[clang] bfe0719 - [ARM][clang] Option b-key must not affect __ARM_FEATURE_PAC_DEFAULT

Thu Dec 9 05:38:13 PST 2021

Author: Ties Stuij
Date: 2021-12-09T13:37:52Z
New Revision: bfe07195bb1f517b2809107098b91767ad8c9460

URL: https://github.com/llvm/llvm-project/commit/bfe07195bb1f517b2809107098b91767ad8c9460
DIFF: https://github.com/llvm/llvm-project/commit/bfe07195bb1f517b2809107098b91767ad8c9460.diff

LOG: [ARM][clang] Option b-key must not affect __ARM_FEATURE_PAC_DEFAULT

When using -mbranch-protection=pac-ret+b-key, macro __ARM_FEATURE_PAC_DEFAULT
should still have the value corresponding to a-key, because b-key is only valid
for AArch64.

This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:

https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension

The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:

https://developer.arm.com/documentation/ddi0553/latest

The following people contributed to this patch:

- Victor Campos

Reviewed By: danielkiss

Differential Revision: https://reviews.llvm.org/D115140

Added: 
    

Modified: 
    clang/lib/Basic/Targets/ARM.cpp
    clang/test/Preprocessor/arm-target-features.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index 81b79cfe19e47..c619d6cde41df 100644

--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -911,7 +911,7 @@ void ARMTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__ARM_FEATURE_BTI_DEFAULT", "1");
 
   if (Opts.hasSignReturnAddress()) {
-    unsigned Value = Opts.isSignReturnAddressWithAKey() ? 1 : 2;
+    unsigned Value = 1;
     if (Opts.isSignReturnAddressScopeAll())
       Value |= 1 << 2;
     Builder.defineMacro("__ARM_FEATURE_PAC_DEFAULT", Twine(Value));

diff  --git a/clang/test/Preprocessor/arm-target-features.c b/clang/test/Preprocessor/arm-target-features.c
index 49a5516e15d0d..bf4e7c41e3e23 100644
--- a/clang/test/Preprocessor/arm-target-features.c
+++ b/clang/test/Preprocessor/arm-target-features.c
@@ -881,20 +881,18 @@
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-NOBTI,CHECK-NOPAC %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-BTI,CHECK-NOPAC %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC,CHECK-NOBTI %s
-// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret+b-key -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-BKEY,CHECK-NOBTI %s
+// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret+b-key -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC,CHECK-NOBTI %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-LEAF,CHECK-NOBTI %s
-// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret+b-key+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-BKEY-LEAF,CHECK-NOBTI %s
+// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=pac-ret+b-key+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-LEAF,CHECK-NOBTI %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC,CHECK-BTI %s
-// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret+b-key -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-BKEY,CHECK-BTI %s
+// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret+b-key -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC,CHECK-BTI %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-LEAF,CHECK-BTI %s
-// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret+b-key+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-BKEY-LEAF,CHECK-BTI %s
+// RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -mbranch-protection=bti+pac-ret+b-key+leaf -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PAC-LEAF,CHECK-BTI %s
 // CHECK-NOBTI-NOT: #define __ARM_FEATURE_BTI_DEFAULT
 // CHECK-NOPAC-NOT: #define __ARM_FEATURE_PAC_DEFAULT
 // CHECK-BTI: #define __ARM_FEATURE_BTI_DEFAULT 1
 // CHECK-PAC: #define __ARM_FEATURE_PAC_DEFAULT 1
-// CHECK-PAC-BKEY: #define __ARM_FEATURE_PAC_DEFAULT 2
 // CHECK-PAC-LEAF: #define __ARM_FEATURE_PAC_DEFAULT 5
-// CHECK-PAC-BKEY-LEAF: #define __ARM_FEATURE_PAC_DEFAULT 6
 
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-NOBTI-EXT,CHECK-NOPAC-EXT %s
 // RUN: %clang -target arm-arm-none-eabi -march=armv7-m+pacbti -x c -E -dM %s -o - | FileCheck --check-prefixes=CHECK-PACBTI-EXT %s


        
