[clang] Update Mach-O ptrauth driver defaults

[nico]

Xcode clang default-enables a bunch of ptrauth flags when targeting arm64e. Let's match that.

[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: Nico Weber (nico)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/132834.diff

3 Files Affected:

• (modified) clang/lib/Driver/ToolChains/Darwin.cpp (+41)
• (modified) clang/lib/Driver/ToolChains/Darwin.h (+8)
• (added) clang/test/Driver/arch-arm64e.c (+66)

diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index e67997314da36..5ac105d82ef6d 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1201,6 +1201,13 @@ void DarwinClang::addClangWarningOptions(ArgStringList &CC1Args) const {
   }
 }
 
+void DarwinClang::addClangTargetOptions(
+  const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
+  Action::OffloadKind DeviceOffloadKind) const {
+
+  Darwin::addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadKind);
+}
+
 /// Take a path that speculatively points into Xcode and return the
 /// `XCODE/Contents/Developer` path if it is an Xcode path, or an empty path
 /// otherwise.
@@ -3060,9 +3067,43 @@ bool Darwin::isSizedDeallocationUnavailable() const {
   return TargetVersion < sizedDeallocMinVersion(OS);
 }
 
+void MachO::addClangTargetOptions(
+    const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
+    Action::OffloadKind DeviceOffloadKind) const {
+
+  ToolChain::addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadKind);
+
+  // On arm64e, enable pointer authentication (for the return address and
+  // indirect calls), as well as usage of the intrinsics.
+  if (getArchName() == "arm64e") {
+    if (!DriverArgs.hasArg(options::OPT_fptrauth_returns,
+                           options::OPT_fno_ptrauth_returns))
+      CC1Args.push_back("-fptrauth-returns");
+
+    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_indirect_gotos,
+                           options::OPT_fno_ptrauth_indirect_gotos))
+      CC1Args.push_back("-fptrauth-indirect-gotos");
+
+    if (!DriverArgs.hasArg(options::OPT_fptrauth_auth_traps,
+                           options::OPT_fno_ptrauth_auth_traps))
+      CC1Args.push_back("-fptrauth-auth-traps");
+  }
+}
+
 void Darwin::addClangTargetOptions(
     const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
     Action::OffloadKind DeviceOffloadKind) const {
+
+  MachO::addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadKind);
+
   // Pass "-faligned-alloc-unavailable" only when the user hasn't manually
   // enabled or disabled aligned allocations.
   if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
diff --git a/clang/lib/Driver/ToolChains/Darwin.h b/clang/lib/Driver/ToolChains/Darwin.h
index c44780c577f4f..41aa07c188868 100644
--- a/clang/lib/Driver/ToolChains/Darwin.h
+++ b/clang/lib/Driver/ToolChains/Darwin.h
@@ -145,6 +145,10 @@ class LLVM_LIBRARY_VISIBILITY MachO : public ToolChain {
   Tool *buildStaticLibTool() const override;
   Tool *getTool(Action::ActionClass AC) const override;
 
+  void addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                             llvm::opt::ArgStringList &CC1Args,
+                             Action::OffloadKind DeviceOffloadKind) const override;
+
 private:
   mutable std::unique_ptr<tools::darwin::Lipo> Lipo;
   mutable std::unique_ptr<tools::darwin::Dsymutil> Dsymutil;
@@ -653,6 +657,10 @@ class LLVM_LIBRARY_VISIBILITY DarwinClang : public Darwin {
 
   void addClangWarningOptions(llvm::opt::ArgStringList &CC1Args) const override;
 
+  void addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                             llvm::opt::ArgStringList &CC1Args,
+                             Action::OffloadKind DeviceOffloadKind) const override;
+
   void AddLinkARCArgs(const llvm::opt::ArgList &Args,
                       llvm::opt::ArgStringList &CmdArgs) const override;
 
