Comment 31 for bug 2007642

The master branch has been updated by Tom Tromey <email address hidden>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=5f056fcb3dce947447063f5ab225042177a59722

commit 5f056fcb3dce947447063f5ab225042177a59722
Author: Tom Tromey <email address hidden>
Date: Fri Feb 24 10:40:16 2023 -0700

    Fix crash in inside_main_func

    gdb 13.1 crashes while running the rust compiler's debugger tests.
    The crash has a number of causes.

    First, the rust compiler still uses the C++-like _Z mangling, but with
    its own twist -- some hex digits added to the end of a symbol. So,
    while gdb finds the correct name of "main":

    (top-gdb) p name
    $13 = 0x292e0c0 "rustc_gdb_1031745::main"

    It isn't found in the minsyms, because C++ demangling yields:

    [99] t 0x90c0 _ZN17rustc_gdb_10317454main17h5b5be7fe16a97225E section .text rustc_gdb_1031745::main::h5b5be7fe16a97225 zko06yobckx336v

    This could perhaps be fixed. I also filed a new PR to suggest
    preferring the linkage name of the main program.

    Next, the rust compiler emits both a DW_TAG_subprogram and a
    DW_TAG_namespace for "main". This happens because the file is named
    "main.rs" -- i.e., the bug is specific to the source file name. The
    crash also seems to require the nested function inside of 'main', at
    least for me. The namespace always is generated, but perhaps this
    changes the ordering in the DWARF.

    When inside_main_func looks up the main symbol, it finds the namespace
    symbol rather than the function. (I filed a bug about fixing gdb's
    symbol tables -- long overdue.)

    Meanwhile, as I think it's important to fix this crash sooner rather
    than later, this patch changes inside_main_func to check that the
    symbol that is found is LOC_BLOCK. This perhaps should have been done
    in the first place, anyway.

    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30158