llvm-6502/include/Support/Annotation.h
2001-09-09 21:00:23 +00:00

210 lines
7.6 KiB
C++

//===-- llvm/Annotation.h - Annotation classes -------------------*- C++ -*--=//
//
// This file contains the declarations for two classes: Annotation & Annotable.
// Using these two simple classes, anything that derives from Annotable can have
// Annotation subclasses attached to them, ready for easy retrieval.
//
// Annotations are designed to be easily attachable to LLVM code (as all Value's
// are Annotable), and can even be serialized to bytecode and to assembly.
//
// The AnnotationManager class (defined in AnnotationManager.h) is essential for
// using these classes. It is responsible for turning Annotation name strings
// into tokens [unique id #'s] that may be used to search for and create
// annotations.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANNOTATION_H
#define LLVM_ANNOTATION_H
#include <string>
class AnnotationID;
class Annotation;
class Annotable;
class AnnotationManager;
//===----------------------------------------------------------------------===//
//
// AnnotationID - This class is a thin wrapper around an unsigned integer that
// is used to hopefully prevent errors using AnnotationID's. They may be copied
// freely around and passed byvalue with little or no overhead.
//
class AnnotationID {
friend class AnnotationManager;
unsigned ID;
AnnotationID(); // Default ctor is disabled
inline AnnotationID(unsigned i) : ID(i) {} // Only creatable from AnnMgr
public:
inline AnnotationID(const AnnotationID &A) : ID(A.ID) {}
inline bool operator==(const AnnotationID &A) const {
return A.ID == ID;
}
inline bool operator<(const AnnotationID &A) const {
return ID < A.ID;
}
};
//===----------------------------------------------------------------------===//
//
// Annotation Class - This class serves as a base class for any specific
// annotations that you might need. Simply subclass this to add extra
// information to the annotations.
//
class Annotation {
friend class Annotable; // Annotable manipulates Next list
AnnotationID ID; // ID number, as obtained from AnnotationManager
Annotation *Next; // The next annotation in the linked list
public:
inline Annotation(AnnotationID id) : ID(id), Next(0) {}
virtual ~Annotation() {} // Designed to be subclassed
// getID - Return the unique ID# of this annotation
inline AnnotationID getID() const { return ID; }
// getNext - Return the next annotation in the list...
inline Annotation *getNext() const { return Next; }
};
//===----------------------------------------------------------------------===//
//
// Annotable - This class is used as a base class for all objects that would
// like to have annotation capability. One notable subclass is Value, which
// means annotations can be attached to almost everything in LLVM.
//
// Annotable objects keep their annotation list sorted as annotations are
// inserted and deleted. This is used to ensure that annotations with identical
// ID#'s are stored sequentially.
//
class Annotable {
mutable Annotation *AnnotationList;
public:
Annotable() : AnnotationList(0) {}
virtual ~Annotable() { // Virtual because it's designed to be subclassed...
Annotation *A = AnnotationList;
while (A) {
Annotation *Next = A->getNext();
delete A;
A = Next;
}
}
// getAnnotation - Search the list for annotations of the specified ID. The
// pointer returned is either null (if no annotations of the specified ID
// exist), or it points to the first element of a potentially list of elements
// with identical ID #'s.
//
Annotation *getAnnotation(AnnotationID ID) const {
for (Annotation *A = AnnotationList; A; A = A->getNext())
if (A->getID() == ID) return A;
return 0;
}
// getOrCreateAnnotation - Search through the annotation list, if there is
// no annotation with the specified ID, then use the AnnotationManager to
// create one.
//
inline Annotation *getOrCreateAnnotation(AnnotationID ID) const;
// addAnnotation - Insert the annotation into the list in a sorted location.
//
void addAnnotation(Annotation *A) const {
assert(A->Next == 0 && "Annotation already in list?!?");
Annotation **AL = &AnnotationList;
while (*AL && (*AL)->ID < A->getID()) // Find where to insert annotation
AL = &((*AL)->Next);
A->Next = *AL; // Link the annotation in
*AL = A;
}
// unlinkAnnotation - Remove the first annotation of the specified ID... and
// then return the unlinked annotation. The annotation object is not deleted.
//
inline Annotation *unlinkAnnotation(AnnotationID ID) const {
for (Annotation **A = &AnnotationList; *A; A = &((*A)->Next))
if ((*A)->getID() == ID) {
Annotation *Ret = *A;
*A = Ret->Next;
Ret->Next = 0;
return Ret;
}
return 0;
}
// deleteAnnotation - Delete the first annotation of the specified ID in the
// list. Unlink unlinkAnnotation, this actually deletes the annotation object
//
bool deleteAnnotation(AnnotationID ID) const {
Annotation *A = unlinkAnnotation(ID);
delete A;
return A != 0;
}
};
//===----------------------------------------------------------------------===//
//
// AnnotationManager - This class is primarily responsible for maintaining a
// one-to-one mapping between string Annotation names and Annotation ID numbers.
//
// Compared to the rest of the Annotation system, these mapping methods are
// relatively slow, so they should be avoided by locally caching Annotation
// ID #'s. These methods are safe to call at any time, even by static ctors, so
// they should be used by static ctors most of the time.
//
// This class also provides support for annotations that are created on demand
// by the Annotable::getOrCreateAnnotation method. To get this to work, simply
// register an annotation handler
//
struct AnnotationManager {
typedef Annotation *(*Factory)(AnnotationID, const Annotable *, void*);
//===--------------------------------------------------------------------===//
// Basic ID <-> Name map functionality
static AnnotationID getID (const string &Name); // Name -> ID
static const string &getName(AnnotationID ID); // ID -> Name
// getID - Name -> ID + registration of a factory function for demand driven
// annotation support.
static AnnotationID getID (const string &Name, Factory Fact, void *Data=0);
//===--------------------------------------------------------------------===//
// Annotation creation on demand support...
// registerAnnotationFactory - This method is used to register a callback
// function used to create an annotation on demand if it is needed by the
// Annotable::getOrCreateAnnotation method.
//
static void registerAnnotationFactory(AnnotationID ID, Factory Func,
void *ExtraData = 0);
// createAnnotation - Create an annotation of the specified ID for the
// specified object, using a register annotation creation function.
//
static Annotation *createAnnotation(AnnotationID ID, const Annotable *Obj);
};
// getOrCreateAnnotation - Search through the annotation list, if there is
// no annotation with the specified ID, then use the AnnotationManager to
// create one.
//
inline Annotation *Annotable::getOrCreateAnnotation(AnnotationID ID) const {
Annotation *A = getAnnotation(ID); // Fast path, check for preexisting ann
if (A) return A;
// No annotation found, ask the annotation manager to create an annotation...
A = AnnotationManager::createAnnotation(ID, this);
assert(A && "AnnotationManager could not create annotation!");
addAnnotation(A);
return A;
}
#endif