5 files changed, 39 insertions, 12 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index cea9df14dfc..26e8f2da853 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -560,7 +560,7 @@ unsigned DIELocList::SizeOf(AsmPrinter *AP, dwarf::Form Form) const {
 ///
 void DIELocList::EmitValue(AsmPrinter *AP, dwarf::Form Form) const {
   DwarfDebug *DD = AP->getDwarfDebug();
-  MCSymbol *Label = AP->GetTempSymbol("debug_loc", Index);
+  MCSymbol *Label = DD->getDebugLocEntries()[Index].Label;
 
   if (AP->MAI->doesDwarfUseRelocationsAcrossSections() && !DD->useSplitDwarf())
     AP->EmitSectionOffset(Label, DD->getDebugLocSym());
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
index 9756054b285..74beec1c955 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
@@ -284,9 +284,10 @@ void DIEHash::hashBlockData(const SmallVectorImpl<DIEValue *> &Values) {
 // Hash the contents of a loclistptr class.
 void DIEHash::hashLocList(const DIELocList &LocList) {
   HashingByteStreamer Streamer(*this);
+  DwarfDebug &DD = *AP->getDwarfDebug();
   for (const auto &Entry :
-       AP->getDwarfDebug()->getDebugLocEntries()[LocList.getValue()])
-    AP->getDwarfDebug()->emitDebugLocEntry(Streamer, Entry);
+       DD.getDebugLocEntries()[LocList.getValue()].List)
+    DD.emitDebugLocEntry(Streamer, Entry);
 }
 
 // Hash an individual attribute \param Attr based on the type of attribute and
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocList.h b/llvm/lib/CodeGen/AsmPrinter/DebugLocList.h
new file mode 100644
index 00000000000..7a51c7bd5b0
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocList.h
@@ -0,0 +1,23 @@
+//===--- lib/CodeGen/DebugLocList.h - DWARF debug_loc list ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_ASMPRINTER_DEBUGLOCLIST_H__
+#define CODEGEN_ASMPRINTER_DEBUGLOCLIST_H__
+
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/ADT/SmallVector.h"
+#include "DebugLocEntry.h"
+
+namespace llvm {
+struct DebugLocList {
+  MCSymbol *Label;
+  SmallVector<DebugLocEntry, 4> List;
+};
+}
+#endif
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 7770cee1b38..1b99ba61d3d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1271,7 +1271,11 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
     // Handle multiple DBG_VALUE instructions describing one variable.
     RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
 
-    SmallVector<DebugLocEntry, 4> DebugLoc;
+    DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
+    DebugLocList &LocList = DotDebugLocEntries.back();
+    LocList.Label =
+        Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
+    SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
     for (SmallVectorImpl<const MachineInstr *>::const_iterator
              HI = History.begin(),
              HE = History.end();
@@ -1313,7 +1317,6 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
       if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
         DebugLoc.push_back(std::move(Loc));
     }
-    DotDebugLocEntries.push_back(std::move(DebugLoc));
   }
 
   // Collect info for variables that were optimized out.
@@ -2406,10 +2409,9 @@ void DwarfDebug::emitDebugLoc() {
       useSplitDwarf() ? Asm->getObjFileLowering().getDwarfLocDWOSection()
                       : Asm->getObjFileLowering().getDwarfLocSection());
   unsigned char Size = Asm->getDataLayout().getPointerSize();
-  unsigned index = 0;
   for (const auto &DebugLoc : DotDebugLocEntries) {
-    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
-    for (const auto &Entry : DebugLoc) {
+    Asm->OutStreamer.EmitLabel(DebugLoc.Label);
+    for (const auto &Entry : DebugLoc.List) {
       // Set up the range. This range is relative to the entry point of the
       // compile unit. This is a hard coded 0 for low_pc when we're emitting
       // ranges, or the DW_AT_low_pc on the compile unit otherwise.
@@ -2440,7 +2442,6 @@ void DwarfDebug::emitDebugLoc() {
       Asm->OutStreamer.EmitIntValue(0, Size);
       Asm->OutStreamer.EmitIntValue(0, Size);
     }
-    ++index;
   }
 }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index fcac25d5207..424595070d8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -17,6 +17,7 @@
 #include "AsmPrinterHandler.h"
 #include "DIE.h"
 #include "DebugLocEntry.h"
+#include "DebugLocList.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -288,8 +289,9 @@ class DwarfDebug : public AsmPrinterHandler {
   // Collection of abstract variables.
   DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
 
-  // Collection of DebugLocEntry.
-  SmallVector<SmallVector<DebugLocEntry, 4>, 4> DotDebugLocEntries;
+  // Collection of DebugLocEntry. Stored in a linked list so that DIELocLists
+  // can refer to them in spite of insertions into this list.
+  SmallVector<DebugLocList, 4> DotDebugLocEntries;
 
   // Collection of subprogram DIEs that are marked (at the end of the module)
   // as DW_AT_inline.
@@ -686,7 +688,7 @@ public:
   const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
 
   /// Returns the entries for the .debug_loc section.
-  const SmallVectorImpl<SmallVector<DebugLocEntry, 4>> &
+  const SmallVectorImpl<DebugLocList> &
   getDebugLocEntries() const {
     return DotDebugLocEntries;
   }