// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
-//
-// This interface is used to build and manipulate a call graph, which is a very
-// useful tool for interprocedural optimization.
-//
-// 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 may contain nodes where the function that they correspond to is
-// null. These 'external' nodes are used to represent control flow that is not
-// represented (or analyzable) in the module. In particular, this analysis
-// builds one external node such that:
-// 1. All functions in the module without internal linkage will have edges
-// from this external node, indicating that they could be called by
-// functions outside of the module.
-// 2. All functions whose address is used for something more than a direct
-// call, for example being stored into a memory location will also have an
-// edge from this external node. Since they may be called by an unknown
-// caller later, they must be tracked as such.
-//
-// There is a second external node added for calls that leave this module.
-// 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 function contains an indirect function call.
-//
-// As an extension in the future, there may be multiple nodes with a null
-// 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 it 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).
-//
+/// \file
+///
+/// This file provides interfaces used to build and manipulate a call graph,
+/// which is a very useful tool for interprocedural optimization.
+///
+/// Every function in a module is represented as a node in the call graph. The
+/// callgraph node keeps track of which functions are called by the function
+/// corresponding to the node.
+///
+/// A call graph may contain nodes where the function that they correspond to
+/// is null. These 'external' nodes are used to represent control flow that is
+/// not represented (or analyzable) in the module. In particular, this
+/// analysis builds one external node such that:
+/// 1. All functions in the module without internal linkage will have edges
+/// from this external node, indicating that they could be called by
+/// functions outside of the module.
+/// 2. All functions whose address is used for something more than a direct
+/// call, for example being stored into a memory location will also have
+/// an edge from this external node. Since they may be called by an
+/// unknown caller later, they must be tracked as such.
+///
+/// There is a second external node added for calls that leave this module.
+/// 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 function contains an indirect function call.
+///
+/// As an extension in the future, there may be multiple nodes with a null
+/// 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 it 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).
+///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_CALLGRAPH_H
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/CallSite.h"
#include "llvm/IR/Function.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/ValueHandle.h"
#include "llvm/Pass.h"
-#include "llvm/Support/CallSite.h"
-#include "llvm/Support/IncludeFile.h"
-#include "llvm/Support/ValueHandle.h"
#include <map>
namespace llvm {
class Module;
class CallGraphNode;
-/// \brief The basic data container for the call graph and the \c ModulePass
-/// which produces it.
+/// \brief The basic data container for the call graph of a \c Module of IR.
///
-/// This class exposes both the interface to the call graph container and the
-/// module pass which runs over a module of IR and produces the call graph.
+/// This class exposes both the interface to the call graph for a module of IR.
///
/// The core call graph itself can also be updated to reflect changes to the IR.
-class CallGraph : public ModulePass {
- Module *M;
+class CallGraph {
+ Module &M;
- typedef std::map<const Function *, CallGraphNode *> FunctionMapTy;
+ typedef std::map<const Function *, std::unique_ptr<CallGraphNode>>
+ FunctionMapTy;
/// \brief A map from \c Function* to \c CallGraphNode*.
FunctionMapTy FunctionMap;
/// \brief This node has edges to it from all functions making indirect calls
/// or calling an external function.
- CallGraphNode *CallsExternalNode;
+ std::unique_ptr<CallGraphNode> CallsExternalNode;
/// \brief Replace the function represented by this node by another.
///
void addToCallGraph(Function *F);
public:
- static char ID; // Class identification, replacement for typeinfo
+ CallGraph(Module &M);
+ // Default move ctor is fine, the dtor just does things to CallsExternalNode
+ // (if non-null) and the values in the FunctionMap, all of which should be
+ // null post-move, so no-op the dtor on the moved-from side.
+ CallGraph(CallGraph &&) = default;
+ ~CallGraph();
+
+ void print(raw_ostream &OS) const;
+ void dump() const;
typedef FunctionMapTy::iterator iterator;
typedef FunctionMapTy::const_iterator const_iterator;
/// \brief Returns the module the call graph corresponds to.
- Module &getModule() const { return *M; }
+ Module &getModule() const { return M; }
inline iterator begin() { return FunctionMap.begin(); }
inline iterator end() { return FunctionMap.end(); }
inline const CallGraphNode *operator[](const Function *F) const {
const_iterator I = FunctionMap.find(F);
assert(I != FunctionMap.end() && "Function not in callgraph!");
- return I->second;
+ return I->second.get();
}
/// \brief Returns the call graph node for the provided function.
inline CallGraphNode *operator[](const Function *F) {
const_iterator I = FunctionMap.find(F);
assert(I != FunctionMap.end() && "Function not in callgraph!");
- return I->second;
+ return I->second.get();
}
/// \brief Returns the \c CallGraphNode which is used to represent
/// undetermined calls into the callgraph.
