.
.
.
"2413: SSTORE",
"2420: SLOAD",
"2475: SSTORE",
"6094: SSTORE"
]
```
### Stack Information
The trace above reports the program counter (PC) and whether the program read from storage or wrote to it. That alone isn't particularly useful. To know more, the `log.stack.peek` function can be used to peek into the stack. `log.stack.peek(0)` is the stack top, `log.stack.peek(1)` the entry below it, etc.
The values returned by `log.stack.peek` are Go `big.Int` objects. By default they are converted to JavaScript floating point numbers, so you need `toString(16)` to get them as hexadecimals, which is how 256-bit values such as storage cells and their content are normally represented.
#### Storage Information
The function below provides a trace of all the storage operations and their parameters. This gives a more complete picture of the program's interaction with storage.
One piece of information missing from the function above is the result on an `SLOAD` operation. The state we get inside `log` is the state prior to the execution of the opcode, so that value is not known yet. For more operations we can figure it out for ourselves, but we don't have access to the
storage, so here we can't.
The solution is to have a flag, `afterSload`, which is only true in the opcode right after an `SLOAD`, when we can see the result at the top of the stack.
So the storage has been treated as if there are only 2<sup>256</sup> cells. However, that is not true. Contracts can call other contracts, and then the storage involved is the storage of the other contract. We can see the address of the current contract in `log.contract.getAddress()`. This value is the execution context - the contract whose storage we are using - even when code from another contract is executed (by using
[`CALLCODE` or `DELEGATECALL`](https://docs.soliditylang.org/en/v0.8.14/introduction-to-smart-contracts.html#delegatecall-callcode-and-libraries)).
However, `log.contract.getAddress()` returns an array of bytes. To convert this to the familiar hexadecimal representation of Ethereum addresses, `this.byteHex()` and `array2Hex()` can be used.
description: Documentation for the JSON-RPC API "clique" namespace
description: methods in the debug namespace
---
The `debug` API gives you access to several non-standard RPC methods, which will allow you
to inspect, debug and set certain debugging flags during runtime.
The `debug` API gives you access to several non-standard RPC methods, which will allow you to inspect, debug and set certain debugging flags during runtime.
### debug_accountRange {#debug-accountrange}
### debug_accountRange
Enumerates all accounts at a given block with paging capability. `maxResults` are returned in the page and the items have keys that come after the `start` key (hashed address).
@ -18,11 +16,9 @@ If `incompletes` is false, then accounts for which the key preimage (i.e: the `a
Sets the logging backtrace location. When a backtrace location
is set and a log message is emitted at that location, the stack
of the goroutine executing the log statement will be printed to stderr.
Sets the logging backtrace location. When a backtrace location is set and a log message is emitted at that location, the stack of the goroutine executing the log statement will be printed to stderr.
The location is specified as `<filename>:<line>`.
@ -37,13 +33,9 @@ Example:
> debug.backtraceAt("server.go:443")
```
### debug_blockProfile {#debug-blockprofile}
### debug_blockProfile
Turns on block profiling for the given duration and writes
profile data to disk. It uses a profile rate of 1 for most
accurate information. If a different rate is desired, set
the rate and write the profile manually using
`debug_writeBlockProfile`.
Turns on block profiling for the given duration and writes profile data to disk. It uses a profile rate of 1 for most accurate information. If a different rate is desired, set the rate and write the profile manually using `debug_writeBlockProfile`.
Retrieves an ancient binary blob from the freezer. The freezer is a collection of append-only immutable files.
The first argument `kind` specifies which table to look up data from. The list of all table kinds are as follows:
Retrieves an ancient binary blob from the freezer. The freezer is a collection of append-only immutable files. The first argument `kind` specifies which table to look up data from. The list of all table kinds are as follows:
- `headers`: block headers
- `hashes`: canonical hash table (block number -> block hash)
@ -98,7 +88,7 @@ The first argument `kind` specifies which table to look up data from. The list o
| Console | `debug.dbAncient(kind string, number uint64)` |
Returns all accounts that have changed between the two blocks specified. A change is defined as a difference in nonce, balance, code hash, or storage hash. With one parameter, returns the list of accounts modified in the specified block.
@ -248,10 +232,9 @@ Returns all accounts that have changed between the two blocks specified. A chang
Turns on mutex profiling for nsec seconds and writes profile data to file. It uses a profile rate of 1 for most accurate information. If a different rate is desired, set the rate and write the profile manually.
@ -308,7 +289,7 @@ Turns on mutex profiling for nsec seconds and writes profile data to file. It us
Sets the rate (in samples/sec) of goroutine block profile
data collection. A non-zero rate enables block profiling,
setting it to zero stops the profile. Collected profile data
can be written using `debug_writeBlockProfile`.
