[AsmPrinter][TLOF] 32-bit MachO support for replacing GOT equivalents

Add MachO 32-bit (i.e. arm and x86) support for replacing global GOT equivalent
symbol accesses. Unlike 64-bit targets, there's no GOTPCREL relocation, and
access through a non_lazy_symbol_pointers section is used instead.

-- before

    _extgotequiv:
       .long _extfoo

    _delta:
       .long _extgotequiv-_delta

-- after

    _delta:
       .long L_extfoo$non_lazy_ptr-_delta

       .section __IMPORT,__pointers,non_lazy_symbol_pointers
    L_extfoo$non_lazy_ptr:
       .indirect_symbol _extfoo
       .long 0

llvm-svn: 231475

4 files changed, 18 insertions, 17 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
index 3c0a3428ff3..8ff58e9864d 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
@@ -13,6 +13,7 @@
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCValue.h"
 #include "llvm/Support/Dwarf.h"
 using namespace llvm;
 using namespace dwarf;
@@ -25,7 +26,6 @@ void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
 
 AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
   : TargetLoweringObjectFileMachO() {
-  SupportIndirectSymViaGOTPCRel = true;
   SupportGOTPCRelWithOffset = false;
 }
 
@@ -58,7 +58,10 @@ MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
 }
 
 const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
-    const MCSymbol *Sym, int64_t Offset, MCStreamer &Streamer) const {
+    const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
+    MachineModuleInfo *MMI, MCStreamer &Streamer) const {
+  assert((Offset+MV.getConstant() == 0) &&
+         "Arch64 does not support GOT PC rel with extra offset");
   // On ARM64 Darwin, we can reference symbols with foo@GOT-., which
   // is an indirect pc-relative reference.
   const MCExpr *Res =
diff --git a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
index 067fda5952b..d41f445292c 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
@@ -36,9 +36,10 @@ public:
                                     const TargetMachine &TM,
                                     MachineModuleInfo *MMI) const override;
 
-  const MCExpr *
-    getIndirectSymViaGOTPCRel(const MCSymbol *Sym, int64_t Offset,
-                              MCStreamer &Streamer) const override;
+  const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
+                                          const MCValue &MV, int64_t Offset,
+                                          MachineModuleInfo *MMI,
+                                          MCStreamer &Streamer) const override;
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/Target/X86/X86TargetObjectFile.cpp b/llvm/lib/Target/X86/X86TargetObjectFile.cpp
index 15a5fddd862..c86a3ee0f49 100644
--- a/llvm/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/llvm/lib/Target/X86/X86TargetObjectFile.cpp
@@ -15,17 +15,13 @@
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCValue.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Target/TargetLowering.h"
 
 using namespace llvm;
 using namespace dwarf;
 
-X86_64MachoTargetObjectFile::X86_64MachoTargetObjectFile()
-  : TargetLoweringObjectFileMachO() {
-  SupportIndirectSymViaGOTPCRel = true;
-}
-
 const MCExpr *X86_64MachoTargetObjectFile::getTTypeGlobalReference(
     const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
     const TargetMachine &TM, MachineModuleInfo *MMI,
@@ -52,13 +48,15 @@ MCSymbol *X86_64MachoTargetObjectFile::getCFIPersonalitySymbol(
 }
 
 const MCExpr *X86_64MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
-    const MCSymbol *Sym, int64_t Offset, MCStreamer &Streamer) const {
+    const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
+    MachineModuleInfo *MMI, MCStreamer &Streamer) const {
   // On Darwin/X86-64, we need to use foo@GOTPCREL+4 to access the got entry
   // from a data section. In case there's an additional offset, then use
   // foo@GOTPCREL+4+<offset>.
+  unsigned FinalOff = Offset+MV.getConstant()+4;
   const MCExpr *Res =
     MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOTPCREL, getContext());
-  const MCExpr *Off = MCConstantExpr::Create(Offset+4, getContext());
+  const MCExpr *Off = MCConstantExpr::Create(FinalOff, getContext());
   return MCBinaryExpr::CreateAdd(Res, Off, getContext());
 }
 
diff --git a/llvm/lib/Target/X86/X86TargetObjectFile.h b/llvm/lib/Target/X86/X86TargetObjectFile.h
index 3c7caabdfdc..252b2774254 100644
--- a/llvm/lib/Target/X86/X86TargetObjectFile.h
+++ b/llvm/lib/Target/X86/X86TargetObjectFile.h
@@ -19,8 +19,6 @@ namespace llvm {
   /// x86-64.
   class X86_64MachoTargetObjectFile : public TargetLoweringObjectFileMachO {
   public:
-    X86_64MachoTargetObjectFile();
-
     const MCExpr *
     getTTypeGlobalReference(const GlobalValue *GV, unsigned Encoding,
                             Mangler &Mang, const TargetMachine &TM,
@@ -33,9 +31,10 @@ namespace llvm {
                                       const TargetMachine &TM,
                                       MachineModuleInfo *MMI) const override;
 
-    const MCExpr *
-      getIndirectSymViaGOTPCRel(const MCSymbol *Sym, int64_t Offset,
-                                MCStreamer &Streamer) const override;
+    const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
+                                            const MCValue &MV, int64_t Offset,
+                                            MachineModuleInfo *MMI,
+                                            MCStreamer &Streamer) const override;
   };
 
   /// \brief This implemenatation is used for X86 ELF targets that don't