[PATCH] Turn off prefix canonicalization

[Ian Lance Taylor]

simonb@google.com (Simon Baldwin) writes:

> This patch exposes a feature of libiberty that is needed if gcc is installed
> as a pure "symlink farm".  It allows the user to suppress calls to realpath()
> on prefixes generated relative to argv[0] in the gcc driver.
>
> Without the patch, prefixes generated by gcc held in a symlink farm will
> not be accurate, and compilations fail.  This can be worked around with copious
> use of -B, -isystem, -L, GCC_EXEC_PREFIX, PATH, and so on, but only in a very
> inelegant and difficult manner.
>
> Tested with full bootstrap on x86_64, and confirmed no testsuite regressions.
> Verified man, info, and pdf doc.  Okay for mainline?  Thanks.
>
>
> gcc/ChangeLog
> 2009-07-02  Simon Baldwin  <simonb@google.com>
>
> 	* gcc.c (option_map): New flag -no-canonical-prefixes.
> 	* (display_help): Print help text for new flag.
> 	* (process_command): Move options translation and language specifics
> 	and handle new flag early.  Use it to set a function pointer to a
> 	prefix builder.  Replace make_relative_prefix calls with calls to
> 	the function pointed to.  Ignore new flag in regular options handling.
> 	* doc/invoke.texi (Overall Options): Documented -no-canonical-prefixes.

This is OK unless somebody objects in the next 24 hours.

Thanks.

Ian