1 //===-- Support/Annotation.h - Annotation classes ---------------*- C++ -*-===//
3 // This file contains the declarations for two classes: Annotation & Annotable.
4 // Using these two simple classes, anything that derives from Annotable can have
5 // Annotation subclasses attached to them, ready for easy retrieval.
7 // Annotations are designed to be easily attachable to various classes.
9 // The AnnotationManager class is essential for using these classes. It is
10 // responsible for turning Annotation name strings into tokens [unique id #'s]
11 // that may be used to search for and create annotations.
13 //===----------------------------------------------------------------------===//
15 #ifndef SUPPORT_ANNOTATION_H
16 #define SUPPORT_ANNOTATION_H
23 class AnnotationManager;
25 //===----------------------------------------------------------------------===//
27 // AnnotationID - This class is a thin wrapper around an unsigned integer that
28 // is used to hopefully prevent errors using AnnotationID's. They may be copied
29 // freely around and passed byvalue with little or no overhead.
32 friend class AnnotationManager;
35 AnnotationID(); // Default ctor is disabled
36 inline AnnotationID(unsigned i) : ID(i) {} // Only creatable from AnnMgr
38 inline AnnotationID(const AnnotationID &A) : ID(A.ID) {}
40 inline bool operator==(const AnnotationID &A) const {
43 inline bool operator<(const AnnotationID &A) const {
49 //===----------------------------------------------------------------------===//
51 // Annotation Class - This class serves as a base class for any specific
52 // annotations that you might need. Simply subclass this to add extra
53 // information to the annotations.
56 friend class Annotable; // Annotable manipulates Next list
57 AnnotationID ID; // ID number, as obtained from AnnotationManager
58 Annotation *Next; // The next annotation in the linked list
60 inline Annotation(AnnotationID id) : ID(id), Next(0) {}
61 virtual ~Annotation() {} // Designed to be subclassed
63 // getID - Return the unique ID# of this annotation
64 inline AnnotationID getID() const { return ID; }
66 // getNext - Return the next annotation in the list...
67 inline Annotation *getNext() const { return Next; }
71 //===----------------------------------------------------------------------===//
73 // Annotable - This class is used as a base class for all objects that would
74 // like to have annotation capability. One notable subclass is Value, which
75 // means annotations can be attached to almost everything in LLVM.
77 // Annotable objects keep their annotation list sorted as annotations are
78 // inserted and deleted. This is used to ensure that annotations with identical
79 // ID#'s are stored sequentially.
82 mutable Annotation *AnnotationList;
84 Annotable(const Annotable &); // Do not implement
85 void operator=(const Annotable &); // Do not implement
87 Annotable() : AnnotationList(0) {}
88 virtual ~Annotable() { // Virtual because it's designed to be subclassed...
89 Annotation *A = AnnotationList;
91 Annotation *Next = A->getNext();
97 // getAnnotation - Search the list for annotations of the specified ID. The
98 // pointer returned is either null (if no annotations of the specified ID
99 // exist), or it points to the first element of a potentially list of elements
100 // with identical ID #'s.
102 Annotation *getAnnotation(AnnotationID ID) const {
103 for (Annotation *A = AnnotationList; A; A = A->getNext())
104 if (A->getID() == ID) return A;
108 // getOrCreateAnnotation - Search through the annotation list, if there is
109 // no annotation with the specified ID, then use the AnnotationManager to
112 inline Annotation *getOrCreateAnnotation(AnnotationID ID) const;
114 // addAnnotation - Insert the annotation into the list in a sorted location.
116 void addAnnotation(Annotation *A) const {
117 assert(A->Next == 0 && "Annotation already in list?!?");
119 Annotation **AL = &AnnotationList;
120 while (*AL && (*AL)->ID < A->getID()) // Find where to insert annotation
122 A->Next = *AL; // Link the annotation in
126 // unlinkAnnotation - Remove the first annotation of the specified ID... and
127 // then return the unlinked annotation. The annotation object is not deleted.
129 inline Annotation *unlinkAnnotation(AnnotationID ID) const {
130 for (Annotation **A = &AnnotationList; *A; A = &((*A)->Next))
131 if ((*A)->getID() == ID) {
132 Annotation *Ret = *A;
140 // deleteAnnotation - Delete the first annotation of the specified ID in the
141 // list. Unlink unlinkAnnotation, this actually deletes the annotation object
143 bool deleteAnnotation(AnnotationID ID) const {
144 Annotation *A = unlinkAnnotation(ID);
151 //===----------------------------------------------------------------------===//
153 // AnnotationManager - This class is primarily responsible for maintaining a
154 // one-to-one mapping between string Annotation names and Annotation ID numbers.
156 // Compared to the rest of the Annotation system, these mapping methods are
157 // relatively slow, so they should be avoided by locally caching Annotation
158 // ID #'s. These methods are safe to call at any time, even by static ctors, so
159 // they should be used by static ctors most of the time.
161 // This class also provides support for annotations that are created on demand
162 // by the Annotable::getOrCreateAnnotation method. To get this to work, simply
163 // register an annotation handler
165 struct AnnotationManager {
166 typedef Annotation *(*Factory)(AnnotationID, const Annotable *, void*);
168 //===--------------------------------------------------------------------===//
169 // Basic ID <-> Name map functionality
171 static AnnotationID getID(const std::string &Name); // Name -> ID
172 static const std::string &getName(AnnotationID ID); // ID -> Name
174 // getID - Name -> ID + registration of a factory function for demand driven
175 // annotation support.
176 static AnnotationID getID(const std::string &Name, Factory Fact,
179 //===--------------------------------------------------------------------===//
180 // Annotation creation on demand support...
182 // registerAnnotationFactory - This method is used to register a callback
183 // function used to create an annotation on demand if it is needed by the
184 // Annotable::getOrCreateAnnotation method.
186 static void registerAnnotationFactory(AnnotationID ID, Factory Func,
187 void *ExtraData = 0);
189 // createAnnotation - Create an annotation of the specified ID for the
190 // specified object, using a register annotation creation function.
192 static Annotation *createAnnotation(AnnotationID ID, const Annotable *Obj);
197 // getOrCreateAnnotation - Search through the annotation list, if there is
198 // no annotation with the specified ID, then use the AnnotationManager to
201 inline Annotation *Annotable::getOrCreateAnnotation(AnnotationID ID) const {
202 Annotation *A = getAnnotation(ID); // Fast path, check for preexisting ann
205 // No annotation found, ask the annotation manager to create an annotation...
206 A = AnnotationManager::createAnnotation(ID, this);
207 assert(A && "AnnotationManager could not create annotation!");