[clang] [clang][Driver] Allow `-fstack-clash-protection` for Fuchsia targets (PR #119633)

[Paul Kirth via cfe-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/119633

Fuchsia uses guard pages for the stack, similar to Linux 
and other targets, which are required for stack-clash-protection.

This patch adds Fuchsia to the list of allowed targets.

>From 68748b066f7c7bddc59977541f8298814a22623f Mon Sep 17 00:00:00 2001
From: Paul Kirth <paulkirth at google.com>
Date: Wed, 11 Dec 2024 14:51:07 -0800
Subject: [PATCH] [clang][Driver] Allow `-fstack-clash-protection` on Fuchsia

Fuchsia uses guard pages for the stack, similar to Linux and other
targets, which are required for stack-clash-protection.
---
 clang/lib/Driver/ToolChains/Clang.cpp      | 3 ++-
 clang/test/Driver/stack-clash-protection.c | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index d3206c3e8e25ed..a020e00cd17392 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3773,7 +3773,8 @@ static void RenderSCPOptions(const ToolChain &TC, const ArgList &Args,
                              ArgStringList &CmdArgs) {
   const llvm::Triple &EffectiveTriple = TC.getEffectiveTriple();
 
-  if (!EffectiveTriple.isOSFreeBSD() && !EffectiveTriple.isOSLinux())
+  if (!EffectiveTriple.isOSFreeBSD() && !EffectiveTriple.isOSLinux() &&
+      !EffectiveTriple.isOSFuchsia())
     return;
 
   if (!EffectiveTriple.isX86() && !EffectiveTriple.isSystemZ() &&
diff --git a/clang/test/Driver/stack-clash-protection.c b/clang/test/Driver/stack-clash-protection.c
index 222452f7897a6f..3b0476db9d3cb1 100644
--- a/clang/test/Driver/stack-clash-protection.c
+++ b/clang/test/Driver/stack-clash-protection.c
@@ -22,6 +22,11 @@
 // SCP-ll-win64-NOT: attributes {{.*}} "probe-stack"="inline-asm"
 // SCP-ll-win64: argument unused during compilation: '-fstack-clash-protection'
 
+// RUN: %clang -target x86_64-unknown-fuchsia -fstack-clash-protection -### %s 2>&1 | FileCheck %s -check-prefix=SCP-FUCHSIA
+// RUN: %clang -target aarch64-unknown-fuchsia -fstack-clash-protection -### %s 2>&1 | FileCheck %s -check-prefix=SCP-FUCHSIA
+// RUN: %clang -target riscv64-unknown-fuchsia -fstack-clash-protection -### %s 2>&1 | FileCheck %s -check-prefix=SCP-FUCHSIA
+// SCP-FUCHSIA: "-fstack-clash-protection"
+
 int foo(int c) {
   int r;
   __asm__("sub %0, %%rsp"