Revert "[SEH] Remove the old __C_specific_handler code now that WinEHPrepare works"

We still have some "uses remain after removal" issues in -O0 builds.

This reverts commit r235557.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235617 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineModuleInfo.h

@@ -77,6 +77,7 @@ struct LandingPadInfo {
   MachineBasicBlock *LandingPadBlock;      // Landing pad block.
   SmallVector<MCSymbol *, 1> BeginLabels;  // Labels prior to invoke.
   SmallVector<MCSymbol *, 1> EndLabels;    // Labels after invoke.
+  SmallVector<MCSymbol *, 1> ClauseLabels; // Labels for each clause.
   SmallVector<SEHHandler, 1> SEHHandlers;  // SEH handlers active at this lpad.
   MCSymbol *LandingPadLabel;               // Label at beginning of landing pad.
   const Function *Personality;             // Personality function.
@@ -360,6 +361,11 @@ public:
   ///
   void addCleanup(MachineBasicBlock *LandingPad);
 
+  /// Add a clause for a landing pad. Returns a new label for the clause. This
+  /// is used by EH schemes that have more than one landing pad. In this case,
+  /// each clause gets its own basic block.
+  MCSymbol *addClauseForLandingPad(MachineBasicBlock *LandingPad);
+
   void addSEHCatchHandler(MachineBasicBlock *LandingPad, const Function *Filter,
                           const BlockAddress *RecoverLabel);
 

lib/CodeGen/AsmPrinter/Win64Exception.cpp

@@ -206,6 +206,12 @@ void Win64Exception::emitCSpecificHandlerTable() {
   for (const CallSiteEntry &CSE : CallSites) {
     if (!CSE.LPad)
       continue; // Ignore gaps.
+    for (int Selector : CSE.LPad->TypeIds) {
+      // Ignore C++ filter clauses in SEH.
+      // FIXME: Implement cleanup clauses.
+      if (isCatchEHSelector(Selector))
+        ++NumEntries;
+    }
     NumEntries += CSE.LPad->SEHHandlers.size();
   }
   Asm->OutStreamer.EmitIntValue(NumEntries, 4);
@@ -261,6 +267,40 @@ void Win64Exception::emitCSpecificHandlerTable() {
       else
         Asm->OutStreamer.EmitIntValue(0, 4);
     }
+    if (!LPad->SEHHandlers.empty())
+      continue;
+
+    // These aren't really type info globals, they are actually pointers to
+    // filter functions ordered by selector. The zero selector is used for
+    // cleanups, so slot zero corresponds to selector 1.
+    const std::vector<const GlobalValue *> &SelectorToFilter = MMI->getTypeInfos();
+
+    // Do a parallel iteration across typeids and clause labels, skipping filter
+    // clauses.
+    size_t NextClauseLabel = 0;
+    for (size_t I = 0, E = LPad->TypeIds.size(); I < E; ++I) {
+      // AddLandingPadInfo stores the clauses in reverse, but there is a FIXME
+      // to change that.
+      int Selector = LPad->TypeIds[E - I - 1];
+
+      // Ignore C++ filter clauses in SEH.
+      // FIXME: Implement cleanup clauses.
+      if (!isCatchEHSelector(Selector))
+        continue;
+
+      Asm->OutStreamer.EmitValue(Begin, 4);
+      Asm->OutStreamer.EmitValue(End, 4);
+      if (isCatchEHSelector(Selector)) {
+        assert(unsigned(Selector - 1) < SelectorToFilter.size());
+        const GlobalValue *TI = SelectorToFilter[Selector - 1];
+        if (TI) // Emit the filter function pointer.
+          Asm->OutStreamer.EmitValue(createImageRel32(Asm->getSymbol(TI)), 4);
+        else  // Otherwise, this is a "catch i8* null", or catch all.
+          Asm->OutStreamer.EmitIntValue(1, 4);
+      }
+      MCSymbol *ClauseLabel = LPad->ClauseLabels[NextClauseLabel++];
+      Asm->OutStreamer.EmitValue(createImageRel32(ClauseLabel), 4);
+    }
   }
 }
 

lib/CodeGen/MachineModuleInfo.cpp

@@ -461,6 +461,14 @@ void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
   LP.TypeIds.push_back(0);
 }
 
