From b0b0e48409df359f3be15ba112a89365b10ecd67 Mon Sep 17 00:00:00 2001
From: Michael Matz <matz@suse.de>
Date: Fri, 22 May 2020 05:07:19 +0200
Subject: [PATCH] macos: Use <dispatch.h> for locking

the global compiler lock can't be a POSIX non-shared semaphore on
Darwin (because not implemented there).  Use the dispatch framework.
---
 libtcc.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/libtcc.c b/libtcc.c
index 81c65444..256dfb68 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -129,6 +129,20 @@ static void wait_sem(void)
 }
 #define WAIT_SEM() wait_sem()
 #define POST_SEM() LeaveCriticalSection(&tcc_cr);
+#elif defined __APPLE__
+/* Half-compatible MacOS doesn't have non-shared (process local)
+   semaphores.  Use the dispatch framework for lightweight locks.  */
+#include <dispatch/dispatch.h>
+static int tcc_sem_init;
+static dispatch_semaphore_t tcc_sem;
+static void wait_sem(void)
+{
+    if (!tcc_sem_init)
+      tcc_sem = dispatch_semaphore_create(1), tcc_sem_init = 1;
+    dispatch_semaphore_wait(tcc_sem, DISPATCH_TIME_FOREVER);
+}
+#define WAIT_SEM() wait_sem()
+#define POST_SEM() dispatch_semaphore_signal(tcc_sem)
 #else
 #include <semaphore.h>
 static int tcc_sem_init;