[ELF] - Eliminate Target::isPicRel method.

As was mentioned in comments for D45158,
isPicRel's name does not make much sense,
because what this method does is checks if
we need to create the dynamic relocation or not.

Instead of renaming it to something different,
we can 'isPicRel' completely.

We can reuse the getDynRel method.
They are logically very close, getDynRel can just return
R_*_NONE in case no dynamic relocation should be produced
and that would simplify things and avoid functionality
correlation/duplication with 'isPicRel'.

The patch does this change.

Differential revision: https://reviews.llvm.org/D45248

llvm-svn: 329275

lld/ELF/Arch/AArch64.cpp

@@ -34,7 +34,7 @@ public:
   AArch64();
   RelExpr getRelExpr(RelType Type, const Symbol &S,
                      const uint8_t *Loc) const override;
-  bool isPicRel(RelType Type) const override;
+  RelType getDynRel(RelType Type) const override;
   void writeGotPlt(uint8_t *Buf, const Symbol &S) const override;
   void writePltHeader(uint8_t *Buf) const override;
   void writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr, uint64_t PltEntryAddr,
@@ -144,8 +144,10 @@ bool AArch64::usesOnlyLowPageBits(RelType Type) const {
   }
 }
 
-bool AArch64::isPicRel(RelType Type) const {
-  return Type == R_AARCH64_ABS32 || Type == R_AARCH64_ABS64;
+RelType AArch64::getDynRel(RelType Type) const {
+  if (Type == R_AARCH64_ABS32 || Type == R_AARCH64_ABS64)
+    return Type;
+  return R_AARCH64_NONE;
 }
 
 void AArch64::writeGotPlt(uint8_t *Buf, const Symbol &) const {

lld/ELF/Arch/ARM.cpp

@@ -29,7 +29,6 @@ public:
   uint32_t calcEFlags() const override;
   RelExpr getRelExpr(RelType Type, const Symbol &S,
                      const uint8_t *Loc) const override;
-  bool isPicRel(RelType Type) const override;
   RelType getDynRel(RelType Type) const override;
   int64_t getImplicitAddend(const uint8_t *Buf, RelType Type) const override;
   void writeGotPlt(uint8_t *Buf, const Symbol &S) const override;
@@ -162,18 +161,10 @@ RelExpr ARM::getRelExpr(RelType Type, const Symbol &S,
   }
 }
 
-bool ARM::isPicRel(RelType Type) const {
-  return (Type == R_ARM_TARGET1 && !Config->Target1Rel) ||
-         (Type == R_ARM_ABS32);
-}
-
 RelType ARM::getDynRel(RelType Type) const {
-  if (Type == R_ARM_TARGET1 && !Config->Target1Rel)
-    return R_ARM_ABS32;
-  if (Type == R_ARM_ABS32)
-    return Type;
-  // Keep it going with a dummy value so that we can find more reloc errors.
+  if ((Type == R_ARM_ABS32) || (Type == R_ARM_TARGET1 && !Config->Target1Rel))
     return R_ARM_ABS32;
+  return R_ARM_NONE;
 }
 
 void ARM::writeGotPlt(uint8_t *Buf, const Symbol &) const {

lld/ELF/Arch/Mips.cpp

@@ -32,7 +32,6 @@ public:
   RelExpr getRelExpr(RelType Type, const Symbol &S,
                      const uint8_t *Loc) const override;
   int64_t getImplicitAddend(const uint8_t *Buf, RelType Type) const override;
-  bool isPicRel(RelType Type) const override;
   RelType getDynRel(RelType Type) const override;
   void writeGotPlt(uint8_t *Buf, const Symbol &S) const override;
   void writePltHeader(uint8_t *Buf) const override;
@@ -184,12 +183,10 @@ RelExpr MIPS<ELFT>::getRelExpr(RelType Type, const Symbol &S,
   }
 }
 
-template <class ELFT> bool MIPS<ELFT>::isPicRel(RelType Type) const {
-  return Type == R_MIPS_32 || Type == R_MIPS_64;
-}
-
 template <class ELFT> RelType MIPS<ELFT>::getDynRel(RelType Type) const {
+  if (Type == R_MIPS_32 || Type == R_MIPS_64)
     return RelativeRel;
+  return R_MIPS_NONE;
 }
 
 template <class ELFT>

lld/ELF/Arch/X86_64.cpp

@@ -28,7 +28,7 @@ public:
   X86_64();
   RelExpr getRelExpr(RelType Type, const Symbol &S,
                      const uint8_t *Loc) const override;
-  bool isPicRel(RelType Type) const override;
+  RelType getDynRel(RelType Type) const override;
   void writeGotPltHeader(uint8_t *Buf) const override;
   void writeGotPlt(uint8_t *Buf, const Symbol &S) const override;
   void writePltHeader(uint8_t *Buf) const override;
@@ -155,9 +155,11 @@ void X86_64<ELFT>::writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr,
   write32le(Buf + 12, -getPltEntryOffset(Index) - 16);
 }
 
-template <class ELFT> bool X86_64<ELFT>::isPicRel(RelType Type) const {
-  return Type == R_X86_64_64 || Type == R_X86_64_PC64 ||
-         Type == R_X86_64_SIZE32 || Type == R_X86_64_SIZE64;
+template <class ELFT> RelType X86_64<ELFT>::getDynRel(RelType Type) const {
+  if (Type == R_X86_64_64 || Type == R_X86_64_PC64 || Type == R_X86_64_SIZE32 ||
+      Type == R_X86_64_SIZE64)
+    return Type;
+  return R_X86_64_NONE;
 }
 
 template <class ELFT>

lld/ELF/Relocations.cpp

@@ -778,9 +778,8 @@ static RelExpr processRelocAux(InputSectionBase &Sec, RelExpr Expr,
       InX::RelaDyn->addReloc(Target->RelativeRel, &Sec, Offset, &Sym, Addend,
                              Expr, Type);
       return Expr;
-    } else if (Target->isPicRel(Type)) {
-      InX::RelaDyn->addReloc(Target->getDynRel(Type), &Sec, Offset, &Sym,
-                             Addend, R_ADDEND, Type);
+    } else if (RelType Rel = Target->getDynRel(Type)) {
+      InX::RelaDyn->addReloc(Rel, &Sec, Offset, &Sym, Addend, R_ADDEND, Type);
 
       // MIPS ABI turns using of GOT and dynamic relocations inside out.
       // While regular ABI uses dynamic relocations to fill up GOT entries

lld/ELF/Target.h

@@ -25,7 +25,6 @@ class Symbol;
 class TargetInfo {
 public:
   virtual uint32_t calcEFlags() const { return 0; }
-  virtual bool isPicRel(RelType Type) const { return true; }
   virtual RelType getDynRel(RelType Type) const { return Type; }
   virtual void writeGotPltHeader(uint8_t *Buf) const {}
   virtual void writeGotHeader(uint8_t *Buf) const {}