pub fn take(reader: *Io.Reader) Io.Reader.Error!BinaryAnnotation {
const op = std.enums.fromInt(
pdb.BinaryAnnotationOpcode,
try takePackedU32(reader),
) orelse return error.ReadFailed;
switch (op) {
// Microsoft's docs say that invalid is used as padding, though it is left ambiguous
// whether padding is allowed internally or only after all instructions are complete.
// Empirically, the latter appears to be the case, at least with the output from LLVM
// that I've tested.
.invalid => return error.EndOfStream,
.code_offset => return .{
.code_offset = try expect(takePackedU32(reader)),
},
.change_code_offset_base => return .{
.change_code_offset_base = try expect(takePackedU32(reader)),
},
.change_code_offset => return .{
.change_code_offset = try expect(takePackedU32(reader)),
},
.change_code_length => return .{
.change_code_length = try expect(takePackedU32(reader)),
},
.change_file => return .{
.change_file = try expect(takePackedU32(reader)),
},
.change_line_offset => return .{
.change_line_offset = try expect(takePackedI32(reader)),
},
.change_line_end_delta => return .{
.change_line_end_delta = try expect(takePackedU32(reader)),
},
.change_range_kind => return .{
.change_range_kind = std.enums.fromInt(
RangeKind,
try expect(takePackedU32(reader)),
) orelse return error.ReadFailed,
},
.change_column_start => return .{
.change_column_start = try expect(takePackedU32(reader)),
},
.change_column_end_delta => return .{
.change_column_end_delta = try expect(takePackedI32(reader)),
},
.change_code_offset_and_line_offset => {
const EncodedArgs = packed struct(u32) {
code_delta: u4,
encoded_line_delta: u28,
};
const args: EncodedArgs = @bitCast(try expect(takePackedU32(reader)));
return .{
.change_code_offset_and_line_offset = .{
.code_delta = args.code_delta,
.line_delta = decodeI32(args.encoded_line_delta),
},
};
},
.change_code_length_and_code_offset => return .{
.change_code_length_and_code_offset = .{
.length = try expect(takePackedU32(reader)),
.delta = try expect(takePackedU32(reader)),
},
},
.change_column_end => return .{
.change_column_end = try expect(takePackedU32(reader)),
},
}
}
