Auto merge of #88354 - Jmc18134:hint-space-pauth-opt, r=nagisa

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.

2 files changed, 30 insertions, 1 deletions

diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 9f24a95482c..bb16bc5dccd 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, PacRet};
 use rustc_session::Session;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;
@@ -242,6 +242,34 @@ pub unsafe fn create_module<'ll>(
         }
     }
 
+    if sess.target.arch == "aarch64" {
+        let BranchProtection { bti, pac_ret: pac } = sess.opts.debugging_opts.branch_protection;
+
+        llvm::LLVMRustAddModuleFlag(
+            llmod,
+            "branch-target-enforcement\0".as_ptr().cast(),
+            bti.into(),
+        );
+
+        llvm::LLVMRustAddModuleFlag(
+            llmod,
+            "sign-return-address\0".as_ptr().cast(),
+            pac.is_some().into(),
+        );
+        let pac_opts = pac.unwrap_or(PacRet { leaf: false, key: PAuthKey::A });
+        llvm::LLVMRustAddModuleFlag(
+            llmod,
+            "sign-return-address-all\0".as_ptr().cast(),
+            pac_opts.leaf.into(),
+        );
+        let is_bkey = if pac_opts.key == PAuthKey::A { false } else { true };
+        llvm::LLVMRustAddModuleFlag(
+            llmod,
+            "sign-return-address-with-bkey\0".as_ptr().cast(),
+            is_bkey.into(),
+        );
+    }
+
     llmod
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/declare.rs b/compiler/rustc_codegen_llvm/src/declare.rs
index 90d0d5caba1..a6e06ffa819 100644
--- a/compiler/rustc_codegen_llvm/src/declare.rs
+++ b/compiler/rustc_codegen_llvm/src/declare.rs
@@ -47,6 +47,7 @@ fn declare_raw_fn<'ll>(
 
     attributes::default_optimisation_attrs(cx.tcx.sess, llfn);
     attributes::non_lazy_bind(cx.sess(), llfn);
+
     llfn
 }