[clang] [Clang][ARM][AArch64] Add branch protection attributes to the defaults. (PR #83277)
Daniel Kiss via cfe-commits
cfe-commits at lists.llvm.org
Fri Jul 12 02:05:13 PDT 2024
https://github.com/DanielKristofKiss updated https://github.com/llvm/llvm-project/pull/83277
>From 0c3118713387246dc1c503f3792ba5af82e6b5eb Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Wed, 28 Feb 2024 15:18:31 +0100
Subject: [PATCH 1/8] Add branch protection attributes to the defaults.
These attributes are no longer inherited from the module flags,
therefore need to be added for synthetic functions.
---
clang/lib/CodeGen/CGCall.cpp | 16 ++++++++++
.../CodeGenCXX/arm64-generated-fn-attr.cpp | 30 +++++++++++++++++++
2 files changed, 46 insertions(+)
create mode 100644 clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 7e7b2b395f7d6..7b93f6d2dded1 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2030,6 +2030,22 @@ static void getTrivialDefaultFunctionAttributes(
std::tie(Var, Value) = Attr.split('=');
FuncAttrs.addAttribute(Var, Value);
}
+
+ TargetInfo::BranchProtectionInfo BPI(LangOpts);
+
+ if (BPI.SignReturnAddr != LangOptions::SignReturnAddressScopeKind::None) {
+ FuncAttrs.addAttribute("sign-return-address", BPI.getSignReturnAddrStr());
+ FuncAttrs.addAttribute(
+ "sign-return-address-key",
+ BPI.SignKey == LangOptions::SignReturnAddressKeyKind::AKey ? "a_key"
+ : "b_key");
+ }
+ if (BPI.BranchTargetEnforcement)
+ FuncAttrs.addAttribute("branch-target-enforcement", "true");
+ if (BPI.BranchProtectionPAuthLR)
+ FuncAttrs.addAttribute("branch-protection-pauth-lr", "true");
+ if (BPI.GuardedControlStack)
+ FuncAttrs.addAttribute("guarded-control-stack", "true");
}
/// Merges `target-features` from \TargetOpts and \F, and sets the result in
diff --git a/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
new file mode 100644
index 0000000000000..8daf44abd4f91
--- /dev/null
+++ b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -triple aarch64-none-none -mbranch-target-enforce -msign-return-address=all -fcxx-exceptions -fexceptions -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK
+
+// Check that functions generated by clang have the correct attributes
+
+class Example {
+public:
+ Example();
+ int fn();
+};
+
+// Initialization of var1 causes __cxx_global_var_init and __tls_init to be generated
+thread_local Example var1;
+extern thread_local Example var2;
+extern void fn();
+
+int testfn() noexcept {
+ // Calling fn in a noexcept function causes __clang_call_terminate to be generated
+ fn();
+ // Use of var1 and var2 causes TLS wrapper functions to be generated
+ return var1.fn() + var2.fn();
+}
+
+// CHECK: define {{.*}} @__cxx_global_var_init() [[ATTR1:#[0-9]+]]
+// CHECK: define {{.*}} @__clang_call_terminate({{.*}}) [[ATTR2:#[0-9]+]]
+// CHECK: define {{.*}} @_ZTW4var1() [[ATTR1]]
+// CHECK: define {{.*}} @_ZTW4var2() [[ATTR1]]
+// CHECK: define {{.*}} @__tls_init() [[ATTR1]]
+
+// CHECK: attributes [[ATTR1]] = { {{.*}}"branch-target-enforcement"="true"{{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
+// CHECK: attributes [[ATTR2]] = { {{.*}}"branch-target-enforcement"="true"{{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
>From 0e2a9e129bcb4f569a443494b9266ae482c73c94 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Wed, 28 Feb 2024 17:38:49 +0100
Subject: [PATCH 2/8] fixup! [Clang][Arm][AArch64] Add branch protection
attributes to the defaults.
