Atexit diff

diff.txt

--- a/uspace/app/cpptest/main.cpp
+++ b/uspace/app/cpptest/main.cpp
@@ -1,12 +1,100 @@
+#include <iostream>
+#include <tuple>
+
+struct Foo
+{
+    Foo()
+    {
+        /* std::ios_base::Init init{}; */
+        std::cout << "Foo::Foo()" << std::endl;
+    }
+
+    ~Foo()
+    {
+        std::cout << "Foo::~Foo()" << std::endl;
+    }
+
+    void say()
+    {
+        std::cout << "Foo::say()" << std::endl;
+    }
+};
+
+Foo foo{};
+
+struct Bar
+{
+    Bar()
+        : foo{}
+    {
+        std::cout << "Bar::Bar()" << std::endl;
+        foo.say();
+    }
+
+    ~Bar()
+    {
+        std::cout << "Bar::~Bar()" << std::endl;
+    }
+
+    void say()
+    {
+        std::cout << "Bar::say()" << std::endl;
+    }
+
+    Foo foo;
+};
+
+Bar bar{};
+
+__attribute__((constructor))
+void start()
+{
+    std::cout << "START" << std::endl;
+}
+
+__attribute__((destructor))
+void end()
+{
+    std::cout << "END" << std::endl;
+}
 
 int main()
 {
+    auto t = std::make_tuple<int, float>(2, 1.23f);
+    std::cout << "tuple<int, float> = " << std::get<0>(t) << ", " << std::get<1>(t) << std::endl;
+    std::get<0>(t) = 1;
+    std::get<1>(t) = 3.14f;
+    std::cout << "tuple<int, float> = " << std::get<0>(t) << ", " << std::get<1>(t) << std::endl;
+
+    int i{};
+    float f{};
+    std::tie(i, f) = t;
+    std::cout << "tie: i = " << i << " | f = " << f << std::endl;
+
+    i = 0;
+    f = 0.f;
+    std::tie(i, std::ignore) = t;
+    std::cout << "tie+ignore: i = " << i << " | f = " << f << std::endl;
+
+    auto t1 = std::make_tuple<int, int>(1, 2);
+    auto t2 = std::make_tuple<int, int>(2, 1);
+    std::cout << "before swap t1: (" << std::get<0>(t1) << ", " << std::get<1>(t1) << ")" << std::endl;
+    std::cout << "before swap t2: (" << std::get<0>(t2) << ", " << std::get<1>(t2) << ")" << std::endl;
+    t1.swap(t2);
+    std::cout << "after swap t1:  (" << std::get<0>(t1) << ", " << std::get<1>(t1) << ")" << std::endl;
+    std::cout << "after swap t2:  (" << std::get<0>(t2) << ", " << std::get<1>(t2) << ")" << std::endl;
+
+    auto t3 = std::make_tuple<float, int>(1.1, 10);
+    std::cout << "get<int>: " << std::get<int>(t3) << std::endl;
+    return 0;
 }

diff --git a/uspace/lib/c/generic/libc.c b/uspace/lib/c/generic/libc.c
index 246d1ae39..07c0b57db 100644
--- a/uspace/lib/c/generic/libc.c
+++ b/uspace/lib/c/generic/libc.c
@@ -117,7 +118,20 @@ void __main(void *pcb_ptr)
 		vfs_root_set(inbox_get("root"));
 		(void) vfs_cwd_set(__pcb->cwd);
 	}
-	
+
+	/*
+	 * C++ Static constructor calls.
+	 */
+	if (__pcb != NULL) {
+		void **ctors = __pcb->cpp_data.ctors;
+		int count = __pcb->cpp_data.ctors_count;
+
+		for (int i = 0; i < count; ++i) {
+			void *ctor = ctors[count - i - 1];
+			((void (*)())ctor)();
+		}
+	}
+
 	/*
 	 * Run main() and set task return value
 	 * according the result
@@ -128,6 +142,29 @@ void __main(void *pcb_ptr)
 
 void exit(int status)
 {
+	/*
+	 * GCC adds __attribute__((constructor)) functions
+	 * before C++ constructors, so we call C++ destructors
+	 * before __attribute((destructor)) functions to keep
+	 * the correct ordering.
+	 */
+	call_atexit_handlers();
+
+	/*
+	 * GCC extension __attribute__((destructor)),
+	 * C++ destructors are added to __cxa_finalize call
+	 * when called.
+	 */
+	if (__pcb != NULL) {
+		void **dtors = __pcb->cpp_data.dtors;
+		int count = __pcb->cpp_data.dtors_count;
+
+		for (int i = 0; i < count; ++i) {
+			void *dtor = dtors[count - i - 1];
+			((void (*)())dtor)();
+		}
+	}
+
 	if (env_setup) {
 		__stdio_done();
 		task_retval(status);

diff --git a/uspace/lib/c/generic/stdlib.c b/uspace/lib/c/generic/stdlib.c
index bede7db6a..7aefd2ec4 100644
--- a/uspace/lib/c/generic/stdlib.c
+++ b/uspace/lib/c/generic/stdlib.c
@@ -46,5 +46,35 @@ void srandom(unsigned int seed)
 	glbl_seed = seed % RAND_MAX;
 }
 
+/**
+ * Standard requires atleast 32, but except
+ * for this upper bound the limit is implementation
+ * defined.
+ */
+#define MAX_ATEXIT_HANDLERS 64
+
+typedef void (*atexit_handler_t)(void);
+
+static atexit_handler_t atexit_handlers[MAX_ATEXIT_HANDLERS];
+static size_t atexit_handler_count = 0;
+
+int atexit(atexit_handler_t handler)
+{
+	if (atexit_handler_count >= MAX_ATEXIT_HANDLERS)
+		return 1;
+	atexit_handlers[atexit_handler_count++] = handler;
+
+	return 0;
+}
+
+void call_atexit_handlers(void)
+{
+	for (size_t i = atexit_handler_count; i > 0; --i)
+	{
+		if (atexit_handlers[i - 1])
+			atexit_handlers[i - 1]();
+	}
+}
+
diff --git a/uspace/lib/c/include/stdlib.h b/uspace/lib/c/include/stdlib.h
index ec7d0a945..99283bbc9 100644
--- a/uspace/lib/c/include/stdlib.h
+++ b/uspace/lib/c/include/stdlib.h
@@ -53,6 +53,8 @@ extern void srandom(unsigned int seed);
 
 extern void abort(void) __attribute__((noreturn));
 extern void exit(int) __attribute__((noreturn));
+extern int atexit(void (*)(void));
+extern void call_atexit_handlers(void);
 
 #ifdef __cplusplus
 }