1 //===-- llvm/Support/Annotation.h - Annotation classes ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declarations for two classes: Annotation & Annotable.
11 // Using these two simple classes, anything that derives from Annotable can have
12 // Annotation subclasses attached to them, ready for easy retrieval.
14 // Annotations are designed to be easily attachable to various classes.
16 // The AnnotationManager class is essential for using these classes. It is
17 // responsible for turning Annotation name strings into tokens [unique id #'s]
18 // that may be used to search for and create annotations.
20 //===----------------------------------------------------------------------===//
22 #ifndef LLVM_SUPPORT_ANNOTATION_H
23 #define LLVM_SUPPORT_ANNOTATION_H
33 struct AnnotationManager;
35 //===----------------------------------------------------------------------===//
37 // AnnotationID - This class is a thin wrapper around an unsigned integer that
38 // is used to hopefully prevent errors using AnnotationID's. They may be copied
39 // freely around and passed byvalue with little or no overhead.
42 friend struct AnnotationManager;
45 AnnotationID(); // Default ctor is disabled
46 inline AnnotationID(unsigned i) : ID(i) {} // Only creatable from AnnMgr
48 inline AnnotationID(const AnnotationID &A) : ID(A.ID) {}
50 inline bool operator==(const AnnotationID &A) const {
53 inline bool operator<(const AnnotationID &A) const {
59 //===----------------------------------------------------------------------===//
61 // Annotation Class - This class serves as a base class for any specific
62 // annotations that you might need. Simply subclass this to add extra
63 // information to the annotations.
66 friend class Annotable; // Annotable manipulates Next list
67 AnnotationID ID; // ID number, as obtained from AnnotationManager
68 Annotation *Next; // The next annotation in the linked list
70 inline Annotation(AnnotationID id) : ID(id), Next(0) {}
71 virtual ~Annotation(); // Designed to be subclassed
73 // getID - Return the unique ID# of this annotation
74 inline AnnotationID getID() const { return ID; }
76 // getNext - Return the next annotation in the list...
77 inline Annotation *getNext() const { return Next; }
81 //===----------------------------------------------------------------------===//
83 // Annotable - This class is used as a base class for all objects that would
84 // like to have annotation capability.
86 // Annotable objects keep their annotation list sorted as annotations are
87 // inserted and deleted. This is used to ensure that annotations with identical
88 // ID#'s are stored sequentially.
91 mutable Annotation *AnnotationList;
93 Annotable(const Annotable &); // Do not implement
94 void operator=(const Annotable &); // Do not implement
96 Annotable() : AnnotationList(0) {}
99 // getAnnotation - Search the list for annotations of the specified ID. The
100 // pointer returned is either null (if no annotations of the specified ID
101 // exist), or it points to the first element of a potentially list of elements
102 // with identical ID #'s.
104 Annotation *getAnnotation(AnnotationID ID) const {
105 for (Annotation *A = AnnotationList; A; A = A->getNext())
106 if (A->getID() == ID) return A;
110 // getOrCreateAnnotation - Search through the annotation list, if there is
111 // no annotation with the specified ID, then use the AnnotationManager to
114 inline Annotation *getOrCreateAnnotation(AnnotationID ID) const;
116 // addAnnotation - Insert the annotation into the list in a sorted location.
118 void addAnnotation(Annotation *A) const {
119 assert(A->Next == 0 && "Annotation already in list?!?");
121 Annotation **AL = &AnnotationList;
122 while (*AL && (*AL)->ID < A->getID()) // Find where to insert annotation
124 A->Next = *AL; // Link the annotation in
128 // unlinkAnnotation - Remove the first annotation of the specified ID... and
129 // then return the unlinked annotation. The annotation object is not deleted.
131 inline Annotation *unlinkAnnotation(AnnotationID ID) const {
132 for (Annotation **A = &AnnotationList; *A; A = &((*A)->Next))
133 if ((*A)->getID() == ID) {
134 Annotation *Ret = *A;
142 // deleteAnnotation - Delete the first annotation of the specified ID in the
143 // list. Unlink unlinkAnnotation, this actually deletes the annotation object
145 bool deleteAnnotation(AnnotationID ID) const {
146 Annotation *A = unlinkAnnotation(ID);
153 //===----------------------------------------------------------------------===//
155 // AnnotationManager - This class is primarily responsible for maintaining a
156 // one-to-one mapping between string Annotation names and Annotation ID numbers.
158 // Compared to the rest of the Annotation system, these mapping methods are
159 // relatively slow, so they should be avoided by locally caching Annotation
160 // ID #'s. These methods are safe to call at any time, even by static ctors, so
161 // they should be used by static ctors most of the time.
163 // This class also provides support for annotations that are created on demand
164 // by the Annotable::getOrCreateAnnotation method. To get this to work, simply
165 // register an annotation handler
167 struct AnnotationManager {
168 typedef Annotation *(*Factory)(AnnotationID, const Annotable *, void*);
170 //===--------------------------------------------------------------------===//
171 // Basic ID <-> Name map functionality
173 static AnnotationID getID(const std::string &Name); // Name -> ID
174 static const std::string &getName(AnnotationID ID); // ID -> Name
176 // getID - Name -> ID + registration of a factory function for demand driven
177 // annotation support.
178 static AnnotationID getID(const std::string &Name, Factory Fact,
181 //===--------------------------------------------------------------------===//
182 // Annotation creation on demand support...
184 // registerAnnotationFactory - This method is used to register a callback
185 // function used to create an annotation on demand if it is needed by the
186 // Annotable::getOrCreateAnnotation method.
188 static void registerAnnotationFactory(AnnotationID ID, Factory Func,
189 void *ExtraData = 0);
191 // createAnnotation - Create an annotation of the specified ID for the
192 // specified object, using a register annotation creation function.
194 static Annotation *createAnnotation(AnnotationID ID, const Annotable *Obj);
199 // getOrCreateAnnotation - Search through the annotation list, if there is
200 // no annotation with the specified ID, then use the AnnotationManager to
203 inline Annotation *Annotable::getOrCreateAnnotation(AnnotationID ID) const {
204 Annotation *A = getAnnotation(ID); // Fast path, check for preexisting ann
207 // No annotation found, ask the annotation manager to create an annotation...
208 A = AnnotationManager::createAnnotation(ID, this);
209 assert(A && "AnnotationManager could not create annotation!");
214 } // End namespace llvm