[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[harald at gigawatt dot nl]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

--- Comment #11 from Harald van Dijk  ---
Thinking about this a bit more, the logic should probably be: pick a file known
to exist. libgcc.a could be a good candidate, but there could be better
options. Look this up twice, once following symlinks, one without. If they both
succeed, and they are the same file (comparing the dev and ino numbers after a
stat() call), do not follow symlinks. If they both succeed, and they are not
the same file, do follow symlinks. And if only one lookup succeeds, go with the
one that succeeds. (If neither succeeds, something is seriously wrong.) This is
a bit complicated, but that's because there is one case where it seems
important to me to continue following symlinks: if you have two GCC builds of
the same version (one probably containing a patch that the other doesn't),
configured exactly the same way, install the first into its configured prefix,
and the second to a custom prefix, calling the second compiler should not pick
up any bits of the first.

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

Eric Gallager  changed:

   What|Removed |Added

 Status|RESOLVED|REOPENED
 Resolution|FIXED   |---

--- Comment #10 from Eric Gallager  ---
(In reply to Harald van Dijk from comment #9)
> (In reply to Eric Gallager from comment #6)
> > (In reply to Jorn Wolfgang Rennecke from comment #4)
> > > The bug is not fixed; the gcc.c patch has not been reviewed.
> > 
> > What about now, after r169891?
> 
> That was only checked in on a Google branch, so this is not fixed,
> regardless of the below.
> 
> The check-in applies almost cleanly to GCC 8.2.0, but actually testing it, I
> find that it does not work in my test case. I suppose it would work when all
> files are put together in a single directory, but that's not the only way
> symlinks can be used. I installed packages with DESTDIR into separate
> directories, and installed symlinks to the files in each of those using cp
> -rs. When the code checks whether spec_machine can be found, it correctly
> sees that it can be: GCC is one of the packages that provides that
> directory. As a result, -canonical-prefixes is used. However, it cannot find
> anything from binutils or glibc there, so things still break.

OK, reopening then

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[harald at gigawatt dot nl]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

Harald van Dijk  changed:

   What|Removed |Added

 CC||harald at gigawatt dot nl

--- Comment #9 from Harald van Dijk  ---
(In reply to Eric Gallager from comment #6)
> (In reply to Jorn Wolfgang Rennecke from comment #4)
> > The bug is not fixed; the gcc.c patch has not been reviewed.
> 
> What about now, after r169891?

That was only checked in on a Google branch, so this is not fixed, regardless
of the below.

The check-in applies almost cleanly to GCC 8.2.0, but actually testing it, I
find that it does not work in my test case. I suppose it would work when all
files are put together in a single directory, but that's not the only way
symlinks can be used. I installed packages with DESTDIR into separate
directories, and installed symlinks to the files in each of those using cp -rs.
When the code checks whether spec_machine can be found, it correctly sees that
it can be: GCC is one of the packages that provides that directory. As a
result, -canonical-prefixes is used. However, it cannot find anything from
binutils or glibc there, so things still break.

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

Eric Gallager  changed:

   What|Removed |Added

 Status|WAITING |RESOLVED
 Resolution|--- |FIXED

--- Comment #8 from Eric Gallager  ---
(In reply to Eric Gallager from comment #7)
> (In reply to Eric Gallager from comment #6)
> > (In reply to Jorn Wolfgang Rennecke from comment #4)
> > > The bug is not fixed; the gcc.c patch has not been reviewed.
> > 
> > What about now, after r169891? As mentioned in the comment after you:
> > 
> > (In reply to simonb from comment #5)
> > > Author: simonb
> > > Date: Mon Feb  7 18:10:15 2011
> > > New Revision: 169891
> > > 
> > > URL: http://gcc.gnu.org/viewcvs?root=gcc=rev=169891
> > > Log:
> > > Auto-detect suitable default behaviour for prefix canonicalization.
> > > 
> > > Current gcc offers -no-canonical-prefixes to turn off realpath() for 
> > > prefixes
> > > generated from the path used to address the gcc driver.  This allows gcc 
> > > to
> > > work in "symlink farm" installations, where every file in gcc is actually 
> > > a
> > > symlink to its real contents.  However, the flag has to be given 
> > > explicitly.
> > > If not, the default is to use realpath() to create prefixes and the result
> > > is usually failure to find cc1[plus], f951, etc.
> > > 
> > > This patch adds a check for a file as a way to auto-detect whether prefix
> > > canonicalization is appropriate or not.  Detection can be overridden by
> > > using the -[no-]canonical-prefixes flags.
> > > 
> > > The patch also completes the fix for PR/29931, adding code that covers the
> > > unadopted portion of this PR's attached patch.
> > > 
> > > gcc/ChangeLog.google:
> > > 2011-02-07  Simon Baldwin  
> > > 
> > >   PR driver/29931
> > >   * doc/invoke.texi: Adjust -[no-]canonical-prefixes documentation.
> > >   * gcc.c (display_help): Help text for -[no-]canonical-prefixes.
> > >   (driver_handle_option): Ignore OPT_canonical_prefixes.
> > >   (process_command): Handle OPT_[no_]canonical_prefixes, auto-detect
> > >   suitable default prefix canonicalization mode.
> > >   * common.opt (canonical-prefixes): New flag.
> > > 
> > > Google ref: 40029, 38719
> > > 
> > > 
> > > Modified:
> > > branches/google/integration/gcc/ChangeLog.google-integration
> > > branches/google/integration/gcc/common.opt
> > > branches/google/integration/gcc/doc/invoke.texi
> > > branches/google/integration/gcc/gcc.c
> 
> WAITING on a reply

