1 files changed, 77 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
new file mode 100644
index 000000000000..f11c7de5ed8a
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
@@ -0,0 +1,77 @@
+//===- llvm/CodeGen/AddressPool.cpp - Dwarf Debug Framework ---------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "AddressPool.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include <utility>
+
+using namespace llvm;
+
+unsigned AddressPool::getIndex(const MCSymbol *Sym, bool TLS) {
+  HasBeenUsed = true;
+  auto IterBool =
+      Pool.insert(std::make_pair(Sym, AddressPoolEntry(Pool.size(), TLS)));
+  return IterBool.first->second.Number;
+}
+
+MCSymbol *AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
+  static const uint8_t AddrSize = Asm.getDataLayout().getPointerSize();
+  StringRef Prefix = "debug_addr_";
+  MCSymbol *BeginLabel = Asm.createTempSymbol(Prefix + "start");
+  MCSymbol *EndLabel = Asm.createTempSymbol(Prefix + "end");
+
+  Asm.OutStreamer->AddComment("Length of contribution");
+  Asm.EmitLabelDifference(EndLabel, BeginLabel,
+                          4); // TODO: Support DWARF64 format.
+  Asm.OutStreamer->EmitLabel(BeginLabel);
+  Asm.OutStreamer->AddComment("DWARF version number");
+  Asm.emitInt16(Asm.getDwarfVersion());
+  Asm.OutStreamer->AddComment("Address size");
+  Asm.emitInt8(AddrSize);
+  Asm.OutStreamer->AddComment("Segment selector size");
+  Asm.emitInt8(0); // TODO: Support non-zero segment_selector_size.
+
+  return EndLabel;
+}
+
+// Emit addresses into the section given.
+void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
+  if (isEmpty())
+    return;
+
+  // Start the dwarf addr section.
+  Asm.OutStreamer->SwitchSection(AddrSection);
+
+  MCSymbol *EndLabel = nullptr;
+
+  if (Asm.getDwarfVersion() >= 5)
+    EndLabel = emitHeader(Asm, AddrSection);
+
+  // Define the symbol that marks the start of the contribution.
+  // It is referenced via DW_AT_addr_base.
+  Asm.OutStreamer->EmitLabel(AddressTableBaseSym);
+
+  // Order the address pool entries by ID
+  SmallVector<const MCExpr *, 64> Entries(Pool.size());
+
+  for (const auto &I : Pool)
+    Entries[I.second.Number] =
+        I.second.TLS
+            ? Asm.getObjFileLowering().getDebugThreadLocalSymbol(I.first)
+            : MCSymbolRefExpr::create(I.first, Asm.OutContext);
+
+  for (const MCExpr *Entry : Entries)
+    Asm.OutStreamer->EmitValue(Entry, Asm.getDataLayout().getPointerSize());
+
+  if (EndLabel)
+    Asm.OutStreamer->EmitLabel(EndLabel);
+}