Implement RULE-6-0-2 by converting to (improved) shared rule with A3-1-4

knewbury01 · knewbury01 · commit e32ee1940dfb · 2026-01-15T13:39:08.000-05:00
diff --git a/change_notes/2026-01-15-a3-1-4-extern-to-full.md b/change_notes/2026-01-15-a3-1-4-extern-to-full.md
@@ -0,0 +1,2 @@
+- `A3-1-4` - `ExternalLinkageArrayWithoutExplicitSizeAutosar.ql`:
+   - `ExternalLinkageArrayWithoutExplicitSize.ql` has been renamed to `ExternalLinkageArrayWithoutExplicitSizeAutosar.ql` to reflect shared query implementation. Additionally the query previously only detected explicit uses of `extern` to determine external linkage, and now would catch other cases that are possible where it is external linkage and an array is declared without an explicit size.
diff --git a/cpp/autosar/src/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.ql b/cpp/autosar/src/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.ql
diff --git a/cpp/autosar/src/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSizeAutosar.ql b/cpp/autosar/src/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSizeAutosar.ql
@@ -0,0 +1,25 @@
+/**
+ * @id cpp/autosar/external-linkage-array-without-explicit-size-autosar
+ * @name A3-1-4: When an array with external linkage is declared, its size shall be stated explicitly
+ * @description A developer can more safely access the elements of an array if the size of the array
+ *              can be explicitly determined.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/autosar/id/a3-1-4
+ *       correctness
+ *       external/autosar/allocated-target/design
+ *       external/autosar/allocated-target/implementation
+ *       external/autosar/enforcement/automated
+ *       external/autosar/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.autosar
+import codingstandards.cpp.rules.externallinkagearraywithoutexplicitsize.ExternalLinkageArrayWithoutExplicitSize
+
+class ExternalLinkageArrayWithoutExplicitSizeAutosarQuery extends ExternalLinkageArrayWithoutExplicitSizeSharedQuery {
+  ExternalLinkageArrayWithoutExplicitSizeAutosarQuery() {
+    this = ScopePackage::externalLinkageArrayWithoutExplicitSizeAutosarQuery()
+  }
+}
diff --git a/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.expected b/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.expected
diff --git a/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.qlref b/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSize.qlref
diff --git a/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSizeAutosar.testref b/cpp/autosar/test/rules/A3-1-4/ExternalLinkageArrayWithoutExplicitSizeAutosar.testref
@@ -0,0 +1 @@
+cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.ql
diff --git a/cpp/autosar/test/rules/A3-1-4/test.cpp b/cpp/autosar/test/rules/A3-1-4/test.cpp
diff --git a/cpp/common/src/codingstandards/cpp/exclusions/cpp/Linkage1.qll b/cpp/common/src/codingstandards/cpp/exclusions/cpp/Linkage1.qll
@@ -0,0 +1,44 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype Linkage1Query =
+  TArrayExternalLinkageSizeExplicitQuery() or
+  TExternalLinkageArrayWithoutExplicitSizeMisraQuery()
+
+predicate isLinkage1QueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `arrayExternalLinkageSizeExplicit` query
+    Linkage1Package::arrayExternalLinkageSizeExplicitQuery() and
+  queryId =
+    // `@id` for the `arrayExternalLinkageSizeExplicit` query
+    "cpp/misra/array-external-linkage-size-explicit" and
+  ruleId = "RULE-6-0-2" and
+  category = "advisory"
+  or
+  query =
+    // `Query` instance for the `externalLinkageArrayWithoutExplicitSizeMisra` query
+    Linkage1Package::externalLinkageArrayWithoutExplicitSizeMisraQuery() and
+  queryId =
+    // `@id` for the `externalLinkageArrayWithoutExplicitSizeMisra` query
+    "cpp/misra/external-linkage-array-without-explicit-size-misra" and
+  ruleId = "RULE-6-5-1" and
+  category = "advisory"
+}
+
+module Linkage1Package {
+  Query arrayExternalLinkageSizeExplicitQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `arrayExternalLinkageSizeExplicit` query
