| 1 | # @webassemblyjs/wasm-edit
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| 2 |
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| 3 | > Rewrite a WASM binary
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| 4 |
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| 5 | Replace in-place an AST node in the binary.
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| 6 |
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| 7 | ## Installation
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| 8 |
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| 9 | ```sh
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| 10 | yarn add @webassemblyjs/wasm-edit
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| 11 | ```
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| 12 |
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| 13 | ## Usage
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| 14 |
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| 15 | Update:
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| 16 |
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| 17 | ```js
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| 18 | import { edit } from "@webassemblyjs/wasm-edit";
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| 19 |
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| 20 | const binary = [/*...*/];
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| 21 |
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| 22 | const visitors = {
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| 23 | ModuleImport({ node }) {
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| 24 | node.module = "foo";
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| 25 | node.name = "bar";
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| 26 | }
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| 27 | };
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| 28 |
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| 29 | const newBinary = edit(binary, visitors);
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| 30 | ```
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| 31 |
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| 32 | Replace:
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| 33 |
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| 34 | ```js
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| 35 | import { edit } from "@webassemblyjs/wasm-edit";
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| 36 |
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| 37 | const binary = [/*...*/];
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| 38 |
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| 39 | const visitors = {
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| 40 | Instr(path) {
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| 41 | const newNode = t.callInstruction(t.indexLiteral(0));
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| 42 | path.replaceWith(newNode);
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| 43 | }
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| 44 | };
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| 45 |
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| 46 | const newBinary = edit(binary, visitors);
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| 47 | ```
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| 48 |
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| 49 | Remove:
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| 50 |
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| 51 | ```js
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| 52 | import { edit } from "@webassemblyjs/wasm-edit";
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| 53 |
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| 54 | const binary = [/*...*/];
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| 55 |
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| 56 | const visitors = {
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| 57 | ModuleExport({ node }) {
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| 58 | path.remove()
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| 59 | }
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| 60 | };
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| 61 |
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| 62 | const newBinary = edit(binary, visitors);
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| 63 | ```
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| 64 |
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| 65 | Insert:
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| 66 |
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| 67 | ```js
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| 68 | import { add } from "@webassemblyjs/wasm-edit";
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| 69 |
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| 70 | const binary = [/*...*/];
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| 71 |
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| 72 | const newBinary = add(actualBinary, [
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| 73 | t.moduleImport("env", "mem", t.memory(t.limit(1)))
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| 74 | ]);
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| 75 | ```
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| 76 |
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| 77 | ## Providing the AST
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| 78 |
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| 79 | Providing an AST allows you to handle the decoding yourself, here is the API:
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| 80 |
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| 81 | ```js
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| 82 | addWithAST(Program, ArrayBuffer, Array<Node>): ArrayBuffer;
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| 83 | editWithAST(Program, ArrayBuffer, visitors): ArrayBuffer;
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| 84 | ```
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| 85 |
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| 86 | Note that the AST will be updated in-place.
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