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

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

@@ -121,6 +121,7 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
 
   const llvm::AArch64::ArchInfo *ArchInfo = &llvm::AArch64::ARMV8A;
 
+protected:
   std::string ABI;
 
 public:
@@ -258,6 +259,16 @@ 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

@@ -374,6 +374,12 @@ 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);
+  }
 };
 
 // NetBSD Target

clang/lib/CodeGen/CodeGenModule.cpp

@@ -144,8 +144,6 @@ 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

@@ -469,7 +469,6 @@ enum class AArch64ABIKind {
   DarwinPCS,
   Win64,
   AAPCSSoft,
-  PAuthTest,
 };
 
 std::unique_ptr<TargetCodeGenInfo>

clang/lib/Driver/ToolChain.cpp

@@ -1110,7 +1110,6 @@ 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

@@ -455,24 +455,3 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
   if (Args.getLastArg(options::OPT_mno_bti_at_return_twice))
     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;
-  }
-}

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

@@ -28,9 +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);
-
 } // end namespace aarch64
 } // end namespace target
 } // end namespace driver

clang/lib/Driver/ToolChains/Clang.cpp

@@ -1501,59 +1501,6 @@ 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 Arg *A = isAArch64
@@ -1783,7 +1730,9 @@ 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";
@@ -1821,9 +1770,6 @@ void Clang::AddAArch64TargetArgs(const ArgList &Args,
   // Enable/disable return address signing and indirect branch targets.
   CollectARMPACBTIOptions(getToolChain(), Args, CmdArgs, true /*isAArch64*/);
 
-  if (Triple.getEnvironment() == llvm::Triple::PAuthTest)
-    handlePAuthABI(Args, CmdArgs);
-
   // Handle -msve_vector_bits=<bits>
   if (Arg *A = Args.getLastArg(options::OPT_msve_vector_bits_EQ)) {
     StringRef Val = A->getValue();

clang/lib/Driver/ToolChains/Linux.cpp

@@ -456,6 +456,102 @@ std::string Linux::computeSysRoot() const {
   return std::string();
 }
 
+static void 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;
+  }
+}
+
+std::string Linux::ComputeEffectiveClangTriple(const llvm::opt::ArgList &Args,
+                                               types::ID InputType) const {
+  std::string TripleString =
+      Generic_ELF::ComputeEffectiveClangTriple(Args, InputType);
+  if (getTriple().isAArch64()) {
+    llvm::Triple Triple(TripleString);
+    setPAuthABIInTriple(getDriver(), Args, Triple);
+    return Triple.getTriple();
+  }
+  return TripleString;
+}
+
+// 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 Driver &D, 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");
+}
+
+void Linux::addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                                  llvm::opt::ArgStringList &CC1Args,
+                                  Action::OffloadKind DeviceOffloadKind) const {
+  llvm::Triple Triple(ComputeEffectiveClangTriple(DriverArgs));
+  if (Triple.isAArch64() && Triple.getEnvironment() == llvm::Triple::PAuthTest)
+    handlePAuthABI(getDriver(), DriverArgs, CC1Args);
+  Generic_ELF::addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadKind);
+}
+
 std::string Linux::getDynamicLinker(const ArgList &Args) const {
   const llvm::Triple::ArchType Arch = getArch();
   const llvm::Triple &Triple = getTriple();

clang/lib/Driver/ToolChains/Linux.h

@@ -51,7 +51,14 @@ class LLVM_LIBRARY_VISIBILITY Linux : public Generic_ELF {
   SanitizerMask getSupportedSanitizers() const override;
   void addProfileRTLibs(const llvm::opt::ArgList &Args,
                         llvm::opt::ArgStringList &CmdArgs) const override;
+  std::string ComputeEffectiveClangTriple(
+      const llvm::opt::ArgList &Args,
+      types::ID InputType = types::TY_INVALID) const override;
   std::string computeSysRoot() const override;
+  void
+  addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                        llvm::opt::ArgStringList &CC1Args,
+                        Action::OffloadKind DeviceOffloadKind) const override;
 
   std::string getDynamicLinker(const llvm::opt::ArgList &Args) const override;
 

clang/test/Driver/aarch64-ptrauth.c

@@ -22,25 +22,39 @@
 // RUN: %clang -### -c --target=aarch64-linux -mabi=pauthtest %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI1
 // RUN: %clang -### -c --target=aarch64-linux-pauthtest %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI1
 // PAUTHABI1:      "-cc1"{{.*}} "-triple" "aarch64-unknown-linux-pauthtest"
-// PAUTHABI1-SAME: "-target-abi" "pauthtest"
 // PAUTHABI1-SAME: "-fptrauth-intrinsics" "-fptrauth-calls" "-fptrauth-returns" "-fptrauth-auth-traps" "-fptrauth-vtable-pointer-address-discrimination" "-fptrauth-vtable-pointer-type-discrimination" "-fptrauth-type-info-vtable-pointer-discrimination" "-fptrauth-indirect-gotos" "-fptrauth-init-fini" "-fptrauth-init-fini-address-discrimination" "-faarch64-jump-table-hardening"
+// PAUTHABI1-SAME: "-target-abi" "pauthtest"
+// PAUTHABI1-NOT: "-fptrauth-function-pointer-type-discrimination"
 