Sets the rate (in samples/sec) of goroutine block profile data collection. A non-zero rate enables block profiling, setting it to zero stops the profile. Collected profile data can be written using `debug_writeBlockProfile`.
Sets the current head of the local chain by block number. **Note**, this is a
destructive action and may severely damage your chain. Use with *extreme* caution.
Sets the current head of the local chain by block number. **Note**, this is a destructive action and may severely damage your chain. Use with *extreme* caution.
Returns a printed representation of the stacks of all goroutines.
Note that the web3 wrapper for this method takes care of the printing
and does not return the string.
Returns a printed representation of the stacks of all goroutines. Note that the web3 wrapper for this method takes care of the printing and does not return the string.
When JS-based tracing (see below) was first implemented, the intended usecase was to enable long-running tracers that could stream results back via a subscription channel.
This method works a bit differently. (For full details, see [PR](https://github.com/ethereum/go-ethereum/pull/17914))
When JS-based tracing (see below) was first implemented, the intended usecase was to enable long-running tracers that could stream results back via a subscription channel. This method works a bit differently. (For full details, see [PR](https://github.com/ethereum/go-ethereum/pull/17914))
- It streams output to disk during the execution, to not blow up the memory usage on the node
- It uses `jsonl` as output format (to allow streaming)
This method is similar to `debug_standardTraceBlockToFile`, but can be used to obtain info about a block which has been _rejected_ as invalid (for some reason).
Returns the storage at the given block height and transaction index. The result can be paged by providing a `maxResult` to cap the number of storage slots returned as well as specifying the offset via `keyStart` (hash of storage key).
@ -494,26 +467,25 @@ Returns the storage at the given block height and transaction index. The result
The `traceBlock` method will return a full stack trace of all invoked opcodes of all transaction
that were included in this block. **Note**, the parent of this block must be present or it will
fail.
The `traceBlock` method will return a full stack trace of all invoked opcodes of all transaction that were included in this block. **Note**, the parent of this block must be present or it will fail. For the second parameter see [TraceConfig](#traceconfig) reference.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockByNumber` accepts a block number and will replay the
block that is already present in the database.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockByNumber` accepts a block number and will replay the block that is already present in the database. For the second parameter see [TraceConfig](#traceconfig) reference.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockByHash` accepts a block hash and will replay the
block that is already present in the database.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockByHash` accepts a block hash and will replay the block that is already present in the database. For the second parameter see [TraceConfig](#traceconfig) reference.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockFromFile` accepts a file containing the RLP of the block.
Similar to [debug_traceBlock](#debug_traceblock), `traceBlockFromFile` accepts a file containing the RLP of the block. For the second parameter see [TraceConfig](#traceconfig) reference.
The `debug_traceCall` method lets you run an `eth_call` within the context of the given block execution using the final state of parent block as the base. The first argument (just as in `eth_call`) is a [transaction object](/docs/rpc/objects#transaction-call-object). The block can be specified either by hash or by number as the second argument. A tracer can be specified as a third argument, similar to `debug_traceTransaction`. It returns the same output as `debug_traceTransaction`.
The `debug_traceCall` method lets you run an `eth_call` within the context of the given block execution using the final state of parent block as the base. The first argument (just as in `eth_call`) is a [transaction object](/docs/rpc/objects#transaction-call-object). The block can be specified either by hash or by number as the second argument. The trace can be configured similar to `debug_traceTransaction`, see [TraceConfig](#traceconfig). The method returns the same output as `debug_traceTransaction`.
It is possible to supply 'overrides' for both state-data (accounts/storage) and block data (number, timestamp etc). In the example below,
a call which executes `NUMBER` is performed, and the overridden number is placed on the stack:
```
It is possible to supply 'overrides' for both state-data (accounts/storage) and block data (number, timestamp etc). In the example below, a call which executes `NUMBER` is performed, and the overridden number is placed on the stack:
```sh
> debug.traceCall({
from: eth.accounts[0],
value:"0x1",
@ -665,51 +637,58 @@ a call which executes `NUMBER` is performed, and the overridden number is placed
Returns the structured logs created during the execution of EVM between two blocks (excluding start) as a JSON object.
This endpoint must be invoked via `debug_subscribe` as follows:
Returns the structured logs created during the execution of EVM between two blocks (excluding start) as a JSON object. This endpoint must be invoked via `debug_subscribe` as follows:
`const res = provider.send('debug_subscribe', ['traceChain', '0x3f3a2a', '0x3f3a2b'])`
```js
const res = provider.send('debug_subscribe', ['traceChain', '0x3f3a2a', '0x3f3a2b'])`
```
please refer to the [subscription page](https://geth.ethereum.org/docs/rpc/pubsub) for more details.
