From 95ac65bc32180744cbc67d4e82a0f6417fb92aa9 Mon Sep 17 00:00:00 2001
From: Oliver Stannard <oliver.stannard@arm.com>
Date: Thu, 13 Sep 2018 10:25:36 +0000
Subject: [PATCH] [AArch64] Enable return address signing for static ctors

Functions generated by clang and included in the .init_array section (such as
static constructors) do not follow the usual code path for adding
target-specific function attributes, so we have to add the return address
signing attribute here too, as is currently done for the sanitisers.

Differential revision: https://reviews.llvm.org/D51418

llvm-svn: 342126
---
 clang/lib/CodeGen/CGDeclCXX.cpp                     |  6 ++++++
 .../aarch64-sign-return-address-static-ctor.cpp     | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 clang/test/CodeGenCXX/aarch64-sign-return-address-static-ctor.cpp

diff --git a/clang/lib/CodeGen/CGDeclCXX.cpp b/clang/lib/CodeGen/CGDeclCXX.cpp
index 4499eb9..3f96fea 100644
--- a/clang/lib/CodeGen/CGDeclCXX.cpp
+++ b/clang/lib/CodeGen/CGDeclCXX.cpp
@@ -359,6 +359,12 @@ llvm::Function *CodeGenModule::CreateGlobalInitOrDestructFunction(
       !isInSanitizerBlacklist(SanitizerKind::ShadowCallStack, Fn, Loc))
     Fn->addFnAttr(llvm::Attribute::ShadowCallStack);
 
+  auto RASignKind = getCodeGenOpts().getSignReturnAddress();
+  if (RASignKind != CodeGenOptions::SignReturnAddressScope::None)
+    Fn->addFnAttr("sign-return-address",
+                  RASignKind == CodeGenOptions::SignReturnAddressScope::All
+                      ? "all"
+                      : "non-leaf");
   return Fn;
 }
 
diff --git a/clang/test/CodeGenCXX/aarch64-sign-return-address-static-ctor.cpp b/clang/test/CodeGenCXX/aarch64-sign-return-address-static-ctor.cpp
new file mode 100644
index 0000000..de24eee
--- /dev/null
+++ b/clang/test/CodeGenCXX/aarch64-sign-return-address-static-ctor.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang -target aarch64-arm-none-eabi -S -emit-llvm -o - -msign-return-address=none  %s | \
+// RUN: FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-NONE
+// RUN: %clang -target aarch64-arm-none-eabi -S -emit-llvm -o - -msign-return-address=non-leaf %s | \
+// RUN: FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-PARTIAL
+// RUN: %clang -target aarch64-arm-none-eabi -S -emit-llvm -o - -msign-return-address=all %s | \
+// RUN: FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-ALL
+
+struct Foo {
+  Foo() {}
+  ~Foo() {}
+};
+
+Foo f;
+
+// CHECK: @llvm.global_ctors {{.*}}i32 65535, void ()* @[[CTOR_FN:.*]], i8* null
+
+// CHECK: @[[CTOR_FN]]() #[[ATTR:[0-9]*]]
+
+// CHECK-NONE-NOT: attributes #[[ATTR]] = { {{.*}} "sign-return-address"={{.*}} }}
+// CHECK-PARTIAL: attributes #[[ATTR]] = { {{.*}} "sign-return-address"="non-leaf" {{.*}}}
+// CHECK-ALL: attributes #[[ATTR]] = { {{.*}} "sign-return-address"="all" {{.*}} }
-- 
2.7.4