| import { encodeU32 } from "@webassemblyjs/wasm-gen"; |
| import { getSectionMetadata, traverse, shiftSection } from "@webassemblyjs/ast"; |
| import { overrideBytesInBuffer } from "@webassemblyjs/helper-buffer"; |
| export function resizeSectionByteSize(ast, uint8Buffer, section, deltaBytes) { |
| var sectionMetadata = getSectionMetadata(ast, section); |
| |
| if (typeof sectionMetadata === "undefined") { |
| throw new Error("Section metadata not found"); |
| } |
| |
| if (typeof sectionMetadata.size.loc === "undefined") { |
| throw new Error("SectionMetadata " + section + " has no loc"); |
| } // keep old node location to be overriden |
| |
| |
| var start = sectionMetadata.size.loc.start.column; |
| var end = sectionMetadata.size.loc.end.column; |
| var newSectionSize = sectionMetadata.size.value + deltaBytes; |
| var newBytes = encodeU32(newSectionSize); |
| /** |
| * update AST |
| */ |
| |
| sectionMetadata.size.value = newSectionSize; |
| var oldu32EncodedLen = end - start; |
| var newu32EncodedLen = newBytes.length; // the new u32 has a different encoded length |
| |
| if (newu32EncodedLen !== oldu32EncodedLen) { |
| var deltaInSizeEncoding = newu32EncodedLen - oldu32EncodedLen; |
| sectionMetadata.size.loc.end.column = start + newu32EncodedLen; |
| deltaBytes += deltaInSizeEncoding; // move the vec size pointer size the section size is now smaller |
| |
| sectionMetadata.vectorOfSize.loc.start.column += deltaInSizeEncoding; |
| sectionMetadata.vectorOfSize.loc.end.column += deltaInSizeEncoding; |
| } // Once we hit our section every that is after needs to be shifted by the delta |
| |
| |
| var encounteredSection = false; |
| traverse(ast, { |
| SectionMetadata: function SectionMetadata(path) { |
| if (path.node.section === section) { |
| encounteredSection = true; |
| return; |
| } |
| |
| if (encounteredSection === true) { |
| shiftSection(ast, path.node, deltaBytes); |
| } |
| } |
| }); |
| return overrideBytesInBuffer(uint8Buffer, start, end, newBytes); |
| } |
| export function resizeSectionVecSize(ast, uint8Buffer, section, deltaElements) { |
| var sectionMetadata = getSectionMetadata(ast, section); |
| |
| if (typeof sectionMetadata === "undefined") { |
| throw new Error("Section metadata not found"); |
| } |
| |
| if (typeof sectionMetadata.vectorOfSize.loc === "undefined") { |
| throw new Error("SectionMetadata " + section + " has no loc"); |
| } // Section has no vector |
| |
| |
| if (sectionMetadata.vectorOfSize.value === -1) { |
| return uint8Buffer; |
| } // keep old node location to be overriden |
| |
| |
| var start = sectionMetadata.vectorOfSize.loc.start.column; |
| var end = sectionMetadata.vectorOfSize.loc.end.column; |
| var newValue = sectionMetadata.vectorOfSize.value + deltaElements; |
| var newBytes = encodeU32(newValue); // Update AST |
| |
| sectionMetadata.vectorOfSize.value = newValue; |
| sectionMetadata.vectorOfSize.loc.end.column = start + newBytes.length; |
| return overrideBytesInBuffer(uint8Buffer, start, end, newBytes); |
| } |