Merge pull request #823 from dave-bartolomeo/dave/IdentityString

C++: Declaration.getIdentityString and Type.getTypeIdentityString

Author: jbj

cpp/ql/src/semmle/code/cpp/Class.qll

@@ -583,26 +583,12 @@ class Class extends UserType {
     class_instantiation(underlyingElement(this), unresolveElement(c))
   }
 
-  /**
-   * Gets a template argument used to instantiate this class from a class
-   * template. When called on a class template, this will return a template
-   * parameter.
-   */
-  Type getATemplateArgument() {
-    exists(int i | this.getTemplateArgument(i) = result )
-  }
-
-  /** Gets the number of template arguments for this class. */
-  int getNumberOfTemplateArguments() {
-    result = count(int i | exists(getTemplateArgument(i)))
-  }
-
   /**
    * Gets the `i`th template argument used to instantiate this class from a
    * class template. When called on a class template, this will return the
    * `i`th template parameter.
    */
-  Type getTemplateArgument(int i) {
+  override Type getTemplateArgument(int i) {
     class_template_argument(underlyingElement(this),i,unresolveElement(result))
   }
 
@@ -886,8 +872,19 @@ class TemplateClass extends Class {
  * A class that is an instantiation of a template.
  */
 class ClassTemplateInstantiation extends Class {
+  TemplateClass tc;
+
   ClassTemplateInstantiation() {
-    exists(TemplateClass tc | tc.getAnInstantiation() = this)
+    tc.getAnInstantiation() = this
+  }
+
+  /**
+   * Gets the class template from which this instantiation was instantiated.
+   *
+   * Example: For `std::vector<float>`, returns `std::vector<T>`.
+   */
+  TemplateClass getTemplate() {
+    result = tc
   }
 }
 

cpp/ql/src/semmle/code/cpp/Declaration.qll

@@ -187,6 +187,27 @@ abstract class Declaration extends Locatable, @declaration {
   Class getDeclaringType() {
     this = result.getAMember()
   }
+
+  /**
+   * Gets a template argument used to instantiate this declaration from a template.
+   * When called on a template, this will return a template parameter.
+   */
+  final Type getATemplateArgument() {
+    result = getTemplateArgument(_)
+  }
+
+  /**
+   * Gets the `i`th template argument used to instantiate this declaration from a
+   * template. When called on a template, this will return the `i`th template parameter.
+   */
+  Type getTemplateArgument(int index) {
+    none()
+  }
+
+  /** Gets the number of template arguments for this declaration. */
+  final int getNumberOfTemplateArguments() {
+    result = count(int i | exists(getTemplateArgument(i)))
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/Function.qll

@@ -20,6 +20,7 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
   override string getName() { functions(underlyingElement(this),result,_) }
 
   /**
+   * DEPRECATED: Use `getIdentityString(Declaration)` from `semmle.code.cpp.Print` instead.
    * Gets the full signature of this function, including return type, parameter
    * types, and template arguments.
    *
@@ -332,18 +333,11 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
   }
 
   /**
-   * Gets an argument used to instantiate this class from a template
-   * class.
+   * Gets the `i`th template argument used to instantiate this function from a
+   * function template. When called on a function template, this will return the
+   * `i`th template parameter.
    */
-  Type getATemplateArgument() {
-    exists(int i | this.getTemplateArgument(i) = result )
-  }
-
-  /**
-   * Gets a particular argument used to instantiate this class from a
-   * template class.
-   */
-  Type getTemplateArgument(int index) {
+  override Type getTemplateArgument(int index) {
     function_template_argument(underlyingElement(this),index,unresolveElement(result))
   }
 
@@ -1088,8 +1082,19 @@ class TemplateFunction extends Function {
  * A function that is an instantiation of a template.
  */
 class FunctionTemplateInstantiation extends Function {
+  TemplateFunction tf;
+
   FunctionTemplateInstantiation() {
-    exists(TemplateFunction tf | tf.getAnInstantiation() = this)
+    tf.getAnInstantiation() = this
+  }
+
+  /**
+   * Gets the function template from which this instantiation was instantiated.
+   *
+   * Example: For `int const& std::min<int>(int const&, int const&)`, returns `T const& min<T>(T const&, T const&)`.
+   */
+  TemplateFunction getTemplate() { 
+    result = tf
   }
 }