Here we add a Go API for running tracing plugins within the main block import process.
As an advanced user of geth, you can now create a Go file in eth/tracers/live/, and within
that file register your custom tracer implementation. Then recompile geth and select your tracer
on the command line. Hooks defined in the tracer will run whenever a block is processed.
The hook system is defined in package core/tracing. It uses a struct with callbacks, instead of
requiring an interface, for several reasons:
- We plan to keep this API stable long-term. The core/tracing hook API does not depend on
on deep geth internals.
- There are a lot of hooks, and tracers will only need some of them. Using a struct allows you
to implement only the hooks you want to actually use.
All existing tracers in eth/tracers/native have been rewritten to use the new hook system.
This change breaks compatibility with the vm.EVMLogger interface that we used to have.
If you are a user of vm.EVMLogger, please migrate to core/tracing, and sorry for breaking
your stuff. But we just couldn't have both the old and new tracing APIs coexist in the EVM.
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Co-authored-by: Matthieu Vachon <matthieu.o.vachon@gmail.com>
Co-authored-by: Delweng <delweng@gmail.com>
Co-authored-by: Martin HS <martin@swende.se>
The prestateTracer was reporting an inaccurate nonce for the contract being created in
post EIP-158 transactions. Correct nonce is 0, due to the issue nonce was being reported as 1.
In the tracing tests, the base fee was generally set to nil. This commit changes this to pass the proper base instead, and fixes the few tests which become broken by the change.
Currently, one can use the "withLogs" parameter to include logs in the
callTracer results, which allows the user to see at which trace level
was each log emitted.
This commit adds a position field to the logs which determine
the exact ordering of a call's logs and its subcalls. This would
be useful e.g. for explorers wishing to display the flow of execution.
Co-authored-by: jsvisa <delweng@gmail.com>
This PR removes the Debug field from vmconfig, making it so that if a tracer is set, debug=true is implied.
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Co-authored-by: 0xTylerHolmes <tyler@ethereum.org>
Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>
This includes a semantic change to the `callTracer` as well as `flatCallTracer`.
The value of field `gas` in the **first** call frame will change as follows:
- It previously contained gas available after initial deductions (i.e. tx costs)
- It will now contain the full tx gasLimit value
Signed-off-by: jsvisa <delweng@gmail.com>
This PR fixes OOM panic in the callTracer as well as panicing on
opcode validation errors (e.g. stack underflow) in callTracer and
prestateTracer.
Co-authored-by: Martin Holst Swende <martin@swende.se>
Here, the core.Message interface turns into a plain struct and
types.Message gets removed.
This is a breaking change to packages core and core/types. While we do
not promise API stability for package core, we do for core/types. An
exception can be made for types.Message, since it doesn't have any
purpose apart from invoking the state transition in package core.
types.Message was also marked deprecated by the same commit it
got added in, 4dca5d4db7 (November 2016).
The core.Message interface was added in December 2014, in commit
db494170dc, for the purpose of 'testing' state transitions. It's the
same change that made transaction struct fields private. Before that,
the state transition used *types.Transaction directly.
Over time, multiple implementations of the interface accrued across
different packages, since constructing a Message is required whenever
one wants to invoke the state transition. These implementations all
looked very similar, a struct with private fields exposing the fields
as accessor methods.
By changing Message into a struct with public fields we can remove all
these useless interface implementations. It will also hopefully
simplify future changes to the type with less updates to apply across
all of go-ethereum when a field is added to Message.
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Co-authored-by: Felix Lange <fjl@twurst.com>
Adds support for a native call tracer with the Parity format, which outputs call frames
in a flat array. This tracer accepts the following options:
- `convertParityErrors: true` will convert error messages to match those of Parity
- `includePrecompiles: true` will report all calls to precompiles. The default
matches Parity's behavior where CALL and STATICCALLs to precompiles are excluded
Incompatibilities with Parity include:
- Parity removes the result object in case of failure. This behavior is maintained
with the exception of reverts. Revert output usually contains useful information,
i.e. Solidity revert reason.