+      TQueryCPP(TLinkage1PackageQuery(TArrayExternalLinkageSizeExplicitQuery()))
+  }
+
+  Query externalLinkageArrayWithoutExplicitSizeMisraQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `externalLinkageArrayWithoutExplicitSizeMisra` query
+      TQueryCPP(TLinkage1PackageQuery(TExternalLinkageArrayWithoutExplicitSizeMisraQuery()))
+  }
+}
diff --git a/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll b/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll
@@ -34,6 +34,7 @@ import IntegerConversion
 import Invariants
 import Iterators
 import Lambdas
+import Linkage1
 import Literals
 import Loops
 import Macros
@@ -96,6 +97,7 @@ newtype TCPPQuery =
   TInvariantsPackageQuery(InvariantsQuery q) or
   TIteratorsPackageQuery(IteratorsQuery q) or
   TLambdasPackageQuery(LambdasQuery q) or
+  TLinkage1PackageQuery(Linkage1Query q) or
   TLiteralsPackageQuery(LiteralsQuery q) or
   TLoopsPackageQuery(LoopsQuery q) or
   TMacrosPackageQuery(MacrosQuery q) or
@@ -158,6 +160,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isInvariantsQueryMetadata(query, queryId, ruleId, category) or
   isIteratorsQueryMetadata(query, queryId, ruleId, category) or
   isLambdasQueryMetadata(query, queryId, ruleId, category) or
+  isLinkage1QueryMetadata(query, queryId, ruleId, category) or
   isLiteralsQueryMetadata(query, queryId, ruleId, category) or
   isLoopsQueryMetadata(query, queryId, ruleId, category) or
   isMacrosQueryMetadata(query, queryId, ruleId, category) or
diff --git a/cpp/common/src/codingstandards/cpp/exclusions/cpp/Scope.qll b/cpp/common/src/codingstandards/cpp/exclusions/cpp/Scope.qll
@@ -5,7 +5,7 @@ import codingstandards.cpp.exclusions.RuleMetadata
 
 newtype ScopeQuery =
   TNonStandardEntitiesInStandardNamespacesQuery() or
-  TExternalLinkageArrayWithoutExplicitSizeQuery() or
+  TExternalLinkageArrayWithoutExplicitSizeAutosarQuery() or
   THiddenInheritedNonOverridableMemberFunctionQuery() or
   THiddenInheritedOverridableMemberFunctionQuery() or
   TDefinitionNotConsideredForUnqualifiedLookupQuery() or
@@ -33,11 +33,11 @@ predicate isScopeQueryMetadata(Query query, string queryId, string ruleId, strin
   category = "required"
   or
   query =
-    // `Query` instance for the `externalLinkageArrayWithoutExplicitSize` query
-    ScopePackage::externalLinkageArrayWithoutExplicitSizeQuery() and
+    // `Query` instance for the `externalLinkageArrayWithoutExplicitSizeAutosar` query
+    ScopePackage::externalLinkageArrayWithoutExplicitSizeAutosarQuery() and
   queryId =
-    // `@id` for the `externalLinkageArrayWithoutExplicitSize` query
-    "cpp/autosar/external-linkage-array-without-explicit-size" and
+    // `@id` for the `externalLinkageArrayWithoutExplicitSizeAutosar` query
+    "cpp/autosar/external-linkage-array-without-explicit-size-autosar" and
   ruleId = "A3-1-4" and
   category = "required"
   or
@@ -185,11 +185,11 @@ module ScopePackage {
       TQueryCPP(TScopePackageQuery(TNonStandardEntitiesInStandardNamespacesQuery()))
   }
 
-  Query externalLinkageArrayWithoutExplicitSizeQuery() {
+  Query externalLinkageArrayWithoutExplicitSizeAutosarQuery() {
     //autogenerate `Query` type
     result =
-      // `Query` type for `externalLinkageArrayWithoutExplicitSize` query
-      TQueryCPP(TScopePackageQuery(TExternalLinkageArrayWithoutExplicitSizeQuery()))
+      // `Query` type for `externalLinkageArrayWithoutExplicitSizeAutosar` query
+      TQueryCPP(TScopePackageQuery(TExternalLinkageArrayWithoutExplicitSizeAutosarQuery()))
   }
 
   Query hiddenInheritedNonOverridableMemberFunctionQuery() {
diff --git a/cpp/common/src/codingstandards/cpp/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.qll b/cpp/common/src/codingstandards/cpp/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.qll
@@ -0,0 +1,29 @@
+/**
+ * Provides a library with a `problems` predicate for the following issue:
+ * Introducing a function or object with external linkage outside of a header file can
+ * cause developer confusion about its translation unit access semantics.
