Set environment variable on remote target

[Jie Zhang]

libmudflap tests set a environment MUDFLAP_OPTIONS=-viol-segv before 
testing such that violations are promoted to SIGSEGV signals in testing. 
Otherwise, the exit value would be 0 even the test has violations. 
libmudflap testsuite depends on the exit value of tests to decide if the 
test PASS or FAIL. Setting MUDFLAP_OPTIONS is done in DejaGNU by

  setenv MUDFLAP_OPTIONS "-viol-segv"
which works fine on native testing. But when doing remote cross testing, 
setenv does not help. I cannot find existing mechanism in DejaGNU. So I 
want to use a global array like remote_env. If remote cross testing, add 
the environment variable in this array. Then set the environment 
variables according to the array when remote execute test case. I wrote 
a draft patch show what I means, which is attached. In mudflap 
testsuite, replace each setenv with

        if { ![is_remote target] } {
            setenv MUDFLAP_OPTIONS "-viol-segv"
        } else {
            remote_setenv MUDFLAP_OPTIONS "-viol-segv"
        }

Is it the right way to do this, or is there existing method I can use 
but I missed?


Thanks,

Jie
diff --git a/lib/rsh.exp b/lib/rsh.exp
index 1a207a8..df3b3d1 100644
--- a/lib/rsh.exp
+++ b/lib/rsh.exp
@@ -225,6 +225,7 @@ proc rsh_upload {desthost srcfile destfile} {
 #
 proc rsh_exec { boardname program pargs inp outp } {
     global timeout
+    global remote_env
 
     verbose "Executing $boardname:$program $pargs < $inp"
 
@@ -261,7 +262,11 @@ proc rsh_exec { boardname program pargs inp outp } {
 	set inp "/dev/null"
     }
 
-    set ret [local_exec "$RSH $rsh_useropts $hostname sh -c '$program $pargs \\; echo XYZ\\\${?}ZYX'" $inp $outp $timeout]
+    set remote_envs ""
+    foreach envvar [array names remote_env] {
+	set remote_envs "$remote_envs $envvar=$remote_env($envvar)"
+    }
+    set ret [local_exec "$RSH $rsh_useropts $hostname sh -c '$remote_envs $program $pargs \\; echo XYZ\\\${?}ZYX'" $inp $outp $timeout]
     set status [lindex $ret 0]
     set output [lindex $ret 1]
 
diff --git a/lib/utils.exp b/lib/utils.exp
index 6c9ff98..8523973 100644
--- a/lib/utils.exp
+++ b/lib/utils.exp
@@ -414,3 +414,33 @@ proc getenv { var } {
     }
 }
 
+#
+# Set an environment variable remotely
+#
+proc remote_setenv { var val } {
+    global remote_env
+
+    set remote_env($var) $val
+}
+
+#
+# Unset an environment variable remotely
+#
+proc remote_unsetenv { var } {
+    global remote_env
+    unset remote_env($var)
+}
+
+#
+# Get a value from an environment variable remotely
+#
+proc remote_getenv { var } {
+    global remote_env
+
+    if {[info exists remote_env($var)]} {
+	return $remote_env($var)
+    } else {
+	return ""
+    }
+}
+