mock parameters

Author: erik-krogh

ql/ql/src/codeql_ql/ast/Ast.qll

@@ -658,11 +658,15 @@ class VarDef extends TVarDef, AstNode {
  * A variable declaration, with a type and a name.
  */
 class VarDecl extends TVarDecl, VarDef, Declaration {
-  QL::VarDecl var;
+  Mocks::VarDeclOrMock var;
 
   VarDecl() { this = TVarDecl(var) }
 
-  override string getName() { result = var.getChild(1).(QL::VarName).getChild().getValue() }
+  override string getName() {
+    result = var.asLeft().getChild(1).(QL::VarName).getChild().getValue()
+    or
+    result = var.asRight().getName()
+  }
 
   override Type getType() { result = this.getTypeExpr().getResolvedType() }
 
@@ -671,14 +675,18 @@ class VarDecl extends TVarDecl, VarDef, Declaration {
   /**
    * Gets the type part of this variable declaration.
    */
-  TypeExpr getTypeExpr() { toQL(result) = var.getChild(0) }
+  TypeExpr getTypeExpr() {
+    toQL(result) = var.asLeft().getChild(0)
+    or
+    toMock(result) = var.asRight().getType()
+  }
 
   /**
    * Holds if this variable declaration is a private field on a class.
    */
   predicate isPrivate() {
     exists(QL::ClassMember member |
-      var = member.getChild(_).(QL::Field).getChild() and
+      var.asLeft() = member.getChild(_).(QL::Field).getChild() and
       member.getAFieldOrChild().(QL::Annotation).getName().getValue() = "private"
     )
   }

ql/ql/src/codeql_ql/ast/internal/AstMocks.qll

@@ -18,7 +18,8 @@ newtype TMockAst =
   TMockModule(string id) { id instanceof MockModule::Range } or
   TMockClass(string id) { id instanceof MockClass::Range } or
   TMockTypeExpr(string id) { id instanceof MockTypeExpr::Range } or
-  TMockClasslessPredicate(string id) { id instanceof MockClasslessPredicate::Range }
+  TMockClasslessPredicate(string id) { id instanceof MockClasslessPredicate::Range } or
+  TMockVarDecl(string id) { id instanceof MockVarDecl::Range }
 
 /** Gets a mocked Ast node from the string ID that represents it. */
 MockAst fromId(string id) {
@@ -29,6 +30,8 @@ MockAst fromId(string id) {
   result = TMockTypeExpr(id)
   or
   result = TMockClasslessPredicate(id)
+  or
+  result = TMockVarDecl(id)
   // TODO: Other nodes.
 }
 
@@ -171,3 +174,31 @@ module MockClasslessPredicate {
 }
 
 class ClasslessPredicateOrMock = Either<QL::ClasslessPredicate, MockClasslessPredicate>::Either;
+
+/**
+ * A mocked `VarDecl`.
+ */
+class MockVarDecl extends MockAst, TMockVarDecl {
+  MockVarDecl::Range range;
+
+  MockVarDecl() { this = TMockVarDecl(range) }
+
+  final string getName() { result = range.getName() }
+
+  final MockTypeExpr getType() { result.getId() = range.getType() }
+}
+
+module MockVarDecl {
+  abstract class Range extends string {
+    bindingset[this]
+    Range() { this = this }
+
+    /** Gets the name of the variable. */
+    abstract string getName();
+
+    /** Gets the type of the variable. */
+    abstract MockTypeExpr::Range getType();
+  }
+}
+
+class VarDeclOrMock = Either<QL::VarDecl, MockVarDecl>::Either;

ql/ql/src/codeql_ql/ast/internal/AstNodes.qll

@@ -10,7 +10,7 @@ newtype TAstNode =
   TBlockComment(QL::BlockComment comment) or
   TLineComment(QL::LineComment comment) or
   TClasslessPredicate(Mocks::ClasslessPredicateOrMock pred) or
-  TVarDecl(QL::VarDecl decl) or
+  TVarDecl(Mocks::VarDeclOrMock decl) or
   TFieldDecl(QL::Field field) or
   TClass(Mocks::ClassOrMock cls) or
   TCharPred(QL::Charpred pred) or
@@ -162,7 +162,7 @@ QL::AstNode toQL(AST::AstNode n) {
   or
   n = TClasslessPredicate(any(Mocks::ClasslessPredicateOrMock m | m.asLeft() = result))
   or
-  n = TVarDecl(result)
+  n = TVarDecl(any(Mocks::VarDeclOrMock m | m.asLeft() = result))
   or
   n = TFieldDecl(result)
   or
@@ -215,6 +215,8 @@ Mocks::MockAst toMock(AST::AstNode n) {
   n = TType(any(Mocks::TypeExprOrMock m | m.asRight() = result))
   or
   n = TClasslessPredicate(any(Mocks::ClasslessPredicateOrMock m | m.asRight() = result))
+  or
+  n = TVarDecl(any(Mocks::VarDeclOrMock m | m.asRight() = result))
 }
 
 class TPredicate =

ql/ql/src/codeql_ql/ast/internal/Builtins.qll

@@ -125,7 +125,7 @@ module QlBuiltinsMocks {
    * module QlBuiltins {
    *  signature class T;
    *  module EdgeSig<T MyT> {
-   *    signature predicate edgeSig(MyT a, MyT b); //
+   *    signature predicate edgeSig(MyT a, MyT b);
    *  }
    *  module EquivalenceRelation<T MyT, EdgeSig<MyT>::edgeSig/2 edge> { //
    *    class EquivalenceClass; //
@@ -164,10 +164,26 @@ module QlBuiltinsMocks {
 
         override string getName() { result = "edgeSig" }
 
-        override string getParameter(int i) {
-          none() // TODO:
+        override EdgeSigPredParam getParameter(int i) {
+          i = 0 and
+          result.getName() = "a"
+          or
+          i = 1 and
+          result.getName() = "b"
         }
       }
+
+      class EdgeSigPredParam extends MockVarDecl::Range {
+        string name;
+
+        EdgeSigPredParam() {
+          this = "Mock: QlBuiltins::EdgeSig::edgeSig::" + name and name = ["a", "b"]
+        }
+
+        override string getName() { result = name }
+
+        override MockTypeExpr::Range getType() { result instanceof EdgeSigType } // TODO: I'm just using one typeexpr for everything, that might break the parent relation.
+      }
     }
 
     class EquivalenceRelationModule extends MockModule::Range {