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| 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); | |
| } |