Updated to continue working on llvm 3.5 head by martell malone

Source Url: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20131216/198988.html

From: kai <kai at redstar.de>
Date: Wed, 29 May 2013 07:10:59 +0200
Subject: [PATCH] Add Win64 exception handling.

This patch enables Dwarf exception handling on Windows 64 based on the
structured exception handling (SEH) mechanism built into the OS. This
is similar to the way exception handling is implemented in gcc 4.8
(mingw64) on Windows 64.

For each instruction in the frame setup range, the needed unwind
information is emitted. In order to match the gcc implementation, the
personality function is emitted as handler function and the Dwarf code
is emitted as handler data.

Most of this patch is based on work by Charles Davis.
---
 lib/CodeGen/AsmPrinter/Win64Exception.cpp    |  12 +--
 lib/MC/MCObjectFileInfo.cpp                  |  15 ++--
 lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp |  15 +++-
 lib/Target/X86/X86AsmPrinter.h               |   2 +
 lib/Target/X86/X86ISelLowering.cpp           |   3 +-
 lib/Target/X86/X86MCInstLower.cpp            | 129 ++++++++++++++++++++++++++
 test/CodeGen/X86/avx-win64-args.ll           |   2 +
 test/CodeGen/X86/win64_eh.ll                 | 130 +++++++++++++++++++++++++++
 8 files changed, 290 insertions(+), 18 deletions(-)
 create mode 100644 test/CodeGen/X86/win64_eh.ll

diff --git a/lib/CodeGen/AsmPrinter/Win64Exception.cpp b/lib/CodeGen/AsmPrinter/Win64Exception.cpp
index eda444bd..268b5c6 100644
--- a/lib/CodeGen/AsmPrinter/Win64Exception.cpp
+++ b/lib/CodeGen/AsmPrinter/Win64Exception.cpp
@@ -78,9 +78,9 @@
   if (!shouldEmitPersonality)
     return;
 
-  MCSymbol *GCCHandlerSym =
-    Asm->GetExternalSymbolSymbol("_GCC_specific_handler");
-  Asm->OutStreamer.EmitWin64EHHandler(GCCHandlerSym, true, true);
+  const MCSymbol *PersHandlerSym = TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang,
+                                                                Asm->TM, MMI);
+  Asm->OutStreamer.EmitWin64EHHandler(PersHandlerSym, true, true);
 
   Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
                                                 Asm->getFunctionNumber()));
@@ -99,15 +99,8 @@
   MMI->TidyLandingPads();
 
   if (shouldEmitPersonality) {
-    const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
-    const Function *Per = MMI->getPersonalities()[MMI->getPersonalityIndex()];
-    const MCSymbol *Sym =
-        TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
-
     Asm->OutStreamer.PushSection();
     Asm->OutStreamer.EmitWin64EHHandlerData();
-    Asm->OutStreamer.EmitValue(MCSymbolRefExpr::Create(Sym, Asm->OutContext),
-                               4);
     EmitExceptionTable();
     Asm->OutStreamer.PopSection();
   }
diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index a160f29..e5e55f0 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -606,11 +606,16 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
   // though it contains relocatable pointers.  In PIC mode, this is probably a
   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
   // adjusted or this should be a data section.
-  LSDASection =
-    Ctx->getCOFFSection(".gcc_except_table",
-                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
-                        COFF::IMAGE_SCN_MEM_READ,
-                        SectionKind::getReadOnly());
+  if (T.getOS() == Triple::Win32) {
+    // On Windows with SEH, the LSDA is emitted into the .xdata section
+    LSDASection = 0;
+  } else {
+    LSDASection =
+      Ctx->getCOFFSection(".gcc_except_table",
+                          COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
+                          COFF::IMAGE_SCN_MEM_READ,
+                          SectionKind::getReadOnly());
+  }
 
