Adds StatementHolder interface and ability to model statements in s…

…tructure declarations (#468)

* Adds CodeHolder interface and abillity to modell code in structure declaration

Some languages allow to write executable code on file, class or even namespace level,
e.g. javas static and initializer blocks or any code outside of functions in scripting
languages.

This commit extracts the statement management from the CompoundStatement into default
implementations of the CodeHolder interface and implements it in RecordDeclaration,
NamespaceDeclaration and TranslationUnitDeclaration.

Additionally the EOG-Pass is adapted to also build EOG-Paths over those code blocks.

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/frontends/java/DeclarationHandler.java

@@ -46,6 +46,7 @@
 import de.fraunhofer.aisec.cpg.graph.declarations.Declaration;
 import de.fraunhofer.aisec.cpg.graph.declarations.ParamVariableDeclaration;
 import de.fraunhofer.aisec.cpg.graph.declarations.RecordDeclaration;
+import de.fraunhofer.aisec.cpg.graph.statements.CompoundStatement;
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.Expression;
 import de.fraunhofer.aisec.cpg.graph.types.ParameterizedType;
 import de.fraunhofer.aisec.cpg.graph.types.Type;
@@ -297,6 +298,12 @@ public RecordDeclaration handleClassOrInterfaceDeclaration(
         recordDeclaration.addConstructor(c);
       } else if (decl instanceof com.github.javaparser.ast.body.ClassOrInterfaceDeclaration) {
         recordDeclaration.addDeclaration(handle(decl));
+      } else if (decl instanceof com.github.javaparser.ast.body.InitializerDeclaration) {
+        InitializerDeclaration id = (InitializerDeclaration) decl;
+        CompoundStatement initializerBlock =
+            lang.getStatementHandler().handleBlockStatement(id.getBody());
+        initializerBlock.setStaticBlock(id.isStatic());
+        recordDeclaration.addStatement(initializerBlock);
       } else {
         log.debug(
             "Member {} of type {} is something that we do not parse yet: {}",
@@ -375,11 +382,6 @@ public de.fraunhofer.aisec.cpg.graph.declarations.FieldDeclaration handleFieldDe
     return fieldDeclaration;
   }
 
-  public Declaration /* TODO refine return type*/ handleInitializerDeclaration(
-      InitializerDeclaration initializerDecl) {
-    return new Declaration();
-  }
-
   public de.fraunhofer.aisec.cpg.graph.declarations.EnumDeclaration handleEnumDeclaration(
       com.github.javaparser.ast.body.EnumDeclaration enumDecl) {
     String name = getAbsoluteName(enumDecl.getNameAsString());

