[clang] [clang][AArch64] Pass down stack clash protection options to LLVM/Backend (PR #68993)

[Momchil Velikov via cfe-commits]

https://github.com/momchil-velikov updated https://github.com/llvm/llvm-project/pull/68993

>From b42de31d5584cddb90c22c94e9d971feaaf0b624 Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov at arm.com>
Date: Wed, 11 Oct 2023 17:22:51 +0100
Subject: [PATCH] [clang][AArch64] Pass down stack clash protection options to
 LLVM/Backend

---
 clang/lib/CodeGen/CodeGenModule.cpp         | 12 +++++++++++-
 clang/lib/Driver/ToolChains/Clang.cpp       |  2 +-
 clang/test/CodeGen/stack-clash-protection.c | 16 ++++++++++++----
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index f1b900be74b2cdf..bbde22fb5d82ee3 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1085,6 +1085,16 @@ void CodeGenModule::Release() {
                                 "sign-return-address-with-bkey", 1);
   }
 
+  if (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_be) {
+    auto *InlineAsm = llvm::MDString::get(TheModule.getContext(), "inline-asm");
+    if (CodeGenOpts.StackClashProtector)
+      getModule().addModuleFlag(llvm::Module::Override, "probe-stack",
+                                InlineAsm);
+    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(
@@ -2296,7 +2306,7 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
 
-  if (CodeGenOpts.StackClashProtector)
+  if (CodeGenOpts.StackClashProtector && !getTarget().getTriple().isAArch64())
     B.addAttribute("probe-stack", "inline-asm");
 
   if (!hasUnwindExceptions(LangOpts))
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index b462f5a44057d94..7add64ac6f2dfd5 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3507,7 +3507,7 @@ 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 67571f5cdb2c14c..2f502ef453d42f4 100644
--- a/clang/test/CodeGen/stack-clash-protection.c
+++ b/clang/test/CodeGen/stack-clash-protection.c
@@ -1,10 +1,12 @@
 // 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-prefixes CHECK-AARCH64
 
 // CHECK: define{{.*}} void @large_stack() #[[A:.*]] {
+// CHECK-AARCH64: define{{.*}} void @large_stack() #[[A:.*]] {
 void large_stack(void) {
   volatile int stack[20000], i;
   for (i = 0; i < sizeof(stack) / sizeof(int); ++i)
@@ -12,14 +14,20 @@ void large_stack(void) {
 }
 
 // CHECK: define{{.*}} void @vla({{.*}}) #[[A:.*]] {
+// CHECK-AARCH64: 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-AARCH64: define{{.*}} void @builtin_alloca({{.*}}) #[[A:.*]] {
 void builtin_alloca(int n) {
   volatile void *mem = __builtin_alloca(n);
 }
 
 // CHECK: attributes #[[A]] = {{.*}} "probe-stack"="inline-asm"
+// CHECK-AARCH64-NOT: attributes #[[A]] = {{.*}} "probe-stack"
+
+// CHECK-AARCH64: !{i32 4, !"probe-stack", !"inline-asm"}
+// CHECK-AARCH64: !{i32 8, !"stack-probe-size", i32 8192}