Merge pull request github#280 from github/rule-17-6

Implement Rule 17.6

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 +1,26 @@
+{
+  "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"
+          ],
+          "implementation_scope": {
+            "description": "The static keyword is associated with particular array types in our model. This means we can get false positives when two parameter use the same array type and size, but only one of which uses the `static` keyword."
+          }
+        }
+      ],
+      "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,