Implement MISRA-C++23 Preprocesser package rules 19-0-4, 19-1-1, and 19-2-1

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

@@ -0,0 +1,78 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype PreprocessorQuery =
+  TUndefOfMacroNotDefinedInFileQuery() or
+  TInvalidTokenInDefinedOperatorQuery() or
+  TDefinedOperatorExpandedInIfDirectiveQuery() or
+  TNoValidIfdefGuardInHeaderQuery()
+
+predicate isPreprocessorQueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `undefOfMacroNotDefinedInFile` query
+    PreprocessorPackage::undefOfMacroNotDefinedInFileQuery() and
+  queryId =
+    // `@id` for the `undefOfMacroNotDefinedInFile` query
+    "cpp/misra/undef-of-macro-not-defined-in-file" and
+  ruleId = "RULE-19-0-4" and
+  category = "advisory"
+  or
+  query =
+    // `Query` instance for the `invalidTokenInDefinedOperator` query
+    PreprocessorPackage::invalidTokenInDefinedOperatorQuery() and
+  queryId =
+    // `@id` for the `invalidTokenInDefinedOperator` query
+    "cpp/misra/invalid-token-in-defined-operator" and
+  ruleId = "RULE-19-1-1" and
+  category = "required"
+  or
+  query =
+    // `Query` instance for the `definedOperatorExpandedInIfDirective` query
+    PreprocessorPackage::definedOperatorExpandedInIfDirectiveQuery() and
+  queryId =
+    // `@id` for the `definedOperatorExpandedInIfDirective` query
+    "cpp/misra/defined-operator-expanded-in-if-directive" and
+  ruleId = "RULE-19-1-1" and
+  category = "required"
+  or
+  query =
+    // `Query` instance for the `noValidIfdefGuardInHeader` query
+    PreprocessorPackage::noValidIfdefGuardInHeaderQuery() and
+  queryId =
+    // `@id` for the `noValidIfdefGuardInHeader` query
+    "cpp/misra/no-valid-ifdef-guard-in-header" and
+  ruleId = "RULE-19-2-1" and
+  category = "required"
+}
+
+module PreprocessorPackage {
+  Query undefOfMacroNotDefinedInFileQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `undefOfMacroNotDefinedInFile` query
+      TQueryCPP(TPreprocessorPackageQuery(TUndefOfMacroNotDefinedInFileQuery()))
+  }
+
+  Query invalidTokenInDefinedOperatorQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `invalidTokenInDefinedOperator` query
+      TQueryCPP(TPreprocessorPackageQuery(TInvalidTokenInDefinedOperatorQuery()))
+  }
+
+  Query definedOperatorExpandedInIfDirectiveQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `definedOperatorExpandedInIfDirective` query
+      TQueryCPP(TPreprocessorPackageQuery(TDefinedOperatorExpandedInIfDirectiveQuery()))
+  }
+
+  Query noValidIfdefGuardInHeaderQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `noValidIfdefGuardInHeader` query
+      TQueryCPP(TPreprocessorPackageQuery(TNoValidIfdefGuardInHeaderQuery()))
+  }
+}

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

@@ -40,6 +40,7 @@ import Operators
 import OrderOfEvaluation
 import OutOfBounds
 import Pointers
+import Preprocessor
 import Representation
 import Scope
 import SideEffects1
@@ -94,6 +95,7 @@ newtype TCPPQuery =
   TOrderOfEvaluationPackageQuery(OrderOfEvaluationQuery q) or
   TOutOfBoundsPackageQuery(OutOfBoundsQuery q) or
   TPointersPackageQuery(PointersQuery q) or
+  TPreprocessorPackageQuery(PreprocessorQuery q) or
   TRepresentationPackageQuery(RepresentationQuery q) or
   TScopePackageQuery(ScopeQuery q) or
   TSideEffects1PackageQuery(SideEffects1Query q) or
@@ -148,6 +150,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isOrderOfEvaluationQueryMetadata(query, queryId, ruleId, category) or
   isOutOfBoundsQueryMetadata(query, queryId, ruleId, category) or
   isPointersQueryMetadata(query, queryId, ruleId, category) or
+  isPreprocessorQueryMetadata(query, queryId, ruleId, category) or
   isRepresentationQueryMetadata(query, queryId, ruleId, category) or
   isScopeQueryMetadata(query, queryId, ruleId, category) or
   isSideEffects1QueryMetadata(query, queryId, ruleId, category) or

