Initial ewasm parsing

Author: fergarrui

package-lock.json

@@ -66,10 +66,13 @@
   },
   "dependencies": {
     "@types/express": "^4.16.0",
+    "@webassemblyjs/leb128": "^1.8.5",
+    "@webassemblyjs/wasm-parser": "^1.8.5",
     "async-polling": "^0.2.1",
     "bn.js": "^4.11.8",
     "body-parser": "^1.18.3",
     "brace": "^0.11.1",
+    "command-exists": "^1.2.8",
     "copyfiles": "^2.1.0",
     "d3": "^5.7.0",
     "d3-graphviz": "^2.6.0",
@@ -90,7 +93,9 @@
     "reflect-metadata": "^0.1.12",
     "solc": "^0.5.8",
     "terser": "3.14.1",
+    "tmp": "^0.1.0",
     "tsoa": "2.3.81",
+    "wabt": "^1.0.12",
     "web3": "1.0.0-beta.37",
     "winston": "^2.2.0"
   },
@@ -120,6 +125,7 @@
     "sass-resources-loader": "^2.0.0",
     "style-loader": "^0.23.1",
     "ts-jest": "^22.4.6",
+    "ts-node": "^8.5.4",
     "tslint-config-prettier": "^1.14.0",
     "typescript": "^3.1.3",
     "webpack": "^4.25.1",

package.json

@@ -1,6 +1,6 @@
 import { Disassembler } from './Disassembler'
 import { Operation } from './Operation'
-import { Opcodes } from './Opcodes'
+import { EVMOpcodes } from './EVMOpcodes'
 import { injectable, inject } from 'inversify'
 import { Opcode } from './Opcode'
 import { DisassembledContract } from './DisassembledContract'
@@ -106,7 +106,7 @@ export class EVMDisassembler implements Disassembler {
 
     for (let i = 0; i < operations.length; i++) {
       const code = operations[i]
-      const opcode: Opcode = Opcodes.opcodes[parseInt(code, 16)] || Opcodes.opcodes[-1]
+      const opcode: Opcode = EVMOpcodes.opcodes[parseInt(code, 16)] || EVMOpcodes.opcodes[-1]
       if (this.isPush(opcode)) {
         const parameters = opcode.parameters
         const argument = `${operations.slice(i + 1, i + parameters + 1).join('')}`

src/api/bytecode/EVMDisassembler.ts

@@ -1,6 +1,6 @@
 import { Opcode } from './Opcode'
 
-export class Opcodes {
+export class EVMOpcodes {
   static opcodes = {}
 
   static populate() {
@@ -161,4 +161,4 @@ export class Opcodes {
   }
 }
 
-Opcodes.populate()
+EVMOpcodes.populate()

src/api/bytecode/Opcodes.ts renamed to src/api/bytecode/EVMOpcodes.ts

@@ -0,0 +1,71 @@
+export class BytesReader {
+
+  private pointer: number
+  private buffer: Buffer
+
+  constructor(buffer: Buffer) {
+    this.buffer = buffer
+    this.pointer = 0
+  }
+  
+  readBytes(bytesNumber: number): Buffer {
+    const result = this.buffer.slice(this.pointer, bytesNumber + this.pointer)
+    this.pointer += bytesNumber
+    return result
+  }
+
+  readBytesToHex(bytesNumber: number): string {
+    const result = this.readBytes(bytesNumber)
+    return result.toString('hex')
+  }
+
+  readBytesToNumber(bytesNumber: number): number {
+    const result = this.readBytesToHex(bytesNumber)
+    return parseInt(result, 16)
+  }
+
+  readBytesToUtf8String(bytesNumber: number): string {
+    const result = this.readBytes(bytesNumber)
+    return result.toString('utf8')
+  }
+
+  readVarUint32(): number {
+    var result = 0
+    var shift = 0
+    while (true) {
+      var byte = parseInt(this.readBytesToHex(1), 16)
+      result |= (byte & 0x7F) << shift
+      shift += 7
+      if ((byte & 0x80) === 0){
+        break
+      }
+    }
+    return result
+  }
+
+  private readVarInt32(): number {
+    var result = 0
+    var shift = 0
+    while (true) {
+      var byte = parseInt(this.readBytesToHex(1), 16)
+      result |= (byte & 0x7F) << shift
+      shift += 7
+      if ((byte & 0x80) === 0) {
+        break;
+      }
+    }
+    if (shift >= 32) {
+      return result
+    }
+    var ashift = (32 - shift)
+    return (result << ashift) >> ashift
+  }
+
+  getPointer(): number {
+    return this.pointer
+  }
+
+  finished(): boolean {
+    return this.pointer >= this.buffer.length
+  }
+}

src/api/bytecode/ewasm/BytesReader.ts

@@ -0,0 +1,7 @@
+import { WasmExternalKind } from "./wasmTypes";
+
+export interface ExportEntry {
+  name: string
+  kind: WasmExternalKind
+  index: number
+}

src/api/bytecode/ewasm/ExportEntry.ts

@@ -0,0 +1,7 @@
+import { WasmValueType } from "./wasmTypes";
+
+export interface FuncType {
+  index: number
+  params: WasmValueType[]
+  results: WasmValueType[]
+}