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 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>
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>
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.