+ */
+
+import cpp
+import codingstandards.cpp.Customizations
+import codingstandards.cpp.Exclusions
+import codingstandards.cpp.Linkage
+
+abstract class ExternalLinkageArrayWithoutExplicitSizeSharedQuery extends Query { }
+
+Query getQuery() { result instanceof ExternalLinkageArrayWithoutExplicitSizeSharedQuery }
+
+query predicate problems(DeclarationEntry declEntry, string message) {
+  exists(Variable v, ArrayType arrayType |
+    not isExcluded(declEntry, getQuery()) and
+    message =
+      "The declared array '" + declEntry.getName() +
+        "' with external linkage doesn't specify the size explicitly." and
+    hasExternalLinkage(v) and
+    not arrayType.hasArraySize() and
+    // Holds is if declEntry is an array variable declaration (not a definition)
+    v.getADeclarationEntry() = declEntry and
+    not declEntry.isDefinition() and
+    arrayType = v.getType().stripTopLevelSpecifiers()
+  )
+}
diff --git a/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.expected b/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.expected
@@ -0,0 +1 @@
+| test.cpp:19:14:19:15 | declaration of e1 | The declared array 'e1' with external linkage doesn't specify the size explicitly. |
diff --git a/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.ql b/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.ql
@@ -0,0 +1,4 @@
+// GENERATED FILE - DO NOT MODIFY
+import codingstandards.cpp.rules.externallinkagearraywithoutexplicitsize.ExternalLinkageArrayWithoutExplicitSize
+
+class TestFileQuery extends ExternalLinkageArrayWithoutExplicitSizeSharedQuery, TestQuery { }
diff --git a/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/test.cpp b/cpp/common/test/rules/externallinkagearraywithoutexplicitsize/test.cpp
@@ -0,0 +1,29 @@
+#define TEST 1
+
+// globals - external linkage
+int a[1]; // COMPLIANT
+int x = 1;
+// int a1[1 + x];  // NON_COMPLIANT - compiler checked
+// int a2[x];      //NON_COMPLIANT - compiler checked
+// int a3[1][x];   // NON_COMPLIANT - compiler checked
+int a4[] = {1}; // COMPLIANT - size explicitly provided
+// int a5[];       // NON_COMPLIANT - compiler checked
+int a6[1 + 1]; // COMPLIANT - size explicitly provided
+// int a7[x][1];   // NON_COMPLIANT - compiler checked
+// int (*a8)[x];   // NON_COMPLIANT - compiler checked
+
+void f(int n) {
+  int a1[] = {1}; // COMPLIANT - not external linkage
+  int a2[1];      // COMPLIANT - not external linkage
+
+  extern int e1[]; // NON_COMPLIANT
+}
+
+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 not in scope for this rule
+  static const int flexibleArrayMember[]; // COMPLIANT
+};
diff --git a/cpp/misra/src/rules/RULE-6-0-2/ExternalLinkageArrayWithoutExplicitSizeMisra.ql b/cpp/misra/src/rules/RULE-6-0-2/ExternalLinkageArrayWithoutExplicitSizeMisra.ql
@@ -0,0 +1,26 @@
+/**
+ * @id cpp/misra/array-external-linkage-size-explicit
+ * @name RULE-6-0-2: Arrays with external linkage declared without explicit size shall not be used
+ * @description Declaring an array with external linkage without its size being explicitly specified
+ *              can disallow consistency and range checks on the array size and usage.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-6-0-2
+ *       maintainability
+ *       readability
+ *       scope/single-translation-unit
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.cpp.misra
+import codingstandards.cpp.rules.externallinkagearraywithoutexplicitsize.ExternalLinkageArrayWithoutExplicitSize
