Target: Add target option for disabling AArch64_ELFTargetObjectFile::SupportIndirectSymViaGOTPCRel

[AnthonyLatsis]

Upstreams swiftlang#10795.

The gold linker that comes with https://github.com/swiftlang/swift-docker/blob/main/swift-ci/main/ubuntu/24.04/Dockerfile (GNU gold (GNU Binutils for Ubuntu 2.42) 1.16) does not support this option and fails to link the standard library, so the Swift compiler needs a way to disable the option for AArch64 ELF.

See:

• Workaround invalid reloc 315 on aarch64 Linux swiftlang/llvm-project#9339
• [llvm] Indirect symbol replacement with GOTPCREL for aarch64 and risc… #78003

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[llvmbot]

@llvm/pr-subscribers-backend-aarch64

Author: Anthony Latsis (AnthonyLatsis)

Changes

The Swift compiler needs to disable this option in order for the standard library to link successfully on Linux.

See:

• Workaround invalid reloc 315 on aarch64 Linux swiftlang/llvm-project#9339
• [llvm] Indirect symbol replacement with GOTPCREL for aarch64 and risc… #78003

---

Full diff: https://github.com/llvm/llvm-project/pull/153910.diff

4 Files Affected:

• (modified) llvm/include/llvm/Target/TargetOptions.h (+5)
• (modified) llvm/lib/Target/AArch64/AArch64TargetMachine.cpp (+5-3)
• (modified) llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp (-1)
• (modified) llvm/lib/Target/AArch64/AArch64TargetObjectFile.h (+4)

diff --git a/llvm/include/llvm/Target/TargetOptions.h b/llvm/include/llvm/Target/TargetOptions.h
index db90f2e4cc7cc..5bba0c0046fb2 100644
--- a/llvm/include/llvm/Target/TargetOptions.h
+++ b/llvm/include/llvm/Target/TargetOptions.h
@@ -140,6 +140,7 @@ class TargetOptions {
         DebugStrictDwarf(false), Hotpatch(false),
         PPCGenScalarMASSEntries(false), JMCInstrument(false),
         EnableCFIFixup(false), MisExpect(false), XCOFFReadOnlyPointers(false),
+        SupportIndirectSymViaGOTPCRel_AArch64_ELF(true),
         VerifyArgABICompliance(true),
         FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}
 
@@ -373,6 +374,10 @@ class TargetOptions {
   /// into the RO data section.
   unsigned XCOFFReadOnlyPointers : 1;
 
+  /// When set to true, enables indirect symbol replacement with GOTPCREL for
+  /// AArch64/ELF. The default is `true`.
+  unsigned SupportIndirectSymViaGOTPCRel_AArch64_ELF : 1;
+
   /// When set to true, call/return argument extensions of narrow integers
   /// are verified in the target backend if it cares about them. This is
   /// not done with internal tools like llc that run many tests that ignore
diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 95eab16511e5a..0a7b1f14fff75 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -280,13 +280,15 @@ void AArch64TargetMachine::reset() { SubtargetMap.clear(); }
 //===----------------------------------------------------------------------===//
 // AArch64 Lowering public interface.
 //===----------------------------------------------------------------------===//
-static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
+static std::unique_ptr<TargetLoweringObjectFile>
+createTLOF(const Triple &TT, const TargetOptions &Options) {
   if (TT.isOSBinFormatMachO())
     return std::make_unique<AArch64_MachoTargetObjectFile>();
   if (TT.isOSBinFormatCOFF())
     return std::make_unique<AArch64_COFFTargetObjectFile>();
 
-  return std::make_unique<AArch64_ELFTargetObjectFile>();
+  return std::make_unique<AArch64_ELFTargetObjectFile>(
+      Options.SupportIndirectSymViaGOTPCRel_AArch64_ELF);
 }
 
 // Helper function to build a DataLayout string
@@ -367,7 +369,7 @@ AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
           computeDefaultCPU(TT, CPU), FS, Options,
           getEffectiveRelocModel(TT, RM),
           getEffectiveAArch64CodeModel(TT, CM, JIT), OL),
-      TLOF(createTLOF(getTargetTriple())), isLittle(LittleEndian) {
+      TLOF(createTLOF(getTargetTriple(), Options)), isLittle(LittleEndian) {
   initAsmInfo();
 
   if (TT.isOSBinFormatMachO()) {
diff --git a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
index 85de2d5010286..0b94b76b1aae8 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.cpp
@@ -26,7 +26,6 @@ void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
                                              const TargetMachine &TM) {
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
   PLTRelativeSpecifier = AArch64::S_PLT;
-  SupportIndirectSymViaGOTPCRel = true;
 
   // AARCH64 ELF ABI does not define static relocation type for TLS offset
   // within a module.  Do not generate AT_location for TLS variables.
diff --git a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
index 6b3381452c70b..45fdcb949b402 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetObjectFile.h
@@ -20,6 +20,10 @@ class AArch64_ELFTargetObjectFile : public TargetLoweringObjectFileELF {
   void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
 
 public:
+  AArch64_ELFTargetObjectFile(bool SupportIndirectSymViaGOTPCRel) {
+    this->SupportIndirectSymViaGOTPCRel = SupportIndirectSymViaGOTPCRel;
+  }
+
   const MCExpr *getIndirectSymViaGOTPCRel(const GlobalValue *GV,
                                           const MCSymbol *Sym,
                                           const MCValue &MV, int64_t Offset,