Having the driver output environment variables when using -v -v?

["François-Xavier Coudert" <fxcoudert at gmail dot com>]

Hi all,

As part of a recent debugging, I modified gcc/gcc.c so that when -v is
used twice, environment variables modification are output, such as:

$ gfortran.exe -v -v a.f90
Driving: C:\msys\1.0.10\home\FX\irun\mingw\bin\gfortran.exe -v -v
a.f90 -lgfortranbegin -lgfortran
Using built-in specs.
Target: i386-pc-mingw32
Configured with: ../trunk/configure --prefix=/mingw
--enable-languages=c,fortran --with-gmp=/home/FX/local
--with-ld=/mingw/bin/ld --with-as=/mingw/bin/as --disable-werror
--enable-bootstrap --enable-threads --disable-nls
--build=i386-pc-mingw32 --enable-libgomp
Thread model: win32
gcc version 4.3.0 20070822 (experimental) (GCC)
Setting environment variable COLLECT_GCC_OPTIONS='-v' '-v' '-mtune=i386'
 c:/msys/1.0.10/home/fx/irun/mingw/bin/../libexec/gcc/i386-pc-mingw32/4.3.0/f951.exe
a.f90 -quiet -dumpbase a.f90 -mtune=i386 -auxbase a -version
-fintrinsic-modules-path
c:/msys/1.0.10/home/fx/irun/mingw/bin/../lib/gcc/i386-pc-mingw32/4.3.0/finclude
-o C:/DOCUME~1/FX/LOCALS~1/Temp/ccpEQksF.s
[...]


I thought it would be nice to have in mainline; what do you think?

FX



Index: gcc.c
===================================================================
--- gcc.c       (revision 127707)
+++ gcc.c       (working copy)
@@ -2632,7 +2632,12 @@
 putenv_from_prefixes (const struct path_prefix *paths, const char *env_var,
                      bool do_multi)
 {
-  putenv (build_search_list (paths, env_var, true, do_multi));
+  const char *str;
+
+  str = build_search_list (paths, env_var, true, do_multi);
+  putenv (str);
+  if (verbose_flag >= 2)
+    notice ("Setting environment variable %s\n", str);
 }


 /* Check whether NAME can be accessed in MODE.  This is like access,
@@ -3413,7 +3418,12 @@
                                                 standard_bindir_prefix,
                                                 standard_libexec_prefix);
       if (gcc_exec_prefix)
-       putenv (concat ("GCC_EXEC_PREFIX=", gcc_exec_prefix, NULL));
+       {
+         const char *str = concat ("GCC_EXEC_PREFIX=", gcc_exec_prefix, NULL);
+         putenv (str);
+         if (verbose_flag >= 2)
+           notice ("Setting environment variable %s\n", str);
+       }
     }
   else
     {
@@ -4286,6 +4296,7 @@
 {
   int i;
   int first_time;
+  const char *str;

   /* Build COLLECT_GCC_OPTIONS to have all of the options specified to
      the compiler.  */
@@ -4332,7 +4343,10 @@
        }
     }
   obstack_grow (&collect_obstack, "\0", 1);
-  putenv (XOBFINISH (&collect_obstack, char *));
+  str = XOBFINISH (&collect_obstack, char *);
+  putenv (str);
+  if (verbose_flag >= 2)
+    notice ("Setting environment variable %s\n", str);
 }


 /* Process a spec string, accumulating and running commands.  */
@@ -6118,6 +6132,7 @@
   int num_linker_inputs = 0;
   char *explicit_link_files;
   char *specs_file;
+  const char *str;
   const char *p;
   struct user_specs *uptr;
   char **old_argv = argv;
@@ -6218,11 +6233,16 @@
   obstack_init (&collect_obstack);
   obstack_grow (&collect_obstack, "COLLECT_GCC=", sizeof ("COLLECT_GCC=") - 1);
   obstack_grow (&collect_obstack, argv[0], strlen (argv[0]) + 1);
-  putenv (XOBFINISH (&collect_obstack, char *));
+  str = XOBFINISH (&collect_obstack, char *);
+  putenv (str);
+  if (verbose_flag >= 2)
+    notice ("Setting environment variable %s\n", str);

 #ifdef INIT_ENVIRONMENT
   /* Set up any other necessary machine specific environment variables.  */
   putenv (INIT_ENVIRONMENT);
+  if (verbose_flag >= 2)
+    notice ("Setting environment variable %s\n", INIT_ENVIRONMENT);
 #endif

   /* Make a table of what switches there are (switches, n_switches).