[clang][AARCH64] Add __ARM_FEATURE_{PAC, BTI}_DEFAULT defines
Summary:
As defined by Arm C Language Extensions (ACLE) these macro defines
should be set to specific values depending on -mbranch-protection.
Reviewers: chill
Reviewed By: chill
Subscribers: danielkiss, cfe-commits, kristof.beyls
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77134
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index 0902633..0a0cbaf 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -367,6 +367,21 @@
/// Return the OpenCL C or C++ version as a VersionTuple.
VersionTuple getOpenCLVersionTuple() const;
+
+ /// Check if return address signing is enabled.
+ bool hasSignReturnAddress() const {
+ return getSignReturnAddressScope() != SignReturnAddressScopeKind::None;
+ }
+
+ /// Check if return address signing uses AKey.
+ bool isSignReturnAddressWithAKey() const {
+ return getSignReturnAddressKey() == SignReturnAddressKeyKind::AKey;
+ }
+
+ /// Check if leaf functions are also signed.
+ bool isSignReturnAddressScopeAll() const {
+ return getSignReturnAddressScope() == SignReturnAddressScopeKind::All;
+ }
};
/// Floating point control options
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index f70a534..8ceb7f2 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -283,6 +283,27 @@
if ((FPU & NeonMode) && HasFP16FML)
Builder.defineMacro("__ARM_FEATURE_FP16FML", "1");
+ if (Opts.hasSignReturnAddress()) {
+ // Bitmask:
+ // 0: Protection using the A key
+ // 1: Protection using the B key
+ // 2: Protection including leaf functions
+ unsigned Value = 0;
+
+ if (Opts.isSignReturnAddressWithAKey())
+ Value |= (1 << 0);
+ else
+ Value |= (1 << 1);
+
+ if (Opts.isSignReturnAddressScopeAll())
+ Value |= (1 << 2);
+
+ Builder.defineMacro("__ARM_FEATURE_PAC_DEFAULT", std::to_string(Value));
+ }
+
+ if (Opts.BranchTargetEnforcement)
+ Builder.defineMacro("__ARM_FEATURE_BTI_DEFAULT", "1");
+
switch (ArchKind) {
default:
break;
diff --git a/clang/test/Preprocessor/aarch64-target-features.c b/clang/test/Preprocessor/aarch64-target-features.c
index c62c82a..9cb12f8 100644
--- a/clang/test/Preprocessor/aarch64-target-features.c
+++ b/clang/test/Preprocessor/aarch64-target-features.c
@@ -39,6 +39,8 @@
// CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
// CHECK-NOT: __ARM_FEATURE_SVE
// CHECK-NOT: __ARM_FEATURE_DOTPROD
+// CHECK-NOT: __ARM_FEATURE_PAC_DEFAULT
+// CHECK-NOT: __ARM_FEATURE_BTI_DEFAULT
// RUN: %clang -target aarch64-none-linux-gnu -march=armv8-a+crypto -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRYPTO %s
// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+crypto -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRYPTO %s
@@ -334,3 +336,33 @@
// ================== Check Memory Tagging Extensions (MTE).
// RUN: %clang -target arm64-none-linux-gnu -march=armv8.5-a+memtag -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-MEMTAG %s
// CHECK-MEMTAG: __ARM_FEATURE_MEMORY_TAGGING 1
+
+// ================== Check Pointer Authentication Extension (PAuth).
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8.5-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=none -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=bti -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=standard -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+b-key -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-BKEY %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+leaf -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-ALL %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+leaf+b-key -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-BKEY-ALL %s
+// CHECK-PAUTH-OFF-NOT: __ARM_FEATURE_PAC_DEFAULT
+// CHECK-PAUTH: #define __ARM_FEATURE_PAC_DEFAULT 1
+// CHECK-PAUTH-BKEY: #define __ARM_FEATURE_PAC_DEFAULT 2
+// CHECK-PAUTH-ALL: #define __ARM_FEATURE_PAC_DEFAULT 5
+// CHECK-PAUTH-BKEY-ALL: #define __ARM_FEATURE_PAC_DEFAULT 6
+
+// ================== Check Branch Target Identification (BTI).
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8.5-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=none -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+leaf -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+b-key -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+leaf+b-key -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI-OFF %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=standard -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=bti -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI %s
+// RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -mbranch-protection=pac-ret+bti -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-BTI %s
+// CHECK-BTI-OFF-NOT: __ARM_FEATURE_BTI_DEFAULT
+// CHECK-BTI: #define __ARM_FEATURE_BTI_DEFAULT 1