Added "-4" switch that enables C style operator precedence (original work by Bastian...

[rmac] / expr.c

diff --git a/expr.c b/expr.c
index 2361817784d7c0eccab31b9060de867613c1ff7d..5a9155c67832c1ee049d899415a0c924b40b4a07 100644 (file)
--- a/expr.c
+++ b/expr.c
@@ -93,24 +93,97 @@ void InitExpression(void)
        symbolNum = 0;
 }
 
+extern int correctMathRules;
+int xor(void);
+int and(void);
+int rel(void);
+int shift(void);
+int sum(void);
+int product(void);
+
 //
-// Binary operators (all the same precedence)
+// Binary operators (all the same precedence,
+// except if -4 is passed to the command line)
 //
+#define precedence(HIERARCHY_HIGHER, HIERARCHY_CURRENT) \
+do \
+{ \
+       if (HIERARCHY_HIGHER() != OK) \
+               return ERROR; \
+       while (tokenClass[*tok] == HIERARCHY_CURRENT) \
+       { \
+               TOKEN t = *tok++; \
+               if (HIERARCHY_HIGHER() != OK) \
+                       return ERROR; \
+               *evalTokenBuffer.u32++ = t; \
+       } \
+}while (0)
+
 int expr0(void)
 {
-       if (expr1() != OK)
-               return ERROR;
-
-       while (tokenClass[*tok] >= MULT)
+       if ( correctMathRules == 0 )
        {
-               TOKEN t = *tok++;
-
                if (expr1() != OK)
                        return ERROR;
 
-               *evalTokenBuffer.u32++ = t;
+               while (tokenClass[*tok] >= MULT)
+               {
+                       TOKEN t = *tok++;
+
+                       if (expr1() != OK)
+                               return ERROR;
+
+                       *evalTokenBuffer.u32++ = t;
+               }
        }
+       else
+       {
+               // The order of C precedence (lower to higher):
+               // bitwise XOR ^
+               // bitwise OR |
+               // bitwise AND &
+               // relational = < <= >= > !=
+               // shifts << >>
+               // sum + -
+               // product * /
+               precedence(xor, OR);
+       }
+       return OK;
+}
 
+int xor(void)
+{
+       precedence(and, XOR);
+       return OK;
+}
+
+int and(void)
+{
+       precedence(rel, AND);
+       return OK;
+}
+
+int rel(void)
+{
+       precedence(shift, REL);
+       return OK;
+}
+
+int shift(void)
+{
+       precedence(sum, SHIFT);
+       return OK;
+}
+
+int sum(void)
+{
+       precedence(product, ADD);
+       return OK;
+}
+
+int product(void)
+{
+       precedence(expr1, MULT);
        return OK;
 }