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* s/method/function

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* BIG CHANGE: The root of the call "graph" is considered to be the external
  node, not the "Root".  This means that users using graph iterators like
  df_begin() will start from the external node.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2957 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-07-18 04:42:35 +00:00
parent 4f5e49c20d
commit b195911eab
1 changed files with 73 additions and 61 deletions
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134
include/llvm/Analysis/CallGraph.h
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@ -3,37 +3,37 @@
// This interface is used to build and manipulate a call graph, which is a very
// useful tool for interprocedural optimization.
//
// Every method in a module is represented as a node in the call graph. The
// callgraph node keeps track of which methods the are called by the method
// Every function in a module is represented as a node in the call graph. The
// callgraph node keeps track of which functions the are called by the function
// corresponding to the node.
//
// A call graph will contain nodes where the method that they correspond to is
// A call graph will contain nodes where the function that they correspond to is
// null. This 'external' node is used to represent control flow that is not
// represented (or analyzable) in the module. As such, the external node will
// have edges to methods with the following properties:
// 1. All methods in the module without internal linkage, since they could
// be called by methods outside of the our analysis capability.
// 2. All methods whose address is used for something more than a direct call,
// for example being stored into a memory location. Since they may be
// called by an unknown caller later, they must be tracked as such.
// have edges to functions with the following properties:
// 1. All functions in the module without internal linkage, since they could
// be called by functions outside of the our analysis capability.
// 2. All functions whose address is used for something more than a direct
// call, for example being stored into a memory location. Since they may
// be called by an unknown caller later, they must be tracked as such.
//
// Similarly, methods have a call edge to the external node iff:
// 1. The method is external, reflecting the fact that they could call
// Similarly, functions have a call edge to the external node iff:
// 1. The function is external, reflecting the fact that they could call
// anything without internal linkage or that has its address taken.
// 2. The method contains an indirect method call.
// 2. The function contains an indirect function call.
//
// As an extension in the future, there may be multiple nodes with a null
// method. These will be used when we can prove (through pointer analysis) that
// an indirect call site can call only a specific set of methods.
// function. These will be used when we can prove (through pointer analysis)
// that an indirect call site can call only a specific set of functions.
//
// Because of these properties, the CallGraph captures a conservative superset
// of all of the caller-callee relationships, which is useful for
// transformations.
//
// The CallGraph class also attempts to figure out what the root of the
// CallGraph is, which is currently does by looking for a method named 'main'.
// If no method named 'main' is found, the external node is used as the entry
// node, reflecting the fact that any method without internal linkage could
// CallGraph is, which is currently does by looking for a function named 'main'.
// If no function named 'main' is found, the external node is used as the entry
// node, reflecting the fact that any function without internal linkage could
// be called into (which is common for libraries).
//
//===----------------------------------------------------------------------===//
@ -53,8 +53,8 @@ class CallGraphNode;
class CallGraph : public Pass {
Module *Mod; // The module this call graph represents
typedef std::map<const Function *, CallGraphNode *> MethodMapTy;
MethodMapTy MethodMap; // Map from a method to its node
typedef std::map<const Function *, CallGraphNode *> FunctionMapTy;
FunctionMapTy FunctionMap; // Map from a function to its node
// Root is root of the call graph, or the external node if a 'main' function
// couldn't be found. ExternalNode is equivalent to (*this)[0].
@ -65,45 +65,56 @@ public:
//===---------------------------------------------------------------------
// Accessors...
//
typedef MethodMapTy::iterator iterator;
typedef MethodMapTy::const_iterator const_iterator;
typedef FunctionMapTy::iterator iterator;
typedef FunctionMapTy::const_iterator const_iterator;
inline CallGraphNode *getRoot() { return Root; }
inline const CallGraphNode *getRoot() const { return Root; }
inline iterator begin() { return MethodMap.begin(); }
inline iterator end() { return MethodMap.end(); }
inline const_iterator begin() const { return MethodMap.begin(); }
inline const_iterator end() const { return MethodMap.end(); }
// getExternalNode - Return the node that points to all functions that are
// accessable from outside of the current program.
//
CallGraphNode *getExternalNode() { return ExternalNode; }
const CallGraphNode *getExternalNode() const { return ExternalNode; }
// getRoot - Return the root of the call graph, which is either main, or if
// main cannot be found, the external node.
