Implement Rule 17.6

Adds a query to identify parameter array types which use the static
keyword.

Note: there is a CodeQL bug which means the static keyword is
associated with the array size, not the specific parameter.

Author: lcartey

c/misra/src/rules/RULE-17-6/UseOfArrayStatic.ql

@@ -0,0 +1,21 @@
+/**
+ * @id c/misra/use-of-array-static
+ * @name RULE-17-6: The declaration of an array parameter shall not contain the static keyword between the [ ]
+ * @description Using the static keyword in an array type is error prone, and relies on the
+ *              programmer to adhere to the guarantees to avoid undefined behavior.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-17-6
+ *       correctness
+ *       external/misra/obligation/mandatory
+ */
+
+import cpp
+import codingstandards.c.misra
+
+from Parameter p
+where
+  not isExcluded(p, StaticPackage::useOfArrayStaticQuery()) and
+  p.getType().(ArrayType).hasSpecifier("static")
+select p, "Parameter " + p + " is declared as an array type using the static keyword."

c/misra/test/rules/RULE-17-6/UseOfArrayStatic.expected

@@ -0,0 +1,3 @@
+| test.c:2:33:2:36 | arr2 | Parameter arr2 is declared as an array type using the static keyword. |
+| test.c:3:39:3:42 | arr3 | Parameter arr3 is declared as an array type using the static keyword. |
+| test.c:5:9:5:12 | arr4 | Parameter arr4 is declared as an array type using the static keyword. |

c/misra/test/rules/RULE-17-6/UseOfArrayStatic.qlref

@@ -0,0 +1 @@
+rules/RULE-17-6/UseOfArrayStatic.ql

c/misra/test/rules/RULE-17-6/test.c

@@ -0,0 +1,8 @@
+void test_array(int arr1[10]) {}                             // COMPLIANT
+void test_array_uses_static(int arr2[static 11]) {}          // NON_COMPLIANT
+void test_array_uses_static_multi(int arr3[static 12][5]) {} // NON_COMPLIANT
+void test_array_uses_static_again(
+    int arr4[11]) { // COMPLIANT[FALSE_POSITIVE] - apparently a CodeQL
+                    // bug where the static is associated with the fixed
+                    // size
+}

cpp/common/src/codingstandards/cpp/exclusions/c/RuleMetadata.qll

@@ -61,6 +61,7 @@ import Statements3
 import Statements4
 import Statements5
 import Statements6
+import Static
 import Strings1
 import Strings2
 import Strings3
@@ -128,6 +129,7 @@ newtype TCQuery =
   TStatements4PackageQuery(Statements4Query q) or
   TStatements5PackageQuery(Statements5Query q) or
   TStatements6PackageQuery(Statements6Query q) or
+  TStaticPackageQuery(StaticQuery q) or
   TStrings1PackageQuery(Strings1Query q) or
   TStrings2PackageQuery(Strings2Query q) or
   TStrings3PackageQuery(Strings3Query q) or
@@ -195,6 +197,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isStatements4QueryMetadata(query, queryId, ruleId, category) or
   isStatements5QueryMetadata(query, queryId, ruleId, category) or
   isStatements6QueryMetadata(query, queryId, ruleId, category) or
+  isStaticQueryMetadata(query, queryId, ruleId, category) or
   isStrings1QueryMetadata(query, queryId, ruleId, category) or
   isStrings2QueryMetadata(query, queryId, ruleId, category) or
   isStrings3QueryMetadata(query, queryId, ruleId, category) or

cpp/common/src/codingstandards/cpp/exclusions/c/Static.qll

@@ -0,0 +1,26 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype StaticQuery = TUseOfArrayStaticQuery()
+
+predicate isStaticQueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `useOfArrayStatic` query
+    StaticPackage::useOfArrayStaticQuery() and
+  queryId =
+    // `@id` for the `useOfArrayStatic` query
+    "c/misra/use-of-array-static" and
+  ruleId = "RULE-17-6" and
+  category = "mandatory"
+}
+
+module StaticPackage {
+  Query useOfArrayStaticQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `useOfArrayStatic` query
+      TQueryC(TStaticPackageQuery(TUseOfArrayStaticQuery()))
+  }
+}

rule_packages/c/Static.json

@@ -0,0 +1,23 @@
+{
+  "MISRA-C-2012": {
+    "RULE-17-6": {
+      "properties": {
+        "obligation": "mandatory"
+      },
+      "queries": [
+        {
+          "description": "Using the static keyword in an array type is error prone, and relies on the programmer to adhere to the guarantees to avoid undefined behavior.",
+          "kind": "problem",
+          "name": "The declaration of an array parameter shall not contain the static keyword between the [ ]",
+          "precision": "very-high",
+          "severity": "error",
+          "short_name": "UseOfArrayStatic",
+          "tags": [
+            "correctness"
+          ]
+        }
+      ],
+      "title": "The declaration of an array parameter shall not contain the static keyword between the [ ]"
+    }
+  }
+}

rules.csv

@@ -716,7 +716,7 @@ c,MISRA-C-2012,RULE-17-2,Yes,Required,,,"Functions shall not call themselves, ei
 c,MISRA-C-2012,RULE-17-3,Yes,Mandatory,,,A function shall not be declared implicitly,,Declarations6,Medium,
 c,MISRA-C-2012,RULE-17-4,Yes,Mandatory,,,All exit paths from a function with non-void return type shall have an explicit return statement with an expression,MSC52-CPP,Statements5,Medium,
 c,MISRA-C-2012,RULE-17-5,Yes,Advisory,,,The function argument corresponding to a parameter declared to have an array type shall have an appropriate number of elements,,Contracts6,Hard,
-c,MISRA-C-2012,RULE-17-6,No,Mandatory,,,The declaration of an array parameter shall not contain the static keyword between the [ ],,,,
+c,MISRA-C-2012,RULE-17-6,Yes,Mandatory,,,The declaration of an array parameter shall not contain the static keyword between the [ ],,Static,Easy,
 c,MISRA-C-2012,RULE-17-7,Yes,Required,,,The value returned by a function having non-void return type shall be used,A0-1-2,Contracts6,Easy,
 c,MISRA-C-2012,RULE-17-8,Yes,Advisory,,,A function parameter should not be modified,,SideEffects2,Medium,
 c,MISRA-C-2012,RULE-18-1,Yes,Required,,,A pointer resulting from arithmetic on a pointer operand shall address an element of the same array as that pointer operand,M5-0-16,Pointers1,Import,