Fix 9491: MISRA addon: False positive for rule 14.2 (loop counter ini…

…tialized in function)

addons/misra.py

@@ -713,7 +713,29 @@ def getForLoopExpressions(forToken):
             lpar.astOperand2.astOperand2.astOperand2]
 
 
-def getForLoopCounterVariables(forToken):
+def get_function_scope(cfg, func):
+    if func:
+        for scope in cfg.scopes:
+            if scope.function == func:
+                return scope
+    return None
+
+
+def is_variable_changed(body_start, body_end, var):
+    """Check if variable is updated between body_start and body_end"""
+    while body_start != body_end:
+        if not body_start.isAssignmentOp:
+            body_start = body_start.next
+            continue
+        tok = body_start
+        while tok.astOperand1:
+            if tok.astOperand1.variable == var:
+                return True
+            tok = tok.astOperand1
+        body_start = body_start.next
+    return False
+
+def getForLoopCounterVariables(forToken, cfg):
     """ Return a set of Variable objects defined in ``for`` statement and
     satisfy requirements to loop counter term from section 8.14 of MISRA
     document.
@@ -741,10 +763,31 @@ def getForLoopCounterVariables(forToken):
                 elif tn.previous and tn.previous.str in ('++', '--'):
                     vars_modified.add(tn.variable)
         if cur_clause == 1 and tn.isAssignmentOp:
-            if tn.astOperand1.variable:
-                vars_initialized.add(tn.astOperand1.variable)
-            elif tn.astOperand1.str == "." and tn.astOperand1.astOperand2 and tn.astOperand1.astOperand2.variable:
-                vars_initialized.add(tn.astOperand1.astOperand2.variable)
+            var_token = tn.astOperand1
+            while var_token and var_token.str == '.':
+                var_token = var_token.astOperand2
+            if var_token and var_token.variable:
+                vars_initialized.add(var_token.variable)
+        if cur_clause == 1 and tn.function:
+            function_args_in_init = getArguments(tn.next);
+            function_args = tn.function.argument
+            function_scope = get_function_scope(cfg, tn.function)
+            for key, args in function_args.items():
+                if args.nameToken and args.nameToken.valueType and args.nameToken.valueType.pointer > 0:
+                    function_body_start = None
+                    function_body_end = None
+                    if function_scope:
+                        function_body_start = function_scope.bodyStart
+                        function_body_end = function_scope.bodyEnd
+                    if function_scope is None or \
+                            (function_scope is not None and
+                             is_variable_changed(function_body_start, function_body_end, args)):
+                        arg_tok = function_args_in_init[int(key) - 1]
+                        if arg_tok.variable:
+                            vars_initialized.add(arg_tok.variable)
+                        elif arg_tok.isOp and arg_tok.valueType and arg_tok.valueType.pointer > 0 \
+                                and arg_tok.astOperand1.variable:
+                            vars_initialized.add(arg_tok.astOperand1.variable)
 
         if tn.str == ';':
             cur_clause += 1
@@ -2768,13 +2811,14 @@ def misra_14_2(self, data):
                 if not expressions:
                     continue
                 if expressions[0] and not expressions[0].isAssignmentOp:
-                    self.reportError(token, 14, 2)
+                    if expressions[0].str != "(" or expressions[0].previous.function is None :
+                        self.reportError(token, 14, 2)
                 if countSideEffectsRecursive(expressions[1]) > 0:
                     self.reportError(token, 14, 2)
                 if countSideEffectsRecursive(expressions[2]) > 1:
                     self.reportError(token, 14, 2)
 
-                counter_vars_first_clause, counter_vars_exit_modified = getForLoopCounterVariables(token)
+                counter_vars_first_clause, counter_vars_exit_modified = getForLoopCounterVariables(token, data)
                 if len(counter_vars_exit_modified) == 0:
                     # if it's not possible to identify a loop counter, all 3 clauses must be empty
                     for idx in range(len(expressions)):

addons/test/misra/misra-test.c

@@ -1183,6 +1183,8 @@ static void misra_14_1(void) {
 static void misra_14_2_init_value(int32_t *var) {
     *var = 0;
 }
+static void misra_14_2_init_value_1(int32_t *var);
+
 static void misra_14_2_fn1(bool b) {
   for (;i++<10;) {} // 14.2
   for (;i<10;dostuff()) {} // 14.2
@@ -1199,8 +1201,10 @@ static void misra_14_2_fn1(bool b) {
     }
     misra_14_2_init_value(&i2); // TODO: Fix false negative in function call
   }
-
-  for (misra_14_2_init_value(&i); i < 10; ++i) {} // no-warning FIXME: False positive for 14.2 Trac #9491
+  int i1;
+  int i2;
+  for (misra_14_2_init_value(&i1); i1 < 10; ++i1) {} // no-warning
+  for (misra_14_2_init_value_1(&i2); i2 < 10; ++i2) {} // no-warning
 
   bool abort = false;
   for (i = 0; (i < 10) && !abort; ++i) { // 14.2 as 'i' is not a variable