resize.js 3.5 KB

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  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", {
  3. value: true
  4. });
  5. exports.resizeSectionByteSize = resizeSectionByteSize;
  6. exports.resizeSectionVecSize = resizeSectionVecSize;
  7. var _wasmGen = require("@webassemblyjs/wasm-gen");
  8. var _ast = require("@webassemblyjs/ast");
  9. var _helperBuffer = require("@webassemblyjs/helper-buffer");
  10. var debug = require("debug")("webassemblyjs:wasm:resizesection");
  11. function resizeSectionByteSize(ast, uint8Buffer, section, deltaBytes) {
  12. var sectionMetadata = (0, _ast.getSectionMetadata)(ast, section);
  13. if (typeof sectionMetadata === "undefined") {
  14. throw new Error("Section metadata not found");
  15. }
  16. if (typeof sectionMetadata.size.loc === "undefined") {
  17. throw new Error("SectionMetadata " + section + " has no loc");
  18. } // keep old node location to be overriden
  19. var start = sectionMetadata.size.loc.start.column;
  20. var end = sectionMetadata.size.loc.end.column;
  21. var newSectionSize = sectionMetadata.size.value + deltaBytes;
  22. var newBytes = (0, _wasmGen.encodeU32)(newSectionSize);
  23. /**
  24. * update AST
  25. */
  26. sectionMetadata.size.value = newSectionSize;
  27. var oldu32EncodedLen = end - start;
  28. var newu32EncodedLen = newBytes.length; // the new u32 has a different encoded length
  29. if (newu32EncodedLen !== oldu32EncodedLen) {
  30. console.warn("LEB128 encoding changed, this might lead to bugs");
  31. var deltaInSizeEncoding = newu32EncodedLen - oldu32EncodedLen;
  32. sectionMetadata.size.loc.end.column = start + newu32EncodedLen;
  33. deltaBytes += deltaInSizeEncoding; // move the vec size pointer size the section size is now smaller
  34. sectionMetadata.vectorOfSize.loc.start.column += deltaInSizeEncoding;
  35. sectionMetadata.vectorOfSize.loc.end.column += deltaInSizeEncoding;
  36. } // Once we hit our section every that is after needs to be shifted by the delta
  37. var encounteredSection = false;
  38. (0, _ast.traverse)(ast, {
  39. SectionMetadata: function SectionMetadata(path) {
  40. if (path.node.section === section) {
  41. encounteredSection = true;
  42. return;
  43. }
  44. if (encounteredSection === true) {
  45. (0, _ast.shiftSection)(ast, path.node, deltaBytes);
  46. debug("shift section section=%s detla=%d", path.node.section, deltaBytes);
  47. }
  48. }
  49. });
  50. debug("resize byte size section=%s newValue=%s start=%d end=%d", section, newSectionSize, start, end);
  51. return (0, _helperBuffer.overrideBytesInBuffer)(uint8Buffer, start, end, newBytes);
  52. }
  53. function resizeSectionVecSize(ast, uint8Buffer, section, deltaElements) {
  54. var sectionMetadata = (0, _ast.getSectionMetadata)(ast, section);
  55. if (typeof sectionMetadata === "undefined") {
  56. throw new Error("Section metadata not found");
  57. }
  58. if (typeof sectionMetadata.vectorOfSize.loc === "undefined") {
  59. throw new Error("SectionMetadata " + section + " has no loc");
  60. } // Section has no vector
  61. if (sectionMetadata.vectorOfSize.value === -1) {
  62. return uint8Buffer;
  63. } // keep old node location to be overriden
  64. var start = sectionMetadata.vectorOfSize.loc.start.column;
  65. var end = sectionMetadata.vectorOfSize.loc.end.column;
  66. var newValue = sectionMetadata.vectorOfSize.value + deltaElements;
  67. var newBytes = (0, _wasmGen.encodeU32)(newValue); // Update AST
  68. sectionMetadata.vectorOfSize.value = newValue;
  69. sectionMetadata.vectorOfSize.loc.end.column = start + newBytes.length;
  70. debug("resize vec size section=%s detla=%d newValue=%s", section, deltaElements, newValue);
  71. return (0, _helperBuffer.overrideBytesInBuffer)(uint8Buffer, start, end, newBytes);
  72. }