test: Fix test-static-code for busybox grep

That does not know about `--text`, so only use that option if it is
available.

Author: martinpitt

tests/test-static-code

@@ -3,11 +3,18 @@ set -e
 
 ROOTDIR=$(dirname $(readlink -f $0))/..
 
+# busybox grep does not know about --text
+if grep --help 2>/dev/null | grep -q -- --text; then
+    GREP="grep --text"
+else
+    GREP=grep
+fi
+
 # split preload code into internal logic and libc wrappers
 CODE_INT=`grep -B 100000 'Overridden libc' $ROOTDIR/src/libumockdev-preload.c`
 CODE_WRAPPERS=`grep -A 100000 'Overridden libc' $ROOTDIR/src/libumockdev-preload.c`
 
-LIBC_OVERRIDES=`echo "$CODE_WRAPPERS" | grep --text '^[a-z_]\+(' | grep -v '^WRAP_' | cut -f1 -d'('`
+LIBC_OVERRIDES=`echo "$CODE_WRAPPERS" | $GREP '^[a-z_]\+(' | grep -v '^WRAP_' | cut -f1 -d'('`
 
 RET=0
 
@@ -23,11 +30,11 @@ check_empty() {
 }
 
 # internal code must not have any exported (non-static) functions
-R=$(echo "$CODE_INT" | grep --text -B1  '^[a-z_]\+(' | awk 'BEGIN { RS="--\n" } !/static/ { print $0 }')
+R=$(echo "$CODE_INT" | $GREP -B1  '^[a-z_]\+(' | awk 'BEGIN { RS="--\n" } !/static/ { print $0 }')
 check_empty "$R" "preload internal code part has exported function(s)"
 
 # wrappers must be exported
-R=$(echo "$CODE_WRAPPERS" | grep --text -B1  '^[a-z_]\+(' | awk 'BEGIN { RS="--\n" } /static/ { print $0 }')
+R=$(echo "$CODE_WRAPPERS" | $GREP -B1  '^[a-z_]\+(' | awk 'BEGIN { RS="--\n" } /static/ { print $0 }')
 check_empty "$R" "preload libc wrapped code part has non-exported function(s)"
 
 # wrappers must not have a '_' in the name, libc doesn't use that style
@@ -36,7 +43,7 @@ check_empty "$R" "preload libc wrapped code part exports function with '_'"
 
 # must not use wrapped functions in internal logic
 for fn in $LIBC_OVERRIDES; do
-    R=$(echo "$CODE_INT" | grep --text -w $fn | grep --text -Ev "(/\*|\"|libc_func|#include|^ \* ).*$fn" || true)
+    R=$(echo "$CODE_INT" | $GREP -w $fn | $GREP -Ev "(/\*|\"|libc_func|#include|^ \* ).*$fn" || true)
     check_empty "$R" "preload internal code part must not use overridden libc function $fn"
 done