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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); | |
} |