LibC: Write mostly functioning stdio

kernel/include/kernel/Process.h

@@ -43,6 +43,7 @@ namespace Kernel
 		BAN::ErrorOr<size_t> read(int, void*, size_t);
 		BAN::ErrorOr<size_t> write(int, const void*, size_t);
 		BAN::ErrorOr<void> creat(BAN::StringView, mode_t);
+		BAN::ErrorOr<void> seek(int, size_t);
 
 		BAN::ErrorOr<void> fstat(int, stat*);
 		BAN::ErrorOr<void> stat(BAN::StringView, stat*);
@@ -54,6 +55,8 @@ namespace Kernel
 		BAN::ErrorOr<BAN::String> working_directory() const;
 		BAN::ErrorOr<void> set_working_directory(BAN::StringView);
 
+		void termid(char*) const;
+
 		static Process& current() { return Thread::current().process(); }
 
 		MMU& mmu() { return m_mmu ? *m_mmu : MMU::get(); }

kernel/include/kernel/Syscall.h

@@ -3,6 +3,10 @@
 #define SYS_EXIT 1
 #define SYS_READ 2
 #define SYS_WRITE 3
+#define SYS_TERMID 4
+#define SYS_CLOSE 5
+#define SYS_SEEK 6
+#define SYS_OPEN 7
 
 #include <stdint.h>
 

kernel/kernel/Process.cpp

@@ -304,6 +304,15 @@ namespace Kernel
 		return ret;
 	}
 
+	BAN::ErrorOr<void> Process::seek(int fd, size_t offset)
+	{
+		LockGuard _(m_lock);
+		TRY(validate_fd(fd));
+		auto& open_fd = open_file_description(fd);
+		open_fd.offset = offset;
+		return {};
+	}
+
 	BAN::ErrorOr<BAN::Vector<BAN::String>> Process::read_directory_entries(int fd)
 	{
 		OpenFileDescription open_fd_copy;
@@ -349,6 +358,14 @@ namespace Kernel
 		return {};
 	}
 
+	void Process::termid(char* buffer) const
+	{
+		if (m_tty == nullptr)
+			buffer[0] = '\0';
+		strcpy(buffer, "/dev/");
+		strcpy(buffer + 5, m_tty->name().data());
+	}
+
 	BAN::ErrorOr<BAN::String> Process::absolute_path_of(BAN::StringView path) const
 	{
 		if (path.empty())

kernel/kernel/Syscall.cpp

@@ -14,7 +14,7 @@ namespace Kernel
 	{
 		auto res = Process::current().read(fd, buffer, size);
 		if (res.is_error())
-			return res.error().get_error_code();
+			return -res.error().get_error_code();
 		return res.value();
 	}
 
@@ -22,7 +22,36 @@ namespace Kernel
 	{
 		auto res = Process::current().write(fd, buffer, size);
 		if (res.is_error())
-			return res.error().get_error_code();
+			return -res.error().get_error_code();
+		return res.value();
+	}
+
+	int sys_close(int fd)
+	{
+		auto res = Process::current().close(fd);
+		if (res.is_error())
+			return -res.error().get_error_code();
+		return 0;
+	}
+
+	int sys_seek(int fd, long offset)
+	{
+		auto res = Process::current().seek(fd, offset);
+		if (res.is_error())
+			return -res.error().get_error_code();
+		return 0;
+	}
+
+	void sys_termid(char* buffer)
+	{
+		Process::current().termid(buffer);
+	}
+
+	int sys_open(const char* path, int oflags)
+	{
+		auto res = Process::current().open(path, oflags);
+		if (res.is_error())
+			return -res.error().get_error_code();
 		return res.value();
 	}
 
