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

[Simon Marchi <simark@simark.ca>]

On 2020-10-05 7:23 a.m., Hannes Domani wrote:
>  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.

Thanks, I pushed it.

Simon