[6a3a178] | 1 | function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
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| 2 |
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| 3 | import { encodeNode } from "@webassemblyjs/wasm-gen";
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| 4 | import { overrideBytesInBuffer } from "@webassemblyjs/helper-buffer";
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| 5 | import constants from "@webassemblyjs/helper-wasm-bytecode";
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| 6 | import * as t from "@webassemblyjs/ast";
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| 7 |
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| 8 | function findLastSection(ast, forSection) {
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| 9 | var targetSectionId = constants.sections[forSection]; // $FlowIgnore: metadata can not be empty
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| 10 |
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| 11 | var moduleSections = ast.body[0].metadata.sections;
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| 12 | var lastSection;
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| 13 | var lastId = 0;
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| 14 |
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| 15 | for (var i = 0, len = moduleSections.length; i < len; i++) {
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| 16 | var section = moduleSections[i]; // Ignore custom section since they can actually occur everywhere
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| 17 |
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| 18 | if (section.section === "custom") {
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| 19 | continue;
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| 20 | }
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| 21 |
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| 22 | var sectionId = constants.sections[section.section];
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| 23 |
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| 24 | if (targetSectionId > lastId && targetSectionId < sectionId) {
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| 25 | return lastSection;
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| 26 | }
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| 27 |
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| 28 | lastId = sectionId;
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| 29 | lastSection = section;
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| 30 | }
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| 31 |
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| 32 | return lastSection;
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| 33 | }
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| 34 |
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| 35 | export function createEmptySection(ast, uint8Buffer, section) {
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| 36 | // previous section after which we are going to insert our section
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| 37 | var lastSection = findLastSection(ast, section);
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| 38 | var start, end;
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| 39 | /**
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| 40 | * It's the first section
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| 41 | */
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| 42 |
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| 43 | if (lastSection == null || lastSection.section === "custom") {
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| 44 | start = 8
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| 45 | /* wasm header size */
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| 46 | ;
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| 47 | end = start;
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| 48 | } else {
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| 49 | start = lastSection.startOffset + lastSection.size.value + 1;
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| 50 | end = start;
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| 51 | } // section id
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| 52 |
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| 53 |
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| 54 | start += 1;
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| 55 | var sizeStartLoc = {
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| 56 | line: -1,
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| 57 | column: start
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| 58 | };
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| 59 | var sizeEndLoc = {
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| 60 | line: -1,
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| 61 | column: start + 1
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| 62 | }; // 1 byte for the empty vector
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| 63 |
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| 64 | var size = t.withLoc(t.numberLiteralFromRaw(1), sizeEndLoc, sizeStartLoc);
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| 65 | var vectorOfSizeStartLoc = {
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| 66 | line: -1,
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| 67 | column: sizeEndLoc.column
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| 68 | };
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| 69 | var vectorOfSizeEndLoc = {
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| 70 | line: -1,
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| 71 | column: sizeEndLoc.column + 1
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| 72 | };
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| 73 | var vectorOfSize = t.withLoc(t.numberLiteralFromRaw(0), vectorOfSizeEndLoc, vectorOfSizeStartLoc);
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| 74 | var sectionMetadata = t.sectionMetadata(section, start, size, vectorOfSize);
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| 75 | var sectionBytes = encodeNode(sectionMetadata);
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| 76 | uint8Buffer = overrideBytesInBuffer(uint8Buffer, start - 1, end, sectionBytes); // Add section into the AST for later lookups
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| 77 |
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| 78 | if (_typeof(ast.body[0].metadata) === "object") {
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| 79 | // $FlowIgnore: metadata can not be empty
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| 80 | ast.body[0].metadata.sections.push(sectionMetadata);
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| 81 | t.sortSectionMetadata(ast.body[0]);
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| 82 | }
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| 83 | /**
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| 84 | * Update AST
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| 85 | */
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| 86 | // Once we hit our section every that is after needs to be shifted by the delta
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| 87 |
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| 88 |
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| 89 | var deltaBytes = +sectionBytes.length;
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| 90 | var encounteredSection = false;
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| 91 | t.traverse(ast, {
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| 92 | SectionMetadata: function SectionMetadata(path) {
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| 93 | if (path.node.section === section) {
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| 94 | encounteredSection = true;
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| 95 | return;
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| 96 | }
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| 97 |
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| 98 | if (encounteredSection === true) {
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| 99 | t.shiftSection(ast, path.node, deltaBytes);
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| 100 | }
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| 101 | }
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| 102 | });
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| 103 | return {
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| 104 | uint8Buffer: uint8Buffer,
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| 105 | sectionMetadata: sectionMetadata
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| 106 | };
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| 107 | } |
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