Add package linkage 2

.vscode/tasks.json

@@ -259,6 +259,8 @@
                 "Language1",
                 "Language2",
                 "Language3",
+                "Linkage1",
+                "Linkage2",
                 "Literals",
                 "Loops",
                 "Macros",

change_notes/2026-01-26-improve-queries.md

@@ -0,0 +1,4 @@
+- `A3-1-1` - `ViolationsOfOneDefinitionRule.ql`:
+  - The query previously would incorrectly allow cases where something was defined with `extern` and did not use the defined external linkage library to find external linkage. This change may result in the query finding more results. Additionally a typo has been fixed in the alert message which will cause the old alerts for this query to now show up as new ones.
+  - `RULE-6-0-2`, `A3-1-4` - `ExternalLinkageArrayWithoutExplicitSizeMisra.ql`, `ExternalLinkageArrayWithoutExplicitSizeAutosar.ql`:
+  - The queries listed now find flexible member arrays in structs, as those do not have an explicit size.

cpp/autosar/src/rules/A3-1-1/ViolationsOfOneDefinitionRule.ql

@@ -20,67 +20,10 @@
 
 import cpp
 import codingstandards.cpp.autosar
-import codingstandards.cpp.AcceptableHeader
+import codingstandards.cpp.rules.violationsofonedefinitionrule.ViolationsOfOneDefinitionRule
 
-predicate isInline(Function decl) {
-  exists(Specifier spec |
-    spec = decl.getASpecifier() and
-    (
-      spec.hasName("inline") or
-      spec.hasName("constexpr")
-    )
-  )
+class ViolationsOfOneDefinitionRuleQuery extends ViolationsOfOneDefinitionRuleSharedQuery {
+  ViolationsOfOneDefinitionRuleQuery() {
+    this = IncludesPackage::violationsOfOneDefinitionRuleQuery()
+  }
 }
-
-predicate isExtern(FunctionDeclarationEntry decl) {
-  exists(string spec |
-    spec = decl.getASpecifier() and
-    spec = "extern"
-  )
-}
-
-from DeclarationEntry decl, string case, string name
-where
-  (
-    //a non-inline/non-extern function defined in a header
-    exists(FunctionDeclarationEntry fn |
-      fn.isDefinition() and
-      not (
-        isInline(fn.getDeclaration())
-        or
-        isExtern(fn)
-        or
-        //any (defined) templates do not violate the ODR
-        fn.isFromUninstantiatedTemplate(_)
-        or
-        fn.isFromTemplateInstantiation(_) and
-        //except for specializations, those do violate ODR
-        not fn.isSpecialization()
-        or
-        fn.getDeclaration().isStatic()
-      ) and
-      decl = fn and
-      case = "function"
-    )
-    or
-    //an non-const object defined in a header
-    exists(GlobalOrNamespaceVariable object |
-      object.hasDefinition() and
-      not (
-        object.isConstexpr()
-        or
-        object.isConst()
-        or
-        object.isStatic()
-      ) and
-      decl = object.getDefinition() and
-      case = "object"
-    )
-  ) and
-  not decl.getDeclaration().getNamespace().isAnonymous() and
-  decl.getFile() instanceof AcceptableHeader and
-  not isExcluded(decl, IncludesPackage::violationsOfOneDefinitionRuleQuery()) and
-  name = decl.getName()
-select decl,
-  "Header file $@ contains " + case + " " + name + " that lead to One Defintion Rule violation.",
-  decl.getFile(), decl.getFile().getBaseName()

cpp/autosar/test/rules/A3-1-1/ViolationsOfOneDefinitionRule.testref

@@ -0,0 +1 @@
+cpp/common/test/rules/violationsofonedefinitionrule/ViolationsOfOneDefinitionRule.ql

cpp/common/src/codingstandards/cpp/Scope.qll

@@ -369,6 +369,9 @@ predicate hidesStrict(UserVariable v1, UserVariable v2) {
 predicate hasNamespaceScope(Declaration decl) {
   // getNamespace always returns a namespace (e.g. the global namespace).
   exists(Namespace n | namespacembrs(unresolveElement(n), underlyingElement(decl)))
+  or
+  decl.isTopLevel() and
+  not namespacembrs(_, decl)
 }
 