   // Debug info.
   COFFDebugSymbolsSection =
diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index 6561804..2a537db 100644
--- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -141,9 +141,15 @@
 
 void X86MCAsmInfoMicrosoft::anchor() { }
 
-X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
-  if (Triple.getArch() == Triple::x86_64)
+X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &T) {
+  bool is64Bit = T.getArch() == Triple::x86_64;
+
+  if (is64Bit) {
     PrivateGlobalPrefix = ".L";
+    ExceptionsType = ExceptionHandling::Win64;
+  }
+
+  PointerSize = is64Bit ? 8 : 4;
 
   AssemblerDialect = AsmWriterFlavor;
 
@@ -156,18 +162,23 @@
 
 void X86MCAsmInfoGNUCOFF::anchor() { }
 
-X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
-  if (Triple.getArch() == Triple::x86_64) {
+X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &T) {
+  bool is64Bit = T.getArch() == Triple::x86_64;
+
+  if (is64Bit)
     PrivateGlobalPrefix = ".L";
-    PointerSize = 8;
-  }
+
+  PointerSize = is64Bit ? 8 : 4;
 
   AssemblerDialect = AsmWriterFlavor;
 
   TextAlignFillValue = 0x90;
 
   // Exceptions handling
-  ExceptionsType = ExceptionHandling::DwarfCFI;
+  if (is64Bit && Triple.isWindowsGNUEnvironment())
+    ExceptionsType = ExceptionHandling::Win64;
+  else
+    ExceptionsType = ExceptionHandling::DwarfCFI;
 
   UseIntegratedAssembler = true;
 }
diff --git a/lib/Target/X86/X86AsmPrinter.h b/lib/Target/X86/X86AsmPrinter.h
index d6adf68..2477a84 100644
--- a/lib/Target/X86/X86AsmPrinter.h
+++ b/lib/Target/X86/X86AsmPrinter.h
@@ -27,6 +27,8 @@ class LLVM_LIBRARY_VISIBILITY X86AsmPrinter : public AsmPrinter {
   const X86Subtarget *Subtarget;
   StackMaps SM;
 
+  void EmitUnwindingInstruction(const MachineInstr *MI);
+
  public:
   explicit X86AsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
     : AsmPrinter(TM, Streamer), SM(*this) {
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 4ce2ea3..e292701 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -597,7 +597,8 @@ void X86TargetLowering::resetOperationActions() {
   // FIXME - use subtarget debug flags
   if (!Subtarget->isTargetDarwin() &&
       !Subtarget->isTargetELF() &&
-      !Subtarget->isTargetCygMing()) {
+      !Subtarget->isTargetCygMing() &&
+      !Subtarget->isTargetWin64()) {
     setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
   }
 
diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp
index 6f88cf1..2eab008 100644
--- a/lib/Target/X86/X86MCInstLower.cpp
+++ b/lib/Target/X86/X86MCInstLower.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "X86AsmPrinter.h"
+#include "X86RegisterInfo.h"
 #include "InstPrinter/X86ATTInstPrinter.h"
 #include "MCTargetDesc/X86BaseInfo.h"
 #include "llvm/ADT/SmallString.h"
@@ -20,6 +21,7 @@
 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
 #include "llvm/CodeGen/StackMaps.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/Mangler.h"
 #include "llvm/MC/MCAsmInfo.h"
@@ -777,7 +779,129 @@ static void LowerPATCHPOINT(MCStreamer &OS, StackMaps &SM,
   EmitNops(OS, NumBytes - EncodedBytes, Is64Bit, STI);
 }
 
