From 90908cb34d73460d3aa83e2194a58d82c6d1f199 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date: Fri, 24 Jul 2015 03:17:08 +0000
Subject: [PATCH] [bpf] initial support for debug_info

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243087 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp | 25 ++++++++++++-------
 .../BPF/MCTargetDesc/BPFELFObjectWriter.cpp   |  4 +++
 lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h    |  2 ++
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp b/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
index 36f99262ed7..8c358cab62e 100644
--- a/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
+++ b/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
@@ -68,16 +68,23 @@ void BPFAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
 
   if (Fixup.getKind() == FK_SecRel_4 || Fixup.getKind() == FK_SecRel_8) {
     assert(Value == 0);
-    return;
-  }
-  assert(Fixup.getKind() == FK_PCRel_2);
-  Value = (uint16_t)((Value - 8) / 8);
-  if (IsLittleEndian) {
-    Data[Fixup.getOffset() + 2] = Value & 0xFF;
-    Data[Fixup.getOffset() + 3] = Value >> 8;
+  } else if (Fixup.getKind() == FK_Data_4 || Fixup.getKind() == FK_Data_8) {
+    unsigned Size = Fixup.getKind() == FK_Data_4 ? 4 : 8;
+
+    for (unsigned i = 0; i != Size; ++i) {
+      unsigned Idx = IsLittleEndian ? i : Size - i;
+      Data[Fixup.getOffset() + Idx] = uint8_t(Value >> (i * 8));
+    }
   } else {
-    Data[Fixup.getOffset() + 2] = Value >> 8;
-    Data[Fixup.getOffset() + 3] = Value & 0xFF;
+    assert(Fixup.getKind() == FK_PCRel_2);
+    Value = (uint16_t)((Value - 8) / 8);
+    if (IsLittleEndian) {
+      Data[Fixup.getOffset() + 2] = Value & 0xFF;
+      Data[Fixup.getOffset() + 3] = Value >> 8;
+    } else {
+      Data[Fixup.getOffset() + 2] = Value >> 8;
+      Data[Fixup.getOffset() + 3] = Value & 0xFF;
+    }
   }
 }
 
diff --git a/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp b/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
index 05ba6183e32..87cdd5eb9da 100644
--- a/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
+++ b/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
@@ -44,6 +44,10 @@ unsigned BPFELFObjectWriter::GetRelocType(const MCValue &Target,
     return ELF::R_X86_64_64;
   case FK_SecRel_4:
     return ELF::R_X86_64_PC32;
+  case FK_Data_8:
+    return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
+  case FK_Data_4:
+    return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
   }
 }
 
diff --git a/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h b/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
index d63bbf49294..1f440fe8787 100644
--- a/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
+++ b/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
@@ -34,6 +34,8 @@ public:
     UsesELFSectionDirectiveForBSS = true;
     HasSingleParameterDotFile = false;
     HasDotTypeDotSizeDirective = false;
+
+    SupportsDebugInformation = true;
   }
 };
 }
-- 
2.34.1