resize.js
2.83 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
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);
}