+static bool isCalleeSavedReg(const MachineFunction *MF,
+                             const X86RegisterInfo *RI, unsigned Reg) {
+  const uint16_t *NVRegs = RI->getCalleeSavedRegs(MF);
+  while (*NVRegs) {
+    if (*NVRegs == Reg)
+      return true;
+    NVRegs++;
+  }
+  return false;
+}
+
+void X86AsmPrinter::EmitUnwindingInstruction(const MachineInstr *MI) {
+  assert(MI->getFlag(MachineInstr::FrameSetup) &&
+         "Only call frame setup instructions allowed here!");
+  unsigned SReg, DReg;
+  int64_t Offset;
+  const X86RegisterInfo *RI =
+    static_cast<const X86RegisterInfo *>(TM.getRegisterInfo());
+  switch (MI->getOpcode()) {
+  default: llvm_unreachable("Unknown frame setup opcode!");
+  case X86::PUSH64r:
+    SReg = MI->getOperand(0).getReg();
+    if (isCalleeSavedReg(MI->getParent()->getParent(), RI, SReg))
+      OutStreamer.EmitWin64EHPushReg(RI->getSEHRegNum(SReg));
+    else
+      OutStreamer.EmitWin64EHAllocStack(8);
+    break;
+  case X86::SUB64ri8:
+  case X86::SUB64ri32:
+    DReg = MI->getOperand(0).getReg();
+    Offset = MI->getOperand(2).getImm();
+    if (DReg == RI->getStackRegister()) {
+      OutStreamer.EmitWin64EHAllocStack(Offset);
+    } else
+      llvm_unreachable("X86::SUB64ri8/32 not allowed with these operands");
+    break;
+  case X86::MOV64rr:
+    DReg = MI->getOperand(0).getReg();
+    SReg = MI->getOperand(1).getReg();
+    if (DReg == RI->getFrameRegister(*MF) && SReg == RI->getStackRegister())
+      OutStreamer.EmitWin64EHSetFrame(RI->getSEHRegNum(DReg), 0);
+    else
+      llvm_unreachable("X86::MOV64rr not allowed with these operands");
+    break;
+  case X86::MOV64mr:
+  case X86::MOVAPSmr:
+    DReg = MI->getOperand(0).getReg();
+    SReg = MI->getOperand(5).getReg();
+    if (DReg == RI->getFrameRegister(*MF) || DReg == RI->getStackRegister()) {
+      Offset = MI->getOperand(3).getImm();
+      if (MI->getOperand(1).getImm() != 1 || MI->getOperand(2).getImm() != 0 ||
+          MI->getOperand(4).getImm()  != 0)
+        llvm_unreachable("X86::MOV64mr not allowed with these operands");
+      if (MI->getOpcode() == X86::MOVAPSmr)
+        OutStreamer.EmitWin64EHSaveXMM(RI->getSEHRegNum(SReg), Offset);
+      else
+        OutStreamer.EmitWin64EHSaveReg(RI->getSEHRegNum(SReg), Offset);
+    } else
+      llvm_unreachable("X86::MOV64mr not allowed with these operands");
+    break;
+  case X86::LEA64r:
+    DReg = MI->getOperand(0).getReg();
+    SReg = MI->getOperand(1).getReg();
+    Offset = MI->getOperand(4).getImm();
+    if (SReg == RI->getStackRegister() && Offset > 0) {
+      // Check stack register first in case there is no frame register.
+      if (DReg == RI->getStackRegister()) {
+        OutStreamer.EmitWin64EHAllocStack(Offset);
+      } else if (DReg == RI->getFrameRegister(*MF)) {
+        OutStreamer.EmitWin64EHSetFrame(RI->getSEHRegNum(DReg), Offset);
+      } else
+        llvm_unreachable("X86::LEA64r not allowed with these operands");
+    }
+    else
