commit 64e0c56717628333554be781d70d5fe45d5b9b0b
author Victor Leschuk <vleschuk@accesssoftek.com> Wed Aug 01 05:48:06 2018 +0000
committer Victor Leschuk <vleschuk@accesssoftek.com> Wed Aug 01 05:48:06 2018 +0000
tree d78c97652ac8f1ab049ea84160ca7fa763a219a1
parent 63ebd3bd24d414737e5404923dcd1b8dbdb8ee46

[DWARF] Basic support for producing DWARFv5 .debug_addr section

This revision implements support for generating DWARFv5 .debug_addr section.
The implementation is pretty straight-forward: we just check the dwarf version
and emit section header if needed.

Reviewers: aprantl, dblaikie, probinson

Reviewed by: dblaikie

Differential Revision: https://reviews.llvm.org/D50005

llvm-svn: 338487

llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp

diff --git a/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
index 4a22652..c8305ad 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
@@ -24,8 +24,26 @@
   return IterBool.first->second.Number;
 }
 
+
+void AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
+  static const uint8_t AddrSize = Asm.getDataLayout().getPointerSize();
+  Asm.OutStreamer->SwitchSection(Section);
+
+  uint64_t Length = sizeof(uint16_t) // version
+                  + sizeof(uint8_t)  // address_size
+                  + sizeof(uint8_t)  // segment_selector_size
+                  + AddrSize * Pool.size(); // entries
+  Asm.emitInt32(Length); // TODO: Support DWARF64 format.
+  Asm.emitInt16(Asm.getDwarfVersion());
+  Asm.emitInt8(AddrSize);
+  Asm.emitInt8(0); // TODO: Support non-zero segment_selector_size.
+}
+
 // Emit addresses into the section given.
 void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
+  if (Asm.getDwarfVersion() >= 5)
+    emitHeader(Asm, AddrSection);
+
   if (Pool.empty())
     return;
 

llvm/lib/CodeGen/AsmPrinter/AddressPool.h

diff --git a/llvm/lib/CodeGen/AsmPrinter/AddressPool.h b/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
index 5350006..d5008fa 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
+++ b/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
@@ -50,6 +50,9 @@
   bool hasBeenUsed() const { return HasBeenUsed; }
 
   void resetUsedFlag() { HasBeenUsed = false; }
+
+private:
+  void emitHeader(AsmPrinter &Asm, MCSection *Section);
 };
 
 } // end namespace llvm

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index e5a457e..0af408ae 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -886,8 +886,7 @@
     emitDebugInfoDWO();
     emitDebugAbbrevDWO();
     emitDebugLineDWO();
-    // Emit DWO addresses.
-    AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
+    emitDebugAddr();
   }
 
   // Emit info into the dwarf accelerator table sections.
@@ -2297,6 +2296,12 @@
                          OffSec, /* UseRelativeOffsets = */ false);
 }
 
+// Emit DWO addresses.
+void DwarfDebug::emitDebugAddr() {
+  assert(useSplitDwarf() && "No split dwarf?");
+  AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
+}
+
 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
   if (!useSplitDwarf())
     return nullptr;

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 0c7be5d..abf2e43 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -447,6 +447,9 @@
   /// Emit the debug str dwo section.
   void emitDebugStrDWO();
 
+  /// Emit DWO addresses.
+  void emitDebugAddr();
+
   /// Flags to let the linker know we have emitted new style pubnames. Only
   /// emit it here if we don't have a skeleton CU for split dwarf.
   void addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const;