From ccb8faf6efbe7cbd52acf2a72f2ce5279152311b Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Wed, 13 Jan 2010 06:26:18 +0000
Subject: [PATCH] produce a warning for the likes of "x - x & y"

---
 tools/qfcc/include/expr.h |  1 +
 tools/qfcc/source/expr.c  | 38 +++++++++++++++++++++++++++++---------
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/tools/qfcc/include/expr.h b/tools/qfcc/include/expr.h
index ffc879366..dcf09b4db 100644
--- a/tools/qfcc/include/expr.h
+++ b/tools/qfcc/include/expr.h
@@ -180,6 +180,7 @@ expr_t *new_short_expr (short short_val);
 
 int is_constant (expr_t *e);
 int is_compare (int op);
+int is_math (int op);
 int is_logic (int op);
 expr_t *constant_expr (expr_t *var);
 
diff --git a/tools/qfcc/source/expr.c b/tools/qfcc/source/expr.c
index 493e1becc..86b9558b8 100644
--- a/tools/qfcc/source/expr.c
+++ b/tools/qfcc/source/expr.c
@@ -1382,6 +1382,14 @@ is_compare (int op)
 	return 0;
 }
 
+int
+is_math (int op)
+{
+	if (op == '*' || op == '/' || op == '+' || op == '-')
+		return 1;
+	return 0;
+}
+
 int
 is_logic (int op)
 {
@@ -1411,9 +1419,7 @@ check_precedence (int op, expr_t *e1, expr_t *e2)
 	if (options.traditional) {
 		if (e2->type == ex_expr && !e2->paren) {
 			if (((op == '&' || op == '|')
-				 && (e2->e.expr.op == '*' || e2->e.expr.op == '/'
-					 || e2->e.expr.op == '+' || e2->e.expr.op == '-'
-					 || is_compare (e2->e.expr.op)))
+				 && (is_math (e2->e.expr.op) || is_compare (e2->e.expr.op)))
 				|| (op == '='
 					&& (e2->e.expr.op == OR || e2->e.expr.op == AND))) {
 				notice (e1, "precedence of `%s' and `%s' inverted for "
@@ -1435,9 +1441,7 @@ check_precedence (int op, expr_t *e1, expr_t *e2)
 			}
 		} else if (e1->type == ex_expr && !e1->paren) {
 			if (((op == '&' || op == '|')
-				 && (e1->e.expr.op == '*' || e1->e.expr.op == '/'
-					 || e1->e.expr.op == '+' || e1->e.expr.op == '-'
-					 || is_compare (e1->e.expr.op)))
+				 && (is_math (e1->e.expr.op) || is_compare (e1->e.expr.op)))
 				|| (op == '='
 					&& (e1->e.expr.op == OR || e1->e.expr.op == AND))) {
 				notice (e1, "precedence of `%s' and `%s' inverted for "
@@ -1451,10 +1455,26 @@ check_precedence (int op, expr_t *e1, expr_t *e2)
 	} else {
 		if (e2->type == ex_expr && !e2->paren) {
 			if ((op == '&' || op == '|' || op == '^')
-				&& is_compare (e2->e.expr.op)) {
+				&& (is_math (e2->e.expr.op) || is_compare (e2->e.expr.op))) {
 				if (options.warnings.precedence)
-					warning (e2, "suggest parentheses around comparison in "
-							 "operand of %c", op);
+					warning (e2, "suggest parentheses around %s in "
+							 "operand of %c",
+							 is_compare (e2->e.expr.op)
+							 		? "comparison"
+							 		: get_op_string (e2->e.expr.op),
+							 op);
+			}
+		}
+		if (e1->type == ex_expr && !e1->paren) {
+			if ((op == '&' || op == '|' || op == '^')
+				&& (is_math (e1->e.expr.op) || is_compare (e1->e.expr.op))) {
+				if (options.warnings.precedence)
+					warning (e1, "suggest parentheses around %s in "
+							 "operand of %c",
+							 is_compare (e1->e.expr.op)
+							 		? "comparison"
+							 		: get_op_string (e1->e.expr.op),
+							 op);
 			}
 		}
 	}