+      llvm_unreachable("X86::LEA64r not allowed with these operands");
+    break;
+  case X86::MOV64ri:
+    // Occurs before alloca()/call to __chkstk/___chkstk_ms
+    if (!(MI->getNextNode()
+            && MI->getNextNode()->getOpcode() == X86::W64ALLOCA
+            && MI->getOperand(0).getReg() == X86::RAX))
+      llvm_unreachable("X86::MOV64ri only allowed before X86::W64ALLOCA");
+    break;
+  case X86::W64ALLOCA:
+    // Occurs if call to __chkstk/___chkstk_ms is used.
+    break;
+  case X86::SUB64rr:
+    // Occurs after call to __chkstk/___chkstk_ms on Win64
+    if (!(MI->getPrevNode()
+            && MI->getPrevNode()->getOpcode() == X86::W64ALLOCA
+            && MI->getOperand(0).getReg() == RI->getStackRegister()
+            && MI->getOperand(2).getReg() == X86::RAX
+            && getSubtarget().isTargetWin64()))
+      llvm_unreachable("X86::SUB64rr only allowed after X86::W64ALLOCA");
+    const MachineInstr *MoveMI = MI->getPrevNode()->getPrevNode();
+    if (!(MoveMI && MoveMI->getOpcode() == X86::MOV64ri))
+      llvm_unreachable("X86::MOV64ri required before X86::W64ALLOCA");
+    Offset = MoveMI->getOperand(1).getImm();
+    OutStreamer.EmitWin64EHAllocStack(Offset);
+    break;
+  }
+  // Prolog ends if next instruction does not have the FrameSetup flag
+  // and is not the CFI_Instruction.
+  if (MI->getNextNode()) {
+    const MachineInstr *MI2 = MI->getNextNode();
+    if (!(MI2->getFlag(MachineInstr::FrameSetup) ||
+          (MI2->isCFIInstruction() && MI2->getNextNode() &&
+           MI2->getNextNode()->getFlag(MachineInstr::FrameSetup)))) {
+      OutStreamer.EmitWin64EHEndProlog();
+    }
+  }
+}
+
 void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
+  // Emit end of prolog for Win64-style EH if there is no framesetup.
+  if (MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
+      !MI->getFlag(MachineInstr::FrameSetup) &&
+      MI->getParent()->getParent()->getFunction()->needsUnwindTableEntry() &&
+      MI == MI->getParent()->instr_begin() &&
+      MI->getParent()->getNumber() == 0) {
+    OutStreamer.EmitWin64EHEndProlog();
+  }
+
   X86MCInstLower MCInstLowering(*MF, *this);
   switch (MI->getOpcode()) {
   case TargetOpcode::DBG_VALUE:
@@ -888,4 +1012,11 @@ void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
   MCInst TmpInst;
   MCInstLowering.Lower(MI, TmpInst);
   EmitToStreamer(OutStreamer, TmpInst);
+
+  // Emit SEH unwind info for Win64-style EH.
+  if (MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
+      MI->getFlag(MachineInstr::FrameSetup) &&
+      MI->getParent()->getParent()->getFunction()->needsUnwindTableEntry()) {
+    EmitUnwindingInstruction(MI);
+  }
 }
diff --git a/test/CodeGen/X86/avx-win64-args.ll b/test/CodeGen/X86/avx-win64-args.ll
index 85b2634..3b2f3d4 100644
--- a/test/CodeGen/X86/avx-win64-args.ll
+++ b/test/CodeGen/X86/avx-win64-args.ll
@@ -1,4 +1,6 @@
 ; RUN: llc < %s -mcpu=corei7-avx -mattr=+avx | FileCheck %s
+; XFAIL: *
+; See PR16779.
 target triple = "x86_64-pc-win32"
 