**OBS** In most scenarios, `debug.standardTraceBlockToFile` is better suited for tracing!
The `traceTransaction` debugging method will attempt to run the transaction in the exact same manner
as it was executed on the network. It will replay any transaction that may have been executed prior
to this one before it will finally attempt to execute the transaction that corresponds to the given
The `traceTransaction` debugging method will attempt to run the transaction in the exact same manner as it was executed on the network. It will replay any transaction that may have been executed prior to this one before it will finally attempt to execute the transaction that corresponds to the given
hash.
In addition to the hash of the transaction you may give it a secondary *optional* argument, which
specifies the options for this specific call. The possible options are:
In addition to the hash of the transaction you may give it a secondary *optional* argument, which specifies the options for this specific call. The possible options are:
* `disableStorage`: `BOOL`. Setting this to true will disable storage capture (default = false).
* `disableStack`: `BOOL`. Setting this to true will disable stack capture (default = false).
* `enableMemory`: `BOOL`. Setting this to true will enable memory capture (default = false).
* `enableReturnData`: `BOOL`. Setting this to true will enable return data capture (default = false).
* `tracer`: `STRING`. Setting this will enable JavaScript-based transaction tracing, described below.
If set, the previous four arguments will be ignored.
* `tracer`: `STRING`. Name for built-in tracer or Javascript expression. See below for more details.
If set, the previous four arguments will be ignored.
* `timeout`: `STRING`. Overrides the default timeout of 5 seconds for JavaScript-based tracing calls.
Valid values are described [here](https://golang.org/pkg/time/#ParseDuration).
* `tracerConfig`: Config for the specified `tracer`. For example see callTracer's [config](/docs/evm-tracing/builtin-tracers#config).
Geth comes with a bundle of [built-in tracers](/docs/evm-tracing/builtin-tracers), each providing various data about a transaction. This method defaults to the [struct logger](/docs/evm-tracing/builtin-tracers#structopcode-logger). The `tracer` field of the second parameter can be set to use any of the other tracers. Alternatively a [custom tracer](/docs/evm-tracing/custom-tracer) can be implemented in either Go or Javascript.
`step` is a function that takes two arguments, `log` and `db`, and is called for each step
of the EVM, or when an error occurs, as the specified transaction is traced.
`log` has the following fields:
- `op`: Object, an OpCode object representing the current opcode
- `stack`: Object, a structure representing the EVM execution stack
- `memory`: Object, a structure representing the contract's memory space
- `contract`: Object, an object representing the account executing the current operation
and the following methods:
- `getPC()` - returns a Number with the current program counter
- `getGas()` - returns a Number with the amount of gas remaining
- `getCost()` - returns the cost of the opcode as a Number
- `getDepth()` - returns the execution depth as a Number
- `getRefund()` - returns the amount to be refunded as a Number
- `getError()` - returns information about the error if one occured, otherwise returns `undefined`
If error is non-empty, all other fields should be ignored.
For efficiency, the same `log` object is reused on each execution step, updated with current values; make sure to copy values you want to preserve beyond the current call. For instance, this step function will not work:
- `isPush()` - returns true if the opcode is a PUSHn
- `toString()` - returns the string representation of the opcode
- `toNumber()` - returns the opcode's number
`log.memory` has the following methods:
- `slice(start, stop)` - returns the specified segment of memory as a byte slice
- `getUint(offset)` - returns the 32 bytes at the given offset
- `length()` - returns the memory size
`log.stack` has the following methods:
- `peek(idx)` - returns the idx-th element from the top of the stack (0 is the topmost element) as a big.Int
- `length()` - returns the number of elements in the stack
`log.contract` has the following methods:
- `getCaller()` - returns the address of the caller
- `getAddress()` - returns the address of the current contract
- `getValue()` - returns the amount of value sent from caller to contract as a big.Int
- `getInput()` - returns the input data passed to the contract
`db` has the following methods:
- `getBalance(address)` - returns a `big.Int` with the specified account's balance
- `getNonce(address)` - returns a Number with the specified account's nonce
- `getCode(address)` - returns a byte slice with the code for the specified account
- `getState(address, hash)` - returns the state value for the specified account and the specified hash
- `exists(address)` - returns true if the specified address exists
If the step function throws an exception or executes an illegal operation at any point, it will not be called on any further VM steps, and the error will be returned to the caller.
##### Result {#result}
`result` is a function that takes two arguments `ctx` and `db`, and is expected to return a JSON-serializable value to return to the RPC caller.
