[Bug symtab/30656] [gdb/symtab] optimized out static handled inconsistently

["cvs-commit at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=30656

--- Comment #5 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tom de Vries <vries@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f4c4456eb4d826f39abb2575ce5c2c4640bb16f3

commit f4c4456eb4d826f39abb2575ce5c2c4640bb16f3
Author: Tom de Vries <tdevries@suse.de>
Date:   Fri Jul 21 08:25:25 2023 +0200

    [gdb/symtab] Add optimized out static var to cooked index

    Consider the test-case:
    ...
    $ cat main.c
    int main (void) { return 0; }
    $ cat static-optimized-out.c
    static int aaa;
    ...
    compiled like this:
    ...
    $ gcc-12 static-optimized-out.c main.c -g -O2 -flto
    ...

    There's a difference in behaviour depending on symtab expansion state:
    ...
    $ gdb -q -batch a.out -ex "print aaa"
    No symbol "aaa" in current context.
    $ gdb -q -batch a.out -ex "maint expand-symtab" -ex "print aaa"
    $1 = <optimized out>
    ...

    The reason for the difference is that the optimized out variable aaa:
    ...
     <1><104>: Abbrev Number: 2 (DW_TAG_variable)
        <105>   DW_AT_name        : aaa
        <109>   DW_AT_decl_file   : 1
        <10a>   DW_AT_decl_line   : 18
        <10b>   DW_AT_decl_column : 12
        <10c>   DW_AT_type        : <0x110>
    ...
    is not added to the cooked index because of this clause in
abbrev_table::read:
    ...
         else if (!has_location && !has_specification_or_origin &&
!has_external
                   && cur_abbrev->tag == DW_TAG_variable)
            cur_abbrev->interesting = false;
    ...

    Fix this inconsistency by making sure that the optimized out variable is
added
    to the cooked index.

    Regression tested on x86_64-linux.

    Add two test-cases, a C test-case gdb.opt/static-optimized-out.exp and a
dwarf
    assembly test-case gdb.dwarf2/static-optimized-out.exp.

    Tested gdb.opt/static-optimized-out.exp with gcc-8 to gcc-12, for which we
now
    consistently get:
    ...
    (gdb) print aaa^M
    $1 = <optimized out>^M
    ...
    and with gcc 7.5.0 and clang 13.0.1, for which we still consistently get:
    ...
    (gdb) print aaa^M
    No symbol "aaa" in current context.^M
    ...
    due to missing debug info for the variable.

    PR symtab/30656
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30656

    Approved-By: Tom Tromey <tom@tromey.com>

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