The mux tracer fanned out every standard hook to its children but never
forwarded OnSystemCall{Start,End}. Tracers that rely on these - like
`logger.jsonLogger`, which uses the start hook to silence its opcode
hook for the duration of a system call - never got the signal when
wrapped behind a mux.
In evm t8n, combining `--trace` with `--opcode-count` (default for geth
with exec specs) produces exactly that wrapping. The first system call
(e.g. `ProcessBeaconBlockRoot`) then fires `OnOpcode` on the json logger
before any `OnTxStart` has run, dereferencing a nil env and crashing
t8n.
Forward both hooks through the mux. The V2 fan-out falls back to V1 for
children that only implement the legacy hook, mirroring the precedence
already used in `core/state_processor.go`.
Adds `--opcode.count=<file>` flag to `evm t8n` that writes per-opcode
execution frequency counts to a JSON file (relative to
`--output.basedir`).
---------
Co-authored-by: MariusVanDerWijden <m.vanderwijden@live.de>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
While updating to latest Geth, I noticed `OnCodeChangeV2` was not
properly handled in `SelfDestruct/6780`, this PR fixes this and bring a
unit test. Let me know if it's deemed more approriate to merge the tests
with the other one.
Breaking changes:
- The ChainConfig was exposed to tracers via VMContext passed in
`OnTxStart`. This is unnecessary specially looking through the lens of
live tracers as chain config remains the same throughout the lifetime of
the program. It was there so that native API-invoked tracers could
access it. So instead we moved it to the constructor of API tracers.
Non-breaking:
- Change the default config of the tracers to be `{}` instead of nil.
This way an extra nil check can be avoided.
Refactoring:
- Rename `supply` struct to `supplyTracer`.
- Un-export some hook definitions.
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>
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>
This removes the 'time' field from logs, as well as from the tracer interface. This change makes the trace output deterministic. If a tracer needs the time they can measure it themselves. No need for evm to do this.
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