+MCSymbol *
+MachineModuleInfo::addClauseForLandingPad(MachineBasicBlock *LandingPad) {
+  MCSymbol *ClauseLabel = Context.CreateTempSymbol();
+  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
+  LP.ClauseLabels.push_back(ClauseLabel);
+  return ClauseLabel;
+}
+
 void MachineModuleInfo::addSEHCatchHandler(MachineBasicBlock *LandingPad,
                                            const Function *Filter,
                                            const BlockAddress *RecoverBA) {

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -955,20 +955,76 @@ bool SelectionDAGISel::PrepareEHLandingPad() {
         // Mark the clause as a landing pad or MI passes will delete it.
         ClauseBB->setIsLandingPad();
       }
+    } else {
+      // Otherwise, we haven't done the preparation, and we need to invent some
+      // clause basic blocks that branch into the landingpad.
+      // FIXME: Remove this code once SEH preparation works.
+      ActionsCall = nullptr;
+
+      // Make virtual registers and a series of labels that fill in values for
+      // the clauses.
+      auto &RI = MF->getRegInfo();
+      FuncInfo->ExceptionSelectorVirtReg = RI.createVirtualRegister(PtrRC);
+
+      // Emit separate machine basic blocks with separate labels for each clause
+      // before the main landing pad block.
+      MachineInstrBuilder SelectorPHI = BuildMI(
+          *MBB, MBB->begin(), SDB->getCurDebugLoc(),
+          TII->get(TargetOpcode::PHI), FuncInfo->ExceptionSelectorVirtReg);
+      for (unsigned I = 0, E = LPadInst->getNumClauses(); I != E; ++I) {
+        // Skip filter clauses, we can't implement them.
+        if (LPadInst->isFilter(I))
+          continue;
+
+        MachineBasicBlock *ClauseBB = MF->CreateMachineBasicBlock(LLVMBB);
+        MF->insert(MBB, ClauseBB);
+
+        // Add the edge from the invoke to the clause.
+        for (MachineBasicBlock *InvokeBB : InvokeBBs)
+          InvokeBB->addSuccessor(ClauseBB);
+
+        // Mark the clause as a landing pad or MI passes will delete it.
+        ClauseBB->setIsLandingPad();
+
+        GlobalValue *ClauseGV = ExtractTypeInfo(LPadInst->getClause(I));
+
+        // Start the BB with a label.
+        MCSymbol *ClauseLabel = MF->getMMI().addClauseForLandingPad(MBB);
+        BuildMI(*ClauseBB, ClauseBB->begin(), SDB->getCurDebugLoc(), II)
+            .addSym(ClauseLabel);
+
+        // Construct a simple BB that defines a register with the typeid
+        // constant.
+        FuncInfo->MBB = ClauseBB;
+        FuncInfo->InsertPt = ClauseBB->end();
+        unsigned VReg = SDB->visitLandingPadClauseBB(ClauseGV, MBB);
+        CurDAG->setRoot(SDB->getRoot());
+        SDB->clear();
+        CodeGenAndEmitDAG();
+
+        // Add the typeid virtual register to the phi in the main landing pad.
+        SelectorPHI.addReg(VReg).addMBB(ClauseBB);
+      }
     }
 
     // Remove the edge from the invoke to the lpad.
     for (MachineBasicBlock *InvokeBB : InvokeBBs)
       InvokeBB->removeSuccessor(MBB);
 
+    // Restore FuncInfo back to its previous state and select the main landing
+    // pad block.
+    FuncInfo->MBB = MBB;
+    FuncInfo->InsertPt = MBB->end();
+
     // Transfer EH state number assigned to the IR block to the MBB.
     if (Personality == EHPersonality::MSVC_CXX) {
       WinEHFuncInfo &FI = MF->getMMI().getWinEHFuncInfo(MF->getFunction());
       MF->getMMI().addWinEHState(MBB, FI.LandingPadStateMap[LPadInst]);
     }
 
-    // Don't select instructions for the landingpad.
-    return false;
+    // Select instructions for the landingpad if there was no llvm.eh.actions
+    // call.
+    return ActionsCall == nullptr;
   }
 
   // Mark exception register as live in.

lib/CodeGen/WinEHPrepare.cpp

@@ -323,6 +323,11 @@ FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {
   return new WinEHPrepare(TM);
 }
 
+// FIXME: Remove this once the backend can handle the prepared IR.
+static cl::opt<bool>
+    SEHPrepare("sehprepare", cl::Hidden,
+               cl::desc("Prepare functions with SEH personalities"));
+
 bool WinEHPrepare::runOnFunction(Function &Fn) {
   // No need to prepare outlined handlers.
   if (Fn.hasFnAttribute("wineh-parent"))
@@ -350,6 +355,16 @@ bool WinEHPrepare::runOnFunction(Function &Fn) {
 
   DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
 
+  if (isAsynchronousEHPersonality(Personality) && !SEHPrepare) {
+    // Replace all resume instructions with unreachable.
+    // FIXME: Remove this once the backend can handle the prepared IR.
+    for (ResumeInst *Resume : Resumes) {
+      IRBuilder<>(Resume).CreateUnreachable();
+      Resume->eraseFromParent();
+    }
+    return true;
+  }
+
   // If there were any landing pads, prepareExceptionHandlers will make changes.
   prepareExceptionHandlers(Fn, LPads);
   return true;

test/CodeGen/WinEH/seh-catch-all.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -winehprepare < %s | FileCheck %s
+; RUN: opt -S -winehprepare -sehprepare < %s | FileCheck %s
 
 target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-pc-windows-msvc"

test/CodeGen/WinEH/seh-inlined-finally.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -winehprepare < %s | FileCheck %s
+; RUN: opt -S -winehprepare -sehprepare < %s | FileCheck %s
 
 ; Check that things work when the mid-level optimizer inlines the finally
 ; block.

test/CodeGen/WinEH/seh-outlined-finally.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -winehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
+; RUN: opt -S -winehprepare -sehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
 
 ; Test case based on this code:
 ;

test/CodeGen/WinEH/seh-prepared-basic.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -sehprepare < %s | FileCheck %s
 
 ; Test case based on this code:
 ; extern "C" unsigned long _exception_code();

test/CodeGen/WinEH/seh-simple.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -winehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
+; RUN: opt -S -winehprepare -sehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-pc-windows-msvc"