Assuming this was FIXED

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

Eric Gallager  changed:

   What|Removed |Added

 Status|NEW |WAITING

--- Comment #7 from Eric Gallager  ---
(In reply to Eric Gallager from comment #6)
> (In reply to Jorn Wolfgang Rennecke from comment #4)
> > The bug is not fixed; the gcc.c patch has not been reviewed.
> 
> What about now, after r169891? As mentioned in the comment after you:
> 
> (In reply to simonb from comment #5)
> > Author: simonb
> > Date: Mon Feb  7 18:10:15 2011
> > New Revision: 169891
> > 
> > URL: http://gcc.gnu.org/viewcvs?root=gcc=rev=169891
> > Log:
> > Auto-detect suitable default behaviour for prefix canonicalization.
> > 
> > Current gcc offers -no-canonical-prefixes to turn off realpath() for 
> > prefixes
> > generated from the path used to address the gcc driver.  This allows gcc to
> > work in "symlink farm" installations, where every file in gcc is actually a
> > symlink to its real contents.  However, the flag has to be given explicitly.
> > If not, the default is to use realpath() to create prefixes and the result
> > is usually failure to find cc1[plus], f951, etc.
> > 
> > This patch adds a check for a file as a way to auto-detect whether prefix
> > canonicalization is appropriate or not.  Detection can be overridden by
> > using the -[no-]canonical-prefixes flags.
> > 
> > The patch also completes the fix for PR/29931, adding code that covers the
> > unadopted portion of this PR's attached patch.
> > 
> > gcc/ChangeLog.google:
> > 2011-02-07  Simon Baldwin  
> > 
> > PR driver/29931
> > * doc/invoke.texi: Adjust -[no-]canonical-prefixes documentation.
> > * gcc.c (display_help): Help text for -[no-]canonical-prefixes.
> > (driver_handle_option): Ignore OPT_canonical_prefixes.
> > (process_command): Handle OPT_[no_]canonical_prefixes, auto-detect
> > suitable default prefix canonicalization mode.
> > * common.opt (canonical-prefixes): New flag.
> > 
> > Google ref: 40029, 38719
> > 
> > 
> > Modified:
> > branches/google/integration/gcc/ChangeLog.google-integration
> > branches/google/integration/gcc/common.opt
> > branches/google/integration/gcc/doc/invoke.texi
> > branches/google/integration/gcc/gcc.c

WAITING on a reply

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

Eric Gallager  changed:

   What|Removed |Added

 CC||egallager at gcc dot gnu.org

--- Comment #6 from Eric Gallager  ---
(In reply to Jorn Wolfgang Rennecke from comment #4)
> The bug is not fixed; the gcc.c patch has not been reviewed.

What about now, after r169891? As mentioned in the comment after you:

