BuildSystem: Rework the whole cmake build system

Now files are installed using the install() command instead of manually
copying files to their destinations. This allows automatic recompilation
of headers that did not work previously

userspace/test-mmap-shared/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(SOURCES
+	main.cpp
+)
+
+add_executable(test-mmap-shared ${SOURCES})
+banan_link_library(test-mmap-shared libc)
+
+install(TARGETS test-mmap-shared)

userspace/test-mmap-shared/main.cpp

@@ -0,0 +1,197 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define FILE_NAME "test-file"
+#define FILE_SIZE (1024*1024)
+
+int prepare_file()
+{
+	int fd = open(FILE_NAME, O_RDWR | O_TRUNC | O_CREAT, 0666);
+	if (fd == -1)
+	{
+		perror("open");
+		return 1;
+	}
+
+	void* null_buffer = malloc(FILE_SIZE);
+	memset(null_buffer, 0x00, FILE_SIZE);
+
+	if (write(fd, null_buffer, FILE_SIZE) == -1)
+	{
+		perror("write");
+		return 1;
+	}
+
+	free(null_buffer);
+	close(fd);
+
+	return 0;
+}
+
+int test1_job1()
+{
+	int fd = open(FILE_NAME, O_RDONLY);
+	if (fd == -1)
+	{
+		perror("open");
+		return 1;
+	}
+
+	void* addr = mmap(nullptr, FILE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED)
+	{
+		perror("mmap");
+		return 1;
+	}
+
+	sleep(4);
+
+	size_t sum = 0;
+	for (int i = 0; i < FILE_SIZE; i++)
+		sum += ((uint8_t*)addr)[i];
+
+	munmap(addr, FILE_SIZE);
+	close(fd);
+
+	printf("got:       %zu\n", sum);
+
+	exit(0);
+}
+
+int test1_job2()
+{
+	sleep(2);
+
+	int fd = open(FILE_NAME, O_RDWR);
+	if (fd == -1)
+	{
+		perror("open");
+		return 1;
+	}
+
+	void* addr = mmap(nullptr, FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED)
+	{
+		perror("mmap");
+		return 1;
+	}
+
+	memset(addr, 'a', FILE_SIZE);
+
+	munmap(addr, FILE_SIZE);
+	close(fd);
+
+	printf("expecting: %zu\n", (size_t)'a' * FILE_SIZE);
+
+	return 0;
+}
+
+int test1()
+{
+	if (int ret = prepare_file())
+		return ret;
+
+	pid_t pid = fork();
+	if (pid == 0)
+		return test1_job1();
+
+	if (pid == -1)
+	{
+		perror("fork");
+		return 1;
+	}
+
+	int ret = test1_job2();
+	waitpid(pid, nullptr, 0);
+	return ret;
+}
+
+int test2_job1()
+{
+	sleep(2);
+
+	int fd = open(FILE_NAME, O_RDWR);
+	if (fd == -1)
+	{
+		perror("open");
+		return 1;
+	}
+
+	size_t value = 0;
+	if (read(fd, &value, sizeof(size_t)) == -1)
+	{
+		perror("read");
+		return 1;
+	}
+
+	printf("got:       %zu\n", value);
+
+	close(fd);
+
+	exit(0);
+}
+
+int test2_job2()
+{
+	int fd = open(FILE_NAME, O_RDWR);
+	if (fd == -1)
+	{
+		perror("open");
+		return 1;
+	}
+
+	void* addr = mmap(nullptr, FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED)
+	{
+		perror("mmap");
+		return 1;
+	}
+
+	*(size_t*)addr = 0x12345678;
+
+	if (msync(addr, sizeof(size_t), MS_SYNC) == -1)
+	{
+		perror("msync");
+		return 1;
+	}
+
+	printf("expecting: %zu\n", *(size_t*)addr);
+
+	sleep(4);
+
+	munmap(addr, FILE_SIZE);
+	close(fd);
+
+	return 0;
+}
+
+int test2()
+{
+	if (int ret = prepare_file())
+		return ret;
+
+	pid_t pid = fork();
+	if (pid == 0)
+		return test2_job1();
+
+	if (pid == -1)
+	{
+		perror("fork");
+		return 1;
+	}
+
+	int ret = test2_job2();
+	waitpid(pid, nullptr, 0);
+	return ret;
+}
+
+int main()
+{
+	test1();
+	test2();
+}