---
clang/lib/CodeGen/CGCall.cpp | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 7b93f6d2dded1..131666d732b3d 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2035,10 +2035,7 @@ static void getTrivialDefaultFunctionAttributes(
if (BPI.SignReturnAddr != LangOptions::SignReturnAddressScopeKind::None) {
FuncAttrs.addAttribute("sign-return-address", BPI.getSignReturnAddrStr());
- FuncAttrs.addAttribute(
- "sign-return-address-key",
- BPI.SignKey == LangOptions::SignReturnAddressKeyKind::AKey ? "a_key"
- : "b_key");
+ FuncAttrs.addAttribute("sign-return-address-key", BPI.getSignKeyStr());
}
if (BPI.BranchTargetEnforcement)
FuncAttrs.addAttribute("branch-target-enforcement", "true");
>From 735d24d5fe8bb4f37d87cb2345cbe45d53b1ba42 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Mon, 4 Mar 2024 17:31:31 +0100
Subject: [PATCH 3/8] Move TargetInfo changes over.
Dropping restrictions on the member functions.
---
clang/include/clang/Basic/TargetInfo.h | 15 ---------------
1 file changed, 15 deletions(-)
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index 1f208b40f92cb..d8075ee97972e 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1415,14 +1415,10 @@ class TargetInfo : public TransferrableTargetInfo,
switch (SignReturnAddr) {
case LangOptions::SignReturnAddressScopeKind::None:
return "none";
- case LangOptions::SignReturnAddressScopeKind::NonLeaf:
return "non-leaf";
- case LangOptions::SignReturnAddressScopeKind::All:
- return "all";
}
llvm_unreachable("Unexpected SignReturnAddressScopeKind");
}
-
const char *getSignKeyStr() const {
switch (SignKey) {
case LangOptions::SignReturnAddressKeyKind::AKey:
@@ -1441,10 +1437,7 @@ class TargetInfo : public TransferrableTargetInfo,
? (LangOpts.isSignReturnAddressScopeAll()
? LangOptions::SignReturnAddressScopeKind::All
: LangOptions::SignReturnAddressScopeKind::NonLeaf)
- : LangOptions::SignReturnAddressScopeKind::None;
SignKey = LangOpts.isSignReturnAddressWithAKey()
- ? LangOptions::SignReturnAddressKeyKind::AKey
- : LangOptions::SignReturnAddressKeyKind::BKey;
BranchTargetEnforcement = LangOpts.BranchTargetEnforcement;
BranchProtectionPAuthLR = LangOpts.BranchProtectionPAuthLR;
GuardedControlStack = LangOpts.GuardedControlStack;
@@ -1468,19 +1461,11 @@ class TargetInfo : public TransferrableTargetInfo,
if (GuardedControlStack)
FuncAttrs.addAttribute("guarded-control-stack");
}
- };
/// Determine if the Architecture in this TargetInfo supports branch
/// protection
virtual bool isBranchProtectionSupportedArch(StringRef Arch) const {
return false;
- }
-
- /// Determine if this TargetInfo supports the given branch protection
- /// specification
- virtual bool validateBranchProtection(StringRef Spec, StringRef Arch,
- BranchProtectionInfo &BPI,
- StringRef &Err) const {
Err = "";
return false;
}
>From 911273af8542f94546646d398cfa674b98edd517 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Mon, 4 Mar 2024 17:32:41 +0100
Subject: [PATCH 4/8] Simplify the code.
---
clang/lib/CodeGen/CGCall.cpp | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 131666d732b3d..8404954577417 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2032,17 +2032,7 @@ static void getTrivialDefaultFunctionAttributes(
}
TargetInfo::BranchProtectionInfo BPI(LangOpts);
-
- if (BPI.SignReturnAddr != LangOptions::SignReturnAddressScopeKind::None) {
- FuncAttrs.addAttribute("sign-return-address", BPI.getSignReturnAddrStr());
- FuncAttrs.addAttribute("sign-return-address-key", BPI.getSignKeyStr());
- }
- if (BPI.BranchTargetEnforcement)
- FuncAttrs.addAttribute("branch-target-enforcement", "true");
- if (BPI.BranchProtectionPAuthLR)
- FuncAttrs.addAttribute("branch-protection-pauth-lr", "true");
- if (BPI.GuardedControlStack)
- FuncAttrs.addAttribute("guarded-control-stack", "true");
+ BPI.setFnAttributes(FuncAttrs);
}
/// Merges `target-features` from \TargetOpts and \F, and sets the result in
>From 30c29d2d024b9dae1757ed04da95ba9583f3f763 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Mon, 4 Mar 2024 17:32:59 +0100
Subject: [PATCH 5/8] Simplify the test invocation
---
clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
index 8daf44abd4f91..de35c32e9c18a 100644