 /** Holds if `decl` has class scope. */

cpp/common/src/codingstandards/cpp/exclusions/cpp/Linkage2.qll

@@ -0,0 +1,44 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype Linkage2Query =
+  TViolationsOfOneDefinitionRuleMisraQuery() or
+  TInternalLinkageSpecifiedAppropriatelyQuery()
+
+predicate isLinkage2QueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `violationsOfOneDefinitionRuleMisra` query
+    Linkage2Package::violationsOfOneDefinitionRuleMisraQuery() and
+  queryId =
+    // `@id` for the `violationsOfOneDefinitionRuleMisra` query
+    "cpp/misra/violations-of-one-definition-rule-misra" and
+  ruleId = "RULE-6-2-4" and
+  category = "required"
+  or
+  query =
+    // `Query` instance for the `internalLinkageSpecifiedAppropriately` query
+    Linkage2Package::internalLinkageSpecifiedAppropriatelyQuery() and
+  queryId =
+    // `@id` for the `internalLinkageSpecifiedAppropriately` query
+    "cpp/misra/internal-linkage-specified-appropriately" and
+  ruleId = "RULE-6-5-2" and
+  category = "advisory"
+}
+
+module Linkage2Package {
+  Query violationsOfOneDefinitionRuleMisraQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `violationsOfOneDefinitionRuleMisra` query
+      TQueryCPP(TLinkage2PackageQuery(TViolationsOfOneDefinitionRuleMisraQuery()))
+  }
+
+  Query internalLinkageSpecifiedAppropriatelyQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `internalLinkageSpecifiedAppropriately` query
+      TQueryCPP(TLinkage2PackageQuery(TInternalLinkageSpecifiedAppropriatelyQuery()))
+  }
+}

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

@@ -35,6 +35,7 @@ import Invariants
 import Iterators
 import Lambdas
 import Linkage1
+import Linkage2
 import Literals
 import Loops
 import Macros
@@ -98,6 +99,7 @@ newtype TCPPQuery =
   TIteratorsPackageQuery(IteratorsQuery q) or
   TLambdasPackageQuery(LambdasQuery q) or
   TLinkage1PackageQuery(Linkage1Query q) or
+  TLinkage2PackageQuery(Linkage2Query q) or
   TLiteralsPackageQuery(LiteralsQuery q) or
   TLoopsPackageQuery(LoopsQuery q) or
   TMacrosPackageQuery(MacrosQuery q) or
@@ -161,6 +163,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isIteratorsQueryMetadata(query, queryId, ruleId, category) or
   isLambdasQueryMetadata(query, queryId, ruleId, category) or
   isLinkage1QueryMetadata(query, queryId, ruleId, category) or
+  isLinkage2QueryMetadata(query, queryId, ruleId, category) or
   isLiteralsQueryMetadata(query, queryId, ruleId, category) or
   isLoopsQueryMetadata(query, queryId, ruleId, category) or
   isMacrosQueryMetadata(query, queryId, ruleId, category) or

cpp/common/src/codingstandards/cpp/rules/violationsofonedefinitionrule/ViolationsOfOneDefinitionRule.qll

@@ -0,0 +1,74 @@
+/**
+ * Provides a library with a `problems` predicate for the following issue:
+ * Placing the definitions of functions or objects that are non-inline and have
+ * external linkage can lead to violations of the ODR and can lead to undefined
+ * behaviour.
+ */
+
+import cpp
+import codingstandards.cpp.Customizations
+import codingstandards.cpp.Exclusions
+import codingstandards.cpp.AcceptableHeader
+import codingstandards.cpp.Linkage
+
+predicate isInline(Function decl) {
+  exists(Specifier spec |
+    spec = decl.getASpecifier() and
+    (
+      spec.hasName("inline") or
+      spec.hasName("constexpr")
+    )
+  )
+}
+
+abstract class ViolationsOfOneDefinitionRuleSharedQuery extends Query { }
+
+Query getQuery() { result instanceof ViolationsOfOneDefinitionRuleSharedQuery }
+
+query predicate problems(DeclarationEntry decl, string message, File declFile, string secondmessage) {
+  exists(string case |
+    not isExcluded(decl, getQuery()) and
+    declFile = decl.getFile() and
+    secondmessage = decl.getFile().getBaseName() and
+    message =
+      "Header file $@ contains " + case + " " + decl.getName() +
+        " that lead to One Definition Rule violation." and
+    hasExternalLinkage(decl.getDeclaration()) and
+    (
+      //a non-inline/non-extern function defined in a header
+      exists(FunctionDeclarationEntry fn |
+        fn.isDefinition() and
+        not (
+          isInline(fn.getDeclaration())
+          or
+          //any (defined) templates do not violate the ODR
+          fn.isFromUninstantiatedTemplate(_)
+          or
+          fn.isFromTemplateInstantiation(_) and
+          //except for specializations, those do violate ODR
+          not fn.isSpecialization()
+          or
+          //static/nonstatic member functions should still not be defined (so do not exclude here)
+          fn.getDeclaration().isStatic() and not fn.getFunction() instanceof MemberFunction
+        ) and
+        decl = fn and
+        case = "function"
+      )
+      or
+      //an non-const object defined in a header
+      exists(Variable object |
+        not (
+          object.isConstexpr()
+          or
+          object.isConst()
+          or
+          object.isStatic()
+        ) and
+        decl = object.getDefinition() and
+        case = "object"
+      )
+    ) and
+    not decl.getDeclaration().getNamespace().isAnonymous() and
+    decl.getFile() instanceof AcceptableHeader
+  )
+}

cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.expected

@@ -1,2 +1,4 @@
 | test.cpp:19:14:19:15 | declaration of e1 | The declared array 'e1' with external linkage doesn't specify the size explicitly. |
+| test.cpp:27:20:27:38 | declaration of flexibleArrayMember | The declared array 'flexibleArrayMember' with external linkage doesn't specify the size explicitly. |
+| test.cpp:28:14:28:33 | declaration of flexibleArrayMember2 | The declared array 'flexibleArrayMember2' with external linkage doesn't specify the size explicitly. |
 | test.hpp:2:13:2:26 | declaration of header_and_cpp | The declared array 'header_and_cpp' with external linkage doesn't specify the size explicitly. |

cpp/common/test/rules/externallinkagearraywithoutexplicitsize/test.cpp

@@ -23,11 +23,9 @@ struct s {
   // Structs must have at least one non-flexible array member.
   int foo;
 
-  // static data members have external linkage - but not currently detected in
-  // our external linkage lib - also FAMs are expected to be detected
-  // specifically in RULE-18-7
-  static const int flexibleArrayMember[]; // NON_COMPLIANT[FALSE_NEGATIVE]
-  static int flexibleArrayMember2[];      // NON_COMPLIANT[FALSE_NEGATIVE]
+  // FAMs are expected to be detected specifically in RULE-18-7
+  static const int flexibleArrayMember[]; // NON_COMPLIANT
+  static int flexibleArrayMember2[];      // NON_COMPLIANT
 };
 
 // test.cpp

cpp/common/test/rules/violationsofonedefinitionrule/ViolationsOfOneDefinitionRule.expected

@@ -0,0 +1,5 @@
+| test.hpp:3:6:3:7 | definition of f1 | Header file $@ contains function f1 that lead to One Definition Rule violation. | test.hpp:0:0:0:0 | test.hpp | test.hpp |
+| test.hpp:8:5:8:5 | definition of i | Header file $@ contains object i that lead to One Definition Rule violation. | test.hpp:0:0:0:0 | test.hpp | test.hpp |
+| test.hpp:9:12:9:13 | definition of i1 | Header file $@ contains object i1 that lead to One Definition Rule violation. | test.hpp:0:0:0:0 | test.hpp | test.hpp |
+| test.hpp:23:5:23:8 | definition of m | Header file $@ contains function m that lead to One Definition Rule violation. | test.hpp:0:0:0:0 | test.hpp | test.hpp |
+| test.hpp:25:5:25:9 | definition of m1 | Header file $@ contains function m1 that lead to One Definition Rule violation. | test.hpp:0:0:0:0 | test.hpp | test.hpp |

cpp/common/test/rules/violationsofonedefinitionrule/ViolationsOfOneDefinitionRule.ql

@@ -0,0 +1,4 @@
+// GENERATED FILE - DO NOT MODIFY
+import codingstandards.cpp.rules.violationsofonedefinitionrule.ViolationsOfOneDefinitionRule
+
+class TestFileQuery extends ViolationsOfOneDefinitionRuleSharedQuery, TestQuery { }

cpp/common/test/rules/violationsofonedefinitionrule/test.hpp

@@ -0,0 +1,24 @@
+void f(); // COMPLIANT
+
+void f1() {}        // NON_COMPLIANT
+inline void f2() {} // COMPLIANT
+
+template <typename T> void f3(T){}; // COMPLIANT - implicitly inline
+
+int i;             // NON_COMPLIANT
+extern int i1 = 1; // NON_COMPLIANT
+
+constexpr auto i2{1}; // COMPLIANT - not external linkage
+
+struct S {
+  int i;                         // COMPLIANT - no linkage
+  inline static const int i1{1}; // COMPLIANT - inline
+};
+
+class C {
+  static int m(); // COMPLIANT
+  int m1();       // COMPLIANT
+};
+
+int C::m() {}  // NON_COMPLIANT
+int C::m1() {} // NON_COMPLIANT

cpp/misra/src/rules/RULE-6-2-4/ViolationsOfOneDefinitionRuleMisra.ql

@@ -0,0 +1,27 @@
+/**
+ * @id cpp/misra/violations-of-one-definition-rule-misra
+ * @name RULE-6-2-4: A header file shall not contain definitions of functions or objects that are non-inline and have external linkage
+ * @description Placing the definitions of functions or objects that are non-inline and have
+ *              external linkage can lead to violations of the ODR and can lead to undefined
+ *              behaviour.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-6-2-4
+ *       correctness
+ *       maintainability
+ *       readability
+ *       scope/single-translation-unit
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.misra
+import codingstandards.cpp.rules.violationsofonedefinitionrule.ViolationsOfOneDefinitionRule
+
+class ViolationsOfOneDefinitionRuleMisraQuery extends ViolationsOfOneDefinitionRuleSharedQuery {
+  ViolationsOfOneDefinitionRuleMisraQuery() {
+    this = Linkage2Package::violationsOfOneDefinitionRuleMisraQuery()
+  }
+}