llvm-6502/lib/Analysis/IPA/CallGraph.cpp
Richard Smith c00ae93432 Remove Support/IncludeFile.h and its only user. This is actively harmful, since
it breaks the modules builds (where CallGraph.h can be quite reasonably
transitively included by an unimported portion of a module, and CallGraph.cpp
not linked in), and appears to have been entirely redundant since PR780 was
fixed back in 2008.

If this breaks anything, please revert; I have only tested this with a single
configuration, and it's possible that this is still somehow fixing something
(though I doubt it, since no other similar file uses this mechanism any more).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215142 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-07 20:41:17 +00:00

285 lines
9.7 KiB
C++

//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CallGraph.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Implementations of the CallGraph class methods.
//
CallGraph::CallGraph(Module &M)
: M(M), Root(nullptr), ExternalCallingNode(getOrInsertFunction(nullptr)),
CallsExternalNode(new CallGraphNode(nullptr)) {
// Add every function to the call graph.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
addToCallGraph(I);
// If we didn't find a main function, use the external call graph node
if (!Root)
Root = ExternalCallingNode;
}
CallGraph::~CallGraph() {
// CallsExternalNode is not in the function map, delete it explicitly.
CallsExternalNode->allReferencesDropped();
delete CallsExternalNode;
// Reset all node's use counts to zero before deleting them to prevent an
// assertion from firing.
#ifndef NDEBUG
for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
I != E; ++I)
I->second->allReferencesDropped();
#endif
for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
I != E; ++I)
delete I->second;
}
void CallGraph::addToCallGraph(Function *F) {
CallGraphNode *Node = getOrInsertFunction(F);
// If this function has external linkage, anything could call it.
if (!F->hasLocalLinkage()) {
ExternalCallingNode->addCalledFunction(CallSite(), Node);
// Found the entry point?
if (F->getName() == "main") {
if (Root) // Found multiple external mains? Don't pick one.
Root = ExternalCallingNode;
else
Root = Node; // Found a main, keep track of it!
}
}
// If this function has its address taken, anything could call it.
if (F->hasAddressTaken())
ExternalCallingNode->addCalledFunction(CallSite(), Node);
// If this function is not defined in this translation unit, it could call
// anything.
if (F->isDeclaration() && !F->isIntrinsic())
Node->addCalledFunction(CallSite(), CallsExternalNode);
// Look for calls by this function.
for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;
++II) {
CallSite CS(cast<Value>(II));
if (CS) {
const Function *Callee = CS.getCalledFunction();
if (!Callee)
// Indirect calls of intrinsics are not allowed so no need to check.
Node->addCalledFunction(CS, CallsExternalNode);
else if (!Callee->isIntrinsic())
Node->addCalledFunction(CS, getOrInsertFunction(Callee));
}
}
}
void CallGraph::print(raw_ostream &OS) const {
OS << "CallGraph Root is: ";
if (Function *F = Root->getFunction())
OS << F->getName() << "\n";
else {
OS << "<<null function: 0x" << Root << ">>\n";
}
for (CallGraph::const_iterator I = begin(), E = end(); I != E; ++I)
I->second->print(OS);
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void CallGraph::dump() const { print(dbgs()); }
#endif
// 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 *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
assert(CGN->empty() && "Cannot remove function from call "
"graph if it references other functions!");
Function *F = CGN->getFunction(); // Get the function for the call graph node
delete CGN; // Delete the call graph node for this func
FunctionMap.erase(F); // Remove the call graph node from the map
M.getFunctionList().remove(F);
return F;
}
/// spliceFunction - Replace the function represented by this node by another.
/// This does not rescan the body of the function, so it is suitable when
/// splicing the body of the old function to the new while also updating all
/// callers from old to new.
///
void CallGraph::spliceFunction(const Function *From, const Function *To) {
assert(FunctionMap.count(From) && "No CallGraphNode for function!");
