[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231475 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/TargetLoweringObjectFileImpl.h

@@ -88,6 +88,7 @@ public:
 class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile {
 public:
   virtual ~TargetLoweringObjectFileMachO() {}
+  TargetLoweringObjectFileMachO();
 
   /// Extract the dependent library name from a linker option string. Returns
   /// StringRef() if the option does not specify a library.
@@ -122,6 +123,12 @@ public:
   MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV, Mangler &Mang,
                                     const TargetMachine &TM,
                                     MachineModuleInfo *MMI) const override;
+
+  /// Get MachO PC relative GOT entry relocation
+  const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
+                                          const MCValue &MV, int64_t Offset,
+                                          MachineModuleInfo *MMI,
+                                          MCStreamer &Streamer) const override;
 };
 
 

include/llvm/Target/TargetLoweringObjectFile.h

@@ -29,19 +29,20 @@ namespace llvm {
   class MCSymbol;
   class MCSymbolRefExpr;
   class MCStreamer;
+  class MCValue;
   class ConstantExpr;
   class GlobalValue;
   class TargetMachine;
 
 class TargetLoweringObjectFile : public MCObjectFileInfo {
   MCContext *Ctx;
-  const DataLayout *DL;
 
   TargetLoweringObjectFile(
     const TargetLoweringObjectFile&) = delete;
   void operator=(const TargetLoweringObjectFile&) = delete;
 
 protected:
+  const DataLayout *DL;
   bool SupportIndirectSymViaGOTPCRel;
   bool SupportGOTPCRelWithOffset;
 
@@ -178,7 +179,9 @@ public:
 
   /// \brief Get the target specific PC relative GOT entry relocation
   virtual const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
+                                                  const MCValue &MV,
                                                   int64_t Offset,
+                                                  MachineModuleInfo *MMI,
                                                   MCStreamer &Streamer) const {
     return nullptr;
   }