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Merged
merged 5 commits into from
Oct 13, 2020
Merged

Support big endian #13

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98e485a
support big endian
guybedford Oct 13, 2020
d3320af
second attempt
guybedford Oct 13, 2020
43d35ba
fixup iterator
guybedford Oct 13, 2020
4e16c06
fixes
guybedford Oct 13, 2020
7c86b91
finally working
guybedford Oct 13, 2020
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21 changes: 17 additions & 4 deletions src/lexer.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,17 +2,21 @@ const strictReserved = new Set(['implements', 'interface', 'let', 'package', 'pr

let wasm;

const isLE = new Uint8Array(new Uint16Array([1]).buffer)[0] === 1;

export function parse (source, name = '@') {
if (!wasm)
throw new Error('Not initialized');

const len = source.length + 1;

// need 2 bytes per code point plus analysis space so we double again
const extraMem = (wasm.__heap_base.value || wasm.__heap_base) + source.length * 4 - wasm.memory.buffer.byteLength;
const extraMem = (wasm.__heap_base.value || wasm.__heap_base) + len * 4 - wasm.memory.buffer.byteLength;
if (extraMem > 0)
wasm.memory.grow(Math.ceil(extraMem / 65536));

const addr = wasm.sa(source.length);
copy(source, new Uint16Array(wasm.memory.buffer, addr, source.length + 1));
const addr = wasm.sa(len);
(isLE ? copyLE : copyBE)(source, new Uint16Array(wasm.memory.buffer, addr, len));

if (!wasm.parseCJS(addr, source.length, 0, 0))
throw Object.assign(new Error(`Parse error ${name}${wasm.e()}:${source.slice(0, wasm.e()).split('\n').length}:${wasm.e() - source.lastIndexOf('\n', wasm.e() - 1)}`), { idx: wasm.e() });
Expand All @@ -29,7 +33,16 @@ export function parse (source, name = '@') {
return { exports: [...exports], reexports: [...reexports] };
}

function copy (src, outBuf16) {
function copyBE (src, outBuf16) {
const len = src.length;
let i = 0;
while (i < len) {
const ch = src.charCodeAt(i);
outBuf16[i++] = (ch & 0xff) << 8 | (ch & 0xff0) >> 8;
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@ExE-Boss ExE-Boss Oct 14, 2020 •
edited
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This is missing a 0, which causes the most significant nibble to be discared:

Suggested change
outBuf16[i++] = (ch & 0xff) << 8 | (ch & 0xff0) >> 8;
outBuf16[i++] = (ch & 0xff) << 8 | (ch & 0xff00) >> 8;

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@guybedford guybedford Oct 14, 2020 •
edited
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Thanks for spotting this, it wasn't causing an issue because the right shift drops these bits anyway, the version on master has the fix.

}
}

function copyLE (src, outBuf16) {
const len = src.length;
let i = 0;
while (i < len)
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