From cb833076aca55d545cf2b6b3c28b07423bc48085 Mon Sep 17 00:00:00 2001
From: Simon Atanasyan <simon@atanasyan.com>
Date: Wed, 16 Aug 2017 19:01:22 +0000
Subject: [PATCH] [mips] Handle R_MIPS_TLS_DTPREL32/64 relocations in the
 RelocVisitor

Debug information for TLS variables on MIPS might have R_MIPS_TLS_DTPREL32
or R_MIPS_TLS_DTPREL64 relocations. This patch adds a support for such
relocations in the `RelocVisitor`.

llvm-svn: 311031
---
 llvm/include/llvm/Object/RelocVisitor.h   |  5 +++++
 llvm/test/DebugInfo/Mips/dwarfdump-tls.ll | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 llvm/test/DebugInfo/Mips/dwarfdump-tls.ll

diff --git a/llvm/include/llvm/Object/RelocVisitor.h b/llvm/include/llvm/Object/RelocVisitor.h
index c358d3996435..35bfc2452364 100644
--- a/llvm/include/llvm/Object/RelocVisitor.h
+++ b/llvm/include/llvm/Object/RelocVisitor.h
@@ -169,6 +169,8 @@ private:
       return (Value + getELFAddend(R)) & 0xFFFFFFFF;
     case ELF::R_MIPS_64:
       return Value + getELFAddend(R);
+    case ELF::R_MIPS_TLS_DTPREL64:
+      return Value + getELFAddend(R) - 0x8000;
     }
     HasError = true;
     return 0;
@@ -260,8 +262,11 @@ private:
   }
 
   uint64_t visitMips32(uint32_t Rel, RelocationRef R, uint64_t Value) {
+    // FIXME: Take in account implicit addends to get correct results.
     if (Rel == ELF::R_MIPS_32)
       return Value & 0xFFFFFFFF;
+    if (Rel == ELF::R_MIPS_TLS_DTPREL32)
+      return Value & 0xFFFFFFFF;
     HasError = true;
     return 0;
   }
diff --git a/llvm/test/DebugInfo/Mips/dwarfdump-tls.ll b/llvm/test/DebugInfo/Mips/dwarfdump-tls.ll
new file mode 100644
index 000000000000..54bb7b765f41
--- /dev/null
+++ b/llvm/test/DebugInfo/Mips/dwarfdump-tls.ll
@@ -0,0 +1,21 @@
+; RUN: llc -O0 -march=mips -mcpu=mips32r2 -filetype=obj -o=%t-32.o < %s
+; RUN: llvm-dwarfdump %t-32.o 2>&1 | FileCheck %s
+; RUN: llc -O0 -march=mips64 -mcpu=mips64r2 -filetype=obj -o=%t-64.o < %s
+; RUN: llvm-dwarfdump %t-64.o 2>&1 | FileCheck %s
+
+@x = thread_local global i32 5, align 4, !dbg !0
+
+; CHECK-NOT: error: failed to compute relocation: R_MIPS_TLS_DTPREL
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8}
+
+!0 = !DIGlobalVariableExpression(var: !1)
+!1 = distinct !DIGlobalVariable(name: "x", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 4.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
+!3 = !DIFile(filename: "tls.c", directory: "/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}