CallGraphNode *getExternalCallingNode() const { return ExternalCallingNode; }
- CallGraphNode *getCallsExternalNode() const { return CallsExternalNode; }
-
- /// \brief Returns the root/main method in the module, or some other root
- /// node, such as the externalcallingnode.
- CallGraphNode *getRoot() { return Root; }
- const CallGraphNode *getRoot() const { return Root; }
+ CallGraphNode *getCallsExternalNode() const {
+ return CallsExternalNode.get();
+ }
//===---------------------------------------------------------------------
// Functions to keep a call graph up to date with a function that has been
/// \brief Similar to operator[], but this will insert a new CallGraphNode for
/// \c F if one does not already exist.
CallGraphNode *getOrInsertFunction(const Function *F);
-
- CallGraph();
- virtual ~CallGraph() { releaseMemory(); }
-
- //===---------------------------------------------------------------------
- // Implementation of the ModulePass interface needed here.
- //
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- virtual bool runOnModule(Module &M);
- virtual void releaseMemory();
-
- void print(raw_ostream &o, const Module *) const;
- void dump() const;
};
/// \brief A node in the call graph for a module.
/// Typically represents a function in the call graph. There are also special
/// "null" nodes used to represent theoretical entries in the call graph.
class CallGraphNode {
- friend class CallGraph;
-
- AssertingVH<Function> F;
-
public:
/// \brief A pair of the calling instruction (a call or invoke)
/// and the call graph node being called.
typedef std::pair<WeakVH, CallGraphNode *> CallRecord;
-private:
- std::vector<CallRecord> CalledFunctions;
-
- /// \brief The number of times that this CallGraphNode occurs in the
- /// CalledFunctions array of this or other CallGraphNodes.
- unsigned NumReferences;
-
- CallGraphNode(const CallGraphNode &) LLVM_DELETED_FUNCTION;
- void operator=(const CallGraphNode &) LLVM_DELETED_FUNCTION;
-
- void DropRef() { --NumReferences; }
- void AddRef() { ++NumReferences; }
-
public:
typedef std::vector<CallRecord> CalledFunctionsVector;
/// \brief Adds a function to the list of functions called by this one.
void addCalledFunction(CallSite CS, CallGraphNode *M) {
assert(!CS.getInstruction() || !CS.getCalledFunction() ||
- !CS.getCalledFunction()->isIntrinsic());
- CalledFunctions.push_back(std::make_pair(CS.getInstruction(), M));
+ !CS.getCalledFunction()->isIntrinsic() ||
+ !Intrinsic::isLeaf(CS.getCalledFunction()->getIntrinsicID()));
+ CalledFunctions.emplace_back(CS.getInstruction(), M);
M->AddRef();
}
/// Note that this method takes linear time, so it should be used sparingly.
void replaceCallEdge(CallSite CS, CallSite NewCS, CallGraphNode *NewNode);
+private:
+ friend class CallGraph;
+
+ AssertingVH<Function> F;
+
+ std::vector<CallRecord> CalledFunctions;
+
+ /// \brief The number of times that this CallGraphNode occurs in the
+ /// CalledFunctions array of this or other CallGraphNodes.
+ unsigned NumReferences;
+
+ CallGraphNode(const CallGraphNode &) = delete;
+ void operator=(const CallGraphNode &) = delete;
+
+ void DropRef() { --NumReferences; }
+ void AddRef() { ++NumReferences; }
+
/// \brief A special function that should only be used by the CallGraph class.
- //
- // FIXME: Make this private?
void allReferencesDropped() { NumReferences = 0; }
};
+/// \brief The \c ModulePass which wraps up a \c CallGraph and the logic to
+/// build it.
+///
+/// This class exposes both the interface to the call graph container and the
+/// module pass which runs over a module of IR and produces the call graph. The
+/// call graph interface is entirelly a wrapper around a \c CallGraph object
+/// which is stored internally for each module.
+class CallGraphWrapperPass : public ModulePass {
+ std::unique_ptr<CallGraph> G;
+
+public:
+ static char ID; // Class identification, replacement for typeinfo
+
+ CallGraphWrapperPass();
+ ~CallGraphWrapperPass() override;
+
+ /// \brief The internal \c CallGraph around which the rest of this interface
+ /// is wrapped.
+ const CallGraph &getCallGraph() const { return *G; }
+ CallGraph &getCallGraph() { return *G; }
+
+ typedef CallGraph::iterator iterator;
+ typedef CallGraph::const_iterator const_iterator;
+
+ /// \brief Returns the module the call graph corresponds to.
+ Module &getModule() const { return G->getModule(); }
+
+ inline iterator begin() { return G->begin(); }
+ inline iterator end() { return G->end(); }
+ inline const_iterator begin() const { return G->begin(); }
+ inline const_iterator end() const { return G->end(); }
+
+ /// \brief Returns the call graph node for the provided function.
+ inline const CallGraphNode *operator[](const Function *F) const {
+ return (*G)[F];
+ }
+
+ /// \brief Returns the call graph node for the provided function.
