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.
---------
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>
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>
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.
---------
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>