diff --git a/clang/test/Driver/arch-arm64e.c b/clang/test/Driver/arch-arm64e.c
new file mode 100644
index 0000000000000..0fb12d4dcc5e3
--- /dev/null
+++ b/clang/test/Driver/arch-arm64e.c
@@ -0,0 +1,66 @@
+// Check that we can manually enable specific ptrauth features.
+
+// RUN: %clang -target arm64-apple-darwin -c %s -### 2>&1 | FileCheck %s --check-prefix NONE
+// NONE: "-cc1"
+// NONE-NOT: "-fptrauth-intrinsics"
+// NONE-NOT: "-fptrauth-calls"
+// NONE-NOT: "-fptrauth-returns"
+// NONE-NOT: "-fptrauth-indirect-gotos"
+// NONE-NOT: "-fptrauth-auth-traps"
+
+// RUN: %clang -target arm64-apple-darwin -fptrauth-calls -c %s -### 2>&1 | FileCheck %s --check-prefix CALL
+// CALL: "-cc1"{{.*}} {{.*}} "-fptrauth-calls"
+
+// RUN: %clang -target arm64-apple-darwin -fptrauth-intrinsics -c %s -### 2>&1 | FileCheck %s --check-prefix INTRIN
+// INTRIN: "-cc1"{{.*}} {{.*}} "-fptrauth-intrinsics"
+
+// RUN: %clang -target arm64-apple-darwin -fptrauth-returns -c %s -### 2>&1 | FileCheck %s --check-prefix RETURN
+// RETURN: "-cc1"{{.*}} {{.*}} "-fptrauth-returns"
+
+// RUN: %clang -target arm64-apple-darwin -fptrauth-indirect-gotos -c %s -### 2>&1 | FileCheck %s --check-prefix INDGOTO
+// INDGOTO: "-cc1"{{.*}} {{.*}} "-fptrauth-indirect-gotos"
+
+// RUN: %clang -target arm64-apple-darwin -fptrauth-auth-traps -c %s -### 2>&1 | FileCheck %s --check-prefix TRAPS
+// TRAPS: "-cc1"{{.*}} {{.*}} "-fptrauth-auth-traps"
+
+
+// Check the arm64e defaults.
+
+// RUN: %clang -target arm64e-apple-ios -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT
+// RUN: %clang -mkernel -target arm64e-apple-ios -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT
+// RUN: %clang -fapple-kext -target arm64e-apple-ios -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT
+// DEFAULT: "-fptrauth-returns" "-fptrauth-intrinsics" "-fptrauth-calls" "-fptrauth-indirect-gotos" "-fptrauth-auth-traps" {{.*}}"-target-cpu" "apple-a12"{{.*}}
+
+// RUN: %clang -target arm64e-apple-none-macho -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT-MACHO
+// DEFAULT-MACHO: "-fptrauth-returns" "-fptrauth-intrinsics" "-fptrauth-calls" "-fptrauth-indirect-gotos" "-fptrauth-auth-traps" {{.*}}"-target-cpu" "apple-a12"{{.*}}
+
+
+// RUN: %clang -target arm64e-apple-ios -fno-ptrauth-calls -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT-NOCALL
+// RUN: %clang -mkernel -target arm64e-apple-ios -fno-ptrauth-calls -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT-NOCALL
+// RUN: %clang -fapple-kext -target arm64e-apple-ios -fno-ptrauth-calls -c %s -### 2>&1 | FileCheck %s --check-prefix DEFAULT-NOCALL
+// DEFAULT-NOCALL-NOT: "-fptrauth-calls"
+// DEFAULT-NOCALL: "-fptrauth-returns" "-fptrauth-intrinsics" "-fptrauth-indirect-gotos" "-fptrauth-auth-traps" {{.*}}"-target-cpu" "apple-a12"
+
+
+// RUN: %clang -target arm64e-apple-ios -fno-ptrauth-returns -c %s -### 2>&1 | FileCheck %s --check-prefix NORET
+
+// NORET-NOT: "-fptrauth-returns"
+// NORET: "-fptrauth-intrinsics" "-fptrauth-calls" "-fptrauth-indirect-gotos" "-fptrauth-auth-traps" {{.*}}"-target-cpu" "apple-a12"
+
+// RUN: %clang -target arm64e-apple-ios -fno-ptrauth-intrinsics -c %s -### 2>&1 | FileCheck %s --check-prefix NOINTRIN
+
+// NOINTRIN: "-fptrauth-returns"
+// NOINTRIN-NOT: "-fptrauth-intrinsics"
+// NOINTRIN: "-fptrauth-calls" "-fptrauth-indirect-gotos" "-fptrauth-auth-traps" {{.*}}"-target-cpu" "apple-a12"{{.*}}
+
+
+// RUN: %clang -target arm64e-apple-ios -fno-ptrauth-auth-traps -c %s -### 2>&1 | FileCheck %s --check-prefix NOTRAP
+// NOTRAP: "-fptrauth-returns" "-fptrauth-intrinsics" "-fptrauth-calls" "-fptrauth-indirect-gotos" {{.*}}"-target-cpu" "apple-a12"
+
+
+// Check the CPU defaults and overrides.
+
+// RUN: %clang -target arm64e-apple-ios -c %s -### 2>&1 | FileCheck %s --check-prefix APPLE-A12
+// RUN: %clang -target arm64e-apple-ios -mcpu=apple-a13 -c %s -### 2>&1 | FileCheck %s --check-prefix APPLE-A13
+// APPLE-A12: "-cc1"{{.*}} "-target-cpu" "apple-a12"
+// APPLE-A13: "-cc1"{{.*}} "-target-cpu" "apple-a13"

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[nico]

Looks like @ahmedbougacha might be out. @francisvm, could you take a look?

[francisvm]

Looks like @ahmedbougacha might be out. @francisvm, could you take a look?

@rjmccall / @jroelofs might be able to help!

[jroelofs]

Looks mechanically okay, but I need to defer to Ahmed on whether you're missing other bits that go along with this. He's around, just need to be patient ;)

[nico]

Thanks! I'm feeling reasonably confident about this one and it's been a few days, so I'll hit the button :)