diff options
Diffstat (limited to 'devtools/client/shared/source-map-loader/wasm-dwarf/wasmDwarfExpressions.js')
| -rw-r--r-- | devtools/client/shared/source-map-loader/wasm-dwarf/wasmDwarfExpressions.js | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/devtools/client/shared/source-map-loader/wasm-dwarf/wasmDwarfExpressions.js b/devtools/client/shared/source-map-loader/wasm-dwarf/wasmDwarfExpressions.js new file mode 100644 index 0000000000..c2f124e99f --- /dev/null +++ b/devtools/client/shared/source-map-loader/wasm-dwarf/wasmDwarfExpressions.js @@ -0,0 +1,260 @@ +/* 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/>. */ + +/* eslint camelcase: 0*/ +/* eslint-disable no-inline-comments */ + +"use strict"; + +class Value { + val; + + constructor(val) { + this.val = val; + } + toString() { + return `${this.val}`; + } +} + +const Int32Formatter = { + fromAddr(addr) { + return `(new DataView(memory0.buffer).getInt32(${addr}, true))`; + }, + fromValue(value) { + return `${value.val}`; + }, +}; + +const Uint32Formatter = { + fromAddr(addr) { + return `(new DataView(memory0.buffer).getUint32(${addr}, true))`; + }, + fromValue(value) { + return `(${value.val} >>> 0)`; + }, +}; + +function createPieceFormatter(bytes) { + let getter; + switch (bytes) { + case 0: + case 1: + getter = "getUint8"; + break; + case 2: + getter = "getUint16"; + break; + case 3: + case 4: + default: + // FIXME 64-bit + getter = "getUint32"; + break; + } + const mask = (1 << (8 * bytes)) - 1; + return { + fromAddr(addr) { + return `(new DataView(memory0.buffer).${getter}(${addr}, true))`; + }, + fromValue(value) { + return `((${value.val} & ${mask}) >>> 0)`; + }, + }; +} + +// eslint-disable-next-line complexity +function toJS(buf, typeFormatter, frame_base = "fp()") { + const readU8 = function () { + return buf[i++]; + }; + const readS8 = function () { + return (readU8() << 24) >> 24; + }; + const readU16 = function () { + const w = buf[i] | (buf[i + 1] << 8); + i += 2; + return w; + }; + const readS16 = function () { + return (readU16() << 16) >> 16; + }; + const readS32 = function () { + const w = + buf[i] | (buf[i + 1] << 8) | (buf[i + 2] << 16) | (buf[i + 3] << 24); + i += 4; + return w; + }; + const readU32 = function () { + return readS32() >>> 0; + }; + const readU = function () { + let n = 0, + shift = 0, + b; + while ((b = readU8()) & 0x80) { + n |= (b & 0x7f) << shift; + shift += 7; + } + return n | (b << shift); + }; + const readS = function () { + let n = 0, + shift = 0, + b; + while ((b = readU8()) & 0x80) { + n |= (b & 0x7f) << shift; + shift += 7; + } + n |= b << shift; + shift += 7; + return shift > 32 ? (n << (32 - shift)) >> (32 - shift) : n; + }; + const popValue = function (formatter) { + const loc = stack.pop(); + if (loc instanceof Value) { + return formatter.fromValue(loc); + } + return formatter.fromAddr(loc); + }; + let i = 0, + a, + b; + const stack = [frame_base]; + while (i < buf.length) { + const code = buf[i++]; + switch (code) { + case 0x03 /* DW_OP_addr */: + stack.push(Uint32Formatter.fromAddr(readU32())); + break; + case 0x08 /* DW_OP_const1u 0x08 1 1-byte constant */: + stack.push(readU8()); + break; + case 0x09 /* DW_OP_const1s 0x09 1 1-byte constant */: + stack.push(readS8()); + break; + case 0x0a /* DW_OP_const2u 0x0a 1 2-byte constant */: + stack.push(readU16()); + break; + case 0x0b /* DW_OP_const2s 0x0b 1 2-byte constant */: + stack.push(readS16()); + break; + case 0x0c /* DW_OP_const2u 0x0a 1 2-byte constant */: + stack.push(readU32()); + break; + case 0x0d /* DW_OP_const2s 0x0b 1 2-byte constant */: + stack.push(readS32()); + break; + case 0x10 /* DW_OP_constu 0x10 1 ULEB128 constant */: + stack.push(readU()); + break; + case 0x11 /* DW_OP_const2s 0x0b 1 2-byte constant */: + stack.push(readS()); + break; + + case 0x1c /* DW_OP_minus */: + b = stack.pop(); + a = stack.pop(); + stack.push(`${a} - ${b}`); + break; + + case 0x22 /* DW_OP_plus */: + b = stack.pop(); + a = stack.pop(); + stack.push(`${a} + ${b}`); + break; + + case 0x23 /* DW_OP_plus_uconst */: + b = readU(); + a = stack.pop(); + stack.push(`${a} + ${b}`); + break; + + case 0x30 /* DW_OP_lit0 */: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3a: + case 0x3b: + case 0x3c: + case 0x3d: + case 0x3e: + case 0x3f: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4a: + case 0x4b: + case 0x4c: + case 0x4d: + case 0x4e: + case 0x4f: + stack.push(`${code - 0x30}`); + break; + + case 0x93 /* DW_OP_piece */: { + a = readU(); + const formatter = createPieceFormatter(a); + stack.push(popValue(formatter)); + break; + } + + case 0x9f /* DW_OP_stack_value */: + stack.push(new Value(stack.pop())); + break; + + case 0xf6 /* WASM ext (old, FIXME phase out) */: + case 0xed /* WASM ext */: + b = readU(); + a = readS(); + switch (b) { + case 0: + stack.push(`var${a}`); + break; + case 1: + stack.push(`global${a}`); + break; + default: + stack.push(`ti${b}(${a})`); + break; + } + break; + + default: + // Unknown encoding, baling out + return null; + } + } + // FIXME use real DWARF type information + return popValue(typeFormatter); +} + +function decodeExpr(expr) { + if (expr.includes("//")) { + expr = expr.slice(0, expr.indexOf("//")).trim(); + } + const code = new Uint8Array(expr.length >> 1); + for (let i = 0; i < code.length; i++) { + code[i] = parseInt(expr.substr(i << 1, 2), 16); + } + const typeFormatter = Int32Formatter; + return toJS(code, typeFormatter) || `dwarf("${expr}")`; +} + +module.exports = { + decodeExpr, +}; |