[PATCH] Fix build on darwin (was Re: [PATCH] gcc.c: Split up the driver's "main" into smaller functions)

[David Malcolm]

On Fri, 2014-10-03 at 11:02 -0400, David Malcolm wrote:
> The "main" function for the driver in gcc.c has grown from ~200 lines
> in its original form (way back in r262) to ~1000 lines today, with a
> dozen locals (if we include the params).
> 
> The following patch splits it up into 15 smaller functions, moving the
> various locals into the places where they're needed, so we can easily
> see e.g where argc/argv get read vs written.
> 
> The functions are private methods of a new "driver" class to give an
> extra level of encapsualation beyond just being static in gcc.c, and so
> that we can hide some state as member data inside the driver instance.
> 
> Turning them into named functions/methods also makes it easier to talk
> about the different phases of "main", and put breakpoints on them.
> 
> Bootstrapped&regrtested on x86_64-unknown-linux-gnu (Fedora 20).
> 
> OK for trunk?
> 
> gcc/ChangeLog:
>       * gcc.c (class driver): New class.
>       (main): Reimplement in terms of driver::main, moving most of the
>       locals to be locals within individual methods of class driver.
>       The remaining locals "explicit_link_files", "decoded_options" and
>       "decoded_options_count" are used by multiple driver:: methods, and
>       so become member data.  Doing so isolates the argc/argv reads and
>       writes.  Replace "goto out" with a special exit code from
>       new method driver::prepare_infiles.  Split out the old
>       implementation of main into the following...
>       (driver::main): New function, corresponding to the old "main"
>       implementation.
>       (driver::set_progname): New function, taken from the old
>       "main" implementation.
>       (driver::expand_at_files): Likewise.
>       (driver::decode_argv): Likewise.
>       (driver::global_initializations): Likewise.
>       (driver::build_multilib_strings): Likewise.
>       (driver::set_up_specs): Likewise.
>       (driver::putenv_COLLECT_GCC): Likewise.
>       (driver::maybe_putenv_COLLECT_LTO_WRAPPER): Likewise.
>       (driver::handle_unrecognized_options): Likewise.
>       (driver::maybe_print_and_exit): Likewise.
>       (driver::prepare_infiles): Likewise.
>       (driver::do_spec_on_infiles): Likewise.
>       (driver::maybe_run_linker): Likewise.
>       (driver::final_actions): Likewise.
>       (driver::get_exit_code): Likewise.

I committed this as r215861 after the approval, but it turns out to
break the build of trunk's gcc.c on darwin, due to the "const" on
driver::global_initializations preventing GCC_DRIVER_HOST_INITIALIZATION
from modifying decoded_options_count and decoded_options:

In file included from ./tm.h:16:0,
                 from ../../src/gcc/gcc.c:34:
../../src/gcc/gcc.c: In member function ‘void driver::global_initializations() 
const’:
../../src/gcc/config/darwin.h:911:63: error: invalid conversion from ‘const 
unsigned int*’ to ‘unsigned int*’ [-fpermissive]
   darwin_driver_init (&decoded_options_count, &decoded_options)
                                                               ^
../../src/gcc/gcc.c:6862:3: note: in expansion of macro 
‘GCC_DRIVER_HOST_INITIALIZATION’
   GCC_DRIVER_HOST_INITIALIZATION;
   ^
../../src/gcc/config/darwin.h:911:63: error: invalid conversion from 
‘cl_decoded_option* const*’ to ‘cl_decoded_option**’ [-fpermissive]
   darwin_driver_init (&decoded_options_count, &decoded_options)
                                                               ^
../../src/gcc/gcc.c:6862:3: note: in expansion of macro 
‘GCC_DRIVER_HOST_INITIALIZATION’
   GCC_DRIVER_HOST_INITIALIZATION;
   ^

The attached patch appears to fix it; with it, gcc.c compiles (in a
simple smoketest of "make gcc.o" in stage1 with
--target=powerpc64-darwin).

Am bootstrapping it on x86_64, fwiw; iains [CCed] said on IRC that he's
attempting a bootstrap with it.

Sorry about the breakage.

gcc/ChangeLog:
        * gcc.c (driver::global_initializations): Remove "const" so
        that GCC_DRIVER_HOST_INITIALIZATION can modify decoded_options
        and decoded_options_count.


Index: gcc/gcc.c
===================================================================
diff --git a/trunk/gcc/gcc.c b/trunk/gcc/gcc.c
--- a/trunk/gcc/gcc.c	(revision 215861)
+++ b/trunk/gcc/gcc.c	(working copy)
@@ -6737,7 +6737,7 @@
   void set_progname (const char *argv0) const;
   void expand_at_files (int *argc, char ***argv) const;
   void decode_argv (int argc, const char **argv);
-  void global_initializations () const;
+  void global_initializations ();
   void build_multilib_strings () const;
   void set_up_specs () const;
   void putenv_COLLECT_GCC (const char *argv0) const;
@@ -6848,7 +6848,7 @@
 /* Perform various initializations and setup.  */
 
 void
-driver::global_initializations () const
+driver::global_initializations ()
 {
   /* Unlock the stdio streams.  */
   unlock_std_streams ();