On Mon, Feb 18, 2019 at 09:46:33AM +0100, Martin Liška wrote:
> Hi.
>
> The patch handles an undefined behavior caused by 1U << 32 shift
> for an integer type.
That will still ICE on 32-bit hosts, won't it?
So, either you need ((uint64_t) 1) << ..., or column_bits && ... >= ...
> 2019-02-18 Martin Liska <mli...@suse.cz>
>
> PR c++/89383
> * line-map.c (linemap_line_start): Use 1UL in order
> to not overflow.
> ---
> libcpp/line-map.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>
> diff --git a/libcpp/line-map.c b/libcpp/line-map.c
> index 0e30b4b2b39..284bbd74009 100644
> --- a/libcpp/line-map.c
> +++ b/libcpp/line-map.c
> @@ -745,7 +745,7 @@ linemap_line_start (struct line_maps *set, linenum_type
> to_line,
> || ( /* We can't reuse the map if the line offset is sufficiently
> large to cause overflow when computing location_t values. */
> (to_line - ORDINARY_MAP_STARTING_LINE_NUMBER (map))
> - >= (1U << (CHAR_BIT * sizeof (linenum_type) - column_bits)))
> + >= (1UL << (CHAR_BIT * sizeof (linenum_type) - column_bits)))
> || range_bits < map->m_range_bits)
> map = linemap_check_ordinary
> (const_cast <line_map *>
>
Jakub
