From 1deaa9b8bdb6c6169ad3fea95e0f2c6c8e99dd01 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Tue, 7 Jun 2022 17:48:09 -0700
Subject: [PATCH] [JITLink][ELF][AArch64] Implement R_AARCH64_ABS64 relocation
 type.

Implement R_AARCH64_ABS64 relocation entry. This relocation type is generated
when creating a static function pointer to symbol.

Reviewed By: lhames, sgraenitz

Differential Revision: https://reviews.llvm.org/D126658
---
 .../ExecutionEngine/JITLink/ELF_aarch64.cpp   |  9 +++++++++
 .../JITLink/AArch64/ELF_aarch64_relocations.s | 19 ++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/ExecutionEngine/JITLink/ELF_aarch64.cpp b/llvm/lib/ExecutionEngine/JITLink/ELF_aarch64.cpp
index 5a24a69f9fd0..8ce1f67d63cf 100644
--- a/llvm/lib/ExecutionEngine/JITLink/ELF_aarch64.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/ELF_aarch64.cpp
@@ -54,6 +54,7 @@ private:
     ELFLdSt32Abs12,
     ELFLdSt64Abs12,
     ELFLdSt128Abs12,
+    ELFAbs64,
   };
 
   static Expected<ELFAArch64RelocationKind>
@@ -76,6 +77,8 @@ private:
       return ELFLdSt64Abs12;
     case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
       return ELFLdSt128Abs12;
+    case ELF::R_AARCH64_ABS64:
+      return ELFAbs64;
     }
 
     return make_error<JITLinkError>("Unsupported aarch64 relocation:" +
@@ -199,6 +202,10 @@ private:
       Kind = aarch64::PageOffset12;
       break;
     }
+    case ELFAbs64: {
+      Kind = aarch64::Pointer64;
+      break;
+    }
     };
 
     Edge GE(Kind, Offset, *GraphSymbol, Addend);
@@ -231,6 +238,8 @@ private:
       return "ELFLdSt64Abs12";
     case ELFLdSt128Abs12:
       return "ELFLdSt128Abs12";
+    case ELFAbs64:
+      return "ELFAbs64";
     default:
       return getGenericEdgeKindName(static_cast<Edge::Kind>(R));
     }
diff --git a/llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s b/llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s
index 1a670c2648a8..7a433e1715ba 100644
--- a/llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s
+++ b/llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s
@@ -1,5 +1,6 @@
 # RUN: rm -rf %t && mkdir -p %t
-# RUN: llvm-mc -triple=aarch64-unknown-linux-gnu -relax-relocations=false -position-independent -filetype=obj -o %t/elf_reloc.o %s
+# RUN: llvm-mc -triple=aarch64-unknown-linux-gnu -relax-relocations=false \
+# RUN:   -position-independent -filetype=obj -o %t/elf_reloc.o %s
 # RUN: llvm-jitlink -noexec -check %s %t/elf_reloc.o
 
         .text
@@ -113,6 +114,15 @@ test_str_64bit:
         str	x0, [x1, :lo12:named_data]
         .size test_str_64bit, .-test_str_64bit
 
+# Check R_AARCH64_ABS64 relocation of a function pointer to local symbol
+#
+# jitlink-check: *{8}local_func_addr_quad = named_func
+        .globl  local_func_addr_quad
+        .p2align  3
+local_func_addr_quad:
+        .xword	named_func
+        .size	local_func_addr_quad, 8
+
         .globl  named_data
         .p2align  4
         .type   named_data,@object
@@ -120,3 +130,10 @@ named_data:
         .quad   0x2222222222222222
         .quad   0x3333333333333333
         .size   named_data, .-named_data
+
+        .globl  named_func
+        .p2align  2
+        .type	named_func,@function
+named_func:
+        ret
+        .size   named_func, .-named_func