@@ -44,10 +73,20 @@ namespace Kernel
 		case SYS_WRITE:
 			ret = sys_write((int)(uintptr_t)arg1, arg2, (size_t)(uintptr_t)arg3);
 			break;
-		default:
-			ret = -1;
-			dprintln("Unknown syscall");
+		case SYS_TERMID:
+			sys_termid((char*)arg1);
 			break;
+		case SYS_CLOSE:
+			ret = sys_close((int)(uintptr_t)arg1);
+			break;
+		case SYS_SEEK:
+			ret = sys_seek((int)(uintptr_t)arg1, (long)arg2);
+			break;
+		case SYS_OPEN:
+			ret = sys_open((const char*)arg1, (int)(uintptr_t)arg2);
+			break;
+		default:
+			Kernel::panic("Unknown syscall {}", syscall);
 		}
 
 		asm volatile("cli");

libc/CMakeLists.txt

@@ -4,6 +4,7 @@ project(libc CXX)
 
 set(LIBC_SOURCES
 	ctype.cpp
+	fcntl.cpp
 	stdio.cpp
 	stdlib.cpp
 	string.cpp

libc/fcntl.cpp

@@ -0,0 +1,15 @@
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+int open(const char* path, int oflag, ...)
+{
+	int ret = syscall(SYS_OPEN, path, oflag);
+	if (ret < 0)
+	{
+		errno = -ret;
+		return -1;
+	}
+	return ret;
+}

libc/include/errno.h

@@ -16,6 +16,9 @@
 #define ENOBUFS 12
 #define ENOTTY 13
 #define ENOTBLK 14
+#define EMFILE 15
+
+#define errno errno
 
 __BEGIN_DECLS
 

libc/include/fcntl.h

@@ -1,8 +1,18 @@
 #pragma once
 
+#include <sys/cdefs.h>
+
 #define O_RDONLY	(1 << 0)
 #define O_WRONLY	(1 << 1)
 #define O_RDWR		(O_RDONLY | O_WRONLY)
 #define O_ACCMODE	(O_RDONLY | O_WRONLY)
 #define O_EXCL		(1 << 2)
 #define O_CREAT		(1 << 3)
+#define O_TRUNC		(1 << 4)
+#define O_APPEND	(1 << 5)
+
+__BEGIN_DECLS
+
+int open(const char*, int, ...);
+
+__END_DECLS

libc/include/stdio.h

@@ -18,28 +18,83 @@
 #define EXIT_FAILURE 1
 #define EXIT_SUCCESS 0
 
+#define L_ctermid 50
+
+#define BUFSIZ 128
+
+#define FOPEN_MAX 16
+
 __BEGIN_DECLS
 
 struct FILE;
 typedef struct FILE FILE;
 
+typedef uint64_t fpos_t;
+
 extern FILE* stdin;
 extern FILE* stdout;
 extern FILE* stderr;
 
