From: Jon Turney <jon.turney@dronecode.org.uk>
To: Simon Marchi <simon.marchi@polymtl.ca>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH 6/7] gdb: select "Cygwin" OS ABI for Cygwin binaries
Date: Mon, 16 Mar 2020 19:03:37 +0000 [thread overview]
Message-ID: <fa6aac9f-e8e4-4dab-4773-92c8fbf8edbb@dronecode.org.uk> (raw)
In-Reply-To: <20200316170845.184386-7-simon.marchi@polymtl.ca>
On 16/03/2020 17:08, Simon Marchi wrote:
> From: Simon Marchi <simon.marchi@efficios.com>
>
> Before this patch, the "Windows" OS ABI is selected for all Windows
> executables, including Cygwin ones. This patch makes GDB differentiate
> Cygwin binaries from non-Cygwin ones, and selects the "Cygwin" OS ABI
> for the Cygwin ones.
>
> To check whether a Windows PE executable is a Cygwin one, we check the
> library list in the .idata section, see if it contains "cygwin1.dll".
>
> I had to add code to parse the .idata section, because BFD doesn't seem
> to expose this information. BFD does parse this information, but only
> to print it in textual form (function pe_print_idata):
>
[...]
> +
> +bool
> +is_linked_with_cygwin_dll (bfd *abfd)
> +{
> + /* The list of DLLs a PE is linked to is in the .idata section. See:
> +
> + https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#the-idata-section
> + */
> + asection *idata_section = bfd_get_section_by_name (abfd, ".idata");
> + if (idata_section == nullptr)
> + return false;
I'm fine with this as-is, but FTR I think this only happens to work
because binutils ld (which is probably the only way to currently build a
cygwin executable) puts the import table in the .idata section.
The strictly correct way to locate the import table is to use the data
directory (as pe_print_idata() does)
(See
https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#optional-header-data-directories-image-only)
(Notwithstanding the MS documentation you linked, I believe MS tools can
put the import table in .rdata)
next prev parent reply other threads:[~2020-03-16 21:29 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-16 17:08 [PATCH 0/7] Add "Windows" OS ABI Simon Marchi
2020-03-16 17:08 ` [PATCH 1/7] gdb: recognize 64 bits Windows executables as Cygwin osabi Simon Marchi
2020-03-16 17:08 ` [PATCH 2/7] gdb: move enum gdb_osabi to osabi.h Simon Marchi
2020-03-16 17:08 ` [PATCH 3/7] gdb: add Windows OS ABI Simon Marchi
2020-03-16 17:08 ` [PATCH 4/7] gdb: rename i386-cygwin-tdep.c to i386-windows-tdep.c Simon Marchi
2020-03-16 17:08 ` [PATCH 5/7] gdb: rename content of i386-windows-tdep.c, cygwin to windows Simon Marchi
2020-03-16 17:08 ` [PATCH 6/7] gdb: select "Cygwin" OS ABI for Cygwin binaries Simon Marchi
2020-03-16 18:16 ` Christian Biesinger
2020-03-16 18:18 ` Simon Marchi
2020-03-16 19:03 ` Jon Turney [this message]
2020-03-16 21:00 ` Simon Marchi
2020-04-01 19:05 ` Tom Tromey
2020-04-01 19:25 ` Simon Marchi
2020-04-01 21:36 ` Pedro Alves
2020-04-01 21:53 ` Simon Marchi
2020-04-02 13:56 ` Pedro Alves
2020-04-02 14:01 ` Simon Marchi
2020-04-02 14:03 ` Pedro Alves
2020-04-02 14:08 ` Simon Marchi
2020-04-02 14:17 ` Simon Marchi
2020-04-02 13:22 ` Tom Tromey
2020-04-02 14:55 ` [PATCH] gdb: use bfd_get_section_contents to read section contents in, is_linked_with_cygwin_dll (was: Re: [PATCH 6/7] gdb: select "Cygwin" OS ABI for Cygwin binaries) Simon Marchi
2020-04-02 14:57 ` [PATCH] gdb: use bfd_get_section_contents to read section contents in, is_linked_with_cygwin_dll Simon Marchi
2020-04-02 19:01 ` Tom Tromey
2020-04-02 19:42 ` Simon Marchi
2020-04-02 19:45 ` Tom Tromey
2020-04-02 19:47 ` Simon Marchi
2020-03-16 17:08 ` [PATCH 7/7] gdb: define builtin long type to be 64 bits on amd64 Cygwin Simon Marchi
2020-03-16 17:46 ` [PATCH 0/7] Add "Windows" OS ABI Eli Zaretskii
2020-03-16 17:48 ` Simon Marchi
2020-03-16 19:04 ` Jon Turney
2020-04-01 21:42 ` Pedro Alves
2020-04-01 21:56 ` Simon Marchi
2020-04-02 3:06 ` [PATCH] gdb: stop using host-dependent signal numbers in, windows-tdep.c (was: Re: [PATCH 0/7] Add "Windows" OS ABI) Simon Marchi
2020-04-02 14:00 ` [PATCH] gdb: stop using host-dependent signal numbers in, windows-tdep.c Pedro Alves
2020-04-02 14:02 ` Simon Marchi
2020-04-02 15:12 ` Eli Zaretskii
2020-04-08 12:45 ` Jon Turney
2020-04-08 18:16 ` Simon Marchi
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