Fix: NUMBER delimiter and opcode count error in tracing (#56)

Author: hazim-j

pkg/entrypoint/simulation.go

@@ -23,13 +23,13 @@ var (
 	dummyPk, _ = crypto.GenerateKey()
 
 	// Up to the first number marker represents factory validation.
-	factoryNumberLevel = "0"
+	factoryNumberLevel = 0
 
 	// After the first number marker and before the second represents account validation.
-	accountNumberLevel = "1"
+	accountNumberLevel = 1
 
 	// After the second number marker represents paymaster validation.
-	paymasterNumberLevel = "2"
+	paymasterNumberLevel = 2
 
 	// Only one create2 opcode is allowed if these two conditions are met:
 	// 	1. op.initcode.length != 0

pkg/tracer/BundlerCollectorTracer.js

@@ -1,79 +1,112 @@
 // This is the same BundlerCollectorTracer from github.com/eth-infinitism/bundler transpiled down to ES5.
 
 var tracer = {
-  numberLevels: {},
+  numberLevels: [],
   currentLevel: null,
   keccak: [],
   calls: [],
   logs: [],
   debug: [],
   lastOp: "",
   numberCounter: 0,
-  count: 0,
 
-  fault: function (log, db) {
-    this.debug.push(["fault", log.getError()]);
+  fault: function fault(log, db) {
+    this.debug.push(
+      "fault depth=" +
+        log.getDepth() +
+        " gas=" +
+        log.getGas() +
+        " cost=" +
+        log.getCost() +
+        " err=" +
+        log.getError()
+    );
   },
-
-  result: function (ctx, db) {
+  result: function result(ctx, db) {
     return {
       numberLevels: this.numberLevels,
       keccak: this.keccak,
       logs: this.logs,
       calls: this.calls,
-      debug: this.debug,
+      debug: this.debug, // for internal debugging.
     };
   },
-
-  enter: function (frame) {
-    this.debug.push([
-      "enter " +
+  enter: function enter(frame) {
+    this.debug.push(
+      "enter gas=" +
+        frame.getGas() +
+        " type=" +
         frame.getType() +
-        " " +
+        " to=" +
         toHex(frame.getTo()) +
-        " " +
-        toHex(frame.getInput()).slice(0, 100),
-    ]);
-
+        " in=" +
+        toHex(frame.getInput()).slice(0, 500)
+    );
     this.calls.push({
       type: frame.getType(),
       from: toHex(frame.getFrom()),
       to: toHex(frame.getTo()),
+      method: toHex(frame.getInput()).slice(0, 10),
+      gas: frame.getGas(),
       value: frame.getValue(),
     });
   },
-
-  exit: function (frame) {
-    this.debug.push(
-      "exit err=" + frame.getError() + ", gas=" + frame.getGasUsed()
-    );
+  exit: function exit(frame) {
+    this.calls.push({
+      type: frame.getError() != null ? "REVERT" : "RETURN",
+      gasUsed: frame.getGasUsed(),
+      data: toHex(frame.getOutput()).slice(0, 1000),
+    });
   },
 
+  // increment the "key" in the list. if the key is not defined yet, then set it to "1"
   countSlot: function countSlot(list, key) {
-    list[key] += typeof list[key] == "number" ? 0 : 1;
+    if (!list[key]) list[key] = 0;
+    list[key] += 1;
   },
-
   step: function step(log, db) {
     var opcode = log.op.toString();
+    // this.debug.push(this.lastOp + '-' + opcode + '-' + log.getDepth() + '-' + log.getGas() + '-' + log.getCost())
+    if (log.getGas() < log.getCost()) {
+      this.currentLevel.oog = true;
+    }
 
-    if (opcode === "NUMBER") this.numberCounter++;
-
-    if (this.numberLevels[this.numberCounter] == null) {
-      this.currentLevel = this.numberLevels[this.numberCounter] = {
-        access: {},
-        opcodes: {},
-      };
+    if (opcode === "REVERT" || opcode === "RETURN") {
+      if (log.getDepth() === 1) {
+        // exit() is not called on top-level return/revert, so we reconstruct it
+        // from opcode
+        var ofs = parseInt(log.stack.peek(0).toString());
+        var len = parseInt(log.stack.peek(1).toString());
+        var data = toHex(log.memory.slice(ofs, ofs + len)).slice(0, 1000);
+        this.debug.push(opcode + " " + data);
+        this.calls.push({
+          type: opcode,
+          gasUsed: 0,
+          data: data,
+        });
+      }
     }
 
     if (log.getDepth() === 1) {
+      // NUMBER opcode at top level split levels
+      if (opcode === "NUMBER") this.numberCounter++;
+      if (this.numberLevels[this.numberCounter] == null) {
+        this.currentLevel = this.numberLevels[this.numberCounter] = {
+          access: {},
+          opcodes: {},
+          contractSize: {},
+        };
+      }
+      this.lastOp = "";
       return;
     }
 
