[PAC][clang] Handle pauthtest environment and ABI in Linux-specific code

Since pauthtest is a Linux-specific ABI, it should not be handled in
common driver code.

Author: kovdan01

clang/lib/Basic/Targets/AArch64.cpp

@@ -206,8 +206,7 @@ AArch64TargetInfo::AArch64TargetInfo(const llvm::Triple &Triple,
 StringRef AArch64TargetInfo::getABI() const { return ABI; }
 
 bool AArch64TargetInfo::setABI(const std::string &Name) {
-  if (Name != "aapcs" && Name != "aapcs-soft" && Name != "darwinpcs" &&
-      Name != "pauthtest")
+  if (Name != "aapcs" && Name != "aapcs-soft" && Name != "darwinpcs")
     return false;
 
   ABI = Name;
@@ -221,12 +220,6 @@ bool AArch64TargetInfo::validateTarget(DiagnosticsEngine &Diags) const {
     Diags.Report(diag::err_target_unsupported_abi_with_fpu) << ABI;
     return false;
   }
-  if (getTriple().getEnvironment() == llvm::Triple::PAuthTest &&
-      getTriple().getOS() != llvm::Triple::Linux) {
-    Diags.Report(diag::err_target_unsupported_abi_for_triple)
-        << getTriple().getEnvironmentName() << getTriple().getTriple();
-    return false;
-  }
   return true;
 }
 

clang/lib/Basic/Targets/AArch64.h

@@ -135,6 +135,7 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
 
   const llvm::AArch64::ArchInfo *ArchInfo = &llvm::AArch64::ARMV8A;
 
+protected:
   std::string ABI;
 
 public:
@@ -277,6 +278,16 @@ class LLVM_LIBRARY_VISIBILITY AArch64leTargetInfo : public AArch64TargetInfo {
   void setDataLayout() override;
 };
 
+template <>
+inline bool
+LinuxTargetInfo<AArch64leTargetInfo>::setABI(const std::string &Name) {
+  if (Name == "pauthtest") {
+    ABI = Name;
+    return true;
+  }
+  return AArch64leTargetInfo::setABI(Name);
+}
+
 class LLVM_LIBRARY_VISIBILITY WindowsARM64TargetInfo
     : public WindowsTargetInfo<AArch64leTargetInfo> {
   const llvm::Triple Triple;

clang/lib/Basic/Targets/OSTargets.cpp

@@ -10,6 +10,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "OSTargets.h"
+#include "AArch64.h"
 #include "clang/Basic/MacroBuilder.h"
 #include "llvm/ADT/StringRef.h"
 

clang/lib/Basic/Targets/OSTargets.h

@@ -396,6 +396,12 @@ class LLVM_LIBRARY_VISIBILITY LinuxTargetInfo : public OSTargetInfo<Target> {
   const char *getStaticInitSectionSpecifier() const override {
     return ".text.startup";
   }
+
+  // This allows template specializations, see
+  // LinuxTargetInfo<AArch64leTargetInfo>::setABI
+  bool setABI(const std::string &Name) override {
+    return OSTargetInfo<Target>::setABI(Name);
+  }
 };
 
 // Managarm Target

clang/lib/CodeGen/CodeGenModule.cpp

@@ -145,8 +145,6 @@ createTargetCodeGenInfo(CodeGenModule &CGM) {
       return createWindowsAArch64TargetCodeGenInfo(CGM, AArch64ABIKind::Win64);
     else if (Target.getABI() == "aapcs-soft")
       Kind = AArch64ABIKind::AAPCSSoft;
-    else if (Target.getABI() == "pauthtest")
-      Kind = AArch64ABIKind::PAuthTest;
 
     return createAArch64TargetCodeGenInfo(CGM, Kind);
   }

clang/lib/CodeGen/TargetInfo.h

@@ -483,7 +483,6 @@ enum class AArch64ABIKind {
   DarwinPCS,
   Win64,
   AAPCSSoft,
-  PAuthTest,
 };
 
 std::unique_ptr<TargetCodeGenInfo>

clang/lib/Driver/ToolChain.cpp

@@ -1251,7 +1251,6 @@ std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
   }
   case llvm::Triple::aarch64: {
     llvm::Triple Triple = getTriple();
-    tools::aarch64::setPAuthABIInTriple(getDriver(), Args, Triple);
     if (!Triple.isOSBinFormatMachO())
       return Triple.getTriple();
 

clang/lib/Driver/ToolChains/Arch/AArch64.cpp

@@ -463,27 +463,6 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
     Features.push_back("+no-bti-at-return-twice");
 }
 
-void aarch64::setPAuthABIInTriple(const Driver &D, const ArgList &Args,
-                                  llvm::Triple &Triple) {
-  Arg *ABIArg = Args.getLastArg(options::OPT_mabi_EQ);
-  bool HasPAuthABI =
-      ABIArg ? (StringRef(ABIArg->getValue()) == "pauthtest") : false;
-
-  switch (Triple.getEnvironment()) {
-  case llvm::Triple::UnknownEnvironment:
-    if (HasPAuthABI)
-      Triple.setEnvironment(llvm::Triple::PAuthTest);
-    break;
-  case llvm::Triple::PAuthTest:
-    break;
-  default:
-    if (HasPAuthABI)
-      D.Diag(diag::err_drv_unsupported_opt_for_target)
-          << ABIArg->getAsString(Args) << Triple.getTriple();
-    break;
-  }
-}
-
 /// Is the triple {aarch64.aarch64_be}-none-elf?
 bool aarch64::isAArch64BareMetal(const llvm::Triple &Triple) {
   if (Triple.getArch() != llvm::Triple::aarch64 &&

clang/lib/Driver/ToolChains/Arch/AArch64.h

@@ -28,8 +28,6 @@ void getAArch64TargetFeatures(const Driver &D, const llvm::Triple &Triple,
 std::string getAArch64TargetCPU(const llvm::opt::ArgList &Args,
                                 const llvm::Triple &Triple, llvm::opt::Arg *&A);
 
