[v2,0/6] Move gdbsupport to top level

From: Pedro Alves <palves@redhat.com>

  On 1/16/20 4:23 AM, Simon Marchi wrote:
> On 2020-01-15 4:35 p.m., Pedro Alves wrote:
>> Here's an improved version, which fixes gdbserver's standalone
>> build, simplifies gdbsupport's config.h (there's no need for
>> #ifdef GDBSERVER stuff since gdbserver doesn't use gdbsupport 
>> as a library yet), and adds copyright/intro comments.
> 
> I have to admit I'm a bit lost in the spaghetti of config.h inclusion.  I don't
> understand, for example, why GDB needs to include gdbsupport's config.  All the
> features that GDB needs are checked by its own configure script, aren't they?

Good question.  I guess the idea is that instead of having all of gdb, gdbserver,
and gdbsupport share tests via gdbsupport/common.m4, having run them more
than once, we can run the tests only once by gdbsupport's configure, and then
include the support-config.h file.

I've given this another thought, and went through the process of thinking
that this more complicated patch isn't really necessary, and then concluded
that having it makes things more normalized between all the dirs.  But
we can simplify it -- don't need to generate the "trampoline" config.h.

My initial thought that led to the more complicated patch was to make
sure that that "#include <config.h>" in gnulib's libc-config.h picks up
gnulib config.h.  But it's really harmless if that picks some other config.h
instead as long as we're sure that the gnulib config.h is also included
somehow.  Which we are sure of, from the fact that common-defs.h
is always included as first thing in every .c file.

So while we're building gdbsupport, we don't have any config.h in the
include path other than the BFD one, and we hit the problem.  We could
add an empty gdbsupport/config/config.h file in the
source and add -Igdbsupport/config/ to gdbsupport's Makefile, or,
add gnulib's build dir to the include path, like in my original patch.

So the original solution of adding the gnulib dir to the include path
isn't that bad, though I call it a hack.

The gdbsupport/config/config.h approach is pedantically less of a hack
and more in line with the "solution" that we happen to have in gdb
and gdbserver's dirs currently, by chance.

OK, so I tried that.  And then, I realized, well, if we have that
new config.h file, then we could as well move the gnulib config.h inclusion
to that file, like I was doing in the complicated patch.  Essentially
it's the same as the complicated patch, except the "trampoline" config.h
isn't generated in the build dir, but instead is put in the source tree.
We'd do the same to gdb and gdbserver, for consistency.

(I actually named the new dirs "config.h", as there's already a config
dir under gdb.  It's more to the point, anyway.)

> 
> I noticed that build/gdb/config.h doesn't get automatically regenerated from
> src/gdb/config.in whenever the latter changes.  It could use a Makefile rule that
> uses config.status to re-generate it, like there is for some other files.

Indeed.  I also noticed that I missed regenerating gdbsupport/Makefile.in ...

> 
> There's also the variable "generated_files" in the Makefile, should gdb-support.h
> be in there?

Yeah, I guess so.

> The gdb-config.h above should be gdbserver-config.h.
Here's v2.  WDYT?  Which of all the approaches discussed would
you prefer?

(If we go this route, I should probably generalize the intro comments
a bit so that the multiple versions have the exact same comment.)

From a50c9d27d8aba77bc3cf619fc029776ea8658dbf Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Wed, 15 Jan 2020 17:49:01 +0000
Subject: [PATCH v2] config.h

---
 gdb/Makefile.in                                  |  9 +--
 gdb/config.h/config.h                            | 40 +++++++++++
 gdb/configure                                    |  6 +-
 gdb/configure.ac                                 |  2 +-
 gdb/{config.in => gdb-config.in}                 |  0
 gdb/gdbserver/Makefile.in                        |  2 +-
 gdb/gdbserver/config.h/config.h                  | 32 +++++++++
 gdb/gdbserver/configure                          |  6 +-
 gdb/gdbserver/configure.ac                       |  2 +-
 gdb/gdbserver/{config.in => gdbserver-config.in} |  0
 gdb/unittests/scoped_fd-selftests.c              |  1 -
 gdb/unittests/scoped_mmap-selftests.c            |  1 -
 gdbsupport/Makefile.am                           |  2 +-
 gdbsupport/Makefile.in                           |  8 +--
 gdbsupport/common-defs.h                         | 24 -------
 gdbsupport/config.h/config.h                     | 32 +++++++++
 gdbsupport/configure                             | 92 ++++++++++++------------
 gdbsupport/configure.ac                          |  2 +-
 gdbsupport/{config.in => support-config.in}      |  0
 19 files changed, 170 insertions(+), 91 deletions(-)
 create mode 100644 gdb/config.h/config.h
 rename gdb/{config.in => gdb-config.in} (100%)
 create mode 100644 gdb/gdbserver/config.h/config.h
 rename gdb/gdbserver/{config.in => gdbserver-config.in} (100%)
 create mode 100644 gdbsupport/config.h/config.h
 rename gdbsupport/{config.in => support-config.in} (100%)

base-commit: aad09917e04b33da463f1703aab8d057cfe3f54e

[v2,0/6] Move gdbsupport to top level

Commit Message

Comments

Patch