-FILE* fopen(const char* __restrict__, const char* __restrict__);
-int fclose(FILE*);
-int fflush(FILE*);
-int fprintf(FILE* __restrict__, const char* __restrict__, ...);
-int fseek(FILE*, long, int);
-int printf(const char* __restrict__, ...);
-int putchar(int);
-int puts(const char*);
-int vfprintf(FILE* __restrict__, const char* __restrict__, va_list);
-long ftell(FILE*);
-size_t fread(void* __restrict__, size_t, size_t, FILE*);
-size_t fwrite(void const* __restrict__, size_t, size_t, FILE*);
-void setbuf(FILE* __restrict__, char* __restrict__);
-int sprintf(char* __restrict__, const char* __restrict__, ...);
+void	clearerr(FILE*);
+char*	ctermid(char*);
+int		fclose(FILE*);
+FILE*	fdopen(int, const char*);
+int		feof(FILE*);
+int		ferror(FILE*);
+int		fflush(FILE*);
+int		fgetc(FILE*);
+int		fgetpos(FILE*, fpos_t*);
+char*	fgets(char*, int, FILE*);
+int		fileno(FILE*);
+void	flockfile(FILE*);
+FILE*	fopen(const char*, const char*);
+int		fprintf(FILE*, const char*, ...);
+int		fputc(int, FILE*);
+int		fputs(const char*, FILE*);
+size_t	fread(void*, size_t, size_t, FILE*);
+FILE*	freopen(const char*, const char*, FILE*);
+int		fscanf(FILE*, const char*, ...);
+int		fseek(FILE*, long, int);
+int		fseeko(FILE*, off_t, int);
+int		fsetpos(FILE*, const fpos_t*);
+long	ftell(FILE*);
+off_t	ftello(FILE*);
+int		ftrylockfile(FILE*);
+void	funlockfile(FILE*);
+size_t	fwrite(const void*, size_t, size_t, FILE*);
+int		getc(FILE*);
+int		getchar(void);
+int		getc_unlocked(FILE*);
+int		getchar_unlocked(void);
+char*	gets(char*);
+int		pclose(FILE*);
+void	perror(const char*);
+FILE*	popen(const char*, const char*);
+int		printf(const char*, ...);
+int		putc(int, FILE*);
+int		putchar(int);
+int		putc_unlocked(int, FILE*);
+int		putchar_unlocked(int);
+int		puts(const char*);
+int		remove(const char*);
+int		rename(const char*, const char*);
+void	rewind(FILE*);
+int		scanf(const char*, ...);
+void	setbuf(FILE*, char*);
+int		setvbuf(FILE*, char*, int, size_t);
+int		snprintf(char*, size_t, const char*, ...);
+int		sprintf(char*, const char*, ...);
+int		sscanf(const char*, const char*, ...);
+char*	tempnam(const char*, const char*);
+FILE*	tmpfile(void);
+char*	tmpnam(char*);
+int		ungetc(int, FILE*);
+int		vfprintf(FILE*, const char*, va_list);
+int		vfscanf(FILE*, const char*, va_list);
+int		vprintf(const char*, va_list);
+int		vscanf(const char*, va_list);
+int		vsnprintf(char*, size_t, const char*, va_list);
+int		vsprintf(char*, const char*, va_list);
+int		vsscanf(const char*, const char*, va_list);
 
 __END_DECLS

libc/stdio.cpp

@@ -1,3 +1,5 @@
+#include <errno.h>
+#include <fcntl.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
@@ -6,92 +8,496 @@
 
 struct FILE
 {
-	int fd;
+	int fd			{ -1 };
+	off_t offset	{ 0 };
+	bool eof		{ false };
+	bool error		{ false };
+
+	unsigned char buffer[BUFSIZ];
+	uint32_t buffer_index { 0 };
 };
 
-static FILE __stdin { .fd = STDIN_FILENO };
-static FILE __stdout { .fd = STDOUT_FILENO };
-static FILE __stderr { .fd = STDERR_FILENO };
+static FILE s_files[FOPEN_MAX] {
+	{ .fd = STDIN_FILENO  },
+	{ .fd = STDOUT_FILENO },
+	{ .fd = STDERR_FILENO },
+};
 
-FILE* stdin = &__stdin;
-FILE* stdout = &__stdout;
-FILE* stderr = &__stderr;
+FILE* stdin  = &s_files[0];
+FILE* stdout = &s_files[1];
+FILE* stderr = &s_files[2];
 
-int fclose(FILE*)
+void clearerr(FILE* file)
 {
-	return -1;
+	file->eof = false;
+	file->error = false;
 }
 
-int fflush(FILE*)
+char* ctermid(char* buffer)
 {
+	static char s_buffer[L_ctermid];
+	char* target = buffer ? buffer : s_buffer;
+	syscall(SYS_TERMID, target);
+	return target;
+}
+
+int fclose(FILE* file)
+{
+	if (int ret = syscall(SYS_CLOSE, file->fd) < 0)
+	{
+		errno = -ret;
+		return EOF;
+	}
+	file->fd = -1;
 	return 0;
 }
 