(In reply to simonb from comment #5)
> Author: simonb
> Date: Mon Feb  7 18:10:15 2011
> New Revision: 169891
> 
> URL: http://gcc.gnu.org/viewcvs?root=gcc=rev=169891
> Log:
> Auto-detect suitable default behaviour for prefix canonicalization.
> 
> Current gcc offers -no-canonical-prefixes to turn off realpath() for prefixes
> generated from the path used to address the gcc driver.  This allows gcc to
> work in "symlink farm" installations, where every file in gcc is actually a
> symlink to its real contents.  However, the flag has to be given explicitly.
> If not, the default is to use realpath() to create prefixes and the result
> is usually failure to find cc1[plus], f951, etc.
> 
> This patch adds a check for a file as a way to auto-detect whether prefix
> canonicalization is appropriate or not.  Detection can be overridden by
> using the -[no-]canonical-prefixes flags.
> 
> The patch also completes the fix for PR/29931, adding code that covers the
> unadopted portion of this PR's attached patch.
> 
> gcc/ChangeLog.google:
> 2011-02-07  Simon Baldwin  
> 
>   PR driver/29931
>   * doc/invoke.texi: Adjust -[no-]canonical-prefixes documentation.
>   * gcc.c (display_help): Help text for -[no-]canonical-prefixes.
>   (driver_handle_option): Ignore OPT_canonical_prefixes.
>   (process_command): Handle OPT_[no_]canonical_prefixes, auto-detect
>   suitable default prefix canonicalization mode.
>   * common.opt (canonical-prefixes): New flag.
> 
> Google ref: 40029, 38719
> 
> 
> Modified:
> branches/google/integration/gcc/ChangeLog.google-integration
> branches/google/integration/gcc/common.opt
> branches/google/integration/gcc/doc/invoke.texi
> branches/google/integration/gcc/gcc.c

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[simonb at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

--- Comment #5 from simonb at gcc dot gnu.org 2011-02-07 18:10:21 UTC ---
Author: simonb
Date: Mon Feb  7 18:10:15 2011
New Revision: 169891

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=169891
Log:
Auto-detect suitable default behaviour for prefix canonicalization.

Current gcc offers -no-canonical-prefixes to turn off realpath() for prefixes
generated from the path used to address the gcc driver.  This allows gcc to
work in symlink farm installations, where every file in gcc is actually a
symlink to its real contents.  However, the flag has to be given explicitly.
If not, the default is to use realpath() to create prefixes and the result
is usually failure to find cc1[plus], f951, etc.

This patch adds a check for a file as a way to auto-detect whether prefix
canonicalization is appropriate or not.  Detection can be overridden by
using the -[no-]canonical-prefixes flags.

The patch also completes the fix for PR/29931, adding code that covers the
unadopted portion of this PR's attached patch.

gcc/ChangeLog.google:
2011-02-07  Simon Baldwin  sim...@google.com

PR driver/29931
* doc/invoke.texi: Adjust -[no-]canonical-prefixes documentation.
* gcc.c (display_help): Help text for -[no-]canonical-prefixes.
(driver_handle_option): Ignore OPT_canonical_prefixes.
(process_command): Handle OPT_[no_]canonical_prefixes, auto-detect
suitable default prefix canonicalization mode.
* common.opt (canonical-prefixes): New flag.

Google ref: 40029, 38719


Modified:
branches/google/integration/gcc/ChangeLog.google-integration
branches/google/integration/gcc/common.opt
branches/google/integration/gcc/doc/invoke.texi
branches/google/integration/gcc/gcc.c

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Last reconfirmed|-00-00 00:00:00 |2007-02-11 20:17:10
   date||
   Target Milestone|4.3.0   |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[amylaar at gcc dot gnu dot org]

--- Comment #4 from amylaar at gcc dot gnu dot org  2006-12-04 14:27 ---
The bug is not fixed; the gcc.c patch has not been reviewed.


-- 

amylaar at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|FIXED   |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[pinskia at gcc dot gnu dot org]

--- Comment #3 from pinskia at gcc dot gnu dot org  2006-12-03 21:32 ---
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||FIXED
   Target Milestone|--- |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931

[Bug driver/29931] following argv[0] symlink in process_command breaks symlinked-together toolchain

[amylaar at gcc dot gnu dot org]

--- Comment #2 from amylaar at gcc dot gnu dot org  2006-11-30 17:06 ---
Subject: Bug 29931

Author: amylaar
Date: Thu Nov 30 17:05:45 2006
New Revision: 119366

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=119366
Log:
include:
2006-05-03  Andrew Stubbs  [EMAIL PROTECTED]
Jorn Rennecke [EMAIL PROTECTED]

PR driver/29931
* libiberty.h (make_relative_prefix_ignore_links): Declare.

libiberty:
2006-05-03  Andrew Stubbs  [EMAIL PROTECTED]
Jorn Rennecke [EMAIL PROTECTED]

PR driver/29931
* make-relative-prefix.c (make_relative_prefix_1): New function,
broken out of make_relative_prefix.  Make link resolution dependent
on new parameter.
(make_relative_prefix): Use make_relative_prefix_1.
(make_relative_prefix_ignore_links): New function.

Modified:
trunk/include/ChangeLog
trunk/include/libiberty.h
trunk/libiberty/ChangeLog
trunk/libiberty/make-relative-prefix.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29931