From da192e499e442fc433ef8ab2290cf0021e214c85 Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov@arm.com>
Date: Thu, 30 Nov 2023 11:18:02 +0000
Subject: [PATCH 2/7] [clang][AArch64] Pass down stack clash protection options
 to LLVM/Backend (#68993)

---
 clang/lib/CodeGen/CodeGenModule.cpp         | 13 +++++++++++++
 clang/lib/Driver/ToolChains/Clang.cpp       |  2 +-
 clang/test/CodeGen/stack-clash-protection.c | 18 +++++++++++-------
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index f09d1129b128..eabc4aabea06 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1067,6 +1067,15 @@ void CodeGenModule::Release() {
                                 "sign-return-address-with-bkey", 1);
   }
 
+  if (CodeGenOpts.StackClashProtector)
+    getModule().addModuleFlag(
+        llvm::Module::Override, "probe-stack",
+        llvm::MDString::get(TheModule.getContext(), "inline-asm"));
+
+  if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
+    getModule().addModuleFlag(llvm::Module::Min, "stack-probe-size",
+                              CodeGenOpts.StackProbeSize);
+
   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
     llvm::LLVMContext &Ctx = TheModule.getContext();
     getModule().addModuleFlag(
@@ -2261,6 +2270,10 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
   if (CodeGenOpts.StackClashProtector)
     B.addAttribute("probe-stack", "inline-asm");
 
+  if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
+    B.addAttribute("stack-probe-size",
+                   std::to_string(CodeGenOpts.StackProbeSize));
+
   if (!hasUnwindExceptions(LangOpts))
     B.addAttribute(llvm::Attribute::NoUnwind);
 
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 6b5930990f11..25627c72f858 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3473,7 +3473,7 @@ static void RenderSCPOptions(const ToolChain &TC, const ArgList &Args,
     return;
 
   if (!EffectiveTriple.isX86() && !EffectiveTriple.isSystemZ() &&
-      !EffectiveTriple.isPPC64())
+      !EffectiveTriple.isPPC64() && !EffectiveTriple.isAArch64())
     return;
 
   Args.addOptInFlag(CmdArgs, options::OPT_fstack_clash_protection,
diff --git a/clang/test/CodeGen/stack-clash-protection.c b/clang/test/CodeGen/stack-clash-protection.c
index 67571f5cdb2c..dab9ee768c28 100644
--- a/clang/test/CodeGen/stack-clash-protection.c
+++ b/clang/test/CodeGen/stack-clash-protection.c
@@ -1,8 +1,9 @@
 // Check the correct function attributes are generated
-// RUN: %clang_cc1 -triple x86_64-linux -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
-// RUN: %clang_cc1 -triple s390x-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
-// RUN: %clang_cc1 -triple powerpc64le-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
-// RUN: %clang_cc1 -triple powerpc64-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-linux -O0 -S -emit-llvm -o- %s -fstack-clash-protection -mstack-probe-size=8192 | FileCheck %s
+// RUN: %clang_cc1 -triple s390x-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection -mstack-probe-size=8192 | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64le-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection -mstack-probe-size=8192 | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection -mstack-probe-size=8192 | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection -mstack-probe-size=8192 | FileCheck %s
 
 // CHECK: define{{.*}} void @large_stack() #[[A:.*]] {
 void large_stack(void) {
@@ -11,15 +12,18 @@ void large_stack(void) {
     stack[i] = i;
 }
 
-// CHECK: define{{.*}} void @vla({{.*}}) #[[A:.*]] {
+// CHECK: define{{.*}} void @vla({{.*}}) #[[A]] {
 void vla(int n) {
   volatile int vla[n];
   __builtin_memset(&vla[0], 0, 1);
 }
 
-// CHECK: define{{.*}} void @builtin_alloca({{.*}}) #[[A:.*]] {
+// CHECK: define{{.*}} void @builtin_alloca({{.*}}) #[[A]] {
 void builtin_alloca(int n) {
   volatile void *mem = __builtin_alloca(n);
 }
 
-// CHECK: attributes #[[A]] = {{.*}} "probe-stack"="inline-asm"
+// CHECK: attributes #[[A]] = {{.*}}"probe-stack"="inline-asm" {{.*}}"stack-probe-size"="8192"
+
+// CHECK: !{i32 4, !"probe-stack", !"inline-asm"}
+// CHECK: !{i32 8, !"stack-probe-size", i32 8192}
-- 
2.42.0.windows.2