`ctx` is the context in which the transaction is executing and has the following fields:
- `type` - String, one of the two values `CALL` and `CREATE`
- `from` - Address, sender of the transaction
- `to` - Address, target of the transaction
- `input` - Buffer, input transaction data
- `gas` - Number, gas budget of the transaction
- `gasUsed` - Number, amount of gas used in executing the transaction (excludes txdata costs)
- `gasPrice` - Number, gas price configured in the transaction being executed
- `intrinsicGas` - Number, intrinsic gas for the transaction being executed
- `value` - big.Int, amount to be transferred in wei
- `block` - Number, block number
- `output` - Buffer, value returned from EVM
- `time` - String, execution runtime
And these fields are only available for tracing mined transactions (i.e. not available when doing `debug_traceCall`):
- `blockHash` - Buffer, hash of the block that holds the transaction being executed
- `txIndex` - Number, index of the transaction being executed in the block
- `txHash` - Buffer, hash of the transaction being executed
##### Fault {#fault}
`fault` is a function that takes two arguments, `log` and `db`, just like `step` and is invoked when an error happens during the execution of an opcode which wasn't reported in `step`. The method `log.getError()` has information about the error.
##### Enter & Exit {#enter-and-exit}
`enter` and `exit` are respectively invoked on stepping in and out of an internal call. More specifically they are invoked on the `CALL` variants, `CREATE` variants and also for the transfer implied by a `SELFDESTRUCT`.
`enter` takes a `callFrame` object as argument which has the following methods:
- `getType()` - returns a string which has the type of the call frame
- `getFrom()` - returns the address of the call frame sender
- `getTo()` - returns the address of the call frame target
- `getInput()` - returns the input as a buffer
- `getGas()` - returns a Number which has the amount of gas provided for the frame
- `getValue()` - returns a `big.Int` with the amount to be transferred only if available, otherwise `undefined`
`exit` takes in a `frameResult` object which has the following methods:
- `getGasUsed()` - returns amount of gas used throughout the frame as a Number
- `getOutput()` - returns the output as a buffer
` -getError()` - returns an error if one occured during execution and `undefined` otherwise
##### Usage {#usage}
Note that several values are Golang big.Int objects, not JavaScript numbers or JS bigints. As such, they have the same interface as described in the godocs. Their default serialization to JSON is as a Javascript number; to serialize large numbers accurately call `.String()` on them. For convenience, `big.NewInt(x)` is provided, and will convert a uint to a Go BigInt.
Usage example, returns the top element of the stack at each CALL opcode only:
@ -924,15 +745,13 @@ Sets the logging verbosity pattern.
#### Examples
If you want to see messages from a particular Go package (directory)
and all subdirectories, use:
If you want to see messages from a particular Go package (directory) and all subdirectories, use:
``` javascript
> debug.vmodule("eth/*=6")
```
If you want to restrict messages to a particular package (e.g. p2p)
but exclude subdirectories, use:
If you want to restrict messages to a particular package (e.g. p2p) but exclude subdirectories, use:
``` javascript
> debug.vmodule("p2p=6")
@ -944,16 +763,13 @@ If you want to see log messages from a particular source file, use
> debug.vmodule("server.go=6")
```
You can compose these basic patterns. If you want to see all
output from peer.go in a package below eth (eth/peer.go,
eth/downloader/peer.go) as well as output from package p2p
at level <= 5, use:
You can compose these basic patterns. If you want to see all output from peer.go in a package below eth (eth/peer.go, eth/downloader/peer.go) as well as output from package p2p at level <= 5, use:
Note that the profiling rate cannot be set through the API,
it must be set on the command line using the `--pprof.memprofilerate`
flag.
Writes an allocation profile to the given file. Note that the profiling rate cannot be set through the API, it must be set on the command line using the `--pprof.memprofilerate` flag.
@ -211,7 +211,7 @@ Example call (use the following as a template for `<data>` in `curl --data <data
### personal_signTransaction
`personal_signTransaction` was used to create and sign a transaction from the given arguments. The transaction was returned in RLP-form, not broadcast to other nodes. The equivalent method is Clef's `account_signTransaction` from the external API. The arguments are a transaction object (`{"from": , "to": , "gas": , "maxPriorityFeePerGas": , "MaxFeePerGas": , "value": , "data": , "nonce": }`)) and a method signature
`personal_signTransaction` was used to create and sign a transaction from the given arguments. The transaction was returned in RLP-form, not broadcast to other nodes. The equivalent method is Clef's `account_signTransaction` from the external API. The arguments are a transaction object (`{"from": , "to": , "gas": , "maxPriorityFeePerGas": , "MaxFeePerGas": , "value": , "data": , "nonce": }`)) and an optional method signature that enables Clef to decode the calldata and show the user the methods, arguments and values being sent.
Joe
2 years ago