[clang][ObjC][PAC] Add ptrauth protections to objective-c (#147899)

This PR introduces the use of pointer authentication to objective-c[++].

This includes:

* __ptrauth qualifier support for ivars
* protection of isa and super fields
* protection of SEL typed ivars
* protection of class_ro_t data
* protection of methodlist pointers and content

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index b9f7579..08cf0ae 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1541,6 +1541,25 @@ void CompilerInvocation::setDefaultPointerAuthOptions(
           Key::ASIA, LangOpts.PointerAuthInitFiniAddressDiscrimination,
           Discrimination::Constant, InitFiniPointerConstantDiscriminator);
     }
+
+    Opts.ObjCMethodListFunctionPointers =
+        PointerAuthSchema(Key::ASIA, true, Discrimination::None);
+    Opts.ObjCMethodListPointer =
+        PointerAuthSchema(Key::ASDA, true, Discrimination::Constant,
+                          MethodListPointerConstantDiscriminator);
+    if (LangOpts.PointerAuthObjcIsa) {
+      Opts.ObjCIsaPointers =
+          PointerAuthSchema(Key::ASDA, true, Discrimination::Constant,
+                            IsaPointerConstantDiscriminator);
+      Opts.ObjCSuperPointers =
+          PointerAuthSchema(Key::ASDA, true, Discrimination::Constant,
+                            SuperPointerConstantDiscriminator);
+    }
+
+    if (LangOpts.PointerAuthObjcClassROPointers)
+      Opts.ObjCClassROPointers =
+          PointerAuthSchema(Key::ASDA, true, Discrimination::Constant,
+                            ClassROConstantDiscriminator);
   }
   Opts.ReturnAddresses = LangOpts.PointerAuthReturns;
   Opts.AuthTraps = LangOpts.PointerAuthAuthTraps;
@@ -3573,6 +3592,12 @@ static void GeneratePointerAuthArgs(const LangOptions &Opts,
     GenerateArg(Consumer, OPT_fptrauth_elf_got);
   if (Opts.AArch64JumpTableHardening)
     GenerateArg(Consumer, OPT_faarch64_jump_table_hardening);
+  if (Opts.PointerAuthObjcIsa)
+    GenerateArg(Consumer, OPT_fptrauth_objc_isa);
+  if (Opts.PointerAuthObjcInterfaceSel)
+    GenerateArg(Consumer, OPT_fptrauth_objc_interface_sel);
+  if (Opts.PointerAuthObjcClassROPointers)
+    GenerateArg(Consumer, OPT_fptrauth_objc_class_ro);
 }
 
 static void ParsePointerAuthArgs(LangOptions &Opts, ArgList &Args,
@@ -3596,6 +3621,15 @@ static void ParsePointerAuthArgs(LangOptions &Opts, ArgList &Args,
   Opts.PointerAuthELFGOT = Args.hasArg(OPT_fptrauth_elf_got);
   Opts.AArch64JumpTableHardening =
       Args.hasArg(OPT_faarch64_jump_table_hardening);
+
+  Opts.PointerAuthObjcIsa = Args.hasArg(OPT_fptrauth_objc_isa);
+  Opts.PointerAuthObjcClassROPointers = Args.hasArg(OPT_fptrauth_objc_class_ro);
+  Opts.PointerAuthObjcInterfaceSel =
+      Args.hasArg(OPT_fptrauth_objc_interface_sel);
+
+  if (Opts.PointerAuthObjcInterfaceSel)
+    Opts.PointerAuthObjcInterfaceSelKey =
+        static_cast<unsigned>(PointerAuthSchema::ARM8_3Key::ASDB);
 }
 
 /// Check if input file kind and language standard are compatible.