+
+class ExternalLinkageArrayWithoutExplicitSizeMisraQuery extends ExternalLinkageArrayWithoutExplicitSizeSharedQuery
+{
+  ExternalLinkageArrayWithoutExplicitSizeMisraQuery() {
+    this = Linkage1Package::externalLinkageArrayWithoutExplicitSizeMisraQuery()
+  }
+}
diff --git a/cpp/misra/test/rules/RULE-6-0-2/ExternalLinkageArrayWithoutExplicitSizeMisra.testref b/cpp/misra/test/rules/RULE-6-0-2/ExternalLinkageArrayWithoutExplicitSizeMisra.testref
@@ -0,0 +1 @@
+cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.ql
diff --git a/rule_packages/cpp/Linkage1.json b/rule_packages/cpp/Linkage1.json
@@ -0,0 +1,49 @@
+{
+  "MISRA-C++-2023": {
+    "RULE-6-0-2": {
+      "properties": {
+        "enforcement": "decidable",
+        "obligation": "advisory"
+      },
+      "queries": [
+        {
+          "description": "Declaring an array with external linkage without its size being explicitly specified can disallow consistency and range checks on the array size and usage.",
+          "kind": "problem",
+          "name": "Arrays with external linkage declared without explicit size shall not be used",
+          "precision": "very-high",
+          "severity": "warning",
+          "short_name": "ArrayExternalLinkageSizeExplicit",
+          "tags": [
+            "maintainability",
+            "readability",
+            "scope/single-translation-unit"
+          ]
+        }
+      ],
+      "title": "When an array with external linkage is declared, its size should be explicitly specified"
+    },
+    "RULE-6-5-1": {
+      "properties": {
+        "enforcement": "decidable",
+        "obligation": "advisory"
+      },
+      "queries": [
+        {
+          "description": "Introducing a function or object with external linkage outside of a header file can cause developer confusion about its translation unit access semantics.",
+          "kind": "problem",
+          "name": "Introducing a function or object with external linkage outside of a header file can cause developer confusion about its translation unit access semantics.",
+          "precision": "very-high",
+          "severity": "warning",
+          "short_name": "ExternalLinkageArrayWithoutExplicitSizeMisra",
+          "shared_implementation_short_name": "ExternalLinkageArrayWithoutExplicitSize",
+          "tags": [
+            "maintainability",
+            "readability",
+            "scope/single-translation-unit"
+          ]
+        }
+      ],
+      "title": "A function or object with external linkage should be introduced in a header file"
+    }
+  }
+}
diff --git a/rule_packages/cpp/Scope.json b/rule_packages/cpp/Scope.json
@@ -40,7 +40,8 @@
           "name": "When an array with external linkage is declared, its size shall be stated explicitly",
           "precision": "very-high",
           "severity": "warning",
-          "short_name": "ExternalLinkageArrayWithoutExplicitSize",
+          "short_name": "ExternalLinkageArrayWithoutExplicitSizeAutosar",
+          "shared_implementation_short_name": "ExternalLinkageArrayWithoutExplicitSize",
           "tags": [
             "correctness"
           ]
diff --git a/rules.csv b/rules.csv
@@ -850,7 +850,7 @@ cpp,MISRA-C++-2023,RULE-5-13-5,Yes,Required,Decidable,Single Translation Unit,Th
 cpp,MISRA-C++-2023,RULE-5-13-6,Yes,Required,Decidable,Single Translation Unit,An integer-literal of type long long shall not use a single L or l in any suffix,,Expressions2,Easy,