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/graph/StatementHolder.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2021, Fraunhofer AISEC. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *                    $$$$$$\  $$$$$$$\   $$$$$$\
+ *                   $$  __$$\ $$  __$$\ $$  __$$\
+ *                   $$ /  \__|$$ |  $$ |$$ /  \__|
+ *                   $$ |      $$$$$$$  |$$ |$$$$\
+ *                   $$ |      $$  ____/ $$ |\_$$ |
+ *                   $$ |  $$\ $$ |      $$ |  $$ |
+ *                   \$$$$$   |$$ |      \$$$$$   |
+ *                    \______/ \__|       \______/
+ *
+ */
+package de.fraunhofer.aisec.cpg.graph;
+
+import de.fraunhofer.aisec.cpg.graph.edge.Properties;
+import de.fraunhofer.aisec.cpg.graph.edge.PropertyEdge;
+import de.fraunhofer.aisec.cpg.graph.statements.Statement;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * This interface denotes an AST-Node that can contain code. This code is stored as statements. This
+ * includes Translation units namespaces and classes as some languages, mainly scripting languages
+ * allow code placement outside of explicit functions.
+ *
+ * <p>The reason for not only using a statement property that encapsulates all code in a dummy
+ * compound statements is that code can be distributed between functions and an encapsulating
+ * compound statement would imply a block of code with a code region containing only the statements.
+ */
+public interface StatementHolder {
+
+  /**
+   * Getter to be implemented by implementing classes to gain read access to the classes member.
+   *
+   * @return List of property Edge statements
+   */
+  @NonNull
+  List<PropertyEdge<Statement>> getStatementEdges();
+
+  void setStatementEdges(@NonNull List<PropertyEdge<Statement>> statements);
+
+  /**
+   * Returns the list of contained statements.
+   *
+   * @return contained statements
+   */
+  @NonNull
+  default List<Statement> getStatements() {
+    return (List<Statement>) PropertyEdge.unwrapPropertyEdge(getStatementEdges(), true);
+  }
+
+  @NonNull
+  default List<PropertyEdge<Statement>> getStatementsPropertyEdge() {
+    return getStatementEdges();
+  }
+
+  default void setStatements(@NonNull List<Statement> statements) {
+    setStatementEdges(PropertyEdge.transformIntoOutgoingPropertyEdgeList(statements, (Node) this));
+  }
+
+  /**
+   * Adds the specified statement to this statement holder. The statements have to be stored as a
+   * list of statements as we try to avoid adding new AST-nodes that do not exist, e.g. a code body
+   * to hold statements
+   *
+   * @param s the statement
+   */
+  default void addStatement(Statement s) {
+    PropertyEdge<Statement> propertyEdge = new PropertyEdge<>((Node) this, s);
+    propertyEdge.addProperty(Properties.INDEX, getStatementEdges().size());
+    getStatementEdges().add(propertyEdge);
+  }
+}

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/graph/declarations/NamespaceDeclaration.java

@@ -26,7 +26,10 @@
 package de.fraunhofer.aisec.cpg.graph.declarations;
 
 import de.fraunhofer.aisec.cpg.graph.DeclarationHolder;
+import de.fraunhofer.aisec.cpg.graph.StatementHolder;
 import de.fraunhofer.aisec.cpg.graph.SubGraph;
+import de.fraunhofer.aisec.cpg.graph.edge.PropertyEdge;
+import de.fraunhofer.aisec.cpg.graph.statements.Statement;
 import de.fraunhofer.aisec.cpg.helpers.Util;
 import java.util.ArrayList;
 import java.util.List;
@@ -35,6 +38,7 @@
 import java.util.stream.Collectors;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.jetbrains.annotations.NotNull;
+import org.neo4j.ogm.annotation.Relationship;
 
 /**
  * Declares the scope of a namespace and appends its own name to the current namespace-prefix to
@@ -46,14 +50,20 @@
  * semantical difference between NamespaceDeclaration and {@link RecordDeclaration} lies in the
  * non-instantiabillity of a namespace.
  */
-public class NamespaceDeclaration extends Declaration implements DeclarationHolder {
+public class NamespaceDeclaration extends Declaration
+    implements DeclarationHolder, StatementHolder {
 
   /**
    * Edges to nested namespaces, records, functions, fields etc. contained in the current namespace.
    */
   @SubGraph("AST")
   private List<Declaration> declarations = new ArrayList<>();
 
+  /** The list of statements. */
+  @Relationship(value = "STATEMENTS", direction = "OUTGOING")
+  @NonNull
+  private @SubGraph("AST") List<PropertyEdge<Statement>> statements = new ArrayList<>();
+
   public List<FieldDeclaration> getFields() {
     return Util.filterCast(declarations, FieldDeclaration.class);
   }
@@ -98,6 +108,16 @@ public <T> T getDeclarationAs(int i, Class<T> clazz) {
     return clazz.cast(getDeclarations().get(i));
   }
 
+  @Override
+  public @NonNull List<PropertyEdge<Statement>> getStatementEdges() {
+    return this.statements;
+  }
+
+  @Override
+  public void setStatementEdges(@NonNull List<PropertyEdge<Statement>> statements) {
+    this.statements = statements;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/graph/declarations/RecordDeclaration.java

