[musl] [C23 printf 1/3] C23: implement the b and B printf specifiers

[musl] [C23 printf 1/3] C23: implement the b and B printf specifiers

[Jens Gustedt]

The b specifier is mandatory for C23. It has been reserved previously,
so we may safely add it, even for older compilation modes.

The B specifier is optional, but recommended for those implementations
that didn't have it reserved previously for other purposes.

The PRIbXXX and PRIBXXX macros are mandatory if the specifiers are
supported and may serve as feature test macros for users.
---
 include/inttypes.h    | 34 ++++++++++++++++++++++++++++++++++
 src/stdio/vfprintf.c  | 19 ++++++++++++++++++-
 src/stdio/vfwprintf.c | 11 +++++++++--
 3 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/include/inttypes.h b/include/inttypes.h
index 61dcb727..73a42e32 100644
--- a/include/inttypes.h
+++ b/include/inttypes.h
@@ -120,12 +120,44 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIXFAST32 "X"
 #define PRIXFAST64 __PRI64 "X"
 
+#define PRIb8  "b"
+#define PRIb16 "b"
+#define PRIb32 "b"
+#define PRIb64 __PRI64 "b"
+
+#define PRIbLEAST8  "b"
+#define PRIbLEAST16 "b"
+#define PRIbLEAST32 "b"
+#define PRIbLEAST64 __PRI64 "b"
+
+#define PRIbFAST8  "b"
+#define PRIbFAST16 "b"
+#define PRIbFAST32 "b"
+#define PRIbFAST64 __PRI64 "b"
+
+#define PRIB8  "B"
+#define PRIB16 "B"
+#define PRIB32 "B"
+#define PRIB64 __PRI64 "B"
+
+#define PRIBLEAST8  "B"
+#define PRIBLEAST16 "B"
+#define PRIBLEAST32 "B"
+#define PRIBLEAST64 __PRI64 "B"
+
+#define PRIBFAST8  "B"
+#define PRIBFAST16 "B"
+#define PRIBFAST32 "B"
+#define PRIBFAST64 __PRI64 "B"
+
 #define PRIdMAX __PRI64 "d"
 #define PRIiMAX __PRI64 "i"
 #define PRIoMAX __PRI64 "o"
 #define PRIuMAX __PRI64 "u"
 #define PRIxMAX __PRI64 "x"
 #define PRIXMAX __PRI64 "X"
+#define PRIbMAX __PRI64 "b"
+#define PRIBMAX __PRI64 "B"
 
 #define PRIdPTR __PRIPTR "d"
 #define PRIiPTR __PRIPTR "i"
@@ -133,6 +165,8 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIuPTR __PRIPTR "u"
 #define PRIxPTR __PRIPTR "x"
 #define PRIXPTR __PRIPTR "X"
+#define PRIbPTR __PRIPTR "b"
+#define PRIBPTR __PRIPTR "B"
 
 #define SCNd8   "hhd"
 #define SCNd16  "hd"
diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index a712d80f..cbc79783 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -48,6 +48,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,6 +59,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -65,17 +67,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -85,11 +90,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -156,6 +163,12 @@ static char *fmt_x(uintmax_t x, char *s, int lower)
 	return s;
 }
 
+static char *fmt_b(uintmax_t x, char *s)
+{
+	for (; x; x>>=1) *--s = '0' + (x&1);
+	return s;
+}
+
 static char *fmt_o(uintmax_t x, char *s)
 {
 	for (; x; x>>=3) *--s = '0' + (x&7);
@@ -437,7 +450,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 	unsigned st, ps;
 	int cnt=0, l=0;
 	size_t i;
-	char buf[sizeof(uintmax_t)*3+3+LDBL_MANT_DIG/4];
+	char buf[sizeof(uintmax_t)*CHAR_BIT+3+LDBL_MANT_DIG/4];
 	const char *prefix;
 	int t, pl;
 	wchar_t wc[2], *ws;
@@ -564,6 +577,10 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 			a = fmt_x(arg.i, z, t&32);
 			if (arg.i && (fl & ALT_FORM)) prefix+=(t>>4), pl=2;
 			if (0) {
+		case 'b': case 'B':
+			a = fmt_b(arg.i, z);
+			if (arg.i && (fl & ALT_FORM)) prefix = (t == 'b' ? "0b" : "0B"), pl=2;
+			} if (0) {
 		case 'o':
 			a = fmt_o(arg.i, z);
 			if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index 53697701..dbc93f74 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -41,6 +41,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -51,6 +52,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,17 +60,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -78,11 +83,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -145,7 +152,7 @@ static int getint(wchar_t **s) {
 
