Declarations3: add RULE-5-5

Author: knewbury01

c/common/src/codingstandards/c/Identifiers.qll

@@ -11,4 +11,6 @@ class InterestingIdentifiers extends Declaration {
     not this.hasName("main") and
     exists(this.getADeclarationLocation())
   }
+
+  string getSignificantName() { result = this.getName().prefix(31) }
 }

c/misra/src/rules/RULE-5-5/IdentifiersNotDistinctFromMacroNames.ql

@@ -0,0 +1,31 @@
+/**
+ * @id c/misra/identifiers-not-distinct-from-macro-names
+ * @name RULE-5-5: Identifiers shall be distinct from macro names
+ * @description Reusing a macro name compared to the name of any other identifier can cause
+ *              confusion and make code harder to read.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-5-5
+ *       readability
+ *       maintainability
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.c.Identifiers
+
+from Macro m, InterestingIdentifiers i, string mName, string iName
+where
+  not isExcluded(m, Declarations3Package::identifiersNotDistinctFromMacroNamesQuery()) and
+  not isExcluded(i, Declarations3Package::identifiersNotDistinctFromMacroNamesQuery()) and
+  mName = iName and
+  (
+    //C99 states the first 31 characters of external identifiers are significant
+    //C90 states the first 6 characters of external identifiers are significant and case is not required to be significant
+    //C90 is not currently considered by this rule
+    if m.getName().length() > 31 then mName = m.getName().prefix(31) else mName = m.getName()
+  ) and
+  if i.getName().length() > 31 then iName = i.getSignificantName() else iName = i.getName()
+select m, "Macro name is nonunique compared to $@.", i, i.getName()

c/misra/test/rules/RULE-5-5/IdentifiersNotDistinctFromMacroNames.expected

@@ -0,0 +1,2 @@
+| test.c:1:1:1:23 | #define Sum(x,y) x + y | Macro name is nonunique compared to $@. | test.c:4:5:4:7 | Sum | Sum |
+| test.c:6:1:6:42 | #define iltiqzxgfqsgigwfuyntzghvzltueeaZ ; | Macro name is nonunique compared to $@. | test.c:7:12:7:43 | iltiqzxgfqsgigwfuyntzghvzltueeaQ | iltiqzxgfqsgigwfuyntzghvzltueeaQ |

c/misra/test/rules/RULE-5-5/IdentifiersNotDistinctFromMacroNames.qlref

@@ -0,0 +1 @@
+rules/RULE-5-5/IdentifiersNotDistinctFromMacroNames.ql

c/misra/test/rules/RULE-5-5/test.c

@@ -0,0 +1,7 @@
+#define Sum(x, y) x + y // NON_COMPLIANT
+#undef Sum
+
+int Sum;
+
+#define iltiqzxgfqsgigwfuyntzghvzltueeaZ ;   // NON_COMPLIANT - length 32
+static int iltiqzxgfqsgigwfuyntzghvzltueeaQ; // NON_COMPLIANT - length 32

cpp/common/src/codingstandards/cpp/exclusions/c/Declarations3.qll

@@ -5,6 +5,7 @@ import codingstandards.cpp.exclusions.RuleMetadata
 
 newtype Declarations3Query =
   TIdentifierHidingCQuery() or
+  TIdentifiersNotDistinctFromMacroNamesQuery() or
   TTypedefNameNotUniqueQuery() or
   TTagNameNotUniqueQuery()
 
@@ -17,6 +18,14 @@ predicate isDeclarations3QueryMetadata(Query query, string queryId, string ruleI
     "c/misra/identifier-hiding-c" and
   ruleId = "RULE-5-3"
   or
+  query =
+    // `Query` instance for the `identifiersNotDistinctFromMacroNames` query
+    Declarations3Package::identifiersNotDistinctFromMacroNamesQuery() and
+  queryId =
+    // `@id` for the `identifiersNotDistinctFromMacroNames` query
+    "c/misra/identifiers-not-distinct-from-macro-names" and
+  ruleId = "RULE-5-5"
+  or
   query =
     // `Query` instance for the `typedefNameNotUnique` query
     Declarations3Package::typedefNameNotUniqueQuery() and
@@ -42,6 +51,13 @@ module Declarations3Package {
       TQueryC(TDeclarations3PackageQuery(TIdentifierHidingCQuery()))
   }
 
+  Query identifiersNotDistinctFromMacroNamesQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `identifiersNotDistinctFromMacroNames` query
+      TQueryC(TDeclarations3PackageQuery(TIdentifiersNotDistinctFromMacroNamesQuery()))
+  }
+
   Query typedefNameNotUniqueQuery() {
     //autogenerate `Query` type
     result =

rule_packages/c/Declarations3.json

@@ -24,6 +24,26 @@
       ],
       "title": "An identifier declared in an inner scope shall not hide an identifier declared in an outer scope."
     },
+    "RULE-5-5": {
+      "properties": {
+        "obligation": "required"
+      },
+      "queries": [
+        {
+          "description": "Reusing a macro name compared to the name of any other identifier can cause confusion and make code harder to read.",
+          "kind": "problem",
+          "name": "Identifiers shall be distinct from macro names",
+          "precision": "very-high",
+          "severity": "error",
+          "short_name": "IdentifiersNotDistinctFromMacroNames",
+          "tags": [
+            "readability",
+            "maintainability"
+          ]
+        }
+      ],
+      "title": "Identifiers shall be distinct from macro names"
+    },
     "RULE-5-6": {
       "properties": {
         "obligation": "required"

rules.csv

@@ -635,7 +635,7 @@ c,MISRA-C-2012,RULE-5-1,Yes,Required,,,External identifiers shall be distinct,,D
 c,MISRA-C-2012,RULE-5-2,Yes,Required,,,Identifiers declared in the same scope and name space shall be distinct,,Declarations,Medium,
 c,MISRA-C-2012,RULE-5-3,Yes,Required,,,An identifier declared in an inner scope shall not hide an identifier declared in an outer scope,A2-10-1,Declarations3,Import,
 c,MISRA-C-2012,RULE-5-4,Yes,Required,,,Macro identifiers shall be distinct,,Declarations1,Easy,
-c,MISRA-C-2012,RULE-5-5,Yes,Required,,,Identifiers shall be distinct from macro names,,Declarations,Easy,
+c,MISRA-C-2012,RULE-5-5,Yes,Required,,,Identifiers shall be distinct from macro names,,Declarations3,Easy,
 c,MISRA-C-2012,RULE-5-6,Yes,Required,,,A typedef name shall be a unique identifier,,Declarations3,Easy,
 c,MISRA-C-2012,RULE-5-7,Yes,Required,,,A tag name shall be a unique identifier,,Declarations3,Easy,
 c,MISRA-C-2012,RULE-5-8,Yes,Required,,,Identifiers that define objects or functions with external linkage shall be unique,,Declarations,Easy,