Completely rewrite ELFObjectWriter::RecordRelocation.

I started trying to fix a small issue, but this code has seen a small fix too
many.

The old code was fairly convoluted. Some of the issues it had:

* It failed to check if a symbol difference was in the some section when
  converting a relocation to pcrel.
* It failed to check if the relocation was already pcrel.
* The pcrel value computation was wrong in some cases (relocation-pc.s)
* It was missing quiet a few cases where it should not convert symbol
  relocations to section relocations, leaving the backends to patch it up.
* It would not propagate the fact that it had changed a relocation to pcrel,
  requiring a quiet nasty work around in ARM.
* It was missing comments.

llvm-svn: 205076

2 files changed, 3 insertions, 20 deletions

diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
index 047a9764380..6e7268de55c 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
@@ -48,7 +48,7 @@ public:
   }
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
   void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
-                  uint64_t Value) const override;
+                  uint64_t Value, bool IsPCRel) const override;
   bool mayNeedRelaxation(const MCInst &Inst) const override {
     return false;
   }
@@ -85,7 +85,8 @@ SystemZMCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 }
 
 void SystemZMCAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
-                                     unsigned DataSize, uint64_t Value) const {
+                                     unsigned DataSize, uint64_t Value,
+                                     bool IsPCRel) const {
   MCFixupKind Kind = Fixup.getKind();
   unsigned Offset = Fixup.getOffset();
   unsigned Size = (getFixupKindInfo(Kind).TargetSize + 7) / 8;
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
index 76e1d24a937..54c6987ca2f 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
@@ -26,9 +26,6 @@ protected:
   // Override MCELFObjectTargetWriter.
   unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
                         bool IsPCRel) const override;
-  const MCSymbol *ExplicitRelSym(const MCAssembler &Asm, const MCValue &Target,
-                                 const MCFragment &F, const MCFixup &Fixup,
-                                 bool IsPCRel) const override;
 };
 } // end anonymous namespace
 
@@ -111,21 +108,6 @@ unsigned SystemZObjectWriter::GetRelocType(const MCValue &Target,
   }
 }
 
-const MCSymbol *SystemZObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
-                                                    const MCValue &Target,
-                                                    const MCFragment &F,
-                                                    const MCFixup &Fixup,
-                                                    bool IsPCRel) const {
-  // The addend in a PC-relative R_390_* relocation is always applied to
-  // the PC-relative part of the address.  If some kind of indirection
-  // is applied to the symbol first, we can't use an addend there too.
-  if (!Target.isAbsolute() &&
-      Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None &&
-      IsPCRel)
-    return &Target.getSymA()->getSymbol().AliasedSymbol();
-  return NULL;
-}
-
 MCObjectWriter *llvm::createSystemZObjectWriter(raw_ostream &OS,
                                                 uint8_t OSABI) {
   MCELFObjectTargetWriter *MOTW = new SystemZObjectWriter(OSABI);