@@ -29,8 +29,10 @@
 
 import de.fraunhofer.aisec.cpg.graph.DeclarationHolder;
 import de.fraunhofer.aisec.cpg.graph.Node;
+import de.fraunhofer.aisec.cpg.graph.StatementHolder;
 import de.fraunhofer.aisec.cpg.graph.SubGraph;
 import de.fraunhofer.aisec.cpg.graph.edge.PropertyEdge;
+import de.fraunhofer.aisec.cpg.graph.statements.Statement;
 import de.fraunhofer.aisec.cpg.graph.types.Type;
 import java.util.*;
 import java.util.stream.Collectors;
@@ -43,7 +45,7 @@
 import org.neo4j.ogm.annotation.Transient;
 
 /** Represents a C++ union/struct/class or Java class */
-public class RecordDeclaration extends Declaration implements DeclarationHolder {
+public class RecordDeclaration extends Declaration implements DeclarationHolder, StatementHolder {
 
   /** The kind, i.e. struct, class, union or enum. */
   private String kind;
@@ -68,6 +70,11 @@ public class RecordDeclaration extends Declaration implements DeclarationHolder
   @SubGraph("AST")
   private List<PropertyEdge<TemplateDeclaration>> templates = new ArrayList<>();
 
+  /** The list of statements. */
+  @Relationship(value = "STATEMENTS", direction = "OUTGOING")
+  @NonNull
+  private @SubGraph("AST") List<PropertyEdge<Statement>> statements = new ArrayList<>();
+
   @Transient private List<Type> superClasses = new ArrayList<>();
   @Transient private List<Type> implementedInterfaces = new ArrayList<>();
 
@@ -300,6 +307,16 @@ public void setStaticImportStatements(List<String> staticImportStatements) {
     this.staticImportStatements = staticImportStatements;
   }
 
+  @Override
+  public @NonNull List<PropertyEdge<Statement>> getStatementEdges() {
+    return this.statements;
+  }
+
+  @Override
+  public void setStatementEdges(@NonNull List<PropertyEdge<Statement>> statements) {
+    this.statements = statements;
+  }
+
   @Override
   public String toString() {
     return new ToStringBuilder(this, Node.TO_STRING_STYLE)

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/graph/declarations/TranslationUnitDeclaration.java

@@ -29,8 +29,10 @@
 
 import de.fraunhofer.aisec.cpg.graph.DeclarationHolder;
 import de.fraunhofer.aisec.cpg.graph.Node;
+import de.fraunhofer.aisec.cpg.graph.StatementHolder;
 import de.fraunhofer.aisec.cpg.graph.SubGraph;
 import de.fraunhofer.aisec.cpg.graph.edge.PropertyEdge;
+import de.fraunhofer.aisec.cpg.graph.statements.Statement;
 import java.util.*;
 import java.util.stream.Collectors;
 import org.apache.commons.lang3.builder.ToStringBuilder;
@@ -40,7 +42,8 @@
 import org.neo4j.ogm.annotation.Relationship;
 
 /** The top most declaration, representing a translation unit, for example a file. */
-public class TranslationUnitDeclaration extends Declaration implements DeclarationHolder {
+public class TranslationUnitDeclaration extends Declaration
+    implements DeclarationHolder, StatementHolder {
 
   /** A list of declarations within this unit. */
   @Relationship(value = "DECLARATIONS", direction = "OUTGOING")
@@ -60,6 +63,11 @@ public class TranslationUnitDeclaration extends Declaration implements Declarati
   @NonNull
   private List<PropertyEdge<Declaration>> namespaces = new ArrayList<>();
 
+  /** The list of statements. */
+  @Relationship(value = "STATEMENTS", direction = "OUTGOING")
+  @NonNull
+  private @SubGraph("AST") List<PropertyEdge<Statement>> statements = new ArrayList<>();
+
   /**
    * Returns the i-th declaration as a specific class, if it can be cast
    *
@@ -150,6 +158,16 @@ public void addDeclaration(@NonNull Declaration declaration) {
     addIfNotContains(declarations, declaration);
   }
 
