Revert r279564. It introduces undefined behavior (binding a reference to a

dereferenced null pointer) in MachineModuleInfo::MachineModuleInfo that causes
-Werror builds (including several buildbots) to fail.

llvm-svn: 279580

7 files changed, 86 insertions, 83 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 674df25e93c..0fed4e91eef 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2571,6 +2571,8 @@ isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
   return true;
 }
 
+
+
 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
   if (!S.usesMetadata())
     return nullptr;
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index cc9ed95be59..f5224350c08 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/llvm/lib/CodeGen/CMakeLists.txt
@@ -59,6 +59,7 @@ add_llvm_library(LLVMCodeGen
   MachineCSE.cpp
   MachineDominanceFrontier.cpp
   MachineDominators.cpp
+  MachineFunctionAnalysis.cpp
   MachineFunction.cpp
   MachineFunctionPass.cpp
   MachineFunctionPrinterPass.cpp
diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
index 27acb306a65..9ed61c6685b 100644
--- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
@@ -15,6 +15,7 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"
+#include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
@@ -102,15 +103,19 @@ TargetIRAnalysis LLVMTargetMachine::getTargetIRAnalysis() {
 }
 
 MachineModuleInfo &
-LLVMTargetMachine::addMachineModuleInfo(PassManagerBase &PM,
-                                        MachineFunctionInitializer *MFI) const {
-  MachineModuleInfo *MMI = new MachineModuleInfo(*this, *getMCAsmInfo(),
+LLVMTargetMachine::addMachineModuleInfo(PassManagerBase &PM) const {
+  MachineModuleInfo *MMI = new MachineModuleInfo(*getMCAsmInfo(),
                                                  *getMCRegisterInfo(),
-                                                 getObjFileLowering(), MFI);
+                                                 getObjFileLowering());
   PM.add(MMI);
   return *MMI;
 }
 
+void LLVMTargetMachine::addMachineFunctionAnalysis(PassManagerBase &PM,
+    MachineFunctionInitializer *MFInitializer) const {
+  PM.add(new MachineFunctionAnalysis(*this, MFInitializer));
+}
+
 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
 static MCContext *
 addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
@@ -145,7 +150,8 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
 
   PassConfig->addISelPrepare();
 
-  MachineModuleInfo &MMI = TM->addMachineModuleInfo(PM, MFInitializer);
+  MachineModuleInfo &MMI = TM->addMachineModuleInfo(PM);
+  TM->addMachineFunctionAnalysis(PM, MFInitializer);
 
   // Enable FastISel with -fast, but allow that to be overridden.
   TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE);
@@ -267,7 +273,6 @@ bool LLVMTargetMachine::addPassesToEmitFile(
     return true;
 
   PM.add(Printer);
-  PM.add(createFreeMachineFunctionPass());
 
   return false;
 }
@@ -314,7 +319,6 @@ bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
     return true;
 
   PM.add(Printer);
-  PM.add(createFreeMachineFunctionPass());
 
   return false; // success!
 }
diff --git a/llvm/lib/CodeGen/MachineFunctionAnalysis.cpp b/llvm/lib/CodeGen/MachineFunctionAnalysis.cpp
new file mode 100644
index 00000000000..3b69ed55fb6
--- /dev/null
+++ b/llvm/lib/CodeGen/MachineFunctionAnalysis.cpp
@@ -0,0 +1,62 @@
+//===-- MachineFunctionAnalysis.cpp ---------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the definitions of the MachineFunctionAnalysis members.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineFunctionAnalysis.h"
+#include "llvm/CodeGen/GCMetadata.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineFunctionInitializer.h"
+using namespace llvm;
+
+char MachineFunctionAnalysis::ID = 0;
+
+MachineFunctionAnalysis::MachineFunctionAnalysis(
+    const TargetMachine &tm, MachineFunctionInitializer *MFInitializer)
+    : FunctionPass(ID), TM(tm), MF(nullptr), MFInitializer(MFInitializer) {
+  initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry());
+}
+
+MachineFunctionAnalysis::~MachineFunctionAnalysis() {
+  releaseMemory();
+  assert(!MF && "MachineFunctionAnalysis left initialized!");
+}
+
+void MachineFunctionAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<MachineModuleInfo>();
+}
+
+bool MachineFunctionAnalysis::doInitialization(Module &M) {
+  MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
+  assert(MMI && "MMI not around yet??");
+  MMI->setModule(&M);
+  NextFnNum = 0;
+  return false;
+}
+
+
+bool MachineFunctionAnalysis::runOnFunction(Function &F) {
+  assert(!MF && "MachineFunctionAnalysis already initialized!");
+  MF = new MachineFunction(&F, TM, NextFnNum++,
+                           getAnalysis<MachineModuleInfo>());
+  if (MFInitializer) {
+    if (MFInitializer->initializeMachineFunction(*MF))
+      report_fatal_error("Unable to initialize machine function");
+  }
+  return false;
+}
+
+void MachineFunctionAnalysis::releaseMemory() {
+  delete MF;
+  MF = nullptr;
+}
diff --git a/llvm/lib/CodeGen/MachineFunctionPass.cpp b/llvm/lib/CodeGen/MachineFunctionPass.cpp
index 43cd2ed64b4..524ebdbf657 100644
--- a/llvm/lib/CodeGen/MachineFunctionPass.cpp
+++ b/llvm/lib/CodeGen/MachineFunctionPass.cpp
@@ -22,7 +22,7 @@
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/StackProtector.h"
 #include "llvm/IR/Dominators.h"
@@ -41,9 +41,7 @@ bool MachineFunctionPass::runOnFunction(Function &F) {
   if (F.hasAvailableExternallyLinkage())
     return false;
 