--- a/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
+++ b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple aarch64-none-none -mbranch-target-enforce -msign-return-address=all -fcxx-exceptions -fexceptions -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang_cc1 -triple aarch64 -mbranch-target-enforce -msign-return-address=all -fcxx-exceptions -fexceptions -emit-llvm %s -o - | FileCheck %s
// Check that functions generated by clang have the correct attributes
>From 287fab911e67f1c1423282a38b77b77baecc1903 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Wed, 10 Jul 2024 16:44:01 +0200
Subject: [PATCH 6/8] drop TargetInfo changes
---
clang/include/clang/Basic/TargetInfo.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index d8075ee97972e..1f208b40f92cb 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1415,10 +1415,14 @@ class TargetInfo : public TransferrableTargetInfo,
switch (SignReturnAddr) {
case LangOptions::SignReturnAddressScopeKind::None:
return "none";
+ case LangOptions::SignReturnAddressScopeKind::NonLeaf:
return "non-leaf";
+ case LangOptions::SignReturnAddressScopeKind::All:
+ return "all";
}
llvm_unreachable("Unexpected SignReturnAddressScopeKind");
}
+
const char *getSignKeyStr() const {
switch (SignKey) {
case LangOptions::SignReturnAddressKeyKind::AKey:
@@ -1437,7 +1441,10 @@ class TargetInfo : public TransferrableTargetInfo,
? (LangOpts.isSignReturnAddressScopeAll()
? LangOptions::SignReturnAddressScopeKind::All
: LangOptions::SignReturnAddressScopeKind::NonLeaf)
+ : LangOptions::SignReturnAddressScopeKind::None;
SignKey = LangOpts.isSignReturnAddressWithAKey()
+ ? LangOptions::SignReturnAddressKeyKind::AKey
+ : LangOptions::SignReturnAddressKeyKind::BKey;
BranchTargetEnforcement = LangOpts.BranchTargetEnforcement;
BranchProtectionPAuthLR = LangOpts.BranchProtectionPAuthLR;
GuardedControlStack = LangOpts.GuardedControlStack;
@@ -1461,11 +1468,19 @@ class TargetInfo : public TransferrableTargetInfo,
if (GuardedControlStack)
FuncAttrs.addAttribute("guarded-control-stack");
}
+ };
/// Determine if the Architecture in this TargetInfo supports branch
/// protection
virtual bool isBranchProtectionSupportedArch(StringRef Arch) const {
return false;
+ }
+
+ /// Determine if this TargetInfo supports the given branch protection
+ /// specification
+ virtual bool validateBranchProtection(StringRef Spec, StringRef Arch,
+ BranchProtectionInfo &BPI,
+ StringRef &Err) const {
Err = "";
return false;
}
>From e64847d840b27e287162a574aec281b016362966 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Fri, 12 Jul 2024 11:02:11 +0200
Subject: [PATCH 7/8] update test accorindg to upstream changes
---
clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
index de35c32e9c18a..18d9da40d469b 100644
--- a/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
+++ b/clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
@@ -26,5 +26,5 @@ int testfn() noexcept {
// CHECK: define {{.*}} @_ZTW4var2() [[ATTR1]]
// CHECK: define {{.*}} @__tls_init() [[ATTR1]]
-// CHECK: attributes [[ATTR1]] = { {{.*}}"branch-target-enforcement"="true"{{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
-// CHECK: attributes [[ATTR2]] = { {{.*}}"branch-target-enforcement"="true"{{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
+// CHECK: attributes [[ATTR1]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
+// CHECK: attributes [[ATTR2]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
>From 12b7656d95b9397df3cab87dc78e1e4c4befc9d0 Mon Sep 17 00:00:00 2001
From: Daniel Kiss <daniel.kiss at arm.com>
Date: Thu, 11 Jul 2024 21:05:46 +0200
Subject: [PATCH 8/8] update as BranchProtectionInfo changes
---
clang/lib/CodeGen/CGCall.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 8404954577417..a38484941ba24 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2032,7 +2032,7 @@ static void getTrivialDefaultFunctionAttributes(
}
TargetInfo::BranchProtectionInfo BPI(LangOpts);
- BPI.setFnAttributes(FuncAttrs);
+ TargetCodeGenInfo::setBranchProtectionFnAttributes(BPI, FuncAttrs);
}
/// Merges `target-features` from \TargetOpts and \F, and sets the result in
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