 static const char sizeprefix['y'-'a'] = {
 ['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
-['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
+['b'-'a']='j', ['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
 ['p'-'a']='j'
 };
 
@@ -321,7 +328,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 		case 'a': case 'e': case 'f': case 'g':
 			l = fprintf(f, charfmt, w, p, arg.f);
 			break;
-		case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
+		case 'b': case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
 			l = fprintf(f, charfmt, w, p, arg.i);
 			break;
 		}
-- 
2.34.1

[musl] [C23 printf 2/3] C23: implement the wN length specifiers for printf

[Jens Gustedt]

These are mandatory for C23 and concern all types for which the
platform has `int_leastN_t` and `uint_leastN_t`. For musl these types
always coincide with `intN_t` and `uintN_t` and are always present for
N equal 8, 16, 32 and 64.

They can be added for general use since all lowercase letters were
previously reserved.

Nevertheless, users that use these modifiers will see a lot of
warnings from compilers in the beginning. This is because the
compilers have not yet integrated this form of a specifier into their
correponding extensions (gcc attributes). So unfortunately also
testing this feature may be a bit noisy for the moment.

The only architecture dependend choice is the type for N == 64, which
may be `long` or `long long`. We just mimick the test that is done in
other places to compare `UINTPTR_MAX` and `UINT64_MAX` to determine
that.
---
 src/stdio/vfprintf.c  | 28 +++++++++++++++++++++++++---
 src/stdio/vfwprintf.c | 28 +++++++++++++++++++++++++---
 2 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index cbc79783..265fb7ad 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -33,7 +33,7 @@
 
 enum {
 	BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
-	ZTPRE, JPRE,
+	ZTPRE, JPRE, WPRE,
 	STOP,
 	PTR, INT, UINT, ULLONG,
 	LONG, ULONG,
@@ -57,7 +57,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
 		S('m') = NOARG,
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
-		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
+		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE, S('w') = WPRE,
 	}, { /* 1: l-prefixed */
 		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
@@ -101,6 +101,12 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
 		S('n') = PTR,
+	}, { /* 8: w-prefixed */
+		S('b') = UINT, S('B') = UINT,
+		S('d') = INT, S('i') = INT,
+		S('o') = UINT, S('u') = UINT,
+		S('x') = UINT, S('X') = UINT,
+		S('n') = PTR,
 	}
 };
 
@@ -447,7 +453,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 	int w, p, xp;
 	union arg arg;
 	int argpos;
-	unsigned st, ps;
+	unsigned st, ps, width=0;
 	int cnt=0, l=0;
 	size_t i;
 	char buf[sizeof(uintmax_t)*CHAR_BIT+3+LDBL_MANT_DIG/4];
@@ -527,9 +533,25 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 			if (OOB(*s)) goto inval;
 			ps=st;
 			st=states[st]S(*s++);
+ 			if (st == WPRE) {
+				if (*s == '0') goto inval;
+				width = getint(&s);
+                        }
 		} while (st-1<STOP);
 		if (!st) goto inval;
 
