Add codegen option for branch protection and pointer authentication on AArch64

The branch-protection codegen option enables the use of hint-space pointer
authentication code for AArch64 targets

1 files changed, 33 insertions, 1 deletions

diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 613a8df891c..da05b5c0cba 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -21,7 +21,7 @@ use rustc_middle::ty::layout::{
 };
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
-use rustc_session::config::{CFGuard, CrateType, DebugInfo};
+use rustc_session::config::{BranchProtection, CFGuard, CrateType, DebugInfo, PAuthKey};
 use rustc_session::Session;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;
@@ -242,6 +242,38 @@ pub unsafe fn create_module(
         }
     }
 
+    if sess.target.arch == "aarch64" {
+        let BranchProtection { bti, pac_ret: pac } = sess.opts.cg.branch_protection;
+
+        llvm::LLVMRustAddModuleFlag(
+            llmod,
+            "branch-target-enforcement\0".as_ptr().cast(),
+            bti.into(),
+        );
+
+        if let Some(pac_opts) = pac {
+            llvm::LLVMRustAddModuleFlag(llmod, "sign-return-address\0".as_ptr().cast(), 1);
+            llvm::LLVMRustAddModuleFlag(
+                llmod,
+                "sign-return-address-all\0".as_ptr().cast(),
+                pac_opts.leaf.into(),
+            );
+            llvm::LLVMRustAddModuleFlag(
+                llmod,
+                "sign-return-address-with-bkey\0".as_ptr().cast(),
+                if pac_opts.key == PAuthKey::A { 0 } else { 1 },
+            );
+        } else {
+            llvm::LLVMRustAddModuleFlag(llmod, "sign-return-address\0".as_ptr().cast(), 0);
+            llvm::LLVMRustAddModuleFlag(llmod, "sign-return-address-all\0".as_ptr().cast(), 0);
+            llvm::LLVMRustAddModuleFlag(
+                llmod,
+                "sign-return-address-with-bkey\0".as_ptr().cast(),
+                0,
+            );
+        }
+    }
+
     llmod
 }