LibC+LibPthread: Implement function forwarding for libpthread

GCC will insert various calls to pthread functions when compiling
C++ code with static initializers, even when the user doesn't link
their program against libpthread explicitly.

This is used to make static initializers thread-safe, e.g. when
building a library that does not itself use thread functionality
and thus does not link against libpthread - but is intended to
be used with other code that does use libpthread explicitly.

This makes these symbols available in libc.

2 files changed, 62 insertions, 3 deletions

diff --git a/Userland/Libraries/LibC/bits/pthread_forward.h b/Userland/Libraries/LibC/bits/pthread_forward.h
new file mode 100644
index 0000000000..d416a01022
--- /dev/null
+++ b/Userland/Libraries/LibC/bits/pthread_forward.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2021, Gunnar Beutner <gunnar@beutner.name>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibPthread/pthread.h>
+
+struct PthreadFunctions {
+    int (*pthread_mutex_trylock)(pthread_mutex_t* mutex);
+    int (*pthread_mutex_destroy)(pthread_mutex_t*);
+
+    int (*pthread_mutexattr_init)(pthread_mutexattr_t*);
+    int (*pthread_mutexattr_settype)(pthread_mutexattr_t*, int);
+    int (*pthread_mutexattr_destroy)(pthread_mutexattr_t*);
+
+    int (*pthread_once)(pthread_once_t*, void (*)(void));
+
+    int (*pthread_cond_broadcast)(pthread_cond_t*);
+    int (*pthread_cond_init)(pthread_cond_t*, const pthread_condattr_t*);
+    int (*pthread_cond_signal)(pthread_cond_t*);
+    int (*pthread_cond_wait)(pthread_cond_t*, pthread_mutex_t*);
+    int (*pthread_cond_destroy)(pthread_cond_t*);
+    int (*pthread_cond_timedwait)(pthread_cond_t*, pthread_mutex_t*, const struct timespec*);
+};
+
+void __init_pthread_forward(PthreadFunctions);
diff --git a/Userland/Libraries/LibC/bits/pthread_integration.h b/Userland/Libraries/LibC/bits/pthread_integration.h
index 5a7b5e24e6..842cfc9fb3 100644
--- a/Userland/Libraries/LibC/bits/pthread_integration.h
+++ b/Userland/Libraries/LibC/bits/pthread_integration.h
@@ -27,6 +27,7 @@
 #pragma once
 
 #include <sys/cdefs.h>
+#include <sys/types.h>
 
 __BEGIN_DECLS
 
@@ -37,12 +38,21 @@ void __pthread_fork_atfork_register_prepare(void (*)(void));
 void __pthread_fork_atfork_register_parent(void (*)(void));
 void __pthread_fork_atfork_register_child(void (*)(void));
 
-int __pthread_mutex_lock(void*);
-int __pthread_mutex_unlock(void*);
-int __pthread_mutex_init(void*, const void*);
+int __pthread_mutex_lock(pthread_mutex_t*);
+int __pthread_mutex_unlock(pthread_mutex_t*);
+int __pthread_mutex_init(pthread_mutex_t*, const pthread_mutexattr_t*);
+
+typedef void (*KeyDestructor)(void*);
+
+int __pthread_key_create(pthread_key_t*, KeyDestructor);
+int __pthread_key_delete(pthread_key_t);
+void* __pthread_getspecific(pthread_key_t);
+int __pthread_setspecific(pthread_key_t, const void*);
 
 int __pthread_self();
 
+void __pthread_key_destroy_for_current_thread();
+
 #define __PTHREAD_MUTEX_NORMAL 0
 #define __PTHREAD_MUTEX_RECURSIVE 1
 #define __PTHREAD_MUTEX_INITIALIZER     \