1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// callTracer is a full blown transaction tracer that extracts and reports all
// the internal calls made by a transaction, along with any useful information.
{
// callstack is the current recursive call stack of the EVM execution.
callstack: [{}],
// descended tracks whether we've just descended from an outer transaction into
// an inner call.
descended: false,
// step is invoked for every opcode that the VM executes.
step: function(log, db) {
// Capture any errors immediately
var error = log.getError();
if (error !== undefined) {
this.fault(log, db);
return;
}
// We only care about system opcodes, faster if we pre-check once
var syscall = (log.op.toNumber() & 0xf0) == 0xf0;
if (syscall) {
var op = log.op.toString();
}
// If a new contract is being created, add to the call stack
if (syscall && (op == 'CREATE' || op == "CREATE2")) {
var inOff = log.stack.peek(1).valueOf();
var inEnd = inOff + log.stack.peek(2).valueOf();
// Assemble the internal call report and store for completion
var call = {
type: op,
from: toHex(log.contract.getAddress()),
input: toHex(log.memory.slice(inOff, inEnd)),
gasIn: log.getGas(),
gasCost: log.getCost(),
value: '0x' + log.stack.peek(0).toString(16)
};
this.callstack.push(call);
this.descended = true
return;
}
// If a contract is being self destructed, gather that as a subcall too
if (syscall && op == 'SELFDESTRUCT') {
var left = this.callstack.length;
if (this.callstack[left-1].calls === undefined) {
this.callstack[left-1].calls = [];
}
this.callstack[left-1].calls.push({type: op});
return
}
// If a new method invocation is being done, add to the call stack
if (syscall && (op == 'CALL' || op == 'CALLCODE' || op == 'DELEGATECALL' || op == 'STATICCALL')) {
// Skip any pre-compile invocations, those are just fancy opcodes
var to = toAddress(log.stack.peek(1).toString(16));
if (isPrecompiled(to)) {
return
}
var off = (op == 'DELEGATECALL' || op == 'STATICCALL' ? 0 : 1);
var inOff = log.stack.peek(2 + off).valueOf();
var inEnd = inOff + log.stack.peek(3 + off).valueOf();
// Assemble the internal call report and store for completion
var call = {
type: op,
from: toHex(log.contract.getAddress()),
to: toHex(to),
input: toHex(log.memory.slice(inOff, inEnd)),
gasIn: log.getGas(),
gasCost: log.getCost(),
outOff: log.stack.peek(4 + off).valueOf(),
outLen: log.stack.peek(5 + off).valueOf()
};
if (op != 'DELEGATECALL' && op != 'STATICCALL') {
call.value = '0x' + log.stack.peek(2).toString(16);
}
this.callstack.push(call);
this.descended = true
return;
}
// If we've just descended into an inner call, retrieve it's true allowance. We
// need to extract if from within the call as there may be funky gas dynamics
// with regard to requested and actually given gas (2300 stipend, 63/64 rule).
if (this.descended) {
if (log.getDepth() >= this.callstack.length) {
this.callstack[this.callstack.length - 1].gas = log.getGas();
} else {
// TODO(karalabe): The call was made to a plain account. We currently don't
// have access to the true gas amount inside the call and so any amount will
// mostly be wrong since it depends on a lot of input args. Skip gas for now.
}
this.descended = false;
}
// If an existing call is returning, pop off the call stack
if (syscall && op == 'REVERT') {
this.callstack[this.callstack.length - 1].error = "execution reverted";
return;
}
if (log.getDepth() == this.callstack.length - 1) {
// Pop off the last call and get the execution results
var call = this.callstack.pop();
if (call.type == 'CREATE' || call.type == "CREATE2") {
// If the call was a CREATE, retrieve the contract address and output code
call.gasUsed = '0x' + bigInt(call.gasIn - call.gasCost - log.getGas()).toString(16);
delete call.gasIn; delete call.gasCost;
var ret = log.stack.peek(0);
if (!ret.equals(0)) {
call.to = toHex(toAddress(ret.toString(16)));
call.output = toHex(db.getCode(toAddress(ret.toString(16))));
} else if (call.error === undefined) {
call.error = "internal failure"; // TODO(karalabe): surface these faults somehow
}
} else {
// If the call was a contract call, retrieve the gas usage and output
if (call.gas !== undefined) {
call.gasUsed = '0x' + bigInt(call.gasIn - call.gasCost + call.gas - log.getGas()).toString(16);
var ret = log.stack.peek(0);
if (!ret.equals(0)) {
call.output = toHex(log.memory.slice(call.outOff, call.outOff + call.outLen));
} else if (call.error === undefined) {
call.error = "internal failure"; // TODO(karalabe): surface these faults somehow
}
}
delete call.gasIn; delete call.gasCost;
delete call.outOff; delete call.outLen;
}
if (call.gas !== undefined) {
call.gas = '0x' + bigInt(call.gas).toString(16);
}
// Inject the call into the previous one
var left = this.callstack.length;
if (this.callstack[left-1].calls === undefined) {
this.callstack[left-1].calls = [];
}
this.callstack[left-1].calls.push(call);
}
},
// fault is invoked when the actual execution of an opcode fails.
fault: function(log, db) {
// If the topmost call already reverted, don't handle the additional fault again
if (this.callstack[this.callstack.length - 1].error !== undefined) {
return;
}
// Pop off the just failed call
var call = this.callstack.pop();
call.error = log.getError();
// Consume all available gas and clean any leftovers
if (call.gas !== undefined) {
call.gas = '0x' + bigInt(call.gas).toString(16);
call.gasUsed = call.gas
}
delete call.gasIn; delete call.gasCost;
delete call.outOff; delete call.outLen;
// Flatten the failed call into its parent
var left = this.callstack.length;
if (left > 0) {
if (this.callstack[left-1].calls === undefined) {
this.callstack[left-1].calls = [];
}
this.callstack[left-1].calls.push(call);
return;
}
// Last call failed too, leave it in the stack
this.callstack.push(call);
},
// result is invoked when all the opcodes have been iterated over and returns
// the final result of the tracing.
result: function(ctx, db) {
var result = {
type: ctx.type,
from: toHex(ctx.from),
to: toHex(ctx.to),
value: '0x' + ctx.value.toString(16),
gas: '0x' + bigInt(ctx.gas).toString(16),
gasUsed: '0x' + bigInt(ctx.gasUsed).toString(16),
input: toHex(ctx.input),
output: toHex(ctx.output),
time: ctx.time,
};
if (this.callstack[0].calls !== undefined) {
result.calls = this.callstack[0].calls;
}
if (this.callstack[0].error !== undefined) {
result.error = this.callstack[0].error;
} else if (ctx.error !== undefined) {
result.error = ctx.error;
}
if (result.error !== undefined) {
|