-FILE* fopen(const char* __restrict__, const char* __restrict__)
+// TODO
+FILE* fdopen(int, const char*);
+
+int feof(FILE* file)
 {
+	return file->eof;
+}
+
+int ferror(FILE* file)
+{
+	return file->error;
+}
+
+int fflush(FILE* file)
+{
+	if (file == nullptr)
+	{
+		for (int i = 0; i < FOPEN_MAX; i++)
+			if (s_files[i].fd != -1)
+				if (int ret = fflush(&s_files[i]); ret != 0)
+					return ret;
+		return 0;
+	}
+
+	if (file->buffer_index == 0)
+		return 0;
+	
+	if (long ret = syscall(SYS_WRITE, file->fd, file->buffer, file->buffer_index); ret < 0)
+	{
+		errno = -ret;
+		file->error = true;
+		return EOF;
+	}
+
+	file->buffer_index = 0;
+	return 0;
+}
+
+int fgetc(FILE* file)
+{
+	if (file->eof)
+		return EOF;
+	
+	unsigned char c;
+	long ret = syscall(SYS_READ, file->fd, &c, 1);
+
+	if (ret < 0)
+	{
+		errno = -ret;
+		return EOF;
+	}
+	else if (ret == 0)
+	{
+		file->eof = true;
+		return EOF;
+	}
+
+	file->offset++;
+	return c;
+}
+
+int fgetpos(FILE* file, fpos_t* pos)
+{
+	*pos = file->offset;
+	return 0;
+}
+
+char* fgets(char* str, int size, FILE* file)
+{
+	if (size == 0)
+		return str;
+	int c = fgetc(file);
+	if (c == EOF)
+		return nullptr;
+	str[0] = c;
+	for (int i = 1; i < size - 1; i++)
+	{
+		str[i] = fgetc(file);
+		if (str[i] == EOF)
+		{
+			str[i] = '\0';
+			return nullptr;
+		}
+		if (str[i] == '\n')
+		{
+			str[i + 1] = '\0';
+			return str;
+		}
+	}
+	str[size - 1] = '\0';
+	return str;
+}
+
+// TODO
+int fileno(FILE*);
+
+// TODO
+void flockfile(FILE*);
+
+FILE* fopen(const char* pathname, const char* mode)
+{
+	uint8_t flags = 0;
+	if (mode[0] == 'r')
+		flags |= O_RDONLY;
+	else if (mode[0] == 'b')
+		flags |= O_WRONLY | O_CREAT | O_TRUNC;
+	else if (mode[0] == 'a')
+		flags |= O_WRONLY | O_CREAT | O_APPEND;
+	else
+	{
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	if (mode[1] && mode[2] && mode[1] == mode[2])
+	{
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	for (int i = 1; i <= 2; i++)
+	{
+		if (mode[i] == 0)
+			break;
+		else if (mode[i] == '+')
+			flags |= O_RDWR;
+		else if (mode[i] == 'b')
+			continue;
+		else
+		{
+			errno = EINVAL;
+			return nullptr;
+		}
+	}
+
+	int fd = open(pathname, flags);
+	if (fd == -1)
+		return nullptr;
+
+	for (int i = 0; i < FOPEN_MAX; i++)
+	{
+		if (s_files[i].fd == -1)
+		{
+			s_files[i] = { .fd = fd };
+			return &s_files[i];
+		}
+	}
+	
+	errno = EMFILE;
 	return nullptr;
 }
 
-int fseek(FILE*, long, int)
+int fprintf(FILE* file, const char* format, ...)
 {
-	return -1;
+	va_list arguments;
+	va_start(arguments, format);
+	int ret = vfprintf(file, format, arguments);
+	va_end(arguments);
+	return ret;
 }
 
-long ftell(FILE*)
+int fputc(int c, FILE* file)
 {
-	return -1;
+	file->buffer[file->buffer_index++] = c;
+	if (c == '\n' || file->buffer_index == sizeof(file->buffer))
+		if (fflush(file) == EOF)
+			return EOF;
+	return (unsigned char)c;
 }
 