assert(!FunctionMap.count(To) &&
"Pointing CallGraphNode at a function that already exists");
FunctionMapTy::iterator I = FunctionMap.find(From);
I->second->F = const_cast<Function*>(To);
FunctionMap[To] = I->second;
FunctionMap.erase(I);
}
// getOrInsertFunction - This method is identical to calling operator[], but
// it will insert a new CallGraphNode for the specified function if one does
// not already exist.
CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
CallGraphNode *&CGN = FunctionMap[F];
if (CGN)
return CGN;
assert((!F || F->getParent() == &M) && "Function not in current module!");
return CGN = new CallGraphNode(const_cast<Function*>(F));
}
//===----------------------------------------------------------------------===//
// Implementations of the CallGraphNode class methods.
//
void CallGraphNode::print(raw_ostream &OS) const {
if (Function *F = getFunction())
OS << "Call graph node for function: '" << F->getName() << "'";
else
OS << "Call graph node <<null function>>";
OS << "<<" << this << ">> #uses=" << getNumReferences() << '\n';
for (const_iterator I = begin(), E = end(); I != E; ++I) {
OS << " CS<" << I->first << "> calls ";
if (Function *FI = I->second->getFunction())
OS << "function '" << FI->getName() <<"'\n";
else
OS << "external node\n";
}
OS << '\n';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void CallGraphNode::dump() const { print(dbgs()); }
#endif
/// removeCallEdgeFor - This method removes the edge in the node for the
/// specified call site. Note that this method takes linear time, so it
/// should be used sparingly.
void CallGraphNode::removeCallEdgeFor(CallSite CS) {
for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
if (I->first == CS.getInstruction()) {
I->second->DropRef();
*I = CalledFunctions.back();
CalledFunctions.pop_back();
return;
}
}
}
// removeAnyCallEdgeTo - This method removes any call edges from this node to
// the specified callee function. This takes more time to execute than
// removeCallEdgeTo, so it should not be used unless necessary.
void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
if (CalledFunctions[i].second == Callee) {
Callee->DropRef();
CalledFunctions[i] = CalledFunctions.back();
CalledFunctions.pop_back();
--i; --e;
}
}
/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
/// from this node to the specified callee function.
void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
CallRecord &CR = *I;
if (CR.second == Callee && CR.first == nullptr) {
Callee->DropRef();
*I = CalledFunctions.back();
CalledFunctions.pop_back();
return;
}
}
}
/// replaceCallEdge - This method replaces the edge in the node for the
/// specified call site with a new one. Note that this method takes linear
/// time, so it should be used sparingly.
void CallGraphNode::replaceCallEdge(CallSite CS,
CallSite NewCS, CallGraphNode *NewNode){
for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
if (I->first == CS.getInstruction()) {
I->second->DropRef();
I->first = NewCS.getInstruction();
I->second = NewNode;
NewNode->AddRef();
return;
}
}
}
//===----------------------------------------------------------------------===//
// Out-of-line definitions of CallGraphAnalysis class members.
//
char CallGraphAnalysis::PassID;
//===----------------------------------------------------------------------===//
// Implementations of the CallGraphWrapperPass class methods.
//
CallGraphWrapperPass::CallGraphWrapperPass() : ModulePass(ID) {
initializeCallGraphWrapperPassPass(*PassRegistry::getPassRegistry());
}
CallGraphWrapperPass::~CallGraphWrapperPass() {}
void CallGraphWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
bool CallGraphWrapperPass::runOnModule(Module &M) {
// All the real work is done in the constructor for the CallGraph.
G.reset(new CallGraph(M));
return false;
}
INITIALIZE_PASS(CallGraphWrapperPass, "basiccg", "CallGraph Construction",
false, true)
char CallGraphWrapperPass::ID = 0;
void CallGraphWrapperPass::releaseMemory() { G.reset(); }
void CallGraphWrapperPass::print(raw_ostream &OS, const Module *) const {
if (!G) {
OS << "No call graph has been built!\n";
return;
}
// Just delegate.
G->print(OS);
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void CallGraphWrapperPass::dump() const { print(dbgs(), nullptr); }
#endif