From b12b974df1ef038d16e5ed5a28679b30c219ad9c Mon Sep 17 00:00:00 2001
From: Dylan McKay <me@dylanmckay.io>
Date: Mon, 21 Jan 2019 04:27:08 +0000
Subject: [PATCH] [AVR] Enable emission of debug information

Prior to this, the code was missing AVR-specific relocation logic in
RelocVisitor.h.

This patch teaches RelocVisitor about R_AVR_16 and R_AVR_32.

Debug information is emitted in the final object file, and understood by
'avr-readelf --debug-dump' from AVR-GCC.

llvm-dwarfdump is yet to understand how to dump AVR DWARF symbols.

llvm-svn: 351720
---
 include/llvm/Object/RelocVisitor.h           | 12 ++++++++++++
 lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp |  1 +
 2 files changed, 13 insertions(+)

diff --git a/include/llvm/Object/RelocVisitor.h b/include/llvm/Object/RelocVisitor.h
index a1696c54daa..1d3d79a2a1a 100644
--- a/include/llvm/Object/RelocVisitor.h
+++ b/include/llvm/Object/RelocVisitor.h
@@ -100,6 +100,8 @@ private:
     case Triple::arm:
     case Triple::armeb:
       return visitARM(Rel, R, Value);
+    case Triple::avr:
+      return visitAVR(Rel, R, Value);
     case Triple::lanai:
       return visitLanai(Rel, R, Value);
     case Triple::mipsel:
@@ -258,6 +260,16 @@ private:
     return 0;
   }
 
+  uint64_t visitAVR(uint32_t Rel, RelocationRef R, uint64_t Value) {
+    if (Rel == ELF::R_AVR_16) {
+      return (Value + getELFAddend(R)) & 0xFFFF;
+    } else if (Rel == ELF::R_AVR_32) {
+      return (Value + getELFAddend(R)) & 0xFFFFFFFF;
+    }
+    HasError = true;
+    return 0;
+  }
+
   uint64_t visitLanai(uint32_t Rel, RelocationRef R, uint64_t Value) {
     if (Rel == ELF::R_LANAI_32)
       return (Value + getELFAddend(R)) & 0xFFFFFFFF;
diff --git a/lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp b/lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp
index 2830f94a5e4..99b2172c562 100644
--- a/lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp
+++ b/lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp
@@ -23,6 +23,7 @@ AVRMCAsmInfo::AVRMCAsmInfo(const Triple &TT) {
   PrivateGlobalPrefix = ".L";
   UsesELFSectionDirectiveForBSS = true;
   UseIntegratedAssembler = true;
+  SupportsDebugInformation = true;
 }
 
 } // end of namespace llvm