test/CodeGen/X86/seh-basic.ll

@@ -0,0 +1,175 @@
+; RUN: llc -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
+
+define void @two_invoke_merged() {
+entry:
+  invoke void @try_body()
+          to label %again unwind label %lpad
+
+again:
+  invoke void @try_body()
+          to label %done unwind label %lpad
+
+done:
+  ret void
+
+lpad:
+  %vals = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+          catch i8* bitcast (i32 (i8*, i8*)* @filt0 to i8*)
+          catch i8* bitcast (i32 (i8*, i8*)* @filt1 to i8*)
+  %sel = extractvalue { i8*, i32 } %vals, 1
+  call void @use_selector(i32 %sel)
+  ret void
+}
+
+; Normal path code
+
+; CHECK-LABEL: {{^}}two_invoke_merged:
+; CHECK: .seh_proc two_invoke_merged
+; CHECK: .seh_handler __C_specific_handler, @unwind, @except
+; CHECK: .Ltmp0:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp1:
+; CHECK: .Ltmp2:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp3:
+; CHECK: retq
+
+; Landing pad code
+
+; CHECK: .Ltmp5:
+; CHECK: movl $1, %ecx
+; CHECK: jmp
+; CHECK: .Ltmp6:
+; CHECK: movl $2, %ecx
+; CHECK: callq use_selector
+
+; CHECK: .seh_handlerdata
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long .Ltmp0@IMGREL
+; CHECK-NEXT: .long .Ltmp3@IMGREL+1
+; CHECK-NEXT: .long filt0@IMGREL
+; CHECK-NEXT: .long .Ltmp5@IMGREL
+; CHECK-NEXT: .long .Ltmp0@IMGREL
+; CHECK-NEXT: .long .Ltmp3@IMGREL+1
+; CHECK-NEXT: .long filt1@IMGREL
+; CHECK-NEXT: .long .Ltmp6@IMGREL
+; CHECK: .text
+; CHECK: .seh_endproc
+
+define void @two_invoke_gap() {
+entry:
+  invoke void @try_body()
+          to label %again unwind label %lpad
+
+again:
+  call void @do_nothing_on_unwind()
+  invoke void @try_body()
+          to label %done unwind label %lpad
+
+done:
+  ret void
+
+lpad:
+  %vals = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+          catch i8* bitcast (i32 (i8*, i8*)* @filt0 to i8*)
+  %sel = extractvalue { i8*, i32 } %vals, 1
+  call void @use_selector(i32 %sel)
+  ret void
+}
+
+; Normal path code
+
+; CHECK-LABEL: {{^}}two_invoke_gap:
+; CHECK: .seh_proc two_invoke_gap
+; CHECK: .seh_handler __C_specific_handler, @unwind, @except
+; CHECK: .Ltmp11:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp12:
+; CHECK: callq do_nothing_on_unwind
+; CHECK: .Ltmp13:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp14:
+; CHECK: retq
+
+; Landing pad code
+
+; CHECK: .Ltmp16:
+; CHECK: movl $1, %ecx
+; CHECK: callq use_selector
+
+; CHECK: .seh_handlerdata
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long .Ltmp11@IMGREL
+; CHECK-NEXT: .long .Ltmp12@IMGREL+1
+; CHECK-NEXT: .long filt0@IMGREL
+; CHECK-NEXT: .long .Ltmp16@IMGREL
+; CHECK-NEXT: .long .Ltmp13@IMGREL
+; CHECK-NEXT: .long .Ltmp14@IMGREL+1
+; CHECK-NEXT: .long filt0@IMGREL
+; CHECK-NEXT: .long .Ltmp16@IMGREL
+; CHECK: .text
+; CHECK: .seh_endproc
+
+define void @two_invoke_nounwind_gap() {
+entry:
+  invoke void @try_body()
+          to label %again unwind label %lpad
+
+again:
+  call void @cannot_unwind()
+  invoke void @try_body()
+          to label %done unwind label %lpad
+
+done:
+  ret void
+
+lpad:
+  %vals = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+          catch i8* bitcast (i32 (i8*, i8*)* @filt0 to i8*)
+  %sel = extractvalue { i8*, i32 } %vals, 1
+  call void @use_selector(i32 %sel)
+  ret void
+}
+
+; Normal path code
+
+; CHECK-LABEL: {{^}}two_invoke_nounwind_gap:
+; CHECK: .seh_proc two_invoke_nounwind_gap
+; CHECK: .seh_handler __C_specific_handler, @unwind, @except
+; CHECK: .Ltmp21:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp22:
+; CHECK: callq cannot_unwind
+; CHECK: .Ltmp23:
+; CHECK: callq try_body
+; CHECK-NEXT: .Ltmp24:
+; CHECK: retq
+
+; Landing pad code
+
+; CHECK: .Ltmp26:
+; CHECK: movl $1, %ecx
+; CHECK: callq use_selector
+
+; CHECK: .seh_handlerdata
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long .Ltmp21@IMGREL
+; CHECK-NEXT: .long .Ltmp24@IMGREL+1
+; CHECK-NEXT: .long filt0@IMGREL
+; CHECK-NEXT: .long .Ltmp26@IMGREL
+; CHECK: .text
+; CHECK: .seh_endproc
+
+declare void @try_body()
+declare void @do_nothing_on_unwind()
+declare void @cannot_unwind() nounwind
+declare void @use_selector(i32)
+
+declare i32 @filt0(i8* %eh_info, i8* %rsp)
+declare i32 @filt1(i8* %eh_info, i8* %rsp)
+
+declare void @handler0()
+declare void @handler1()
+
+declare i32 @__C_specific_handler(...)
+declare i32 @llvm.eh.typeid.for(i8*) readnone nounwind

test/CodeGen/X86/seh-catch-all.ll

@@ -1,3 +1,4 @@
+; RUN: llc -sehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
 ; RUN: llc -mtriple=x86_64-windows-msvc < %s | FileCheck %s
 
 @str = internal unnamed_addr constant [10 x i8] c"recovered\00", align 1

test/CodeGen/X86/seh-except-finally.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -sehprepare < %s | FileCheck %s
 
 ; Test case based on this source:
 ; int puts(const char*);

test/CodeGen/X86/seh-finally.ll

@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=x86_64-windows-msvc < %s | FileCheck %s
+; RUN: llc -sehprepare -mtriple=x86_64-windows-msvc < %s | FileCheck %s
 
 @str_recovered = internal unnamed_addr constant [10 x i8] c"recovered\00", align 1
 

test/CodeGen/X86/seh-safe-div.ll

@@ -1,4 +1,4 @@
-; RUN: llc -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
+; RUN: llc -sehprepare -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
 
 ; This test case is also intended to be run manually as a complete functional
 ; test. It should link, print something, and exit zero rather than crashing.

test/CodeGen/X86/win_eh_prepare.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -winehprepare -dwarfehprepare -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
+; RUN: opt -S -winehprepare -sehprepare -dwarfehprepare -mtriple x86_64-pc-windows-msvc < %s | FileCheck %s
 
 ; FIXME: Add and test outlining here.