Fix issue 755 and typo in A18-1-1 test

change_notes/2024-10-22-fix-fp-m6-5-3.md

@@ -0,0 +1,2 @@
+- `M6-5-3` - `Loops.qll`:
+  - Fixes #755. Specifies that the access to the loop counter must be via non-const address.

cpp/autosar/test/rules/A18-1-1/test.cpp

@@ -11,6 +11,6 @@ int test_c_arrays() {
   int x[100];                 // NON_COMPLIANT
   constexpr int a[]{0, 1, 2}; // NON_COMPLIANT
 
-  __func__; // COMPLAINT
+  __func__; // COMPLIANT
   return 0;
-}
+}

cpp/autosar/test/rules/M6-5-3/LoopCounterModifiedWithinStatement.expected

@@ -2,3 +2,4 @@
 | test.cpp:25:35:25:35 | x | Loop counters should not be modified within a statement in a for loop. |
 | test.cpp:36:5:36:5 | x | Loop counters should not be modified within a statement in a for loop. |
 | test.cpp:43:9:43:9 | i | Loop counters should not be modified within a statement in a for loop. |
+| test.cpp:99:15:99:15 | i | Loop counters should not be modified within a statement in a for loop. |

cpp/autosar/test/rules/M6-5-3/test.cpp

@@ -43,3 +43,54 @@ void test_loop_counter_mod_in_side_effect() {
     inc(i); // NON_COMPLIANT - modifies `i`
   }
 }
+
+void test_loop_counter_reference_mod_in_condition() {
+  auto loop = [](int &i) {
+    for (; (i++ < 10); i++) { // NON_COMPLIANT
+    }
+  };
+  int i = 0;
+  loop(i);
+}
+
+void test_loop_counter_reference_mod() {
+  auto loop = [](int &i) {
+    for (; i < 10; i++) { // COMPLIANT
+    }
+  };
+  int i = 0;
+  loop(i);
+}
+
+void test_loop_const_reference() {
+  auto loop = []([[maybe_unused]] int const &i) {
+    for (int i = 0; i < 10; i++) { // COMPLIANT
+    }
+  };
+  int i = 0;
+  loop(i);
+}
+
+void test_loop_counter_reference_mod_in_statement() {
+  auto loop = [](int &i) {
+    for (; (i < 10); i++) {
+      i++; // NON_COMPLIANT
+    }
+  };
+  int i = 0;
+  loop(i);
+}
+
+int const_reference(int const &i) { return i; }
+
+int reference(int &i) { return i; }
+
+int copy(int i) { return i; }
+
+void test_pass_argument_by() {
+  for (int i = 0; i < 10; i++) {
+    const_reference(i); // COMPLIANT
+    reference(i);       // NON_COMPLIANT
+    copy(i);            // COMPLIANT
+  }
+}

cpp/common/src/codingstandards/cpp/Loops.qll

@@ -204,7 +204,7 @@ predicate isLoopCounterModifiedInCondition(ForStmt forLoop, VariableAccess loopC
   loopCounterAccess = getAnIterationVariable(forLoop).getAnAccess() and
   (
     loopCounterAccess.isModified() or
-    loopCounterAccess.isAddressOfAccess()
+    loopCounterAccess.isAddressOfAccessNonConst()
   )
 }
 
@@ -219,7 +219,7 @@ predicate isLoopCounterModifiedInStatement(
   loopCounterAccess = loopCounter.getAnAccess() and
   (
     loopCounterAccess.isModified() or
-    loopCounterAccess.isAddressOfAccess()
+    loopCounterAccess.isAddressOfAccessNonConst()
   ) and
   forLoop.getStmt().getChildStmt*() = loopCounterAccess.getEnclosingStmt()
 }