Re: [PATCH 2/2] Handle Windows drives in auto-load script paths

[Hannes Domani <ssbssa@yahoo.de>]

 Am Montag, 5. Oktober 2020, 04:06:31 MESZ hat Simon Marchi <simark@simark.ca> Folgendes geschrieben:

> Hi Hannes,
>
> On 2020-05-29 11:08 a.m., Hannes Domani via Gdb-patches wrote:
> > Fixes this testsuite fail on Windows:
> > FAIL: gdb.base/auto-load.exp: print $script_loaded
> >
> > Converts the debugfile path from c:/dir/file to /c/dir/file, so it can be
> > appended to the auto-load path.
> >
> > gdb/ChangeLog:
> >
> > 2020-05-29  Hannes Domani  <ssbssa@yahoo.de>
> >
> >     * auto-load.c (auto_load_objfile_script_1): Convert drive part
> >     of debugfile path on Windows.
> >
> > gdb/doc/ChangeLog:
> >
> > 2020-05-29  Hannes Domani  <ssbssa@yahoo.de>
> >
> >     * gdb.texinfo: Document Windows drive conversion of
> >     'set auto-load scripts-directory'.
> > ---
> > v2:
> > - Document Windows drive conversion of 'set auto-load scripts-directory'.
> > ---
> >  gdb/auto-load.c    | 7 +++++++
> >  gdb/doc/gdb.texinfo | 4 ++++
> >  2 files changed, 11 insertions(+)
> >
> > diff --git a/gdb/auto-load.c b/gdb/auto-load.c
> > index 99bd96b971..88221d9f3d 100644
> > --- a/gdb/auto-load.c
> > +++ b/gdb/auto-load.c
> > @@ -784,6 +784,13 @@ auto_load_objfile_script_1 (struct objfile *objfile, const char *realname,
> >                        "scripts-directory' path \"%s\".\n"),
> >                  auto_load_dir);
> >
> > +      /* Convert Windows debugfile path from c:/dir/file to /c/dir/file.  */
> > +      if (HAS_DRIVE_SPEC (debugfile))
> > +    {
> > +      debugfile_holder = STRIP_DRIVE_SPEC (debugfile);
>
> I looked at this patch a bit before realizing it is already merged.  I
> was going to make a comment about the line above, so I made it a patch
> instead, WDYT?

Eli later noticed this problem as well, in this thread:
https://sourceware.org/pipermail/gdb-patches/2020-July/170204.html


> From 602e996b26d592ecda500ed64adafac30e0e9ce7 Mon Sep 17 00:00:00 2001
> From: Simon Marchi <simon.marchi@polymtl.ca>
> Date: Sun, 4 Oct 2020 22:00:17 -0400
> Subject: [PATCH] gdb: avoid unnecessary string copy in
> auto_load_objfile_script_1
>
> Assigning the result of STRIP_DRIVE_SPEC to an std::string creates an
> unnecessary copy of the string.  STRIP_DRIVE_SPEC is defined as:
>
>   #define STRIP_DRIVE_SPEC(f) ((f) + 2)
>
> So if it is passed a "const char *", it returns a "const char *".  We
> could use a "const char *" intermediary variable instead of an
> std::string, or (as implemented in this patch) just use it directly in
> the concatenation right after.
>
> gdb/ChangeLog:
>
>     * auto-load.c (auto_load_objfile_script_1): Don't use
>     debugfile_holder as temporary variable when stripping drive
>     letter.
>
> Change-Id: If2ccc7a156b22100754d9cdf6778ac7eeb93da4c
> ---
> gdb/auto-load.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/gdb/auto-load.c b/gdb/auto-load.c
> index 9a51d2f3dc6c..43d007ca5b03 100644
> --- a/gdb/auto-load.c
> +++ b/gdb/auto-load.c
> @@ -777,10 +777,8 @@ auto_load_objfile_script_1 (struct objfile *objfile, const char *realname,
>
>       /* Convert Windows file name from c:/dir/file to /c/dir/file.  */
>       if (HAS_DRIVE_SPEC (debugfile))
> -    {
> -      debugfile_holder = STRIP_DRIVE_SPEC (debugfile);
> -      filename = std::string("\\") + debugfile[0] + debugfile_holder;
> -    }
> +    filename = (std::string("\\") + debugfile[0]
> +            + STRIP_DRIVE_SPEC (debugfile));
>
>       for (const gdb::unique_xmalloc_ptr<char> &dir : vec)
>
>     {
> --
> 2.28.0

Ummm, LGTM.


Hannes