-// RUN: %clang -### -c --target=aarch64 -mabi=pauthtest -fno-ptrauth-intrinsics \
+// RUN: %clang -### -c --target=aarch64-linux -mabi=pauthtest -fno-ptrauth-intrinsics \
 // RUN:   -fno-ptrauth-calls -fno-ptrauth-returns -fno-ptrauth-auth-traps \
 // RUN:   -fno-ptrauth-vtable-pointer-address-discrimination -fno-ptrauth-vtable-pointer-type-discrimination \
 // RUN:   -fno-ptrauth-type-info-vtable-pointer-discrimination -fno-ptrauth-indirect-gotos \
 // RUN:   -fno-ptrauth-init-fini -fno-ptrauth-init-fini-address-discrimination \
 // RUN:   -fno-aarch64-jump-table-hardening %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI2
-// RUN: %clang -### -c --target=aarch64-pauthtest -fno-ptrauth-intrinsics \
+// RUN: %clang -### -c --target=aarch64-linux-pauthtest -fno-ptrauth-intrinsics \
 // RUN:   -fno-ptrauth-calls -fno-ptrauth-returns -fno-ptrauth-auth-traps \
 // RUN:   -fno-ptrauth-vtable-pointer-address-discrimination -fno-ptrauth-vtable-pointer-type-discrimination \
 // RUN:   -fno-ptrauth-type-info-vtable-pointer-discrimination -fno-ptrauth-indirect-gotos \
 // RUN:   -fno-ptrauth-init-fini -fno-ptrauth-init-fini-address-discrimination \
 // RUN:   -fno-aarch64-jump-table-hardening %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI2
-// PAUTHABI2:     "-cc1"
-// PAUTHABI2-NOT: "-fptrauth-
+
+//// Non-linux OS: pauthtest ABI has no effect in terms of passing ptrauth cc1 flags.
+//// An error about unsupported ABI will be emitted later in pipeline (see ERR2 below)
+// RUN: %clang -### -c --target=aarch64 -mabi=pauthtest %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI2
+
+// PAUTHABI2:      "-cc1"
+// PAUTHABI2-SAME: "-target-abi" "pauthtest"
+// PAUTHABI2-NOT:  "-fptrauth-
 // PAUTHABI2-NOT: "-faarch64-jump-table-hardening"
 
+//// Non-linux OS: pauthtest environment does not correspond to pauthtest ABI; aapcs is the default.
+// RUN: %clang -### -c --target=aarch64-pauthtest %s 2>&1 | FileCheck %s --check-prefix=PAUTHABI3
+// PAUTHABI3:      "-cc1"
+// PAUTHABI3-SAME: "-target-abi" "aapcs"
+// PAUTHABI3-NOT:  "-fptrauth-
+// PAUTHABI3-NOT: "-faarch64-jump-table-hardening"
+
 // RUN: not %clang -### -c --target=x86_64 -fptrauth-intrinsics -fptrauth-calls -fptrauth-returns -fptrauth-auth-traps \
 // RUN:   -fptrauth-vtable-pointer-address-discrimination -fptrauth-vtable-pointer-type-discrimination \
 // RUN:   -fptrauth-type-info-vtable-pointer-discrimination -fptrauth-indirect-gotos -fptrauth-init-fini \
@@ -57,10 +71,12 @@
 // ERR1-NEXT: error: unsupported option '-fptrauth-init-fini-address-discrimination' for target '{{.*}}'
 // ERR1-NEXT: error: unsupported option '-faarch64-jump-table-hardening' for target '{{.*}}'
 
-//// Only support PAuth ABI for Linux as for now.
-// RUN: not %clang -o /dev/null -c --target=aarch64-unknown -mabi=pauthtest %s 2>&1 | FileCheck %s --check-prefix=ERR2
-// RUN: not %clang -o /dev/null -c --target=aarch64-unknown-pauthtest       %s 2>&1 | FileCheck %s --check-prefix=ERR2
-// ERR2: error: ABI 'pauthtest' is not supported for 'aarch64-unknown-unknown-pauthtest'
+
+// RUN: not %clang -c --target=aarch64 -mabi=pauthtest %s 2>&1 | FileCheck %s --check-prefix=ERR2
+//// The ABI is not specified explicitly, and for non-Linux pauthtest environment does not correspond
+//// to pauthtest ABI (each OS target defines this behavior separately). Do not emit an error.
+// RUN:     %clang -c --target=aarch64-pauthtest       %s -o /dev/null
+// ERR2: error: unknown target ABI 'pauthtest'
 
 //// PAuth ABI is encoded as environment part of the triple, so don't allow to explicitly set other environments.
 // RUN: not %clang -### -c --target=aarch64-linux-gnu -mabi=pauthtest %s 2>&1 | FileCheck %s --check-prefix=ERR3