core/vm: Refactor tracing to make Tracer the main interface

This CL makes several refactors:
 - Define a Tracer interface, implementing the `CaptureState` method
 - Add the VM environment as the first argument of
   `Tracer.CaptureState`
 - Rename existing functionality `StructLogger` an make it an
   implementation of `Tracer`
 - Delete `StructLogCollector` and make `StructLogger` collect the logs
   directly
 - Change all callers to use the new `StructLogger` where necessary and
   extract logs from that.
 - Deletes the apparently obsolete and likely nonfunctional 'TraceCall'
   from the eth API.

Callers that only wish accumulated logs can use the `StructLogger`
implementation straightforwardly. Callers that wish to efficiently
capture VM traces and operate on them without excessive copying can now
implement the `Tracer` interface to receive VM state at each step and
do with it as they wish.

This CL also removes the accumulation of logs from the vm.Environment;
this was necessary as part of the refactor, but also simplifies it by
removing a responsibility that doesn't directly belong to the
Environment.

1 files changed, 3 insertions, 3 deletions

diff --git a/core/vm/jit.go b/core/vm/jit.go
index e2374df42..460a68ddd 100644
--- a/core/vm/jit.go
+++ b/core/vm/jit.go
@@ -303,7 +303,7 @@ func RunProgram(program *Program, env Environment, contract *Contract, input []b
 	return runProgram(program, 0, NewMemory(), newstack(), env, contract, input)
 }
 
-func runProgram(program *Program, pcstart uint64, mem *Memory, stack *stack, env Environment, contract *Contract, input []byte) ([]byte, error) {
+func runProgram(program *Program, pcstart uint64, mem *Memory, stack *Stack, env Environment, contract *Contract, input []byte) ([]byte, error) {
 	contract.Input = input
 
 	var (
@@ -357,7 +357,7 @@ func validDest(dests map[uint64]struct{}, dest *big.Int) bool {
 
 // jitCalculateGasAndSize calculates the required given the opcode and stack items calculates the new memorysize for
 // the operation. This does not reduce gas or resizes the memory.
-func jitCalculateGasAndSize(env Environment, contract *Contract, instr instruction, statedb Database, mem *Memory, stack *stack) (*big.Int, *big.Int, error) {
+func jitCalculateGasAndSize(env Environment, contract *Contract, instr instruction, statedb Database, mem *Memory, stack *Stack) (*big.Int, *big.Int, error) {
 	var (
 		gas                 = new(big.Int)
 		newMemSize *big.Int = new(big.Int)
@@ -491,7 +491,7 @@ func jitCalculateGasAndSize(env Environment, contract *Contract, instr instructi
 
 // jitBaseCheck is the same as baseCheck except it doesn't do the look up in the
 // gas table. This is done during compilation instead.
-func jitBaseCheck(instr instruction, stack *stack, gas *big.Int) error {
+func jitBaseCheck(instr instruction, stack *Stack, gas *big.Int) error {
 	err := stack.require(instr.spop)
 	if err != nil {
 		return err