-size_t fread(void* __restrict__, size_t, size_t, FILE*)
+int fputs(const char* str, FILE* file)
 {
+	while (*str)
+	{
+		if (putc(*str, file) == EOF)
+			return EOF;
+		str++;
+	}
 	return 0;
 }
 
-size_t fwrite(void const* __restrict__, size_t, size_t, FILE*)
+size_t fread(void* buffer, size_t size, size_t nitems, FILE* file)
 {
+	unsigned char* ubuffer = (unsigned char*)buffer;
+	for (size_t byte = 0; byte < nitems * size; byte++)
+		if ((ubuffer[byte] = fgetc(file)) == EOF)
+			return byte / size;
+	return nitems;
+}
+
+// TODO
+FILE* freopen(const char*, const char*, FILE*);
+
+// TODO
+int fscanf(FILE*, const char*, ...);
+
+int fseek(FILE* file, long offset, int whence)
+{
+	return fseeko(file, offset, whence);
+}
+
+int fseeko(FILE* file, off_t offset, int whence)
+{
+	if (whence == SEEK_CUR)
+		file->offset += offset;
+	else if (whence == SEEK_SET)
+		file->offset = offset;
+	else if (whence == SEEK_END)
+	{
+		errno = ENOTSUP;
+		return -1;
+	}
+	else
+	{
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (file->offset < 0)
+	{
+		file->offset -= offset;
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (long ret = syscall(SYS_SEEK, file->fd, file->offset); ret < 0)
+	{
+		errno = -ret;
+		return -1;
+	}
+
+	file->eof = false;
+
 	return 0;
 }
 
-int fprintf(FILE* __restrict__ file, const char* __restrict__ format, ...)
+int fsetpos(FILE* file, const fpos_t* pos)
 {
-	va_list args;
-	va_start(args, format);
-	int res = vfprintf(stdout, format, args);
-	va_end(args);
-	return res;
+	return fseek(file, *pos, SEEK_SET);
 }
 
-
-void setbuf(FILE* __restrict__, char* __restrict__)
+long ftell(FILE* file)
 {
-
+	return ftello(file);
 }
 
-int vfprintf(FILE* __restrict__, const char* __restrict__, va_list)
+off_t ftello(FILE* file)
 {
-	return -1;
+	return file->offset;
 }
 
-int printf(const char* __restrict__ format, ...)
+// TODO
+int ftrylockfile(FILE*);
+
+// TODO
+void funlockfile(FILE*);
+
+size_t fwrite(const void* buffer, size_t size, size_t nitems, FILE* file)
 {
-	va_list args;
-	va_start(args, format);
-	int res = vfprintf(stdout, format, args);
-	va_end(args);
-	return res;
+	unsigned char* ubuffer = (unsigned char*)buffer;
+	for (size_t byte = 0; byte < nitems * size; byte++)
+		if (fputc(ubuffer[byte], file) == EOF)
+			return byte / size;
+	return nitems;
 }
 
-int putchar(int ch)
+int getc(FILE* file)
 {
-	return printf("%c", ch);
+	return fgetc(file);
 }
 
-int puts(const char* str)
+int getchar(void)
 {
-	return syscall(SYS_WRITE, STDOUT_FILENO, str, strlen(str));
+	return getc(stdin);
 }
 
