1 //===-- Support/Annotation.h - Annotation classes ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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 SUPPORT_ANNOTATION_H
23 #define SUPPORT_ANNOTATION_H
33 class 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 class 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. One notable subclass is Value, which
85 // means annotations can be attached to almost everything in LLVM.
87 // Annotable objects keep their annotation list sorted as annotations are
88 // inserted and deleted. This is used to ensure that annotations with identical
89 // ID#'s are stored sequentially.
92 mutable Annotation *AnnotationList;
94 Annotable(const Annotable &); // Do not implement
95 void operator=(const Annotable &); // Do not implement
97 Annotable() : AnnotationList(0) {}
98 virtual ~Annotable() { // Virtual because it's designed to be subclassed...
99 Annotation *A = AnnotationList;
101 Annotation *Next = A->getNext();
107 // getAnnotation - Search the list for annotations of the specified ID. The
108 // pointer returned is either null (if no annotations of the specified ID
109 // exist), or it points to the first element of a potentially list of elements
110 // with identical ID #'s.
112 Annotation *getAnnotation(AnnotationID ID) const {
113 for (Annotation *A = AnnotationList; A; A = A->getNext())
114 if (A->getID() == ID) return A;
118 // getOrCreateAnnotation - Search through the annotation list, if there is
119 // no annotation with the specified ID, then use the AnnotationManager to
122 inline Annotation *getOrCreateAnnotation(AnnotationID ID) const;
124 // addAnnotation - Insert the annotation into the list in a sorted location.
126 void addAnnotation(Annotation *A) const {
127 assert(A->Next == 0 && "Annotation already in list?!?");
129 Annotation **AL = &AnnotationList;
130 while (*AL && (*AL)->ID < A->getID()) // Find where to insert annotation
132 A->Next = *AL; // Link the annotation in
136 // unlinkAnnotation - Remove the first annotation of the specified ID... and
137 // then return the unlinked annotation. The annotation object is not deleted.
139 inline Annotation *unlinkAnnotation(AnnotationID ID) const {
140 for (Annotation **A = &AnnotationList; *A; A = &((*A)->Next))
141 if ((*A)->getID() == ID) {
142 Annotation *Ret = *A;
150 // deleteAnnotation - Delete the first annotation of the specified ID in the
151 // list. Unlink unlinkAnnotation, this actually deletes the annotation object
153 bool deleteAnnotation(AnnotationID ID) const {
154 Annotation *A = unlinkAnnotation(ID);
161 //===----------------------------------------------------------------------===//
163 // AnnotationManager - This class is primarily responsible for maintaining a
164 // one-to-one mapping between string Annotation names and Annotation ID numbers.
166 // Compared to the rest of the Annotation system, these mapping methods are
167 // relatively slow, so they should be avoided by locally caching Annotation
168 // ID #'s. These methods are safe to call at any time, even by static ctors, so
169 // they should be used by static ctors most of the time.
171 // This class also provides support for annotations that are created on demand
172 // by the Annotable::getOrCreateAnnotation method. To get this to work, simply
173 // register an annotation handler
175 struct AnnotationManager {
176 typedef Annotation *(*Factory)(AnnotationID, const Annotable *, void*);
178 //===--------------------------------------------------------------------===//
179 // Basic ID <-> Name map functionality
181 static AnnotationID getID(const std::string &Name); // Name -> ID
182 static const std::string &getName(AnnotationID ID); // ID -> Name
184 // getID - Name -> ID + registration of a factory function for demand driven
185 // annotation support.
186 static AnnotationID getID(const std::string &Name, Factory Fact,
189 //===--------------------------------------------------------------------===//
190 // Annotation creation on demand support...
192 // registerAnnotationFactory - This method is used to register a callback
193 // function used to create an annotation on demand if it is needed by the
194 // Annotable::getOrCreateAnnotation method.
196 static void registerAnnotationFactory(AnnotationID ID, Factory Func,
197 void *ExtraData = 0);
199 // createAnnotation - Create an annotation of the specified ID for the
200 // specified object, using a register annotation creation function.
202 static Annotation *createAnnotation(AnnotationID ID, const Annotable *Obj);
207 // getOrCreateAnnotation - Search through the annotation list, if there is
208 // no annotation with the specified ID, then use the AnnotationManager to
211 inline Annotation *Annotable::getOrCreateAnnotation(AnnotationID ID) const {
212 Annotation *A = getAnnotation(ID); // Fast path, check for preexisting ann
215 // No annotation found, ask the annotation manager to create an annotation...
216 A = AnnotationManager::createAnnotation(ID, this);
217 assert(A && "AnnotationManager could not create annotation!");
222 } // End namespace llvm