Merge pull request #4687 from tamasvajk/feature/csharp9-records

C#: Extract record declarations

Author: tamasvajk

csharp/change-notes/2021-02-04-Records.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* Record types (`Record`) are extracted.

csharp/extractor/Semmle.Extraction.CSharp/Populators/TypeContainerVisitor.cs

@@ -43,6 +43,11 @@ public override void VisitDelegateDeclaration(DelegateDeclarationSyntax node)
             Entities.NamedType.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
         }
 
+        public override void VisitRecordDeclaration(RecordDeclarationSyntax node)
+        {
+            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
+        }
+
         public override void VisitClassDeclaration(ClassDeclarationSyntax classDecl)
         {
             Entities.Type.Create(cx, cx.GetModel(classDecl).GetDeclaredSymbol(classDecl)).ExtractRecursive(trapFile, parent);

csharp/ql/src/semmle/code/cil/Declaration.qll

@@ -51,30 +51,23 @@ private predicate toCSharpTypeParameterJoin(TypeParameter tp, int i, CS::Unbound
  * A member of a type. Either a type (`Type`), a method (`Method`), a property (`Property`), or an event (`Event`).
  */
 class Member extends DotNet::Member, Declaration, @cil_member {
-  /** Holds if this member is declared `public`. */
-  predicate isPublic() { cil_public(this) }
+  override predicate isPublic() { cil_public(this) }
 
-  /** Holds if this member is declared `protected.` */
-  predicate isProtected() { cil_protected(this) }
+  override predicate isProtected() { cil_protected(this) }
 
-  /** Holds if this member is `private`. */
-  predicate isPrivate() { cil_private(this) }
+  override predicate isPrivate() { cil_private(this) }
 
-  /** Holds if this member is `internal`. */
-  predicate isInternal() { cil_internal(this) }
+  override predicate isInternal() { cil_internal(this) }
 
-  /** Holds if this member is `sealed`. */
-  predicate isSealed() { cil_sealed(this) }
+  override predicate isSealed() { cil_sealed(this) }
 
-  /** Holds if this member is `abstract`. */
-  predicate isAbstract() { cil_abstract(this) }
+  override predicate isAbstract() { cil_abstract(this) }
+
+  override predicate isStatic() { cil_static(this) }
 
   /** Holds if this member has a security attribute. */
   predicate hasSecurity() { cil_security(this) }
 
-  /** Holds if this member is `static`. */
-  predicate isStatic() { cil_static(this) }
-
   override Location getLocation() { result = getDeclaringType().getLocation() }
 }
 

csharp/ql/src/semmle/code/cil/Types.qll

@@ -60,6 +60,11 @@ class Class extends ValueOrRefType {
   Class() { this.isClass() }
 }
 
+/** A `record`. */
+class Record extends Class {
+  Record() { this.isRecord() }
+}
+
 /** An `interface`. */
 class Interface extends ValueOrRefType {
   Interface() { this.isInterface() }

csharp/ql/src/semmle/code/csharp/Member.qll

@@ -120,6 +120,20 @@ class Modifiable extends Declaration, @modifiable {
 class Member extends DotNet::Member, Modifiable, @member {
   /** Gets an access to this member. */
   MemberAccess getAnAccess() { result.getTarget() = this }
+
+  override predicate isPublic() { Modifiable.super.isPublic() }
+
+  override predicate isProtected() { Modifiable.super.isProtected() }
+
+  override predicate isPrivate() { Modifiable.super.isPrivate() }
+
+  override predicate isInternal() { Modifiable.super.isInternal() }
+
+  override predicate isSealed() { Modifiable.super.isSealed() }
+
+  override predicate isAbstract() { Modifiable.super.isAbstract() }
+
+  override predicate isStatic() { Modifiable.super.isStatic() }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/PrintAst.qll

