1 files changed, 82 insertions, 0 deletions
diff --git a/src/stdio/_format.h b/src/stdio/_format.h
new file mode 100644
index 00000000..5930fdb6
--- /dev/null
+++ b/src/stdio/_format.h
@@ -0,0 +1,82 @@
+#ifndef __STDIO__FORMAT_H__
+#define __STDIO__FORMAT_H__
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include "_stdio.h"
+#include "_safety.h"
+
+#define UNDEFINED_FMT(__conv, __fmt, ...) do { \
+	char __buf[128]; \
+	snprintf(__buf, sizeof(__buf), "In call to %s() with format string \"%s\": Invalid conversion specification: ", __conv->func, __conv->fmt); \
+	__undefined("%s" __fmt, __buf, __VA_ARGS__); \
+} while (0)
+
+struct io_options {
+	const char *fnname;	/* the calling function */
+	char *string;		/* NULL or the output string */
+	wchar_t *wstring;	/* NULL or the output wide string */
+	FILE *stream;		/* NULL or the output stream */
+	int fd;			/* -1 or the output file descriptor */
+	size_t maxlen;		/* max number of bytes to write to string */
+	size_t pos;		/* current index in string */
+	int ret;		/* return value */
+};
+
+struct io_conversion {
+	const char *func;
+	const char *fmt;
+	enum { IO_IN, IO_OUT } dir;
+	enum conversion_flags {
+		/* explicit */
+		F_STAR = (1<<0),
+		F_LEFT = (1<<1),
+		F_SIGN = (1<<2),
+		F_SPACE = (1<<3),
+		F_ALT = (1<<4),
+		F_ZERO = (1<<5),
+
+		/* inferred */
+		F_UPPER = (1<<10),
+		F_WIDTH = (1<<11),
+		F_PRECISION = (1<<12),
+	} flags;
+	enum conversion_length {
+		L_default,
+		L_hh,
+		L_ll,
+		L_h,
+		L_l,
+		L_j,
+		L_z,
+		L_t,
+		L_L,
+	} length;
+	uintmax_t width;
+	uintmax_t precision;
+	char spec;
+	union {
+		uintmax_t u;
+		intmax_t i;
+		float f;
+		double d;
+		long double ld;
+		char *s;
+		wchar_t *wcs;
+		char c;
+		wchar_t wc;
+		void *ptr;
+	} val;
+};
+
+size_t __conv(const char *, struct io_conversion *, va_list);
+int __printf(struct io_options * restrict, const char * restrict, va_list);
+int __scanf(struct io_options * restrict, const char * restrict, va_list);
+
+/*
+STDC(-1)
+*/
+
+#endif