Add RegexExecution in Concepts.qll

Author: owen-mc

java/ql/lib/java.qll

@@ -9,6 +9,7 @@ import semmle.code.Unit
 import semmle.code.java.Annotation
 import semmle.code.java.Compilation
 import semmle.code.java.CompilationUnit
+import semmle.code.java.Concepts
 import semmle.code.java.ControlFlowGraph
 import semmle.code.java.Dependency
 import semmle.code.java.Element

java/ql/lib/semmle/code/java/Concepts.qll

@@ -0,0 +1,88 @@
+/**
+ * Provides abstract classes representing generic concepts such as file system
+ * access or system command execution, for which individual framework libraries
+ * provide concrete subclasses.
+ */
+overlay[local?]
+module;
+
+import java
+private import semmle.code.java.dataflow.DataFlow
+
+/**
+ * A data-flow node that executes a regular expression.
+ *
+ * Extend this class to refine existing API models. If you want to model new APIs,
+ * extend `RegexExecution::Range` instead.
+ */
+class RegexExecution extends DataFlow::Node instanceof RegexExecution::Range {
+  /** Gets the data flow node for the regex being executed by this node. */
+  DataFlow::Node getRegex() { result = super.getRegex() }
+
+  /** Gets a dataflow node for the string to be searched or matched against. */
+  DataFlow::Node getString() { result = super.getString() }
+
+  /**
+   * Gets the name of this regex execution, typically the name of an executing method.
+   * This is used for nice alert messages and should include the module if possible.
+   */
+  string getName() { result = super.getName() }
+}
+
+/** Provides classes for modeling new regular-expression execution APIs. */
+module RegexExecution {
+  /**
+   * A data flow node that executes a regular expression.
+   *
+   * Extend this class to model new APIs. If you want to refine existing API models,
+   * extend `RegexExecution` instead.
+   */
+  abstract class Range extends DataFlow::Node {
+    /** Gets the data flow node for the regex being executed by this node. */
+    abstract DataFlow::Node getRegex();
+
+    /** Gets a data flow node for the string to be searched or matched against. */
+    abstract DataFlow::Node getString();
+
+    /**
+     * Gets the name of this regex execution, typically the name of an executing method.
+     * This is used for nice alert messages and should include the module if possible.
+     */
+    abstract string getName();
+  }
+
+  private class RangeFromExpr extends Range {
+    private RegexExecutionExpr::Range ree;
+
+    RangeFromExpr() { this.asExpr() = ree }
+
+    override DataFlow::Node getRegex() { result.asExpr() = ree.getRegex() }
+
+    override DataFlow::Node getString() { result.asExpr() = ree.getString() }
+
+    override string getName() { result = ree.getName() }
+  }
+}
+
+/** Provides classes for modeling new regular-expression execution APIs. */
+module RegexExecutionExpr {
+  /**
+   * An expression that executes a regular expression.
+   *
+   * Extend this class to model new APIs. If you want to refine existing API models,
+   * extend `RegexExecution` instead.
+   */
+  abstract class Range extends Expr {
+    /** Gets the expression for the regex being executed by this node. */
+    abstract Expr getRegex();
+
+    /** Gets a expression for the string to be searched or matched against. */
+    abstract Expr getString();
+
+    /**
+     * Gets the name of this regex execution, typically the name of an executing method.
+     * This is used for nice alert messages and should include the module if possible.
+     */
+    abstract string getName();
+  }
+}