Re: GNU poke 2.0.92 with ubsan

[Jose E. Marchesi]

Hi Bruno.

Thanks for the analysis and solution.
The patch is OK for both master and maint/poke-2.

>>From 2149d470a32bcb79f5eadba8dfdaa5e1b676096e Mon Sep 17 00:00:00 2001
> From: Bruno Haible <bruno@clisp.org>
> Date: Mon, 7 Feb 2022 02:42:34 +0100
> Subject: [PATCH] Avoid undefined behaviour on signed integer.
>
> * libpoke/pvm-val.h (PVM_MAKE_INT): Cast to unsigned integer before
> shifting.
> ---
>  ChangeLog         | 6 ++++++
>  libpoke/pvm-val.h | 6 +++---
>  2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index 57ac491b..b934f6ac 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,9 @@
> +2022-02-06  Bruno Haible  <bruno@clisp.org>
> +
> +     Avoid undefined behaviour on signed integer.
> +     * libpoke/pvm-val.h (PVM_MAKE_INT): Cast to unsigned integer before
> +     shifting.
> +
>  2022-02-06  Jose E. Marchesi  <jemarch@gnu.org>
>  
>       * configure.ac: Bump version to 2.0.92.
> diff --git a/libpoke/pvm-val.h b/libpoke/pvm-val.h
> index 9489bf4a..6dc5e884 100644
> --- a/libpoke/pvm-val.h
> +++ b/libpoke/pvm-val.h
> @@ -63,9 +63,9 @@
>  #define PVM_VAL_INT(V) (((int32_t) ((V) >> 32))                \
>                          << (32 - PVM_VAL_INT_SIZE ((V)))       \
>                          >> (32 - PVM_VAL_INT_SIZE ((V))))
> -#define PVM_MAKE_INT(V,S)                       \
> -  (((((int64_t) (V)) & 0xffffffff) << 32)       \
> -   | ((((S) - 1) & 0x1f) << 3)                  \
> +#define PVM_MAKE_INT(V,S)                            \
> +  (((((uint64_t) (int64_t) (V)) & 0xffffffff) << 32) \
> +   | ((((S) - 1) & 0x1f) << 3)                       \
>     | PVM_VAL_TAG_INT)
>  
>  #define PVM_VAL_UINT_SIZE(V) (((int) (((V) >> 3) & 0x1f)) + 1)