misra: implement rule 21.16

addons/misra.py

@@ -3522,6 +3522,26 @@ class MisraChecker:
                 continue
             self.reportError(token, 21, 15)
 
+    def misra_21_16(self, cfg):
+        for token in cfg.tokenlist:
+            if token.str != 'memcmp':
+                continue
+            name, args = cppcheckdata.get_function_call_name_args(token)
+            if name is None:
+                continue
+            if len(args) != 3:
+                continue
+            for arg in args[:2]:
+                if arg.valueType is None:
+                    continue
+                if arg.valueType.pointer > 1:
+                    continue
+                if arg.valueType.sign in ('unsigned', 'signed'):
+                    continue
+                if arg.valueType.isEnum():
+                    continue
+                self.reportError(token, 21, 16)
+
     def misra_21_21(self, cfg):
         for token in cfg.tokenlist:
             if token.str == 'system':
@@ -4168,6 +4188,7 @@ class MisraChecker:
             self.executeCheck(2112, self.misra_21_12, cfg)
             self.executeCheck(2114, self.misra_21_14, cfg)
             self.executeCheck(2115, self.misra_21_15, cfg)
+            self.executeCheck(2116, self.misra_21_16, cfg)
             self.executeCheck(2121, self.misra_21_21, cfg)
             # 22.4 is already covered by Cppcheck writeReadOnlyFile
             self.executeCheck(2205, self.misra_22_5, cfg)

addons/test/misra/misra-test.c

@@ -1652,7 +1652,7 @@ static void misra_21_12(void) {
 static void misra_21_14(uint8_t *x) {
     (void)strcpy(x, "123");
     (void)memcmp(x, y, 100); // 21.14
-    (void)memcmp("abc", y, 100); // 21.14
+    (void)memcmp("abc", y, 100); // 21.14 21.16
 }
 
 static void misra_21_15(uint8_t *x, uint16_t *y) {
@@ -1661,6 +1661,14 @@ static void misra_21_15(uint8_t *x, uint16_t *y) {
     (void)memcmp(x, y, 10); // 21.15
 }
 
+struct misra_21_16_S { int a; int b; };
+static void misra_21_16_f1(struct misra_21_16_S *s1, struct misra_21_16_S *s2) {
+    (void)memcmp(s1, s2, 10); // 21.16
+}
+static void misra_21_16_f2(char *x, char *y) {
+    (void)memcmp(x, y, 10); // 21.16
+}
+
 // Large arrays for R13.1. Size exceeds default Python's max recursion depth.
 static uint8_t misra_13_1_large_ok[1024] = {
 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,