build.sh: Check for lex and yacc.

Warn the user, if lex(1) and yacc(1) cannot be found. This is not
necessarily an error, as flex(1) or bison(1) might be available.

As suggested by Kevin Trumbull (onebinary) on IRC.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/build.sh b/build.sh
index 3efb44f64047c5bdeedf6dc5d646230645a4afcd..cede2e48f2fc8cf3725ae04c9928e7862f1dd864 100755 (executable)
--- a/build.sh
+++ b/build.sh
@@ -1,5 +1,15 @@
 #! /bin/sh
 
+if ! which lex > /dev/null 2>&1; then
+       echo "WARNING: lex not found!" >&2
+       echo "Make sure that you have a flex compatible tool available." >&2
+fi
+
+if ! which yacc > /dev/null 2>&1; then
+       echo "WARNING: yacc not found!" >&2
+       echo "Make sure that you have a GNU bison compatible tool available." >&2
+fi
+
 libtoolize=libtoolize
 
 if which glibtoolize > /dev/null 2>&1; then