@@ -102,15 +102,16 @@ private ValueOrRefType getAnInterestingBaseType(ValueOrRefType type) {
   not type instanceof ArrayType and
   not type instanceof NullableType and
   result = type.getABaseType() and
-  isInterestingBaseType(result)
+  isInterestingBaseType(type, result)
 }
 
-private predicate isInterestingBaseType(ValueOrRefType base) {
+private predicate isInterestingBaseType(ValueOrRefType type, ValueOrRefType base) {
   not base instanceof ObjectType and
   not base.getQualifiedName() = "System.ValueType" and
   not base.getQualifiedName() = "System.Delegate" and
   not base.getQualifiedName() = "System.MulticastDelegate" and
-  not base.getQualifiedName() = "System.Enum"
+  not base.getQualifiedName() = "System.Enum" and
+  exists(TypeMention tm | tm.getTarget() = type and tm.getType() = base)
 }
 
 /**
@@ -570,11 +571,12 @@ final class TypeNode extends ElementNode {
     result.(BaseTypesNode).getValueOrRefType() = type
     or
     result.(ElementNode).getElement() =
-      rank[childIndex - 3](Member m, string file, int line, int column |
+      rank[childIndex - 3](Member m, string file, int line, int column, string name |
         m = type.getAMember() and
+        name = m.getName() and
         locationSortKeys(m, file, line, column)
       |
-        m order by file, line, column
+        m order by file, line, column, name
       )
   }
 }

csharp/ql/src/semmle/code/csharp/Type.qll

@@ -736,6 +736,21 @@ class Class extends RefType, @class_type {
   override string getAPrimaryQlClass() { result = "Class" }
 }
 
+/**
+ * A `record`, for example
+ *
+ * ```csharp
+ * record R(object Prop) {
+ *   ...
+ * }
+ * ```
+ */
+class Record extends Class {
+  Record() { this.isRecord() }
+
+  override string getAPrimaryQlClass() { result = "Record" }
+}
+
 /**
  * A class generated by the compiler from an anonymous object creation.
  *

csharp/ql/src/semmle/code/dotnet/Declaration.qll

@@ -58,7 +58,28 @@ class Declaration extends NamedElement, @dotnet_declaration {
 }
 
 /** A member of a type. */
-class Member extends Declaration, @dotnet_member { }
+class Member extends Declaration, @dotnet_member {
+  /** Holds if this member is declared `public`. */
+  predicate isPublic() { none() }
+
+  /** Holds if this member is declared `protected.` */
+  predicate isProtected() { none() }
+
+  /** Holds if this member is `private`. */
+  predicate isPrivate() { none() }
+
+  /** Holds if this member is `internal`. */
+  predicate isInternal() { none() }
+
+  /** Holds if this member is `sealed`. */
+  predicate isSealed() { none() }
+
+  /** Holds if this member is `abstract`. */
+  predicate isAbstract() { none() }
+
+  /** Holds if this member is `static`. */
+  predicate isStatic() { none() }
+}
 
 /** A property. */
 class Property extends Member, @dotnet_property {

csharp/ql/src/semmle/code/dotnet/Type.qll

@@ -49,6 +49,18 @@ class ValueOrRefType extends Type, @dotnet_valueorreftype {
 
   /** Gets a base type of this type, if any. */
   ValueOrRefType getABaseType() { none() }
+
+  /** Holds if this type is a `record`. */
+  predicate isRecord() {
+    exists(Callable c |
+      c.getDeclaringType() = this and
+      c.hasName("<Clone>$") and
+      c.getNumberOfParameters() = 0 and
+      c.getReturnType() = this.getABaseType*() and
+      c.(Member).isPublic() and
+      not c.(Member).isStatic()
+    )
+  }
 }
 
 /**

csharp/ql/test/library-tests/csharp9/InitOnlyProperty.cs

@@ -1,12 +1,5 @@
 using System;
 
-namespace System.Runtime.CompilerServices
-{
-    public sealed class IsExternalInit
-    {
-    }
-}
-
 public class Base
 {
     public int Prop0 { get { return 1; } init { Prop1 = value; } }