SjLj based exception handling unwinding support. This patch is nasty, brutish

and short. Well, it's kinda short. Definitely nasty and brutish.

The front-end generates the register/unregister calls into the SjLj runtime,
call-site indices and landing pad dispatch. The back end fills in the LSDA
with the call-site information provided by the front end. Catch blocks are
not yet implemented.

Built on Darwin and verified no llvm-core "make check" regressions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78625 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 48 insertions, 4 deletions

diff --git a/lib/Target/ARM/ARMConstantPoolValue.cpp b/lib/Target/ARM/ARMConstantPoolValue.cpp
index a75ed3bd53..adf03e04b8 100644
--- a/lib/Target/ARM/ARMConstantPoolValue.cpp
+++ b/lib/Target/ARM/ARMConstantPoolValue.cpp
@@ -34,7 +34,7 @@ ARMConstantPoolValue::ARMConstantPoolValue(const char *s, unsigned id,
                                            const char *Modif,
                                            bool AddCA)
   : MachineConstantPoolValue((const Type*)Type::Int32Ty),
-    GV(NULL), S(s), LabelId(id), Kind(k), PCAdjust(PCAdj),
+    GV(NULL), S(strdup(s)), LabelId(id), Kind(k), PCAdjust(PCAdj),
     Modifier(Modif), AddCurrentAddress(AddCA) {}
 
 ARMConstantPoolValue::ARMConstantPoolValue(GlobalValue *gv,
diff --git a/lib/Target/ARM/ARMConstantPoolValue.h b/lib/Target/ARM/ARMConstantPoolValue.h
index fcaf2e6885..37a2c80478 100644
--- a/lib/Target/ARM/ARMConstantPoolValue.h
+++ b/lib/Target/ARM/ARMConstantPoolValue.h
@@ -53,6 +53,8 @@ public:
                        bool AddCurrentAddress = false);
   ARMConstantPoolValue(GlobalValue *GV, ARMCP::ARMCPKind Kind,
                        const char *Modifier);
+  ARMConstantPoolValue();
+  ~ARMConstantPoolValue() {free((void*)S);}
 
 
   GlobalValue *getGV() const { return GV; }
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index aedddaa20b..61722d44fa 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1392,6 +1392,37 @@ ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) {
     EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
     return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
   }
+  case Intrinsic::eh_sjlj_lsda: {
+    // blah. horrible, horrible hack with the forced magic name.
+    // really need to clean this up. It belongs in the target-independent
+    // layer somehow that doesn't require the coupling with the asm
+    // printer.
+    MachineFunction &MF = DAG.getMachineFunction();
+    EVT PtrVT = getPointerTy();
+    DebugLoc dl = Op.getDebugLoc();
+    Reloc::Model RelocM = getTargetMachine().getRelocationModel();
+    SDValue CPAddr;
+    unsigned PCAdj = (RelocM != Reloc::PIC_)
+      ? 0 : (Subtarget->isThumb() ? 4 : 8);
+    ARMCP::ARMCPKind Kind = ARMCP::CPValue;
+    // Save off the LSDA name for the AsmPrinter to use when it's time
+    // to emit the table
+    std::string LSDAName = "L_lsda_";
+    LSDAName += MF.getFunction()->getName();
+    ARMConstantPoolValue *CPV =
+      new ARMConstantPoolValue(LSDAName.c_str(), ARMPCLabelIndex, Kind, PCAdj);
+    CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
+    CPAddr = DAG.getNode(ARMISD::Wrapper, dl, EVT::i32, CPAddr);
+    SDValue Result =
+      DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr, NULL, 0);
+    SDValue Chain = Result.getValue(1);
+
+    if (RelocM == Reloc::PIC_) {
+      SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex++, EVT::i32);
+      Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
+    }
+    return Result;
+  }
   case Intrinsic::eh_sjlj_setjmp:
     return DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, EVT::i32, Op.getOperand(1));
   }
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 5190492b64..4a2ce4be78 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -1427,9 +1427,12 @@ let Defs =
   def Int_eh_sjlj_setjmp : XI<(outs), (ins GPR:$src),
                                AddrModeNone, SizeSpecial, IndexModeNone,
                                Pseudo, NoItinerary,
-                               "add r0, pc, #4\n\t"
-                               "str r0, [$src, #+4]\n\t"
-                               "mov r0, #0 @ eh_setjmp", "",
+                               "str sp, [$src, #+8] @ eh_setjmp begin\n\t"
+                               "add ip, pc, #8\n\t"
+                               "str ip, [$src, #+4]\n\t"
+                               "mov r0, #0\n\t"
+                               "add pc, pc, #0\n\t"
+                               "mov r0, #1 @ eh_setjmp end\n\t", "",
                                [(set R0, (ARMeh_sjlj_setjmp GPR:$src))]>;
 }
 
diff --git a/lib/Target/ARM/ARMTargetAsmInfo.cpp b/lib/Target/ARM/ARMTargetAsmInfo.cpp
index e3348a90d4..653219bf74 100644
--- a/lib/Target/ARM/ARMTargetAsmInfo.cpp
+++ b/lib/Target/ARM/ARMTargetAsmInfo.cpp
@@ -47,6 +47,12 @@ ARMDarwinTargetAsmInfo::ARMDarwinTargetAsmInfo() {
   ProtectedDirective = NULL;
   HasDotTypeDotSizeDirective = false;
   SupportsDebugInformation = true;
+
+  // Exceptions handling
+  ExceptionsType = ExceptionHandling::SjLj;
+  GlobalEHDirective = "\t.globl\t";
+  SupportsWeakOmittedEHFrame = false;
+  AbsoluteEHSectionOffsets = false;
 }
 
 ARMELFTargetAsmInfo::ARMELFTargetAsmInfo() {
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index a909b66413..9de9af60e6 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -208,6 +208,8 @@ namespace {
       } else {
         if (GV)
           Name = Mang->getMangledName(GV);
+        else if (!strncmp(ACPV->getSymbol(), "L_lsda_", 7))
+          Name = ACPV->getSymbol();
         else
           Name = Mang->makeNameProper(ACPV->getSymbol());
       }