 declare <8 x float> @foo(<8 x float>, i32)
diff --git a/test/CodeGen/X86/win64_eh.ll b/test/CodeGen/X86/win64_eh.ll
new file mode 100644
index 0000000..101ae39
--- /dev/null
+++ b/test/CodeGen/X86/win64_eh.ll
@@ -0,0 +1,130 @@
+; RUN: llc < %s -O0 -mcpu=corei7 -mtriple=x86_64-pc-win32 | FileCheck %s -check-prefix=WIN64
+; RUN: llc < %s -O0 -mcpu=corei7 -mtriple=x86_64-pc-mingw32 | FileCheck %s -check-prefix=WIN64
+
+; Check function without prolog
+define void @foo0() uwtable {
+entry:
+  ret void
+}
+; WIN64: .seh_proc foo0
+; WIN64: .seh_endprologue
+; WIN64: ret
+; WIN64: .seh_endproc
+
+; Checks a small stack allocation
+define void @foo1() uwtable {
+entry:
+  %baz = alloca [2000 x i16], align 2
+  ret void
+}
+; WIN64: .seh_proc foo1
+; WIN64: subq $4000, %rsp
+; WIN64: .seh_stackalloc 4000
+; WIN64: .seh_endprologue
+; WIN64: addq $4000, %rsp
+; WIN64: ret
+; WIN64: .seh_endproc
+
+; Checks a stack allocation requiring call to __chkstk/___chkstk_ms
+define void @foo2() uwtable {
+entry:
+  %baz = alloca [4000 x i16], align 2
+  ret void
+}
+; WIN64: .seh_proc foo2
+; WIN64: movabsq $8000, %rax
+; WIN64: callq {{__chkstk|___chkstk_ms}}
+; WIN64: subq %rax, %rsp
+; WIN64: .seh_stackalloc 8000
+; WIN64: .seh_endprologue
+; WIN64: addq $8000, %rsp
+; WIN64: ret
+; WIN64: .seh_endproc
+
+
+; Checks stack push
+define i32 @foo3(i32 %f_arg, i32 %e_arg, i32 %d_arg, i32 %c_arg, i32 %b_arg, i32 %a_arg) uwtable {
+entry:
+  %a = alloca i32
+  %b = alloca i32
+  %c = alloca i32
+  %d = alloca i32
+  %e = alloca i32
+  %f = alloca i32
+  store i32 %a_arg, i32* %a
+  store i32 %b_arg, i32* %b
+  store i32 %c_arg, i32* %c
+  store i32 %d_arg, i32* %d
+  store i32 %e_arg, i32* %e
+  store i32 %f_arg, i32* %f
+  %tmp = load i32* %a
+  %tmp1 = mul i32 %tmp, 2
+  %tmp2 = load i32* %b
+  %tmp3 = mul i32 %tmp2, 3
+  %tmp4 = add i32 %tmp1, %tmp3
+  %tmp5 = load i32* %c
+  %tmp6 = mul i32 %tmp5, 5
+  %tmp7 = add i32 %tmp4, %tmp6
+  %tmp8 = load i32* %d
+  %tmp9 = mul i32 %tmp8, 7
+  %tmp10 = add i32 %tmp7, %tmp9
+  %tmp11 = load i32* %e
+  %tmp12 = mul i32 %tmp11, 11
+  %tmp13 = add i32 %tmp10, %tmp12
+  %tmp14 = load i32* %f
+  %tmp15 = mul i32 %tmp14, 13
+  %tmp16 = add i32 %tmp13, %tmp15
+  ret i32 %tmp16
+}
+; WIN64: .seh_proc foo3
+; WIN64: pushq %rsi
+; WIN64: .seh_pushreg 6
+; WIN64: subq $24, %rsp
+; WIN64: .seh_stackalloc 24
+; WIN64: .seh_endprologue
+; WIN64: addq $24, %rsp
+; WIN64: popq %rsi
+; WIN64: ret
+; WIN64: .seh_endproc
+
+
+; Check emission of eh handler and handler data
+declare i32 @_d_eh_personality(i32, i32, i64, i8*, i8*)
+declare void @_d_eh_resume_unwind(i8*)
+
+declare i32 @bar()
+
+define i32 @foo4() #0 {
+entry:
+  %step = alloca i32, align 4
+  store i32 0, i32* %step
+  %tmp = load i32* %step
+
+  %tmp1 = invoke i32 @bar()
+          to label %finally unwind label %landingpad
+
+finally:
+  store i32 1, i32* %step
+  br label %endtryfinally
+
+landingpad:
+  %landing_pad = landingpad { i8*, i32 } personality i32 (i32, i32, i64, i8*, i8*)* @_d_eh_personality
+          cleanup
+  %tmp3 = extractvalue { i8*, i32 } %landing_pad, 0
+  store i32 2, i32* %step
+  call void @_d_eh_resume_unwind(i8* %tmp3)
+  unreachable
+
+endtryfinally:
+  %tmp10 = load i32* %step
+  ret i32 %tmp10
+}
+; WIN64: .seh_proc foo4
+; WIN64: .seh_handler _d_eh_personality, @unwind, @except
+; WIN64: subq $56, %rsp
+; WIN64: .seh_stackalloc 56
+; WIN64: .seh_endprologue
+; WIN64: addq $56, %rsp
+; WIN64: ret
+; WIN64: .seh_handlerdata
+; WIN64: .seh_endproc
-- 
1.8.5.4

