[LegacyPassManager] Remove TargetMachine constructors

This provides a new way to access the TargetMachine through
TargetPassConfig, as a dependency.

The patterns replaced here are:

* Passes handling a null TargetMachine call
  `getAnalysisIfAvailable<TargetPassConfig>`.

* Passes not handling a null TargetMachine
  `addRequired<TargetPassConfig>` and call
  `getAnalysis<TargetPassConfig>`.

* MachineFunctionPasses now use MF.getTarget().

* Remove all the TargetMachine constructors.
* Remove INITIALIZE_TM_PASS.

This fixes a crash when running `llc -start-before prologepilog`.

PEI needs StackProtector, which gets constructed without a TargetMachine
by the pass manager. The StackProtector pass doesn't handle the case
where there is no TargetMachine, so it segfaults.

Related to PR30324.

Differential Revision: https://reviews.llvm.org/D33222

llvm-svn: 303360

1 files changed, 13 insertions, 19 deletions

diff --git a/llvm/lib/CodeGen/DwarfEHPrepare.cpp b/llvm/lib/CodeGen/DwarfEHPrepare.cpp
index 38af19a0444..1ef4d866065 100644
--- a/llvm/lib/CodeGen/DwarfEHPrepare.cpp
+++ b/llvm/lib/CodeGen/DwarfEHPrepare.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/CFG.h"
@@ -34,8 +35,6 @@ STATISTIC(NumResumesLowered, "Number of resume calls lowered");
 
 namespace {
   class DwarfEHPrepare : public FunctionPass {
-    const TargetMachine *TM;
-
     // RewindFunction - _Unwind_Resume or the target equivalent.
     Constant *RewindFunction;
 
@@ -52,15 +51,9 @@ namespace {
   public:
     static char ID; // Pass identification, replacement for typeid.
 
-    // INITIALIZE_TM_PASS requires a default constructor, but it isn't used in
-    // practice.
     DwarfEHPrepare()
-        : FunctionPass(ID), TM(nullptr), RewindFunction(nullptr), DT(nullptr),
-          TLI(nullptr) {}
-
-    DwarfEHPrepare(const TargetMachine *TM)
-        : FunctionPass(ID), TM(TM), RewindFunction(nullptr), DT(nullptr),
-          TLI(nullptr) {}
+        : FunctionPass(ID), RewindFunction(nullptr), DT(nullptr), TLI(nullptr) {
+    }
 
     bool runOnFunction(Function &Fn) override;
 
@@ -78,18 +71,18 @@ namespace {
 } // end anonymous namespace
 
 char DwarfEHPrepare::ID = 0;
-INITIALIZE_TM_PASS_BEGIN(DwarfEHPrepare, "dwarfehprepare",
-                         "Prepare DWARF exceptions", false, false)
+INITIALIZE_PASS_BEGIN(DwarfEHPrepare, "dwarfehprepare",
+                      "Prepare DWARF exceptions", false, false)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_TM_PASS_END(DwarfEHPrepare, "dwarfehprepare",
-                       "Prepare DWARF exceptions", false, false)
+INITIALIZE_PASS_END(DwarfEHPrepare, "dwarfehprepare",
+                    "Prepare DWARF exceptions", false, false)
 
-FunctionPass *llvm::createDwarfEHPass(const TargetMachine *TM) {
-  return new DwarfEHPrepare(TM);
-}
+FunctionPass *llvm::createDwarfEHPass() { return new DwarfEHPrepare(); }
 
 void DwarfEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<TargetPassConfig>();
   AU.addRequired<TargetTransformInfoWrapperPass>();
   AU.addRequired<DominatorTreeWrapperPass>();
 }
@@ -254,9 +247,10 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
 }
 
 bool DwarfEHPrepare::runOnFunction(Function &Fn) {
-  assert(TM && "DWARF EH preparation requires a target machine");
+  const TargetMachine &TM =
+      getAnalysis<TargetPassConfig>().getTM<TargetMachine>();
   DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  TLI = TM->getSubtargetImpl(Fn)->getTargetLowering();
+  TLI = TM.getSubtargetImpl(Fn)->getTargetLowering();
   bool Changed = InsertUnwindResumeCalls(Fn);
   DT = nullptr;
   TLI = nullptr;