-void setPAuthABIInTriple(const Driver &D, const llvm::opt::ArgList &Args,
-                         llvm::Triple &triple);
 bool isAArch64BareMetal(const llvm::Triple &Triple);
 
 } // end namespace aarch64

clang/lib/Driver/ToolChains/Clang.cpp

@@ -1340,59 +1340,6 @@ void AddUnalignedAccessWarning(ArgStringList &CmdArgs) {
 }
 }
 
-// Each combination of options here forms a signing schema, and in most cases
-// each signing schema is its own incompatible ABI. The default values of the
-// options represent the default signing schema.
-static void handlePAuthABI(const ArgList &DriverArgs, ArgStringList &CC1Args) {
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_intrinsics,
-                         options::OPT_fno_ptrauth_intrinsics))
-    CC1Args.push_back("-fptrauth-intrinsics");
-
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_calls,
-                         options::OPT_fno_ptrauth_calls))
-    CC1Args.push_back("-fptrauth-calls");
-
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_returns,
-                         options::OPT_fno_ptrauth_returns))
-    CC1Args.push_back("-fptrauth-returns");
-
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_auth_traps,
-                         options::OPT_fno_ptrauth_auth_traps))
-    CC1Args.push_back("-fptrauth-auth-traps");
-
-  if (!DriverArgs.hasArg(
-          options::OPT_fptrauth_vtable_pointer_address_discrimination,
-          options::OPT_fno_ptrauth_vtable_pointer_address_discrimination))
-    CC1Args.push_back("-fptrauth-vtable-pointer-address-discrimination");
-
-  if (!DriverArgs.hasArg(
-          options::OPT_fptrauth_vtable_pointer_type_discrimination,
-          options::OPT_fno_ptrauth_vtable_pointer_type_discrimination))
-    CC1Args.push_back("-fptrauth-vtable-pointer-type-discrimination");
-
-  if (!DriverArgs.hasArg(
-          options::OPT_fptrauth_type_info_vtable_pointer_discrimination,
-          options::OPT_fno_ptrauth_type_info_vtable_pointer_discrimination))
-    CC1Args.push_back("-fptrauth-type-info-vtable-pointer-discrimination");
-
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_indirect_gotos,
-                         options::OPT_fno_ptrauth_indirect_gotos))
-    CC1Args.push_back("-fptrauth-indirect-gotos");
-
-  if (!DriverArgs.hasArg(options::OPT_fptrauth_init_fini,
-                         options::OPT_fno_ptrauth_init_fini))
-    CC1Args.push_back("-fptrauth-init-fini");
-
-  if (!DriverArgs.hasArg(
-          options::OPT_fptrauth_init_fini_address_discrimination,
-          options::OPT_fno_ptrauth_init_fini_address_discrimination))
-    CC1Args.push_back("-fptrauth-init-fini-address-discrimination");
-
-  if (!DriverArgs.hasArg(options::OPT_faarch64_jump_table_hardening,
-                         options::OPT_fno_aarch64_jump_table_hardening))
-    CC1Args.push_back("-faarch64-jump-table-hardening");
-}
-
 static void CollectARMPACBTIOptions(const ToolChain &TC, const ArgList &Args,
                                     ArgStringList &CmdArgs, bool isAArch64) {
   const llvm::Triple &Triple = TC.getEffectiveTriple();
@@ -1630,7 +1577,9 @@ void RenderAArch64ABI(const llvm::Triple &Triple, const ArgList &Args,
     ABIName = A->getValue();
   else if (Triple.isOSDarwin())
     ABIName = "darwinpcs";
-  else if (Triple.getEnvironment() == llvm::Triple::PAuthTest)
+  // TODO: we probably want to have some target hook here.
+  else if (Triple.isOSLinux() &&
+           Triple.getEnvironment() == llvm::Triple::PAuthTest)
     ABIName = "pauthtest";
   else
     ABIName = "aapcs";
@@ -1665,6 +1614,9 @@ void Clang::AddAArch64TargetArgs(const ArgList &Args,
       CmdArgs.push_back("-aarch64-enable-global-merge=true");
   }
 
+  // Enable/disable return address signing and indirect branch targets.
+  CollectARMPACBTIOptions(getToolChain(), Args, CmdArgs, true /*isAArch64*/);
+
   // Handle -msve_vector_bits=<bits>
   auto HandleVectorBits = [&](Arg *A, StringRef VScaleMin,
                               StringRef VScaleMax) {
@@ -1750,8 +1702,6 @@ void Clang::AddAArch64TargetArgs(const ArgList &Args,
                     options::OPT_fno_ptrauth_objc_interface_sel);
   Args.addOptInFlag(CmdArgs, options::OPT_fptrauth_objc_class_ro,
                     options::OPT_fno_ptrauth_objc_class_ro);
-  if (Triple.getEnvironment() == llvm::Triple::PAuthTest)
-    handlePAuthABI(Args, CmdArgs);
 
   // Enable/disable return address signing and indirect branch targets.
   CollectARMPACBTIOptions(getToolChain(), Args, CmdArgs, true /*isAArch64*/);