vala: improve comments to AM_PROG_VALAC

* m4/vala.m4 (AM_PROG_VALAC): Here.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/m4/vala.m4 b/m4/vala.m4
index 7155176..2355c85 100644 (file)
--- a/m4/vala.m4
+++ b/m4/vala.m4
@@ -6,9 +6,15 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# Check whether the Vala compiler exists in $PATH. If it is found, the
-# variable VALAC is set. Optionally a minimum release number of the
-# compiler can be requested.
+# Check whether the Vala compiler exists in $PATH.  If it is found, the
+# variable VALAC is set pointing to its absolute path.  Otherwise, it is
+# simply set to 'valac'.
+# Optionally a minimum release number of the compiler can be requested.
+# If the ACTION-IF-FOUND parameter is given, it will be run if a proper
+# Vala compiler is found.
+# Similarly, if the ACTION-IF-FOUND is given, it will be run if no proper
+# Vala compiler is found.  It defaults to simply print a warning about the
+# situation, but otherwise proceeding with the configuration.
 #
 # AM_PROG_VALAC([MINIMUM-VERSION], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
 # --------------------------------------------------------------------------