 cpp,MISRA-C++-2023,RULE-5-13-7,No,Required,Decidable,Single Translation Unit,String literals with different encoding prefixes shall not be concatenated,A2-13-2,,,
 cpp,MISRA-C++-2023,RULE-6-0-1,Yes,Required,Decidable,Single Translation Unit,Block scope declarations shall not be visually ambiguous,"M3-1-2,DCL53-CPP",Declarations2,Easy,
-cpp,MISRA-C++-2023,RULE-6-0-2,Yes,Advisory,Decidable,Single Translation Unit,"When an array with external linkage is declared, its size should be explicitly specified",RULE-18-8,Linkage,Easy,
+cpp,MISRA-C++-2023,RULE-6-0-2,Yes,Advisory,Decidable,Single Translation Unit,"When an array with external linkage is declared, its size should be explicitly specified",RULE-18-8,Linkage1,Easy,
 cpp,MISRA-C++-2023,RULE-6-0-3,Yes,Advisory,Decidable,Single Translation Unit,"The only declarations in the global namespace should be main, namespace declarations and extern ""C"" declarations",M7-3-1,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-0-4,Yes,Required,Decidable,Single Translation Unit,The identifier main shall not be used for a function other than the global function main,M7-3-2,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-2-1,Yes,Required,Decidable,System,The one-definition rule shall not be violated,M3-2-2,ImportMisra23,Import,
@@ -860,7 +860,7 @@ cpp,MISRA-C++-2023,RULE-6-2-4,Yes,Required,Decidable,Single Translation Unit,A h
 cpp,MISRA-C++-2023,RULE-6-4-1,Yes,Required,Decidable,Single Translation Unit,A variable declared in an inner scope shall not hide a variable declared in an outer scope,A2-10-1,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-4-2,Yes,Required,Decidable,Single Translation Unit,Derived classes shall not conceal functions that are inherited from their bases,A7-3-1,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-4-3,Yes,Required,Decidable,Single Translation Unit,A name that is present in a dependent base shall not be resolved by unqualified lookup,M14-6-1,ImportMisra23,Import,
-cpp,MISRA-C++-2023,RULE-6-5-1,Yes,Advisory,Decidable,Single Translation Unit,A function or object with external linkage should be introduced in a header file,,Linkage,Medium,
+cpp,MISRA-C++-2023,RULE-6-5-1,Yes,Advisory,Decidable,Single Translation Unit,A function or object with external linkage should be introduced in a header file,,Linkage1,Medium,
 cpp,MISRA-C++-2023,RULE-6-5-2,Yes,Advisory,Decidable,Single Translation Unit,Internal linkage should be specified appropriately,,Linkage,Medium,
 cpp,MISRA-C++-2023,RULE-6-7-1,Yes,Required,Decidable,Single Translation Unit,Local variables shall not have static storage duration,,Declarations2,Easy,
 cpp,MISRA-C++-2023,RULE-6-7-2,Yes,Required,Decidable,Single Translation Unit,Global variables shall not be used,,Banned,Easy,

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+- `A3-1-4` - `ExternalLinkageArrayWithoutExplicitSizeAutosar.ql`:
	`2`	+ - `ExternalLinkageArrayWithoutExplicitSize.ql` has been renamed to `ExternalLinkageArrayWithoutExplicitSizeAutosar.ql` to reflect shared query implementation. Additionally the query previously only detected explicit uses of `extern` to determine external linkage, and now would catch other cases that are possible where it is external linkage and an array is declared without an explicit size.
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+cpp/common/test/rules/externallinkagearraywithoutexplicitsize/ExternalLinkageArrayWithoutExplicitSize.ql`