[clang] Add arm64e ABI-defined key assignments to ptrauth.h.

[ahmedbougacha]

These are currently gated by __APPLE__; we can figure out a way to define these on ELF targets as well, and maybe have them be defined by clang itself, depending on ABI modes.

[llvmbot]

@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-clang

Author: Ahmed Bougacha (ahmedbougacha)

Changes

These are currently gated by APPLE; we can figure out a way to define these on ELF targets as well, and maybe have them be defined by clang itself, depending on ABI modes.

---

Full diff: https://github.com/llvm/llvm-project/pull/93901.diff

1 Files Affected:

• (modified) clang/lib/Headers/ptrauth.h (+23)

diff --git a/clang/lib/Headers/ptrauth.h b/clang/lib/Headers/ptrauth.h
index 56c3c3636c9bc..036665d75a91b 100644
--- a/clang/lib/Headers/ptrauth.h
+++ b/clang/lib/Headers/ptrauth.h
@@ -15,6 +15,29 @@ typedef enum {
   ptrauth_key_asib = 1,
   ptrauth_key_asda = 2,
   ptrauth_key_asdb = 3,
+
+#ifdef __APPLE__
+  /* A process-independent key which can be used to sign code pointers.
+     Signing and authenticating with this key is a no-op in processes
+     which disable ABI pointer authentication. */
+  ptrauth_key_process_independent_code = ptrauth_key_asia,
+
+  /* A process-specific key which can be used to sign code pointers.
+     Signing and authenticating with this key is enforced even in processes
+     which disable ABI pointer authentication. */
+  ptrauth_key_process_dependent_code = ptrauth_key_asib,
+
+  /* A process-independent key which can be used to sign data pointers.
+     Signing and authenticating with this key is a no-op in processes
+     which disable ABI pointer authentication. */
+  ptrauth_key_process_independent_data = ptrauth_key_asda,
+
+  /* A process-specific key which can be used to sign data pointers.
+     Signing and authenticating with this key is a no-op in processes
+     which disable ABI pointer authentication. */
+  ptrauth_key_process_dependent_data = ptrauth_key_asdb,
+#endif /* __APPLE__ */
+
 } ptrauth_key;
 
 /* An integer type of the appropriate size for a discriminator argument. */