+  @Override
+  public @NonNull List<PropertyEdge<Statement>> getStatementEdges() {
+    return this.statements;
+  }
+
+  @Override
+  public void setStatementEdges(@NonNull List<PropertyEdge<Statement>> statements) {
+    this.statements = statements;
+  }
+
   @Override
   public String toString() {
     return new ToStringBuilder(this, Node.TO_STRING_STYLE)

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/graph/statements/CompoundStatement.java

@@ -26,12 +26,11 @@
 package de.fraunhofer.aisec.cpg.graph.statements;
 
 import de.fraunhofer.aisec.cpg.graph.Node;
+import de.fraunhofer.aisec.cpg.graph.StatementHolder;
 import de.fraunhofer.aisec.cpg.graph.SubGraph;
 import de.fraunhofer.aisec.cpg.graph.declarations.FunctionDeclaration;
-import de.fraunhofer.aisec.cpg.graph.edge.Properties;
 import de.fraunhofer.aisec.cpg.graph.edge.PropertyEdge;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import org.apache.commons.lang3.builder.ToStringBuilder;
@@ -42,40 +41,38 @@
  * A statement which contains a list of statements. A common example is a function body within a
  * {@link FunctionDeclaration}.
  */
-public class CompoundStatement extends Statement {
+public class CompoundStatement extends Statement implements StatementHolder {
 
   /** The list of statements. */
   @Relationship(value = "STATEMENTS", direction = "OUTGOING")
   @NonNull
   private @SubGraph("AST") List<PropertyEdge<Statement>> statements = new ArrayList<>();
 
-  @NonNull
-  public List<Statement> getStatements() {
-    List<Statement> targets = new ArrayList<>();
-    for (PropertyEdge<Statement> propertyEdge : this.statements) {
-      targets.add(propertyEdge.getEnd());
-    }
-    return Collections.unmodifiableList(targets);
-  }
+  /**
+   * This variable helps to differentiate between static and non static initializer blocks. Static
+   * initializer blocks are executed when the enclosing declaration is first referred to, e.g.
+   * loaded into the jvm or parsed. Non static initializers are executed on Record construction.
+   *
+   * <p>If a compound statement is part of a method body, this notion is not relevant.
+   */
+  private boolean staticBlock = false;
 
-  @NonNull
-  public List<PropertyEdge<Statement>> getStatementsPropertyEdge() {
+  @Override
+  public @NonNull List<PropertyEdge<Statement>> getStatementEdges() {
     return this.statements;
   }
 
-  public void setStatements(@NonNull List<Statement> statements) {
-    this.statements = PropertyEdge.transformIntoOutgoingPropertyEdgeList(statements, this);
+  @Override
+  public void setStatementEdges(@NonNull List<PropertyEdge<Statement>> statements) {
+    this.statements = statements;
   }
 
-  @NonNull
-  public List<PropertyEdge<Statement>> getStatementEdges() {
-    return this.statements;
+  public boolean isStaticBlock() {
+    return staticBlock;
   }
 
-  public void addStatement(Statement s) {
-    PropertyEdge<Statement> propertyEdge = new PropertyEdge<>(this, s);
-    propertyEdge.addProperty(Properties.INDEX, this.statements.size());
-    this.statements.add(propertyEdge);
+  public void setStaticBlock(boolean staticBlock) {
+    this.staticBlock = staticBlock;
   }
 
   @Override

cpg-library/src/main/java/de/fraunhofer/aisec/cpg/passes/ControlFlowSensitiveDFGPass.java

@@ -94,7 +94,7 @@ private void removeValues(ControlFlowSensitiveDFGPass.FunctionLevelFixpointItera
    * @param node every node in the TranslationResult
    */
   public void handle(Node node) {
-    if (node instanceof FunctionDeclaration) {
+    if (node instanceof FunctionDeclaration || node instanceof StatementHolder) {
       ControlFlowSensitiveDFGPass.FunctionLevelFixpointIterator flfIterator =
           new ControlFlowSensitiveDFGPass.FunctionLevelFixpointIterator();
       flfIterator.handle(node);