From b92b10f3ec4897c07655aab0999817ba503ebf71 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Tue, 3 Apr 2018 23:19:20 +0000
Subject: [PATCH] [RuntimeDyld][AArch64] Add some error pluming / generation to
 catch unhandled relocation types on AArch64.

llvm-svn: 329133
---
 .../Targets/RuntimeDyldMachOAArch64.h         | 36 ++++++++++++++++---
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
index 31cedffa15b3..6cee7278524c 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOAArch64.h
@@ -13,6 +13,8 @@
 #include "../RuntimeDyldMachO.h"
 #include "llvm/Support/Endian.h"
 
+#include <sstream>
+
 #define DEBUG_TYPE "dyld"
 
 namespace llvm {
@@ -32,7 +34,7 @@ public:
   unsigned getStubAlignment() override { return 8; }
 
   /// Extract the addend encoded in the instruction / memory location.
-  int64_t decodeAddend(const RelocationEntry &RE) const {
+  Expected<int64_t> decodeAddend(const RelocationEntry &RE) const {
     const SectionEntry &Section = Sections[RE.SectionID];
     uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);
     unsigned NumBytes = 1 << RE.Size;
@@ -40,9 +42,15 @@ public:
     // Verify that the relocation has the correct size and alignment.
     switch (RE.RelType) {
     default:
-      llvm_unreachable("Unsupported relocation type!");
+      return make_error<StringError>((std::ostringstream()
+                                       << "Unsupported relocation type: "
+                                       << getRelocName(RE.RelType)).str(),
+                                     inconvertibleErrorCode());
     case MachO::ARM64_RELOC_UNSIGNED:
-      assert((NumBytes == 4 || NumBytes == 8) && "Invalid relocation size.");
+      if (NumBytes != 4 && NumBytes != 8)
+        return make_error<StringError>("Invalid relocation size for "
+                                       "ARM64_RELOC_UNSIGNED",
+                                       inconvertibleErrorCode());
       break;
     case MachO::ARM64_RELOC_BRANCH26:
     case MachO::ARM64_RELOC_PAGE21:
@@ -282,7 +290,10 @@ public:
       return processSubtractRelocation(SectionID, RelI, Obj, ObjSectionToID);
 
     RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
-    RE.Addend = decodeAddend(RE);
+    if (auto Addend = decodeAddend(RE))
+      RE.Addend = *Addend;
+    else
+      return Addend.takeError();
 
     assert((ExplicitAddend == 0 || RE.Addend == 0) && "Relocation has "\
       "ARM64_RELOC_ADDEND and embedded addend in the instruction.");
@@ -463,6 +474,23 @@ private:
     return ++RelI;
   }
 
+  static const char *getRelocName(uint32_t RelocType) {
+    switch (RelocType) {
+      case MachO::ARM64_RELOC_UNSIGNED: return "ARM64_RELOC_UNSIGNED";
+      case MachO::ARM64_RELOC_SUBTRACTOR: return "ARM64_RELOC_SUBTRACTOR";
+      case MachO::ARM64_RELOC_BRANCH26: return "ARM64_RELOC_BRANCH26";
+      case MachO::ARM64_RELOC_PAGE21: return "ARM64_RELOC_PAGE21";
+      case MachO::ARM64_RELOC_PAGEOFF12: return "ARM64_RELOC_PAGEOFF12";
+      case MachO::ARM64_RELOC_GOT_LOAD_PAGE21: return "ARM64_RELOC_GOT_LOAD_PAGE21";
+      case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: return "ARM64_RELOC_GOT_LOAD_PAGEOFF12";
+      case MachO::ARM64_RELOC_POINTER_TO_GOT: return "ARM64_RELOC_POINTER_TO_GOT";
+      case MachO::ARM64_RELOC_TLVP_LOAD_PAGE21: return "ARM64_RELOC_TLVP_LOAD_PAGE21";
+      case MachO::ARM64_RELOC_TLVP_LOAD_PAGEOFF12: return "ARM64_RELOC_TLVP_LOAD_PAGEOFF12";
+      case MachO::ARM64_RELOC_ADDEND: return "ARM64_RELOC_ADDEND";
+    }
+    return "Unrecognized arm64 addend";
+  }
+
 };
 }