cpp/common/src/codingstandards/cpp/util/CondensedList.qll

@@ -0,0 +1,105 @@
+private import codeql.util.DenseRank
+
+/**
+ * Describes how to construct a condensed list from sparse but orderable data, and how that data
+ * should be connected, with one such list per specified division.
+ */
+signature module CondensedListSig {
+  /**
+   * The division specifies which items are connected into lists, with one list per division.
+   *
+   * For instance, if connecting variables defined in a file, the division will be the file.
+   */
+  class Division;
+
+  /**
+   * The class of the items to be condensed into lists.
+   *
+   * For instance, when connecting variables defined in a file, the items are the variables.
+   */
+  class Item {
+    string toString();
+  }
+
+  /**
+   * The index specifies the order of the items in the condensed list, and may be sparse (have
+   * gaps).
+   *
+   * For instance, if connecting variables defined in a file, the index will be the line number of
+   * the variable in the file.
+   *
+   * The sparse index (which may have gaps) is used to determine the ordering of the items in the
+   * condensed list. Once the condensed list is created, the items in the list will automatically be
+   * assigned a dense index (which has no gaps).
+   *
+   * There must be no duplicate indices for the same division for correctness.
+   */
+  int getSparseIndex(Division d, Item l);
+}
+
+/**
+ * A module to take orderable data (which may not be continuous) and condense it into one or more
+ * dense lists, with one such list per specified division.
+ *
+ * To instantiate this module, you need to provide a `CondensedListSig` module that
+ * specifies the spare index and division of the items to be connected.
+ *
+ * For instance, to create a condensed list of variables defined in every file, you can
+ * create a `CondensedListSig` module that specifies the file as the division and
+ * the line number as the sparse index.
+ *
+ * ```ql
+ *   module ConfigFileListConfig {
+ *     class Division = File;
+ *     class Item = Variable;
+ *     int getSparseIndex(File file, Variable var) {
+ *       file = var.getLocation().getFile() and
+ *       var.getLocation().getStartLine()
+ *     }
+ *   }
+ *
+ *   import Condense<ConfigFileListConfig>
+ *
+ *   from Condense::ListEntry l
+ *   select l, l.getItem(), l.getDenseIndex(), l.getNext(), l.getPrev(),
+ * ```
+ */
+module Condense<CondensedListSig Config> {
+  newtype TList =
+    THead(Config::Item l, Config::Division t) { denseRank(t, l) = 1 } or
+    TCons(ListEntry prev, Config::Item l) {
+      prev.getDenseIndex() = denseRank(prev.getDivision(), l) - 1
+    }
+
+  private module DenseRankConfig implements DenseRankInputSig2 {
+    class Ranked = Config::Item;
+
+    class C = Config::Division;
+
+    predicate getRank = Config::getSparseIndex/2;
+  }
+
+  private import DenseRank2<DenseRankConfig>
+
+  class ListEntry extends TList {
+    Config::Division getDivision() {
+      this = THead(_, result)
+      or
+      exists(ListEntry prev | this = TCons(prev, _) and result = prev.getDivision())
+    }
+
+    string toString() { result = getItem().toString() + " [index " + getDenseIndex() + "]" }
+
+    Config::Item getItem() {
+      this = THead(result, _)
+      or
+      this = TCons(_, result)
+    }
+
+    int getDenseIndex() { result = denseRank(getDivision(), getItem()) }
+
+    ListEntry getPrev() { this = TCons(result, _) }
+
+    ListEntry getNext() { result.getPrev() = this }
+  }
+}

cpp/common/src/codingstandards/cpp/util/Pair.qll

@@ -0,0 +1,21 @@
+bindingset[this]
+signature class ItemSig {
+  bindingset[this]
+  string toString();
+}
+
+module Pair<ItemSig A, ItemSig B> {
+  signature predicate pred(A a, B b);
+
+  module Where<pred/2 ctor> {
+    private newtype TAll = TSome(A a, B b) { ctor(a, b) }
+
+    class Pair extends TAll {
+      A getFirst() { this = TSome(result, _) }
+
+      B getSecond() { this = TSome(_, result) }
+
+      string toString() { result = getFirst().toString() + ", " + getSecond().toString() }
+    }
+  }
+}

