expand: add explanation to 'conservative'

The variable 'conservative' is used to allow testing some
characteristics of an expression while inhibiting any possible
side-efects like issuing a warning or marking the expression
as erroneous. But this role is not immedialtely apparent.

So, add a comment to the variable declaration.

Suggested-by: Thomas Weißschuh <thomas@t-8ch.de>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/expand.c b/expand.c
index 95f9fda6..455d5bae 100644
--- a/expand.c
+++ b/expand.c
@@ -47,6 +47,11 @@
 
 static int expand_expression(struct expression *);
 static int expand_statement(struct statement *);
+
+// If set, don't issue a warning on divide-by-0, invalid shift, ...
+// and don't mark the expression as erroneous but leave it as-is.
+// This allows testing some characteristics of the expression
+// without creating any side-effects (e.g.: is_zero_constant()).
 static int conservative;
 
 static int expand_symbol_expression(struct expression *expr)