[clang] [Arm][AArch64][Clang] Respect function's branch protection attributes. (PR #101978)
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Mon Aug 5 06:31:17 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-codegen
Author: Daniel Kiss (DanielKristofKiss)
<details>
<summary>Changes</summary>
Default attributes assigned to all functions according to the command line parameters. Some functions might have their own attributes and we need to set or remove attributes accordingly.
Tests are updated to test this scenarios too.
---
Full diff: https://github.com/llvm/llvm-project/pull/101978.diff
4 Files Affected:
- (modified) clang/lib/CodeGen/TargetInfo.cpp (+22-3)
- (modified) clang/lib/CodeGen/TargetInfo.h (+3)
- (modified) clang/test/CodeGen/aarch64-branch-protection-attr.c (+12-1)
- (modified) clang/test/CodeGen/arm-branch-protection-attr-1.c (+6)
``````````diff
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 38faa50cf19cf..ec05db0ecfac5 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -209,9 +209,28 @@ llvm::Value *TargetCodeGenInfo::createEnqueuedBlockKernel(
void TargetCodeGenInfo::setBranchProtectionFnAttributes(
const TargetInfo::BranchProtectionInfo &BPI, llvm::Function &F) {
- llvm::AttrBuilder FuncAttrs(F.getContext());
- setBranchProtectionFnAttributes(BPI, FuncAttrs);
- F.addFnAttrs(FuncAttrs);
+ if (BPI.SignReturnAddr != LangOptions::SignReturnAddressScopeKind::None) {
+ F.addFnAttr("sign-return-address", BPI.getSignReturnAddrStr());
+ F.addFnAttr("sign-return-address-key", BPI.getSignKeyStr());
+ } else {
+ if (F.hasFnAttribute("sign-return-address"))
+ F.removeFnAttr("sign-return-address");
+ if (F.hasFnAttribute("sign-return-address-key"))
+ F.removeFnAttr("sign-return-address-key");
+ }
+
+ auto AddRemoveAttributeAsSet = [&](bool Set, const StringRef &ModAttr) {
+ if (Set)
+ F.addFnAttr(ModAttr);
+ else if (F.hasFnAttribute(ModAttr))
+ F.removeFnAttr(ModAttr);
+ };
+
+ AddRemoveAttributeAsSet(BPI.BranchTargetEnforcement,
+ "branch-target-enforcement");
+ AddRemoveAttributeAsSet(BPI.BranchProtectionPAuthLR,
+ "branch-protection-pauth-lr");
+ AddRemoveAttributeAsSet(BPI.GuardedControlStack, "guarded-control-stack");
}
void TargetCodeGenInfo::setBranchProtectionFnAttributes(
diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index 8f17c053f4783..639717bd9580d 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -418,10 +418,13 @@ class TargetCodeGenInfo {
return nullptr;
}
+ // Set the Branch Protection Attributes of the Function accordingly to the
+ // BPI. Might remove attributes if contradicts with the pass request.
static void
setBranchProtectionFnAttributes(const TargetInfo::BranchProtectionInfo &BPI,
llvm::Function &F);
+ // Add the Branch Protection Attributes of the FuncAttrs.
static void
setBranchProtectionFnAttributes(const TargetInfo::BranchProtectionInfo &BPI,
llvm::AttrBuilder &FuncAttrs);
diff --git a/clang/test/CodeGen/aarch64-branch-protection-attr.c b/clang/test/CodeGen/aarch64-branch-protection-attr.c
index e7ae7fb1570c9..c66bce1bee6d3 100644
--- a/clang/test/CodeGen/aarch64-branch-protection-attr.c
+++ b/clang/test/CodeGen/aarch64-branch-protection-attr.c
@@ -1,6 +1,18 @@
// REQUIRES: aarch64-registered-target
// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a %s -o - \
// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -mbranch-target-enforce %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -mguarded-control-stack %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -msign-return-address=non-leaf -msign-return-address-key=a_key %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -msign-return-address=all -msign-return-address-key=b_key %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -mbranch-protection-pauth-lr -msign-return-address=all -msign-return-address-key=a_key %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple aarch64 -emit-llvm -target-cpu generic -target-feature +v8.5a -mguarded-control-stack -mbranch-target-enforce -mbranch-protection-pauth-lr -msign-return-address=all -msign-return-address-key=a_key %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
__attribute__ ((target("branch-protection=none")))
void none() {}
@@ -83,7 +95,6 @@ void gcs() {}
// CHECK-DAG: attributes #[[#BTIPACLEAF]] = { {{.*}} "branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
-
// CHECK-DAG: attributes #[[#PAUTHLR]] = { {{.*}} "branch-protection-pauth-lr" {{.*}}"sign-return-address"="non-leaf" "sign-return-address-key"="a_key"
// CHECK-DAG: attributes #[[#PAUTHLR_BKEY]] = { {{.*}} "branch-protection-pauth-lr" {{.*}}"sign-return-address"="non-leaf" "sign-return-address-key"="b_key"
diff --git a/clang/test/CodeGen/arm-branch-protection-attr-1.c b/clang/test/CodeGen/arm-branch-protection-attr-1.c
index dd38cf347f04f..5ca6a1a4d13b4 100644
--- a/clang/test/CodeGen/arm-branch-protection-attr-1.c
+++ b/clang/test/CodeGen/arm-branch-protection-attr-1.c
@@ -1,6 +1,12 @@
// REQUIRES: arm-registered-target
// RUN: %clang_cc1 -triple thumbv7m-unknown-unknown-eabi -emit-llvm %s -o - \
// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple thumbv7m-unknown-unknown-eabi -mbranch-target-enforce -emit-llvm %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple thumbv7m-unknown-unknown-eabi -msign-return-address=all -emit-llvm %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -triple thumbv7m-unknown-unknown-eabi -mbranch-target-enforce -msign-return-address=all -emit-llvm %s -o - \
+// RUN: | FileCheck %s --check-prefix=CHECK
__attribute__((target("branch-protection=none"))) void none() {}
// CHECK: define{{.*}} void @none() #[[#NONE:]]
``````````
</details>
https://github.com/llvm/llvm-project/pull/101978
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