+ inline CallGraphNode *operator[](const Function *F) { return (*G)[F]; }
+
+ /// \brief Returns the \c CallGraphNode which is used to represent
+ /// undetermined calls into the callgraph.
+ CallGraphNode *getExternalCallingNode() const {
+ return G->getExternalCallingNode();
+ }
+
+ CallGraphNode *getCallsExternalNode() const {
+ return G->getCallsExternalNode();
+ }
+
+ //===---------------------------------------------------------------------
+ // Functions to keep a call graph up to date with a function that has been
+ // modified.
+ //
+
+ /// \brief 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 *removeFunctionFromModule(CallGraphNode *CGN) {
+ return G->removeFunctionFromModule(CGN);
+ }
+
+ /// \brief Similar to operator[], but this will insert a new CallGraphNode for
+ /// \c F if one does not already exist.
+ CallGraphNode *getOrInsertFunction(const Function *F) {
+ return G->getOrInsertFunction(F);
+ }
+
+ //===---------------------------------------------------------------------
+ // Implementation of the ModulePass interface needed here.
+ //
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+ bool runOnModule(Module &M) override;
+ void releaseMemory() override;
+
+ void print(raw_ostream &o, const Module *) const override;
+ void dump() const;
+};
+
//===----------------------------------------------------------------------===//
// GraphTraits specializations for call graphs so that they can be treated as
// graphs by the generic graph algorithms.
template <> struct GraphTraits<const CallGraphNode *> {
typedef const CallGraphNode NodeType;
- typedef NodeType::const_iterator ChildIteratorType;
+
+ typedef CallGraphNode::CallRecord CGNPairTy;
+ typedef std::pointer_to_unary_function<CGNPairTy, const CallGraphNode *>
+ CGNDerefFun;
static NodeType *getEntryNode(const CallGraphNode *CGN) { return CGN; }
+
+ typedef mapped_iterator<NodeType::const_iterator, CGNDerefFun>
+ ChildIteratorType;
+
static inline ChildIteratorType child_begin(NodeType *N) {
- return N->begin();
+ return map_iterator(N->begin(), CGNDerefFun(CGNDeref));
+ }
+ static inline ChildIteratorType child_end(NodeType *N) {
+ return map_iterator(N->end(), CGNDerefFun(CGNDeref));
}
- static inline ChildIteratorType child_end(NodeType *N) { return N->end(); }
+
+ static const CallGraphNode *CGNDeref(CGNPairTy P) { return P.second; }
};
template <>
static NodeType *getEntryNode(CallGraph *CGN) {
return CGN->getExternalCallingNode(); // Start at the external node!
}
- typedef std::pair<const Function *, CallGraphNode *> PairTy;
- typedef std::pointer_to_unary_function<PairTy, CallGraphNode &> DerefFun;
+ typedef std::pair<const Function *const, std::unique_ptr<CallGraphNode>>
+ PairTy;
+ typedef std::pointer_to_unary_function<const PairTy &, CallGraphNode &>
+ DerefFun;
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef mapped_iterator<CallGraph::iterator, DerefFun> nodes_iterator;
return map_iterator(CG->end(), DerefFun(CGdereference));
}
- static CallGraphNode &CGdereference(PairTy P) { return *P.second; }
+ static CallGraphNode &CGdereference(const PairTy &P) { return *P.second; }
};
template <>
struct GraphTraits<const CallGraph *> : public GraphTraits<
const CallGraphNode *> {
static NodeType *getEntryNode(const CallGraph *CGN) {
- return CGN->getExternalCallingNode();
+ return CGN->getExternalCallingNode(); // Start at the external node!
}
+ typedef std::pair<const Function *const, std::unique_ptr<CallGraphNode>>
+ PairTy;
+ typedef std::pointer_to_unary_function<const PairTy &, const CallGraphNode &>
+ DerefFun;
+
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
- typedef CallGraph::const_iterator nodes_iterator;
- static nodes_iterator nodes_begin(const CallGraph *CG) { return CG->begin(); }
- static nodes_iterator nodes_end(const CallGraph *CG) { return CG->end(); }
+ typedef mapped_iterator<CallGraph::const_iterator, DerefFun> nodes_iterator;
+ static nodes_iterator nodes_begin(const CallGraph *CG) {
+ return map_iterator(CG->begin(), DerefFun(CGdereference));
+ }
+ static nodes_iterator nodes_end(const CallGraph *CG) {
+ return map_iterator(CG->end(), DerefFun(CGdereference));
+ }
+
+ static const CallGraphNode &CGdereference(const PairTy &P) {
+ return *P.second;
+ }
};
} // End llvm namespace
-// Make sure that any clients of this file link in CallGraph.cpp
-FORCE_DEFINING_FILE_TO_BE_LINKED(CallGraph)
-
#endif
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