1 files changed, 93 insertions, 0 deletions
diff --git a/devtools/client/shared/sourceeditor/wasm.js b/devtools/client/shared/sourceeditor/wasm.js
new file mode 100644
index 0000000000..ed3ef4df63
--- /dev/null
+++ b/devtools/client/shared/sourceeditor/wasm.js
@@ -0,0 +1,93 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const wasmparser = require("resource://devtools/client/shared/vendor/WasmParser.js");
+const wasmdis = require("resource://devtools/client/shared/vendor/WasmDis.js");
+
+const wasmStates = new WeakMap();
+
+function getWasmText(subject, data) {
+  const parser = new wasmparser.BinaryReader();
+  parser.setData(data.buffer, 0, data.length);
+  const dis = new wasmdis.WasmDisassembler();
+  dis.addOffsets = true;
+  const done = dis.disassembleChunk(parser);
+  let result = dis.getResult();
+  if (result.lines.length === 0) {
+    result = { lines: ["No luck with wast conversion"], offsets: [0], done };
+  }
+
+  const offsets = result.offsets,
+    lines = [];
+  for (let i = 0; i < offsets.length; i++) {
+    lines[offsets[i]] = i;
+  }
+
+  wasmStates.set(subject, { offsets, lines });
+
+  return { lines: result.lines, done: result.done };
+}
+
+function getWasmLineNumberFormatter(subject) {
+  const codeOf0 = 48,
+    codeOfA = 65;
+  const buffer = [
+    codeOf0,
+    codeOf0,
+    codeOf0,
+    codeOf0,
+    codeOf0,
+    codeOf0,
+    codeOf0,
+    codeOf0,
+  ];
+  let last0 = 7;
+  return function (number) {
+    const offset = lineToWasmOffset(subject, number - 1);
+    if (offset === undefined) {
+      return "";
+    }
+    let i = 7;
+    for (let n = offset | 0; n !== 0 && i >= 0; n >>= 4, i--) {
+      const nibble = n & 15;
+      buffer[i] = nibble < 10 ? codeOf0 + nibble : codeOfA - 10 + nibble;
+    }
+    for (let j = i; j > last0; j--) {
+      buffer[j] = codeOf0;
+    }
+    last0 = i;
+    return String.fromCharCode.apply(null, buffer);
+  };
+}
+
+function isWasm(subject) {
+  return wasmStates.has(subject);
+}
+
+function lineToWasmOffset(subject, number) {
+  const wasmState = wasmStates.get(subject);
+  if (!wasmState) {
+    return undefined;
+  }
+  let offset = wasmState.offsets[number];
+  while (offset === undefined && number > 0) {
+    offset = wasmState.offsets[--number];
+  }
+  return offset;
+}
+
+function wasmOffsetToLine(subject, offset) {
+  const wasmState = wasmStates.get(subject);
+  return wasmState.lines[offset];
+}
+
+module.exports = {
+  getWasmText,
+  getWasmLineNumberFormatter,
+  isWasm,
+  lineToWasmOffset,
+  wasmOffsetToLine,
+};