Search path environment variables for cross-compilers.  See the discussion
at <http://gcc.gnu.org/ml/gcc/2013-02/msg00124.html>.

Note: Touch 'C_INCLUDE_PATH' et al. rather than 'CPATH', as discussed
at <http://bugs.gnu.org/22186>.

diff --git a/gcc/gcc.c b/gcc/gcc.c
index eced0d5..08dec2b 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -4317,7 +4317,7 @@ process_command (unsigned int decoded_options_count,
     }
 
   temp = env.get (LIBRARY_PATH_ENV);
-  if (temp && *cross_compile == '0')
+  if (temp)
     {
       const char *startp, *endp;
       char *nstore = (char *) alloca (strlen (temp) + 3);
diff --git a/gcc/incpath.c b/gcc/incpath.c
index 98fe5ec..96aff65 100644
--- a/gcc/incpath.c
+++ b/gcc/incpath.c
@@ -461,8 +461,8 @@ register_include_chains (cpp_reader *pfile, const char *sysroot,
 			 int stdinc, int cxx_stdinc, int verbose)
 {
   static const char *const lang_env_vars[] =
-    { "C_INCLUDE_PATH", "CPLUS_INCLUDE_PATH",
-      "OBJC_INCLUDE_PATH", "OBJCPLUS_INCLUDE_PATH" };
+    { "CROSS_C_INCLUDE_PATH", "CROSS_CPLUS_INCLUDE_PATH",
+      "CROSS_OBJC_INCLUDE_PATH", "CROSS_OBJCPLUS_INCLUDE_PATH" };
   cpp_options *cpp_opts = cpp_get_options (pfile);
   size_t idx = (cpp_opts->objc ? 2: 0);
 
@@ -473,7 +473,7 @@ register_include_chains (cpp_reader *pfile, const char *sysroot,
 
   /* CPATH and language-dependent environment variables may add to the
      include chain.  */
-  add_env_var_paths ("CPATH", BRACKET);
+  add_env_var_paths ("CROSS_CPATH", BRACKET);
   add_env_var_paths (lang_env_vars[idx], SYSTEM);
 
   target_c_incpath.extra_pre_includes (sysroot, iprefix, stdinc);
diff --git a/gcc/system.h b/gcc/system.h
index 0cbf60a..3242c68 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -1169,4 +1169,6 @@ helper_const_non_const_cast (const char *p)
 /* Get definitions of HOST_WIDE_INT.  */
 #include "hwint.h"
 
+#define LIBRARY_PATH_ENV "CROSS_LIBRARY_PATH"
+
 #endif /* ! GCC_SYSTEM_H */
diff --git a/gcc/tlink.c b/gcc/tlink.c
index a2a7db0..2d96872 100644
--- a/gcc/tlink.c
+++ b/gcc/tlink.c
@@ -456,7 +456,7 @@ recompile_files (void)
   file *f;
 
   putenv (xstrdup ("COMPILER_PATH="));
-  putenv (xstrdup ("LIBRARY_PATH="));
+  putenv (xstrdup (LIBRARY_PATH_ENV "="));
 
   while ((f = file_pop ()) != NULL)
     {
eft'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/machine?id=7376424844e0dc1103a9d86799c2fb9bd4aa35eb&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-11-17 22:27:39 +0100'>2022-11-17</span></td><td><a href='/guix/commit/gnu/machine?id=17b01d546306885ff3c07e7b6aaffb541a8b9043'>machine: ssh: Validate 'system' field.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-11-09 13:45:24 +0100'>2022-11-09</span></td><td><a href='/guix/commit/gnu/machine?id=8d7cb7f2a4d0b7ce49764e4ba24026762d640da7'>machine/digital-ocean: Pull operating system definition out of string.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-11-09 13:45:24 +0100'>2022-11-09</span></td><td><a href='/guix/commit/gnu/machine?id=ebb88e2bed889b67ea83893c907ab29e3bc81e8b'>machine/digital-ocean: Set load path to Guile 3.0 directories.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-11-09 13:45:24 +0100'>2022-11-09</span></td><td><a href='/guix/commit/gnu/machine?id=e8dcd008a0be8bd967efabab6960d19e5424d93e'>machine/digital-ocean: Use static-networking-service-type.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-11-09 13:45:24 +0100'>2022-11-09</span></td><td><a href='/guix/commit/gnu/machine?id=c8e41af7be47fdd3ae16765d5cf892582f5a407a'>machine/digital-ocean: Use nightly Guix.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-10-17 07:29:09 +0200'>2022-10-17</span></td><td><a href='/guix/commit/gnu/machine?id=82b0f3755d12e04578a54ee53b3a8051958e8143'>guix: Fix typos.</a><span class='msg-avail'>...</span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2022-09-26 23:29:35 +0200'>2022-09-26</span></td><td><a href='/guix/commit/gnu/machine?id=1033645e9d3899edd6b052b19e24c0a718b95e88'>machine: ssh: Parameterize '%current-system' early on.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-09-04 17:57:02 +0200'>2022-09-04</span></td><td><a href='/guix/commit/gnu/machine?id=a451a809d5537035cc8888cfde5349842a68e934'>Fix misspelling of GUIX_DIGITAL_OCEAN_TOKEN.</a><span class='msg-avail'>...</span></td><td>Matthew James Kraai</td></tr>
<tr><td><span title='2022-03-01 10:30:17 -0500'>2022-03-01</span></td><td><a href='/guix/commit/gnu/machine?id=0dc019e19a23fea614be5623360849ab9bc35e74'>initrd: Use non-hyphenated kernel command-line parameter names.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-01-16 23:56:55 +0100'>2022-01-16</span></td><td><a href='/guix/commit/gnu/machine?id=084b76a70a6b302529f3450e6d07f1d105a10f7d'>machine: ssh: Add 'safety-checks?' field.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-01-09 23:17:17 +0100'>2022-01-09</span></td><td><a href='/guix/commit/gnu/machine?id=7f20e59a13a6acc3331e04185b8f1ed2538dcd0a'>machine: ssh: Open a single SSH session per machine.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>