[clang] [llvm] [llvm] Enable TLSDESC by default on Fuchsia targets (PR #124990)

[Paul Kirth via llvm-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/124990

Fuchsia uses TLSDESC by default for all target architectures.

>From 6b6eb8cb15b8af034d6d79cbd28e9e5d31916f86 Mon Sep 17 00:00:00 2001
From: Paul Kirth <paulkirth at google.com>
Date: Wed, 29 Jan 2025 19:12:17 +0000
Subject: [PATCH] [llvm] Enable TLSDESC by default on Fuchsia targets

Fuchsia uses TLSDESC by default for all target architectures.
---
 clang/test/Driver/tls-dialect.c         | 5 +++++
 llvm/include/llvm/TargetParser/Triple.h | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/clang/test/Driver/tls-dialect.c b/clang/test/Driver/tls-dialect.c
index 3471b55b0ebae9..9ab79e87353d88 100644
--- a/clang/test/Driver/tls-dialect.c
+++ b/clang/test/Driver/tls-dialect.c
@@ -10,6 +10,11 @@
 /// TLSDESC is not on by default in Linux, even on RISC-V, and is covered above
 // RUN: %clang -### --target=riscv64-android %s 2>&1 | FileCheck --check-prefix=DESC %s
 
+/// Fuchsia supports TLSDESC by default for all architectures.
+// RUN: %clang -### --target=riscv64-unknown-fuchsia %s 2>&1 | FileCheck --check-prefix=DESC %s
+// RUN: %clang -### --target=aarch64-unknown-fuchsia %s 2>&1 | FileCheck --check-prefix=DESC %s
+// RUN: %clang -### --target=x86_64-unknown-fuchsia %s 2>&1 | FileCheck --check-prefix=DESC %s
+
 /// LTO
 // RUN: %clang -### --target=loongarch64-linux -flto -mtls-dialect=desc %s 2>&1 | FileCheck --check-prefix=LTO-DESC %s
 // RUN: %clang -### --target=loongarch64-linux -flto %s 2>&1 | FileCheck --check-prefix=LTO-NODESC %s
diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index 8097300c6e630c..6afc6ec974ca72 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -1119,7 +1119,9 @@ class Triple {
 
   /// True if the target supports both general-dynamic and TLSDESC, and TLSDESC
   /// is enabled by default.
-  bool hasDefaultTLSDESC() const { return isAndroid() && isRISCV64(); }
+  bool hasDefaultTLSDESC() const {
+    return (isAndroid() && isRISCV64()) || isOSFuchsia();
+  }
 
   /// Tests whether the target uses -data-sections as default.
   bool hasDefaultDataSections() const {