- The `gasUsed` field accounts for intrinsic gas (e.g. 21000 for simple transfers)
and refunds unlike Parity
- Block rewards are not reported
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
This is a breaking change in the tracing hooks API as well as semantics of the callTracer:
- CaptureEnter hook provided a nil value argument in case of DELEGATECALL. However to stay consistent with how delegate calls behave in EVM this hook is changed to pass in the value of the parent call.
- callTracer will return parent call's value for DELEGATECALL frames.
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Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
This PR changes the API so that uint64 is used for fork timestamps.
It's a good choice because types.Header also uses uint64 for time.
Co-authored-by: Felix Lange <fjl@twurst.com>
This makes non-JS tracers execute all block txs on a single goroutine.
In the previous implementation, we used to prepare every tx pre-state
on one goroutine, and then run the transactions again with tracing enabled.
Native tracers are usually faster, so it is faster overall to use their output as
the pre-state for tracing the next transaction.
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
In some cases, it is desirable to capture what is triggered by each trace, when using the `callTracer`. For example: call `USDT.transfer` will trigger a `Transfer(from, to, value)` event.
This PR adds the option to capture logs to the call tracer, by specifying `{"withLog": true}` in the tracerconfig.
Any logs belonging to failed/reverted call-scopes are removed from the output, to prevent interpretation mistakes.
Signed-off-by: Delweng <delweng@gmail.com>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
Inner call reverts will now return the reason similar to the top-level call. Separately, if top-level call is of type CREATE and it fails, its `to` field will now be cleared to `0x00...00` instead of being set to the created address.
* eth/tracers: fix gasUsed in call tracer
* fix js tracers gasUsed
* fix legacy prestate tracer
* fix restGas in test
* drop intrinsicGas field from js tracers
The prestate tracer did not report accounts that existed at a given address prior to a contract being created at that address.
Signed-off-by: Delweng <delweng@gmail.com>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
In some cases, inner contract creation may not be successful, and an inner contract was not created. This PR fixes a crash that could occur when doing tracing in such situations.
Backwards compatibility warning: The result will from now on omit empty fields instead
of including a zero value (e.g. no more `balance: '0x'`).
The prestateTracer will now take an option `diffMode: bool`. In this mode
the tracer will output the pre state and post data for the modified parts of state.
Read-only accesses will be completely omitted. Creations (be it account or slot)
will be signified by omission in the `pre` list and inclusion in `post`. Whereas
deletion (be it account or slot) will be signified by inclusion in `pre` and omission
in `post` list.
Signed-off-by: Delweng <delweng@gmail.com>
This PR allows users to pass in a config object directly to the tracers. Previously only the struct logger was configurable.
It also adds an option to the call tracer which if enabled makes it ignore any subcall and collect only information about the top-level call. See #25419 for discussion.
The tracers will silently ignore if they are passed a config they don't care about.
#23773 added a JS tracer which uses Goja as its engine. In this PR I remove the previous tracer which used duktape as well as remove the dependencies.
This PR also comes with 2 fixes in the Goja tracer and one small behavioural change:
I had handled errors in the native Go functions by panicing. My oversight was that Goja only handles panics with a Goja.Value as argument. The difference is panic(goja.Value) allows JS to catch the exception whereas Interrupt(error) doesn't.
There was a race in how I handled Stop.
Because of 1. some of the methods that simply return nil on error (like memory.slice) now throw an exception.
This adds a JS tracer runtime environment based on the Goja VM. The new
runtime replaces the duktape runtime, which will be removed soon.
Goja is implemented in Go and is faster for cases where the Go <-> JS
transition overhead dominates overall performance. It is faster because
duktape is written in C, and the transition cost includes the cost of using
cgo. Another reason for using Goja is that go-duktape is not maintained
anymore.
We expect the performace of JS tracing to be at least as good or better with
this change.
This change introduces 2 new optional methods; `enter()` and `exit()` for js tracers, and makes `step()` optiona. The two new methods are invoked when entering and exiting a call frame (but not invoked for the outermost scope, which has it's own methods). Currently these are the data fields passed to each of them:
enter: type (opcode), from, to, input, gas, value
exit: output, gasUsed, error
The PR also comes with a re-write of the callTracer. As a backup we keep the previous tracing script under the name `callTracerLegacy`. Behaviour of both tracers are equivalent for the most part, although there are some small differences (improvements), where the new tracer is more correct / has more information.
