From dbcb9f3598b51be317618a854294f07eff935673 Mon Sep 17 00:00:00 2001
From: Christopher Friedt <chris@friedt.co>
Date: Mon, 19 Feb 2024 06:27:40 -0500
Subject: [PATCH] libc: add option for c11 threads

Add a config option for C11 threads.

Signed-off-by: Christopher Friedt <chris@friedt.co>
---
 config/libc.in          | 10 ++++++++++
 config/libc/newlib.in   |  4 ++++
 scripts/build/cc/gcc.sh | 23 ++++++++++++++---------
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/config/libc.in b/config/libc.in
index c132fc6928..c556bd2fe4 100644
--- a/config/libc.in
+++ b/config/libc.in
@@ -19,6 +19,10 @@ config LIBC_SUPPORT_THREADS_POSIX
     bool
     select LIBC_SUPPORT_THREADS_ANY
 
+config LIBC_SUPPORT_THREADS_C11
+    bool
+    select LIBC_SUPPORT_THREADS_ANY
+
 config LIBC_SUPPORT_THREADS_NONE
     bool
 
@@ -40,6 +44,7 @@ choice
     default THREADS_NATIVE         if LIBC_SUPPORT_THREADS_NATIVE
     default THREADS_LT             if LIBC_SUPPORT_THREADS_LT
     default THREADS_POSIX          if LIBC_SUPPORT_THREADS_POSIX
+    default THREADS_C11            if LIBC_SUPPORT_THREADS_C11
     default THREADS_NONE
 
 config THREADS_NATIVE
@@ -63,6 +68,11 @@ config THREADS_POSIX
     prompt "posix"
     depends on LIBC_SUPPORT_THREADS_POSIX
 
+config THREADS_C11
+    bool
+    prompt "c11"
+    depends on LIBC_SUPPORT_THREADS_C11
+
 config THREADS_NONE
     bool
     prompt "none"
diff --git a/config/libc/newlib.in b/config/libc/newlib.in
index f1cb29be52..2c5af409fc 100644
--- a/config/libc/newlib.in
+++ b/config/libc/newlib.in
@@ -2,6 +2,7 @@
 
 ## depends on BARE_METAL
 ## select LIBC_PROVIDES_CXA_ATEXIT
+## select LIBC_SUPPORT_THREADS_C11
 ## select LIBC_SUPPORT_THREADS_NONE
 ## select CC_CORE_NEEDED
 
@@ -12,6 +13,9 @@
 ## help array of processors, and will usually work on any architecture with
 ## help the addition of a few low-level routines.
 
+config THREADS
+    default "c11" if THREADS_C11
+
 config LIBC_NEWLIB_TARGET_CFLAGS
     string
     prompt "Target CFLAGS for newlib"
diff --git a/scripts/build/cc/gcc.sh b/scripts/build/cc/gcc.sh
index a8fd42b9cd..0601c59f50 100644
--- a/scripts/build/cc/gcc.sh
+++ b/scripts/build/cc/gcc.sh
@@ -1073,16 +1073,21 @@ do_gcc_backend() {
         extra_config+=("--with-host-libstdcxx=${host_libstdcxx_flags[*]}")
     fi
 
-    if [ "${CT_THREADS}" = "none" ]; then
+    case "${CT_THREADS}" in
+    none)
         extra_config+=("--disable-threads")
-    else
-        if [ "${CT_THREADS}" = "win32" ]; then
-            extra_config+=("--enable-threads=win32")
-            extra_config+=("--disable-win32-registry")
-        else
-            extra_config+=("--enable-threads=posix")
-        fi
-    fi
+        ;;
+    win32)
+        extra_config+=("--enable-threads=win32")
+        extra_config+=("--disable-win32-registry")
+        ;;
+    c11)
+        extra_config+=("--enable-threads=c11")
+        ;;
+    *)
+        extra_config+=("--enable-threads=posix")
+        ;;
+    esac
 
     if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ] || \
        [ "${enable_optspace}" = "yes" ]; then