1 files changed, 63 insertions, 3 deletions

diff --git a/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp b/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
index 0971c5942203..d94b0e5c2118 100644
--- a/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
+++ b/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
@@ -13,16 +13,76 @@
 //===----------------------------------------------------------------------===//
 
 #include "DebugHandlerBase.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/MC/MCStreamer.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
 
 using namespace llvm;
 
+Optional<DbgVariableLocation>
+DbgVariableLocation::extractFromMachineInstruction(
+    const MachineInstr &Instruction) {
+  DbgVariableLocation Location;
+  if (!Instruction.isDebugValue())
+    return None;
+  if (!Instruction.getOperand(0).isReg())
+    return None;
+  Location.Register = Instruction.getOperand(0).getReg();
+  Location.FragmentInfo.reset();
+  // We only handle expressions generated by DIExpression::appendOffset,
+  // which doesn't require a full stack machine.
+  int64_t Offset = 0;
+  const DIExpression *DIExpr = Instruction.getDebugExpression();
+  auto Op = DIExpr->expr_op_begin();
+  while (Op != DIExpr->expr_op_end()) {
+    switch (Op->getOp()) {
+    case dwarf::DW_OP_constu: {
+      int Value = Op->getArg(0);
+      ++Op;
+      if (Op != DIExpr->expr_op_end()) {
+        switch (Op->getOp()) {
+        case dwarf::DW_OP_minus:
+          Offset -= Value;
+          break;
+        case dwarf::DW_OP_plus:
+          Offset += Value;
+          break;
+        default:
+          continue;
+        }
+      }
+    } break;
+    case dwarf::DW_OP_plus_uconst:
+      Offset += Op->getArg(0);
+      break;
+    case dwarf::DW_OP_LLVM_fragment:
+      Location.FragmentInfo = {Op->getArg(1), Op->getArg(0)};
+      break;
+    case dwarf::DW_OP_deref:
+      Location.LoadChain.push_back(Offset);
+      Offset = 0;
+      break;
+    default:
+      return None;
+    }
+    ++Op;
+  }
+
+  // Do one final implicit DW_OP_deref if this was an indirect DBG_VALUE
+  // instruction.
+  // FIXME: Replace these with DIExpression.
+  if (Instruction.isIndirectDebugValue())
+    Location.LoadChain.push_back(Offset);
+
+  return Location;
+}
+
 DebugHandlerBase::DebugHandlerBase(AsmPrinter *A) : Asm(A), MMI(Asm->MMI) {}
 
 // Each LexicalScope has first instruction and last instruction to mark
@@ -119,7 +179,7 @@ static bool hasDebugInfo(const MachineModuleInfo *MMI,
                          const MachineFunction *MF) {
   if (!MMI->hasDebugInfo())
     return false;
-  auto *SP = MF->getFunction()->getSubprogram();
+  auto *SP = MF->getFunction().getSubprogram();
   if (!SP)
     return false;
   assert(SP->getUnit());
@@ -163,7 +223,7 @@ void DebugHandlerBase::beginFunction(const MachineFunction *MF) {
     // label, so arguments are visible when breaking at function entry.
     const DILocalVariable *DIVar = Ranges.front().first->getDebugVariable();
     if (DIVar->isParameter() &&
-        getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
+        getDISubprogram(DIVar->getScope())->describes(&MF->getFunction())) {
       LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
       if (Ranges.front().first->getDebugExpression()->isFragment()) {
         // Mark all non-overlapping initial fragments.