[ELF] Change Ctx::target to unique_ptr (llvm#111260)

also rename `TargetInfo *getXXXTargetInfo` to `void setXXXTargetInfo`
and change it to set `ctx.target`. This ensures that when `ctx` becomes
a local variable, two lld invocations will not reuse the function-local
static variable.

Author: MaskRay

lld/ELF/Arch/AArch64.cpp

@@ -1208,12 +1208,10 @@ void elf::createTaggedSymbols(Ctx &ctx) {
   }
 }
 
-TargetInfo *elf::getAArch64TargetInfo(Ctx &ctx) {
+void elf::setAArch64TargetInfo(Ctx &ctx) {
   if ((ctx.arg.andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) ||
-      ctx.arg.zPacPlt) {
-    static AArch64BtiPac t(ctx);
-    return &t;
-  }
-  static AArch64 t(ctx);
-  return &t;
+      ctx.arg.zPacPlt)
+    ctx.target.reset(new AArch64BtiPac(ctx));
+  else
+    ctx.target.reset(new AArch64(ctx));
 }

lld/ELF/Arch/AMDGPU.cpp

@@ -219,7 +219,4 @@ int64_t AMDGPU::getImplicitAddend(const uint8_t *buf, RelType type) const {
   }
 }
 
-TargetInfo *elf::getAMDGPUTargetInfo(Ctx &ctx) {
-  static AMDGPU target(ctx);
-  return ⌖
-}
+void elf::setAMDGPUTargetInfo(Ctx &ctx) { ctx.target.reset(new AMDGPU(ctx)); }

lld/ELF/Arch/ARM.cpp

@@ -1533,10 +1533,7 @@ template <typename ELFT> void elf::writeARMCmseImportLib(Ctx &ctx) {
           "': " + toString(std::move(e)));
 }
 
-TargetInfo *elf::getARMTargetInfo(Ctx &ctx) {
-  static ARM target(ctx);
-  return &target;
-}
+void elf::setARMTargetInfo(Ctx &ctx) { ctx.target.reset(new ARM(ctx)); }
 
 template void elf::writeARMCmseImportLib<ELF32LE>(Ctx &);
 template void elf::writeARMCmseImportLib<ELF32BE>(Ctx &);

lld/ELF/Arch/AVR.cpp

@@ -267,10 +267,7 @@ void AVR::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
   }
 }
 
-TargetInfo *elf::getAVRTargetInfo(Ctx &ctx) {
-  static AVR target(ctx);
-  return ⌖
-}
+void elf::setAVRTargetInfo(Ctx &ctx) { ctx.target.reset(new AVR(ctx)); }
 
 static uint32_t getEFlags(InputFile *file) {
   return cast<ObjFile<ELF32LE>>(file)->getObj().getHeader().e_flags;

lld/ELF/Arch/Hexagon.cpp

@@ -404,7 +404,4 @@ int64_t Hexagon::getImplicitAddend(const uint8_t *buf, RelType type) const {
   }
 }
 
-TargetInfo *elf::getHexagonTargetInfo(Ctx &ctx) {
-  static Hexagon target(ctx);
-  return ⌖
-}
+void elf::setHexagonTargetInfo(Ctx &ctx) { ctx.target.reset(new Hexagon(ctx)); }

lld/ELF/Arch/LoongArch.cpp

@@ -893,7 +893,6 @@ void LoongArch::finalizeRelax(int passes) const {
   }
 }
 
-TargetInfo *elf::getLoongArchTargetInfo(Ctx &ctx) {
-  static LoongArch target(ctx);
-  return ⌖
+void elf::setLoongArchTargetInfo(Ctx &ctx) {
+  ctx.target.reset(new LoongArch(ctx));
 }

lld/ELF/Arch/MSP430.cpp

@@ -88,7 +88,4 @@ void MSP430::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
   }
 }
 
-TargetInfo *elf::getMSP430TargetInfo(Ctx &ctx) {
-  static MSP430 target(ctx);
-  return ⌖
-}
+void elf::setMSP430TargetInfo(Ctx &ctx) { ctx.target.reset(new MSP430(ctx)); }

lld/ELF/Arch/Mips.cpp

@@ -779,23 +779,23 @@ template <class ELFT> bool elf::isMipsPIC(const Defined *sym) {
   return cast<ObjFile<ELFT>>(file)->getObj().getHeader().e_flags & EF_MIPS_PIC;
 }
 
-TargetInfo *elf::getMipsTargetInfo(Ctx &ctx) {
+void elf::setMipsTargetInfo(Ctx &ctx) {
   switch (ctx.arg.ekind) {
   case ELF32LEKind: {
-    static MIPS<ELF32LE> t(ctx);
-    return &t;
+    ctx.target.reset(new MIPS<ELF32LE>(ctx));
+    return;
   }
   case ELF32BEKind: {
-    static MIPS<ELF32BE> t(ctx);
-    return &t;
+    ctx.target.reset(new MIPS<ELF32BE>(ctx));
+    return;
   }
   case ELF64LEKind: {
-    static MIPS<ELF64LE> t(ctx);
-    return &t;
+    ctx.target.reset(new MIPS<ELF64LE>(ctx));
+    return;
   }
   case ELF64BEKind: {
-    static MIPS<ELF64BE> t(ctx);
-    return &t;
+    ctx.target.reset(new MIPS<ELF64BE>(ctx));
+    return;
   }
   default:
     llvm_unreachable("unsupported target");

lld/ELF/Arch/PPC.cpp

@@ -523,7 +523,4 @@ void PPC::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const {
   }
 }
 
-TargetInfo *elf::getPPCTargetInfo(Ctx &ctx) {
-  static PPC target(ctx);
-  return ⌖
-}
+void elf::setPPCTargetInfo(Ctx &ctx) { ctx.target.reset(new PPC(ctx)); }

lld/ELF/Arch/PPC64.cpp

@@ -1747,7 +1747,4 @@ bool PPC64::adjustPrologueForCrossSplitStack(uint8_t *loc, uint8_t *end,
   return true;
 }
 
-TargetInfo *elf::getPPC64TargetInfo(Ctx &ctx) {
-  static PPC64 target(ctx);
-  return ⌖
-}
+void elf::setPPC64TargetInfo(Ctx &ctx) { ctx.target.reset(new PPC64(ctx)); }