Implement "Statements" package

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

@@ -49,6 +49,7 @@ import SideEffects1
 import SideEffects2
 import SmartPointers1
 import SmartPointers2
+import Statements
 import Strings
 import Templates
 import Toolchain
@@ -106,6 +107,7 @@ newtype TCPPQuery =
   TSideEffects2PackageQuery(SideEffects2Query q) or
   TSmartPointers1PackageQuery(SmartPointers1Query q) or
   TSmartPointers2PackageQuery(SmartPointers2Query q) or
+  TStatementsPackageQuery(StatementsQuery q) or
   TStringsPackageQuery(StringsQuery q) or
   TTemplatesPackageQuery(TemplatesQuery q) or
   TToolchainPackageQuery(ToolchainQuery q) or
@@ -163,6 +165,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isSideEffects2QueryMetadata(query, queryId, ruleId, category) or
   isSmartPointers1QueryMetadata(query, queryId, ruleId, category) or
   isSmartPointers2QueryMetadata(query, queryId, ruleId, category) or
+  isStatementsQueryMetadata(query, queryId, ruleId, category) or
   isStringsQueryMetadata(query, queryId, ruleId, category) or
   isTemplatesQueryMetadata(query, queryId, ruleId, category) or
   isToolchainQueryMetadata(query, queryId, ruleId, category) or

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

@@ -0,0 +1,61 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype StatementsQuery =
+  TAppropriateStructureOfSwitchStatementQuery() or
+  TLegacyForStatementsShouldBeSimpleQuery() or
+  TForRangeInitializerAtMostOneFunctionCallQuery()
+
+predicate isStatementsQueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `appropriateStructureOfSwitchStatement` query
+    StatementsPackage::appropriateStructureOfSwitchStatementQuery() and
+  queryId =
+    // `@id` for the `appropriateStructureOfSwitchStatement` query
+    "cpp/misra/appropriate-structure-of-switch-statement" and
+  ruleId = "RULE-9-4-2" and
+  category = "required"
+  or
+  query =
+    // `Query` instance for the `legacyForStatementsShouldBeSimple` query
+    StatementsPackage::legacyForStatementsShouldBeSimpleQuery() and
+  queryId =
+    // `@id` for the `legacyForStatementsShouldBeSimple` query
+    "cpp/misra/legacy-for-statements-should-be-simple" and
+  ruleId = "RULE-9-5-1" and
+  category = "advisory"
+  or
+  query =
+    // `Query` instance for the `forRangeInitializerAtMostOneFunctionCall` query
+    StatementsPackage::forRangeInitializerAtMostOneFunctionCallQuery() and
+  queryId =
+    // `@id` for the `forRangeInitializerAtMostOneFunctionCall` query
+    "cpp/misra/for-range-initializer-at-most-one-function-call" and
+  ruleId = "RULE-9-5-2" and
+  category = "required"
+}
+
+module StatementsPackage {
+  Query appropriateStructureOfSwitchStatementQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `appropriateStructureOfSwitchStatement` query
+      TQueryCPP(TStatementsPackageQuery(TAppropriateStructureOfSwitchStatementQuery()))
+  }
+
+  Query legacyForStatementsShouldBeSimpleQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `legacyForStatementsShouldBeSimple` query
+      TQueryCPP(TStatementsPackageQuery(TLegacyForStatementsShouldBeSimpleQuery()))
+  }
+
+  Query forRangeInitializerAtMostOneFunctionCallQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `forRangeInitializerAtMostOneFunctionCall` query
+      TQueryCPP(TStatementsPackageQuery(TForRangeInitializerAtMostOneFunctionCallQuery()))
+  }
+}

cpp/misra/src/rules/RULE-9-4-2/AppropriateStructureOfSwitchStatement.ql

@@ -0,0 +1,92 @@
+/**
+ * @id cpp/misra/appropriate-structure-of-switch-statement
+ * @name RULE-9-4-2: The structure of a switch statement shall be appropriate
+ * @description A switch statement should have an appropriate structure with proper cases, default
+ *              labels, and break statements to ensure clear control flow and prevent unintended
+ *              fall-through behavior.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-9-4-2
+ *       correctness
+ *       maintainability
+ *       readability
+ *       external/misra/allocated-target/single-translation-unit
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.misra
+import codingstandards.cpp.SwitchStatement
+import codingstandards.cpp.Noreturn
+
+from SwitchStmt switch, string message
+where
+  not isExcluded(switch, StatementsPackage::appropriateStructureOfSwitchStatementQuery()) and
+  /* 1. There is a statement that appears as an initializer and is not a declaration statement. */
+  exists(Stmt initializer | initializer = switch.getInitialization() |
+    not initializer instanceof DeclStmt
+  ) and
+  message = "contains a statement that that is not a simple declaration"
+  or
+  /* 2. There is a switch case label that does not lead a branch (i.e. a switch case label is nested). */
+  exists(SwitchCase case | case = switch.getASwitchCase() | case instanceof NestedSwitchCase) and
+  message = "contains a switch label that is not directly within the switch body"
+  or
+  /* 3. There is a non-case label in a label group. */
+  exists(SwitchCase case | case = switch.getASwitchCase() |
+    case.getAStmt().getChildStmt*() instanceof LabelStmt
+  ) and
+  message = "contains a statement label that is not a case label"
+  or
+  /* 4. There is a statement before the first case label. */
+  exists(Stmt switchBody | switchBody = switch.getStmt() |
+    not switchBody.getChild(0) instanceof SwitchCase
+  ) and
+  message = "has a statement that is not a case label as its first element"
+  or
+  /* 5. There is a switch case whose terminator is not one of the allowed kinds. */
+  exists(SwitchCase case, Stmt lastStmt |
+    case = switch.getASwitchCase() and lastStmt = case.getLastStmt()
+  |
+    not (
+      lastStmt instanceof BreakStmt or
+      lastStmt instanceof ReturnStmt or
+      lastStmt instanceof GotoStmt or
+      lastStmt instanceof ContinueStmt or
+      lastStmt.(ExprStmt).getExpr() instanceof ThrowExpr or
+      lastStmt.(ExprStmt).getExpr().(Call).getTarget() instanceof NoreturnFunction or
+      lastStmt.getAnAttribute().getName().matches("%fallthrough") // We'd like to consider compiler variants such as `clang::fallthrough`.
+    )
+  ) and
+  message = "is missing a terminator that moves the control out of its body"
+  or
+  /* 6. The switch statement does not have more than two unique branches. */
+  count(SwitchCase case |
+    case = switch.getASwitchCase() and
+    /*
+     * If the next switch case is the following statement of this switch case, then the two
+     * switch cases are consecutive and should be considered as constituting one branch
+     * together.
+     */
+
+    not case.getNextSwitchCase() = case.getFollowingStmt()
+  |
+    case
+  ) < 2 and
+  message = "contains less than two branches"
+  or
+  /* 7-1. The switch statement is not an enum switch statement and is missing a default case. */
+  not switch instanceof EnumSwitch and
+  not switch.hasDefaultCase() and
+  message = "lacks a default case"
+  or
+  /*
+   * 7-2. The switch statement is an enum switch statement and is missing a branch for a
+   * variant.
+   */
+
+  exists(switch.(EnumSwitch).getAMissingCase()) and
+  message = "lacks a case for one of its variants"
+select switch, "Switch statement " + message + "."