-int sprintf(char* __restrict__ stream, const char* __restrict__ format, ...)
+// TODO
+int getc_unlocked(FILE*);
+
+// TODO
+int getchar_unlocked(void);
+
+char* gets(char* buffer)
 {
-	return -1;
+	if (stdin->eof)
+		return nullptr;
+
+	unsigned char* ubuffer = (unsigned char*)buffer;
+	
+	int first = fgetc(stdin);
+	if (first == EOF)
+		return nullptr;
+	*ubuffer++ = first;
+
+	for (;;)
+	{
+		int c = fgetc(stdin);
+		if (c == '\n' || c == EOF)
+		{
+			*ubuffer++ = '\0';
+			return buffer;
+		}
+		*ubuffer++ = c;
+	}
 }
+
+// TODO
+int pclose(FILE*);
+
+void perror(const char* string)
+{
+	if (string && *string)
+	{
+		fputs(string, stderr);
+		fputs(": ", stderr);
+	}
+	fputs(strerror(errno), stderr);
+	fflush(stderr);
+	stderr->error = true;
+}
+
+// TODO
+FILE* popen(const char*, const char*);
+
+int printf(const char* format, ...)
+{
+	va_list arguments;
+	va_start(arguments, format);
+	int ret = vfprintf(stdout, format, arguments);
+	va_end(arguments);
+	return ret;
+}
+
+int putc(int c, FILE* file)
+{
+	return fputc(c, file);
+}
+
+int putchar(int c)
+{
+	return putc(c, stdout);
+}
+
+// TODO
+int putc_unlocked(int, FILE*);
+
+// TODO
+int putchar_unlocked(int);
+
+int puts(const char* string)
+{
+	if (fputs(string, stdout) == EOF)
+		return EOF;
+	if (fputc('\n', stdout) == EOF)
+		return EOF;
+	return 0;
+}
+
+// TODO
+int remove(const char*);
+
+// TODO
+int rename(const char*, const char*);
+
+// TODO
+void rewind(FILE*);
+
+// TODO
+int scanf(const char*, ...);
+
+// TODO
+void setbuf(FILE*, char*);
+
+// TODO
+int setvbuf(FILE*, char*, int, size_t);
+
+// TODO
+int snprintf(char*, size_t, const char*, ...);
+
+// TODO
+int sprintf(char*, const char*, ...);
+
+// TODO
+int sscanf(const char*, const char*, ...);
+
+// TODO
+char* tempnam(const char*, const char*);
+
+// TODO
+FILE* tmpfile(void);
+
+// TODO
+char* tmpnam(char*);
+
+// TODO
+int ungetc(int, FILE*);
+
+int vfprintf(FILE* file, const char* format, va_list arguments)
+{
+	int written = 0;
+	while (*format)
+	{
+		if (*format == '%')
+		{
+			format++;
+			switch (*format)
+			{
+			case '%':
+				break;
+			case 's':
+			{
+				const char* string = va_arg(arguments, const char*);
+				if (fputs(string, file) == EOF)
+					return -1;
+				written += strlen(string);
+				format++;
+				break;
+			}
+			default:
+				break;
+			}
+		}
+		if (fputc(*format, file) == EOF)
+			return -1;
+		written++;
+		format++;
+	}
+	return written;
+}
+
+// TODO
+int vfscanf(FILE*, const char*, va_list);
+
+int vprintf(const char* format, va_list arguments)
+{
+	return vfprintf(stdout, format, arguments);
+}
+
+// TODO
+int vscanf(const char*, va_list);
+
+// TODO
+int vsnprintf(char*, size_t, const char*, va_list);
+
+// TODO
+int vsprintf(char*, const char*, va_list);
+
+// TODO
+int vsscanf(const char*, const char*, va_list);

libc/stdlib.cpp

@@ -1,5 +1,6 @@
 #include <BAN/Assert.h>
 #include <ctype.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -13,6 +14,7 @@ void abort(void)
 
 void exit(int status)
 {
+	fflush(nullptr);
 	_fini();
 	_exit(status);
 	ASSERT_NOT_REACHED();

libc/string.cpp

@@ -125,6 +125,9 @@ char* strerror(int error)
 	case ENOTBLK:
 		strcpy(buffer, "Block device required");
 		break;
+	case EMFILE:
+		strcpy(buffer, "File descriptor value too large");
+		break;
 	default:
 		{
 			// FIXME: sprintf

userspace/test.c

@@ -2,6 +2,7 @@
 
 int main()
 {
-	puts("Hello World!");
+	if (printf("Hello %s!", "World") == -1)
+		perror(NULL);
 	return 0;
 }