parseBlockInfoBlock

fn parseBlockInfoBlock(bc: *BitcodeReader) !void {
    var block_id: ?u32 = null;
    while (true) {
        const record = (try bc.nextRecord()) orelse return error.EndOfStream;
        switch (record.id) {
            Abbrev.Builtin.end_block.toRecordId() => break,
            Abbrev.Builtin.define_abbrev.toRecordId() => {
                const gop = try bc.block_info.getOrPut(bc.allocator, block_id orelse
                    return error.UnspecifiedBlockId);
                if (!gop.found_existing) gop.value_ptr.* = Block.Info.default;
                try gop.value_ptr.abbrevs.addOwnedAbbrev(
                    bc.allocator,
                    try record.toOwnedAbbrev(bc.allocator),
                );
            },
            Block.Info.set_bid_id => block_id = std.math.cast(u32, record.operands[0]) orelse
                return error.Overflow,
            Block.Info.block_name_id => if (bc.keep_names) {
                const gop = try bc.block_info.getOrPut(bc.allocator, block_id orelse
                    return error.UnspecifiedBlockId);
                if (!gop.found_existing) gop.value_ptr.* = Block.Info.default;
                const name = try bc.allocator.alloc(u8, record.operands.len);
                errdefer bc.allocator.free(name);
                for (name, record.operands) |*byte, operand|
                    byte.* = std.math.cast(u8, operand) orelse return error.InvalidName;
                gop.value_ptr.block_name = name;
            },
            Block.Info.set_record_name_id => if (bc.keep_names) {
                const gop = try bc.block_info.getOrPut(bc.allocator, block_id orelse
                    return error.UnspecifiedBlockId);
                if (!gop.found_existing) gop.value_ptr.* = Block.Info.default;
                const name = try bc.allocator.alloc(u8, record.operands.len - 1);
                errdefer bc.allocator.free(name);
                for (name, record.operands[1..]) |*byte, operand|
                    byte.* = std.math.cast(u8, operand) orelse return error.InvalidName;
                try gop.value_ptr.record_names.put(
                    bc.allocator,
                    std.math.cast(u32, record.operands[0]) orelse return error.Overflow,
                    name,
                );
            },
            else => return error.UnsupportedBlockInfoRecord,
        }
    }
}