-  MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();
-  MachineFunction &MF = MMI.getMachineFunction(F);
-
+  MachineFunction &MF = getAnalysis<MachineFunctionAnalysis>().getMF();
   MachineFunctionProperties &MFProps = MF.getProperties();
 
 #ifndef NDEBUG
@@ -67,8 +65,8 @@ bool MachineFunctionPass::runOnFunction(Function &F) {
 }
 
 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<MachineModuleInfo>();
-  AU.addPreserved<MachineModuleInfo>();
+  AU.addRequired<MachineFunctionAnalysis>();
+  AU.addPreserved<MachineFunctionAnalysis>();
 
   // MachineFunctionPass preserves all LLVM IR passes, but there's no
   // high-level way to express this. Instead, just list a bunch of
diff --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp
index e5fc5cd5903..244e3fbc4e8 100644
--- a/llvm/lib/CodeGen/MachineModuleInfo.cpp
+++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp
@@ -13,7 +13,6 @@
 #include "llvm/Analysis/EHPersonalities.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionInitializer.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/IR/Constants.h"
@@ -187,19 +186,15 @@ void MMIAddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
 
 //===----------------------------------------------------------------------===//
 
-MachineModuleInfo::MachineModuleInfo(const TargetMachine &TM,
-                                     const MCAsmInfo &MAI,
+MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI,
                                      const MCRegisterInfo &MRI,
-                                     const MCObjectFileInfo *MOFI,
-                                     MachineFunctionInitializer *MFI)
-  : ImmutablePass(ID), TM(TM), Context(&MAI, &MRI, MOFI, nullptr, false),
-    MFInitializer(MFI) {
+                                     const MCObjectFileInfo *MOFI)
+  : ImmutablePass(ID), Context(&MAI, &MRI, MOFI, nullptr, false) {
   initializeMachineModuleInfoPass(*PassRegistry::getPassRegistry());
 }
 
 MachineModuleInfo::MachineModuleInfo()
-  : ImmutablePass(ID), TM(*((TargetMachine*)nullptr)),
-    Context(nullptr, nullptr, nullptr) {
+  : ImmutablePass(ID), Context(nullptr, nullptr, nullptr) {
   llvm_unreachable("This MachineModuleInfo constructor should never be called, "
                    "MMI should always be explicitly constructed by "
                    "LLVMTargetMachine");
@@ -218,7 +213,7 @@ bool MachineModuleInfo::doInitialization(Module &M) {
   DbgInfoAvailable = UsesVAFloatArgument = UsesMorestackAddr = false;
   PersonalityTypeCache = EHPersonality::Unknown;
   AddrLabelSymbols = nullptr;
-  TheModule = &M;
+  TheModule = nullptr;
 
   return false;
 }
@@ -466,63 +461,3 @@ try_next:;
   FilterIds.push_back(0); // terminator
   return FilterID;
 }
-
-MachineFunction &MachineModuleInfo::getMachineFunction(const Function &F) {
-  // Shortcut for the common case where a sequence of MachineFunctionPasses
-  // all query for the same Function.
-  if (LastRequest == &F)
-    return *LastResult;
-
-  auto I = MachineFunctions.insert(
-      std::make_pair(&F, std::unique_ptr<MachineFunction>()));
-  MachineFunction *MF;
-  if (I.second) {
-    // No pre-existing machine function, create a new one.
-    MF = new MachineFunction(&F, TM, NextFnNum++, *this);
-    // Update the set entry.
-    I.first->second.reset(MF);
-
-    if (MFInitializer)
-      if (MFInitializer->initializeMachineFunction(*MF))
-        report_fatal_error("Unable to initialize machine function");
-  } else {
-    MF = I.first->second.get();
-  }
-
-  LastRequest = &F;
-  LastResult = MF;
-  return *MF;
-}
-
-void MachineModuleInfo::deleteMachineFunctionFor(Function &F) {
-  MachineFunctions.erase(&F);
-  LastRequest = nullptr;
-  LastResult = nullptr;
-}
-
-namespace {
-/// This pass frees the MachineFunction object associated with a Function.
-class FreeMachineFunction : public FunctionPass {
-public:
-  static char ID;
-  FreeMachineFunction() : FunctionPass(ID) {}
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<MachineModuleInfo>();
-    AU.addPreserved<MachineModuleInfo>();
-  }
-
-  bool runOnFunction(Function &F) override {
-    MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();
-    MMI.deleteMachineFunctionFor(F);
-    return true;
-  }
-};
-char FreeMachineFunction::ID;
-} // end anonymous namespace
-
-namespace llvm {
-FunctionPass *createFreeMachineFunctionPass() {
-  return new FreeMachineFunction();
-}
-} // end namespace llvm
diff --git a/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp b/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
index 86dab766508..9da22db505e 100644
--- a/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
+++ b/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
@@ -17,6 +17,7 @@
 #include "llvm/CodeGen/LivePhysRegs.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/Support/CommandLine.h"