     if (this.lastOp === "GAS" && !opcode.includes("CALL")) {
+      // count "GAS" opcode only if not followed by "CALL"
       this.countSlot(this.currentLevel.opcodes, "GAS");
     }
-
     if (opcode !== "GAS") {
+      // ignore "unimportant" opcodes:
       if (
         opcode.match(
           /^(DUP\d+|PUSH\d+|SWAP\d+|POP|ADD|SUB|MUL|DIV|EQ|LTE?|S?GTE?|SLT|SH[LR]|AND|OR|NOT|ISZERO)$/
@@ -82,51 +115,57 @@ var tracer = {
         this.countSlot(this.currentLevel.opcodes, opcode);
       }
     }
+    if (
+      opcode.match(/^(EXT.*|CALL|CALLCODE|DELEGATECALL|STATICCALL|CREATE2)$/) !=
+      null
+    ) {
+      // this.debug.push('op=' + opcode + ' last=' + this.lastOp + ' stacksize=' + log.stack.length())
+      var idx = opcode.startsWith("EXT") ? 0 : 1;
+      var addr = toAddress(log.stack.peek(idx).toString(16));
+      var addrHex = toHex(addr);
+      if (this.currentLevel.contractSize[addrHex] == null) {
+        this.currentLevel.contractSize[addrHex] = db.getCode(addr).length;
+      }
+    }
 
     this.lastOp = opcode;
 
     if (opcode === "SLOAD" || opcode === "SSTORE") {
       var slot = log.stack.peek(0).toString(16);
-      var addr = toHex(log.contract.getAddress());
+      var _addr = toHex(log.contract.getAddress());
       var access = void 0;
-
-      if ((access = this.currentLevel.access[addr]) == null) {
-        this.currentLevel.access[addr] = access = {
+      if ((access = this.currentLevel.access[_addr]) == null) {
+        this.currentLevel.access[_addr] = access = {
           reads: {},
           writes: {},
         };
       }
-
       this.countSlot(opcode === "SLOAD" ? access.reads : access.writes, slot);
     }
 
-    if (opcode === "REVERT" || opcode === "RETURN") {
-      var ofs = parseInt(log.stack.peek(0).toString());
-      var len = parseInt(log.stack.peek(1).toString());
-
-      this.debug.push(
-        opcode + " " + toHex(log.memory.slice(ofs, ofs + len)).slice(0, 100)
-      );
-    } else if (opcode === "KECCAK256") {
+    if (opcode === "KECCAK256") {
+      // collect keccak on 64-byte blocks
       var _ofs = parseInt(log.stack.peek(0).toString());
       var _len = parseInt(log.stack.peek(1).toString());
-
-      if (_len < 512) {
+      // currently, solidity uses only 2-word (6-byte) for a key. this might change..
+      // still, no need to return too much
+      if (_len > 20 && _len < 512) {
+        // if (len == 64) {
         this.keccak.push(toHex(log.memory.slice(_ofs, _ofs + _len)));
       }
     } else if (opcode.startsWith("LOG")) {
       var count = parseInt(opcode.substring(3));
       var _ofs2 = parseInt(log.stack.peek(0).toString());
       var _len2 = parseInt(log.stack.peek(1).toString());
-
       var topics = [];
       for (var i = 0; i < count; i++) {
+        // eslint-disable-next-line @typescript-eslint/restrict-plus-operands
         topics.push("0x" + log.stack.peek(2 + i).toString(16));
       }
-
+      var _data = toHex(log.memory.slice(_ofs2, _ofs2 + _len2));
       this.logs.push({
         topics: topics,
-        data: toHex(log.memory.slice(_ofs2, _ofs2 + _len2)),
+        data: _data,
       });
     }
   },

pkg/tracer/types.go

@@ -35,9 +35,9 @@ type LogInfo struct {
 
 // BundlerCollectorReturn is the return value from performing an EVM trace with BundlerCollectorTracer.js.
 type BundlerCollectorReturn struct {
-	NumberLevels map[string]NumberLevelInfo `json:"numberLevels"`
-	Keccak       []string                   `json:"keccak"`
-	Calls        []CallInfo                 `json:"calls"`
-	Logs         []LogInfo                  `json:"logs"`
-	Debug        []any                      `json:"debug"`
+	NumberLevels []NumberLevelInfo `json:"numberLevels"`
+	Keccak       []string          `json:"keccak"`
+	Calls        []CallInfo        `json:"calls"`
+	Logs         []LogInfo         `json:"logs"`
+	Debug        []any             `json:"debug"`
 }