egcs 1.1a problem and solution

[Don Badrak]

EGCS interested parties,

I've run into a problem with egcs-1.1a.  And a solution.

version: gcc version egcs-2.91.57 19980901 (egcs-1.1 release)

configure:
[IRIX]
   configure --prefix=/opt/gnu --exec-prefix=/opt/gnu-irix \
	     --enable-threads
[Solaris]
   configure --prefix=/opt/gnu --exec-prefix=/opt/gnu-solaris \
	     --enable-threads --with-stabs

machine(s): mips-sgi-irix6.2	(SGI Indigo2 IRIX 6.2)
	    mips-sgi-irix6.5	(SGI Octane IRIX 6.5)
	    sparc-solaris2.6	(Sun UltraSparc Solaris 2.6)

description: 

After configuring as listed above, and then installing, a "gcc -v" gives
"using builtin specs".  Then, when compiling, it can't find cpp or anything
else installed under the binary directory
/opt/gnu-irix/lib/gcc-lib/mips-sgi-irix62/egcs-2.91/57.  It doesn't matter
what OS, it does it on both IRIX and Solaris.

I had this exact same problem with gcc 2.8.1, which is when I went to 
egcs 1.0.3a (this didn't have the newer code in it).  I reported this to
the newsgroup, not sure how big a problem it was, but I didn't email the
bug report in.

I did some poking around this time, to see if I could figure it out.  I
believe I've found the problem.

In the code update_path() in gcc/prefix.c (line 293), if prefix passed in
starts with the compiled-in prefix, the compiled-in prefix replaces it.
Since I configure with prefix=/opt/gnu and exec_prefix=/opt/gnu-irix, this
matches, and it gets replaced.  For me, this is a problem.  Anyone else
who uses an exec_prefix that is starts with the prefix will also have this
problem (most people probably put it in one directory).

This is called in gcc/gcc.c when trying to determine the standard_exec_prefix.

If the prefix is a substring of exec_prefix, this breaks.  All the software
gets installed in the right places, but the compiler won't call it.

You can set the GCC_EXEC_PREFIX to the correct directory, but you also have
to set the COMPILER_PATH variable for it to pick up the system-specific
include files.  Arg.  What a mess.

I've included a patch that will replace the path only if there is a substring
match AND the character following the compiled-in prefix, if there is one,
is null, a /, or a directory separator.

This code may not be the best way to do it.  Please change it as necessary
to fit into the coding style.

Thanks.

###
### prefix.patch
###
--- gcc/prefix.c.orig	Sat Apr  4 12:38:22 1998
+++ gcc/prefix.c	Thu Sep  3 19:39:06 1998
@@ -294,7 +294,12 @@
      char *path;
      char *key;
 {
-  if (! strncmp (path, std_prefix, strlen (std_prefix)) && key != 0)
+  if ( strncmp (path, std_prefix, strlen (std_prefix)) == 0 &&
+       ( path[strlen (std_prefix)] == 0 || path[strlen (std_prefix)] == '/'
+#ifdef DIR_SEPARATOR
+	 || path[strlen (std_prefix)] == DIR_SEPARATOR
+#endif
+       ) && key != 0)
     {
       if (key[0] != '$')
 	key = concat ("@", key, NULL_PTR);

--
Don Badrak <dbadrak@census.gov>              301.457.1125 work MWThF
Geography Division                           301.457.2157 work Tu
U.S. Bureau of the Census                    301.457.4710 fax
Upper Marlboro MD, USA