cpp/misra/src/rules/RULE-19-0-4/UndefOfMacroNotDefinedInFile.ql

@@ -0,0 +1,66 @@
+/**
+ * @id cpp/misra/undef-of-macro-not-defined-in-file
+ * @name RULE-19-0-4: #undef should only be used for macros defined previously in the same file
+ * @description Using #undef to undefine a macro that is not defined in the same file can lead to
+ *              confusion.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-19-0-4
+ *       scope/single-translation-unit
+ *       readability
+ *       maintainability
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.cpp.misra
+import codingstandards.cpp.util.CondensedList
+import codingstandards.cpp.util.Pair
+
+class DefOrUndef extends PreprocessorDirective {
+  string name;
+
+  DefOrUndef() {
+    name = this.(PreprocessorUndef).getName() or
+    name = this.(Macro).getName()
+  }
+
+  string getName() { result = name }
+}
+
+predicate relevantNameAndFile(string name, File file) {
+  exists(DefOrUndef m |
+    m.getName() = name and
+    m.getFile() = file
+  )
+}
+
+class StringFilePair = Pair<string, File>::Where<relevantNameAndFile/2>::Pair;
+
+module DefUndefListConfig implements CondensedListSig {
+  class Division = StringFilePair;
+
+  class Item = DefOrUndef;
+
+  int getSparseIndex(StringFilePair division, DefOrUndef directive) {
+    directive.getName() = division.getFirst() and
+    directive.getFile() = division.getSecond() and
+    result = directive.getLocation().getStartLine()
+  }
+}
+
+class ListEntry = Condense<DefUndefListConfig>::ListEntry;
+
+from PreprocessorUndef undef, ListEntry defUndefListEntry
+where
+  not isExcluded(undef, PreprocessorPackage::undefOfMacroNotDefinedInFileQuery()) and
+  // There exists a def or undef for a given name and file, and it is an #undef
+  undef = defUndefListEntry.getItem() and
+  // Exclude cases where the previous def or undef with the same name in the same file is a #define
+  not exists(ListEntry prev |
+    prev = defUndefListEntry.getPrev() and
+    prev.getItem() instanceof Macro
+  )
+select undef, "Undef of name '" + undef.getName() + "' not defined in the same file."

cpp/misra/src/rules/RULE-19-1-1/DefinedOperatorExpandedInIfDirective.ql

@@ -0,0 +1,27 @@
+/**
+ * @id cpp/misra/defined-operator-expanded-in-if-directive
+ * @name RULE-19-1-1: The defined preprocessor operator shall be used appropriately
+ * @description Macro expansions that produce the token 'defined' inside of an if directive result
+ *              in undefined behavior.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-19-1-1
+ *       scope/single-translation-unit
+ *       correctness
+ *       maintainability
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.misra
+
+from PreprocessorIf ifDirective, MacroInvocation mi
+where
+  not isExcluded(ifDirective, PreprocessorPackage::definedOperatorExpandedInIfDirectiveQuery()) and
+  ifDirective.getLocation().subsumes(mi.getLocation()) and
+  mi.getMacro().getBody().regexpMatch(".*defined.*")
+select ifDirective,
+  "If directive contains macro expansion including the token 'defined' from macro $@, which results in undefined behavior.",
+  mi.getMacro(), mi.getMacroName()

cpp/misra/src/rules/RULE-19-1-1/InvalidTokenInDefinedOperator.ql

@@ -0,0 +1,42 @@
+/**
+ * @id cpp/misra/invalid-token-in-defined-operator
+ * @name RULE-19-1-1: The defined preprocessor operator shall be used appropriately
+ * @description Using the defined operator without an immediately following optionally parenthesized
+ *              identifier results in undefined behavior.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-19-1-1
+ *       scope/single-translation-unit
+ *       correctness
+ *       maintainability
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.misra
+
+string idRegex() { result = "[a-zA-Z_]([a-zA-Z_0-9]*)" }
+
+bindingset[body]
+predicate hasInvalidDefinedOperator(string body) {
+  body.regexpMatch(".*\\bdefined" +
+      // Contains text "defined" at a word break
+      // Negative zero width lookahead:
+      "(?!(" +
+      // (group) optional whitespace followed by a valid identifier
+      "(\\s*" + idRegex() + ")" +
+      // or
+      "|" +
+      // (group) optional whitespace followed by parenthesis and valid identifier
+      "(\\s*\\(\\s*" + idRegex() + "\\s*\\))" +
+      // End negative zero width lookahead, match remaining text
+      ")).*")
+}
+
+from PreprocessorIf ifDirective
+where
+  not isExcluded(ifDirective, PreprocessorPackage::invalidTokenInDefinedOperatorQuery()) and
+  hasInvalidDefinedOperator(ifDirective.getHead())
+select ifDirective, "Invalid use of defined operator in if directive."