[PATCH] genmultilib: Add sanity check

[Christophe Lyon <christophe.lyon@arm.com>]

When a list of dirnames is provided to genmultilib, its length is
expected to match the number of options.  If this is not the case, the
build fails later for reasons not obviously related to this mistake.
This patch adds a sanity check to help diagnose such cases.

Tested by adding an option to t-aarch64 and no corresponding dirname,
with both bash and dash.

OK for trunk?

gcc/ChangeLog:

	* genmultilib: Add sanity check.
---
 gcc/genmultilib | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/gcc/genmultilib b/gcc/genmultilib
index 1e387fb1589..ef121e77d17 100644
--- a/gcc/genmultilib
+++ b/gcc/genmultilib
@@ -141,6 +141,20 @@ multiarch=$9
 multilib_reuse=${10}
 enable_multilib=${11}
 
+# Sanity check: make sure we have as many dirnames as options
+if [ -n "${dirnames}" ]; then
+    options_arr=($options)
+    dirnames_arr=($dirnames)
+    nboptions=${#options_arr[@]}
+    nbdirnames=${#dirnames_arr[@]}
+    if [ $nbdirnames -ne $nboptions ]; then
+	echo 1>&2 "Error calling $0: Number of dirnames ($nbdirnames) does not match number of options ($nboptions)"
+	echo 1>&2 "options: ${options}"
+	echo 1>&2 "dirnames: ${dirnames}"
+	exit 1
+    fi
+fi
+
 echo "static const char *const multilib_raw[] = {"
 
 mkdir tmpmultilib.$$ || exit 1
-- 
2.34.1