[llvm-branch-commits] [clang] release/21.x: [Driver] DragonFly does not support C11 threads (#154886) (PR #154897)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/154897

Backport 0fff4605922d137252875f072b3fb2973dbf9693

Requested by: @brad0

>From 0fe516b9350e5a08ee24a2be318d0971c1b2b0b3 Mon Sep 17 00:00:00 2001
From: Brad Smith <brad at comstyle.com>
Date: Fri, 22 Aug 2025 02:02:52 -0400
Subject: [PATCH] [Driver] DragonFly does not support C11 threads (#154886)

(cherry picked from commit 0fff4605922d137252875f072b3fb2973dbf9693)
---
 clang/lib/Basic/Targets/OSTargets.h | 3 +++
 clang/test/Preprocessor/init.c      | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index 97b2caa22d8e4..c1a68f464e831 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -174,6 +174,9 @@ class LLVM_LIBRARY_VISIBILITY DragonFlyBSDTargetInfo
     DefineStd(Builder, "unix", Opts);
     if (this->HasFloat128)
       Builder.defineMacro("__FLOAT128__");
+
+    if (Opts.C11)
+      Builder.defineMacro("__STDC_NO_THREADS__");
   }
 
 public:
diff --git a/clang/test/Preprocessor/init.c b/clang/test/Preprocessor/init.c
index bed39dc3e34dc..7e0df96141364 100644
--- a/clang/test/Preprocessor/init.c
+++ b/clang/test/Preprocessor/init.c
@@ -1622,6 +1622,14 @@
 // RUN: %clang_cc1 -x c -std=c99 -E -dM -ffreestanding -triple=amd64-unknown-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD-STDC-N %s
 // OPENBSD-STDC-N-NOT:#define __STDC_NO_THREADS__ 1
 //
+// RUN: %clang_cc1 -x c -std=c11 -E -dM -ffreestanding -triple=x86_64-unknown-dragonfly < /dev/null | FileCheck -match-full-lines -check-prefix DRAGONFLY-STDC %s
+// RUN: %clang_cc1 -x c -std=gnu11 -E -dM -ffreestanding -triple=x86_64-unknown-dragonfly < /dev/null | FileCheck -match-full-lines -check-prefix DRAGONFLY-STDC %s
+// RUN: %clang_cc1 -x c -std=c17 -E -dM -ffreestanding -triple=x86_64-unknown-dragonfly < /dev/null | FileCheck -match-full-lines -check-prefix DRAGONFLY-STDC %s
+// DRAGONFLY-STDC:#define __STDC_NO_THREADS__ 1
+//
+// RUN: %clang_cc1 -x c -std=c99 -E -dM -ffreestanding -triple=x86_64-unknown-dragonfly < /dev/null | FileCheck -match-full-lines -check-prefix DRAGONFLY-STDC-N %s
+// DRAGONFLY-STDC-N-NOT:#define __STDC_NO_THREADS__ 1
+//
 // RUN: %clang_cc1 -triple=aarch64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s
 // RUN: %clang_cc1 -triple=riscv64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s
 // RUN: %clang_cc1 -triple=x86_64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s