[AArch64] Branch Protection and Return Address Signing B Key Support

- Add support for -mbranch-protection=<type>[+<type>]* where
  - <type> ::= [standard, none, bti, pac-ret[+b-key,+leaf]*]
- The protection emits relevant function attributes
  - sign-return-address=<scope>
  - sign-return-address-key=<key>
  - branch-protection

llvm-svn: 345273

1 files changed, 20 insertions, 2 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index abbf027ae01..52c8109818c 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1138,8 +1138,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   Opts.Addrsig = Args.hasArg(OPT_faddrsig);
 
-  if (Arg *A = Args.getLastArg(OPT_msign_return_address)) {
+  if (Arg *A = Args.getLastArg(OPT_msign_return_address_EQ)) {
     StringRef SignScope = A->getValue();
+
     if (SignScope.equals_lower("none"))
       Opts.setSignReturnAddress(CodeGenOptions::SignReturnAddressScope::None);
     else if (SignScope.equals_lower("all"))
@@ -1149,9 +1150,26 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
           CodeGenOptions::SignReturnAddressScope::NonLeaf);
     else
       Diags.Report(diag::err_drv_invalid_value)
-          << A->getAsString(Args) << A->getValue();
+          << A->getAsString(Args) << SignScope;
+
+    if (Arg *A = Args.getLastArg(OPT_msign_return_address_key_EQ)) {
+      StringRef SignKey = A->getValue();
+      if (!SignScope.empty() && !SignKey.empty()) {
+        if (SignKey.equals_lower("a_key"))
+          Opts.setSignReturnAddressKey(
+              CodeGenOptions::SignReturnAddressKeyValue::AKey);
+        else if (SignKey.equals_lower("b_key"))
+          Opts.setSignReturnAddressKey(
+              CodeGenOptions::SignReturnAddressKeyValue::BKey);
+        else
+          Diags.Report(diag::err_drv_invalid_value)
+              << A->getAsString(Args) << SignKey;
+      }
+    }
   }
 
+  Opts.BranchTargetEnforcement = Args.hasArg(OPT_mbranch_target_enforce);
+
   Opts.KeepStaticConsts = Args.hasArg(OPT_fkeep_static_consts);
 
   Opts.SpeculativeLoadHardening = Args.hasArg(OPT_mspeculative_load_hardening);