[Bug preprocessor/23479] Implement binary constants with a "0b" prefix

timturnerc at yahoo dot com gcc-bugzilla@gcc.gnu.org
Fri Nov 5 23:18:36 GMT 2021


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=23479

Tim Turner <timturnerc at yahoo dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |timturnerc at yahoo dot com

--- Comment #34 from Tim Turner <timturnerc at yahoo dot com> ---
gdb: fix value_subscript when array upper bound is not known
http://www-look-4.com/category/health/

    Since commit 7c6f27129631 ("gdb: make get_discrete_bounds check for
https://komiya-dental.com/category/crypto/ 
    non-constant range bounds"), subscripting  flexible array member fails:
    http://www.iu-bloomington.com/category/health/
        struct no_size
        { https://waytowhatsnext.com/category/health/
          int n;
          int items[];
        };
     http://www.wearelondonmade.com/category/health/
        (gdb) p *ns
        $1 = {n = 3, items = 0x5555555592a4}
        (gdb) p ns->items[0] http://www.jopspeech.com/category/health/
        Cannot access memory at address 0xfffe555b733a0164
        (gdb) p *((int *) 0x5555555592a4)
        $2 = 101  <--- we would expect that http://joerg.li/category/health/
        (gdb) p &ns->items[0]
        $3 = (int *) 0xfffe5559ee829a24  <--- wrong address
http://connstr.net/category/health/

    Since the flexible array member (items) has an unspecified size, the array
type https://www.mktrade.fi/muottivalmistus
    created for it in the DWARF doesn't have dimensions (this is with gcc
9.3.0, http://embermanchester.uk/category/health/
    Ubuntu 20.04):
    http://www.slipstone.co.uk/category/health/
        0x000000a4:   DW_TAG_array_type
                        DW_AT_type [DW_FORM_ref4]       (0x00000038 "int")
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                        DW_AT_sibling [DW_FORM_ref4]    (0x000000b3)
http://www.logoarts.co.uk/category/health/

        0x000000ad:     DW_TAG_subrange_type
                          DW_AT_type [DW_FORM_ref4]     (0x00000031 "long
unsigned int")
    http://www.acpirateradio.co.uk/category/health/
    This causes GDB to create a range type (TYPE_CODE_RANGE) with a defined
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    constant low bound (dynamic _prop with kind PROP_CONST) and an undefined
    high bound (dynamic_prop with kind PROP_UNDEFINED).
http://www.compilatori.com/category/health/

    value_subscript gets both bounds of that range using
    get_discrete_bounds.  Before commit 7c6f27129631, get_discrete_bounds
http://www.mconstantine.co.uk/health/shanghai/
    didn't check the kind of the dynamic_props and would just blindly read
    them as if they were PROP_CONST.
https://www.webb-dev.co.uk/category/health/  It would return 0 for the high
bound,
    because we zero-initialize the range_bounds structure.  And it didn't
    really matter in this case, because the returned high bound wasn't used
    in the end.


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