Initial support for the local dynamic model ARM TLS relocations:

- R_ARM_TLS_LDM32
- R_ARM_TLS_LDO32

The local dynamic implementation and tests follows the same model as 
the other ARM TLS models. The R_ARM_TLS_LDO32 is implemented as R_ABS 
expr type as the getVA() for a TLS symbol will return the offset from the 
start of the TLS block.

Differential Revision https://reviews.llvm.org/D22563
 

llvm-svn: 276123
diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index 88628f6..8c5959c 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -178,6 +178,7 @@
   RelExpr getRelExpr(uint32_t Type, const SymbolBody &S) const override;
   uint32_t getDynRel(uint32_t Type) const override;
   uint64_t getImplicitAddend(const uint8_t *Buf, uint32_t Type) const override;
+  bool isTlsLocalDynamicRel(uint32_t Type) const override;
   bool isTlsGlobalDynamicRel(uint32_t Type) const override;
   bool isTlsInitialExecRel(uint32_t Type) const override;
   void writeGotPlt(uint8_t *Buf, const SymbolBody &S) const override;
@@ -1523,6 +1524,8 @@
     return R_GOT_PC;
   case R_ARM_TLS_GD32:
     return R_TLSGD_PC;
+  case R_ARM_TLS_LDM32:
+    return R_TLSLD_PC;
   case R_ARM_BASE_PREL:
     // B(S) + A - P
     // FIXME: currently B(S) assumed to be .got, this may not hold for all
@@ -1624,6 +1627,8 @@
   case R_ARM_REL32:
   case R_ARM_TLS_GD32:
   case R_ARM_TLS_IE32:
+  case R_ARM_TLS_LDM32:
+  case R_ARM_TLS_LDO32:
   case R_ARM_TLS_LE32:
     write32le(Loc, Val);
     break;
@@ -1749,6 +1754,8 @@
   case R_ARM_GOT_PREL:
   case R_ARM_REL32:
   case R_ARM_TLS_GD32:
+  case R_ARM_TLS_LDM32:
+  case R_ARM_TLS_LDO32:
   case R_ARM_TLS_IE32:
   case R_ARM_TLS_LE32:
     return SignExtend64<32>(read32le(Buf));
@@ -1808,6 +1815,10 @@
   }
 }
 
+bool ARMTargetInfo::isTlsLocalDynamicRel(uint32_t Type) const {
+  return Type == R_ARM_TLS_LDO32 || Type == R_ARM_TLS_LDM32;
+}
+
 bool ARMTargetInfo::isTlsGlobalDynamicRel(uint32_t Type) const {
   return Type == R_ARM_TLS_GD32;
 }