misra: implement rule 21.19

addons/misra.py

@@ -3542,6 +3542,31 @@ class MisraChecker:
                     continue
                 self.reportError(token, 21, 16)
 
+    def misra_21_19(self, cfg):
+        for token in cfg.tokenlist:
+            if token.str in ('localeconv', 'getenv', 'setlocale', 'strerror') and simpleMatch(token.next, '('):
+                name, _ = cppcheckdata.get_function_call_name_args(token)
+                if name is None or name != token.str:
+                    continue
+                parent = token.next
+                while simpleMatch(parent.astParent, '+'):
+                    parent = parent.astParent
+                # x = f()
+                if simpleMatch(parent.astParent, '=') and parent == parent.astParent.astOperand2:
+                    lhs = parent.astParent.astOperand1
+                    if lhs and lhs.valueType and lhs.valueType.pointer > 0 and lhs.valueType.constness == 0:
+                        self.reportError(token, 21, 19)
+            if token.str == '=':
+                lhs = token.astOperand1
+                while simpleMatch(lhs, '*') and lhs.astOperand2 is None:
+                    lhs = lhs.astOperand1
+                if not simpleMatch(lhs, '.'):
+                    continue
+                while simpleMatch(lhs, '.'):
+                    lhs = lhs.astOperand1
+                if lhs and lhs.variable and simpleMatch(lhs.variable.typeStartToken, 'lconv'):
+                    self.reportError(token, 21, 19)
+
     def misra_21_21(self, cfg):
         for token in cfg.tokenlist:
             if token.str == 'system':
@@ -4189,6 +4214,7 @@ class MisraChecker:
             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_19, 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

@@ -1803,6 +1803,12 @@ static void misra_21_16_f2(char *x, char *y) {
     (void)memcmp(x, y, 10); // 21.16
 }
 
+static void misra_21_19(void) {
+    char *s = setlocale(LC_ALL,0); // 21.19
+    const struct lconv *conv = localeconv ();
+    conv->decimal_point = "^"; // 21.19
+}
+
 static void misra_21_21(void) {
     (void)system("ls"); // 21.21
 }