//
CallGraphNode *getRoot() { return Root; }
const CallGraphNode *getRoot() const { return Root; }
inline iterator begin() { return FunctionMap.begin(); }
inline iterator end() { return FunctionMap.end(); }
inline const_iterator begin() const { return FunctionMap.begin(); }
inline const_iterator end() const { return FunctionMap.end(); }
// Subscripting operators, return the call graph node for the provided method
// Subscripting operators, return the call graph node for the provided
// function
inline const CallGraphNode *operator[](const Function *F) const {
const_iterator I = MethodMap.find(F);
assert(I != MethodMap.end() && "Method not in callgraph!");
const_iterator I = FunctionMap.find(F);
assert(I != FunctionMap.end() && "Function not in callgraph!");
return I->second;
}
inline CallGraphNode *operator[](const Function *F) {
const_iterator I = MethodMap.find(F);
assert(I != MethodMap.end() && "Method not in callgraph!");
const_iterator I = FunctionMap.find(F);
assert(I != FunctionMap.end() && "Function not in callgraph!");
return I->second;
}
//===---------------------------------------------------------------------
// Methods to keep a call graph up to date with a method that has been
// Functions to keep a call graph up to date with a function that has been
// modified
//
void addMethodToModule(Function *Meth);
void addFunctionToModule(Function *Meth);
// removeMethodFromModule - Unlink the method from this module, returning it.
// Because this removes the method from the module, the call graph node is
// destroyed. This is only valid if the method does not call any other
// methods (ie, there are no edges in it's CGN). The easiest way to do this
// removeFunctionFromModule - Unlink the function from this module, returning
// it. Because this removes the function from the module, the call graph node
// is destroyed. This is only valid if the function does not call any other
// functions (ie, there are no edges in it's CGN). The easiest way to do this
// is to dropAllReferences before calling this.
//
Function *removeMethodFromModule(CallGraphNode *CGN);
Function *removeMethodFromModule(Function *Meth) {
return removeMethodFromModule((*this)[Meth]);
Function *removeFunctionFromModule(CallGraphNode *CGN);
Function *removeFunctionFromModule(Function *Meth) {
return removeFunctionFromModule((*this)[Meth]);
}
@ -142,7 +153,7 @@ private:
CallGraphNode *getNodeFor(Function *F);
// addToCallGraph - Add a function to the call graph, and link the node to all
// of the methods that it calls.
// of the functions that it calls.
//
void addToCallGraph(Function *F);
@ -156,7 +167,7 @@ private:
//
class CallGraphNode {
Function *Meth;
std::vector<CallGraphNode*> CalledMethods;
std::vector<CallGraphNode*> CalledFunctions;
CallGraphNode(const CallGraphNode &); // Do not implement
public:
@ -167,38 +178,39 @@ public:
typedef std::vector<CallGraphNode*>::iterator iterator;
typedef std::vector<CallGraphNode*>::const_iterator const_iterator;
// getMethod - Return the method that this call graph node represents...
Function *getMethod() const { return Meth; }
// getFunction - Return the function that this call graph node represents...
Function *getFunction() const { return Meth; }
inline iterator begin() { return CalledMethods.begin(); }
inline iterator end() { return CalledMethods.end(); }
inline const_iterator begin() const { return CalledMethods.begin(); }
inline const_iterator end() const { return CalledMethods.end(); }
inline unsigned size() const { return CalledMethods.size(); }
inline iterator begin() { return CalledFunctions.begin(); }
inline iterator end() { return CalledFunctions.end(); }
inline const_iterator begin() const { return CalledFunctions.begin(); }
inline const_iterator end() const { return CalledFunctions.end(); }
inline unsigned size() const { return CalledFunctions.size(); }
// Subscripting operator - Return the i'th called method...
// Subscripting operator - Return the i'th called function...
//
inline CallGraphNode *operator[](unsigned i) const { return CalledMethods[i];}
CallGraphNode *operator[](unsigned i) const { return CalledFunctions[i];}
//===---------------------------------------------------------------------
// Methods to keep a call graph up to date with a method that has been
// Methods to keep a call graph up to date with a function that has been
// modified
//
void removeAllCalledMethods() {
CalledMethods.clear();
void removeAllCalledFunctions() {
CalledFunctions.clear();
}
private: // Stuff to construct the node, used by CallGraph
friend class CallGraph;
// CallGraphNode ctor - Create a node for the specified method...
// CallGraphNode ctor - Create a node for the specified function...
inline CallGraphNode(Function *F) : Meth(F) {}
// addCalledMethod add a method to the list of methods called by this one
void addCalledMethod(CallGraphNode *M) {
CalledMethods.push_back(M);
// addCalledFunction add a function to the list of functions called by this
// one
void addCalledFunction(CallGraphNode *M) {
CalledFunctions.push_back(M);
}
};
@ -233,13 +245,13 @@ template <> struct GraphTraits<const CallGraphNode*> {
template<> struct GraphTraits<CallGraph*> :
public GraphTraits<CallGraphNode*> {
static NodeType *getEntryNode(CallGraph *CGN) {
return CGN->getRoot();
return CGN->getExternalNode(); // Start at the external node!
}
};
template<> struct GraphTraits<const CallGraph*> :
public GraphTraits<const CallGraphNode*> {
static NodeType *getEntryNode(const CallGraph *CGN) {
return CGN->getRoot();
return CGN->getExternalNode();
}
};