Prevent negitive numbers from being used as the left operand of shift operator.

[xonotic/gmqcc.git] / lexer.h

diff --git a/lexer.h b/lexer.h
index 24ac39a63f7f574d1e9a8a7dfc1f8236cc51612a..2573fb209c6077ff8931546845e952053e268367 100644 (file)
--- a/lexer.h
+++ b/lexer.h
@@ -163,9 +163,14 @@ typedef struct {
     unsigned int flags;
 } oper_info;
 
-#define opid1(a) (a)
-#define opid2(a,b) ((a<<8)|b)
-#define opid3(a,b,c) ((a<<16)|(b<<8)|c)
+/*
+ * Explicit uint8_t casts since the left operand of shift operator cannot
+ * be negative, even though it won't happen, this supresses the future
+ * possibility.
+ */
+#define opid1(a)     ((uint8_t)a)
+#define opid2(a,b)   (((uint8_t)a<<8) |(uint8_t)b)
+#define opid3(a,b,c) (((uint8_t)a<<16)|((uint8_t)b<<8)|(uint8_t)c)
 
 static const oper_info c_operators[] = {
     { "(",   0, opid1('('),         ASSOC_LEFT,  99, OP_PREFIX}, /* paren expression - non function call */