+		if (ps == WPRE) switch (width) {
+		case 8:   ps = HHPRE; st = (st == UINT) ? UCHAR  : ((st == INT) ? CHAR  : PTR); break;
+		case 16:  ps = HPRE;  st = (st == UINT) ? USHORT : ((st == INT) ? SHORT : PTR); break;
+		case 32:  ps = BARE;  break;
+#if UINTPTR_MAX >= UINT64_MAX
+		case 64:  ps = LPRE;  st = (st == UINT) ? ULONG  : ((st == INT) ? LONG  : PTR); break;
+#else
+		case 64:  ps = LLPRE; st = (st == UINT) ? ULLONG : ((st == INT) ? LLONG : PTR); break;
+#endif
+		default:  goto inval;
+		}
+
 		/* Check validity of argument type (nl/normal) */
 		if (st==NOARG) {
 			if (argpos>=0) goto inval;
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index dbc93f74..c3e81d2a 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -26,7 +26,7 @@
 
 enum {
 	BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
-	ZTPRE, JPRE,
+	ZTPRE, JPRE, WPRE,
 	STOP,
 	PTR, INT, UINT, ULLONG,
 	LONG, ULONG,
@@ -50,7 +50,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
 		S('m') = NOARG,
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
-		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
+		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE, S('w') = WPRE,
 	}, { /* 1: l-prefixed */
 		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
@@ -94,6 +94,12 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
 		S('n') = PTR,
+	}, { /* 8: w-prefixed */
+		S('b') = UINT, S('B') = UINT,
+		S('d') = INT, S('i') = INT,
+		S('o') = UINT, S('u') = UINT,
+		S('x') = UINT, S('X') = UINT,
+		S('n') = PTR,
 	}
 };
 
@@ -163,7 +169,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 	int w, p, xp;
 	union arg arg;
 	int argpos;
-	unsigned st, ps;
+	unsigned st, ps, width=0;
 	int cnt=0, l=0;
 	int i;
 	int t;
@@ -242,9 +248,25 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 			if (OOB(*s)) goto inval;
 			ps=st;
 			st=states[st]S(*s++);
+ 			if (st == WPRE) {
+				if (*s == L'0') goto inval;
+				width = getint(&s);
+                        }
 		} while (st-1<STOP);
 		if (!st) goto inval;
 
+		if (ps == WPRE) switch (width) {
+		case 8:   ps = HHPRE; st = (st == UINT) ? UCHAR  : ((st == INT) ? CHAR  : PTR); break;
+		case 16:  ps = HPRE;  st = (st == UINT) ? USHORT : ((st == INT) ? SHORT : PTR); break;
+		case 32:  ps = BARE;  break;
+#if UINTPTR_MAX >= UINT64_MAX
+		case 64:  ps = LPRE;  st = (st == UINT) ? ULONG  : ((st == INT) ? LONG  : PTR); break;
+#else
+		case 64:  ps = LLPRE; st = (st == UINT) ? ULLONG : ((st == INT) ? LLONG : PTR); break;
+#endif
+		default:  goto inval;
+		}
+
 		/* Check validity of argument type (nl/normal) */
 		if (st==NOARG) {
 			if (argpos>=0) goto inval;
-- 
2.34.1

[musl] [C23 printf 3/3] C23: implement the wfN length modifiers for printf

[Jens Gustedt]

Musl only has a difference between fixed-width and fastest-width
integer types for N == 16. And even here all architectures have made
the same choice, namely mapping to 32 bit types.
---
 src/stdio/vfprintf.c  | 3 +++
 src/stdio/vfwprintf.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index 265fb7ad..a531a513 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -534,8 +534,11 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 			ps=st;
 			st=states[st]S(*s++);
  			if (st == WPRE) {
+                        	_Bool fast = (*s == 'f');
+                                if (fast) ++s;
 				if (*s == '0') goto inval;
 				width = getint(&s);
+                                if (fast && width == 16) width = 32;
                         }
 		} while (st-1<STOP);
 		if (!st) goto inval;
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index c3e81d2a..3689c2d5 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -249,8 +249,11 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 			ps=st;
 			st=states[st]S(*s++);
  			if (st == WPRE) {
+                        	_Bool fast = (*s == L'f');
+                                if (fast) ++s;
 				if (*s == L'0') goto inval;
 				width = getint(&s);
+                                if (fast && width == 16) width = 32;
                         }
 		} while (st-1<STOP);
 		if (!st) goto inval;
-- 
2.34.1

Re: [musl] [C23 printf 2/3] C23: implement the wN length specifiers for printf

[Rich Felker]

On Tue, May 30, 2023 at 08:55:27AM +0200, Jens Gustedt wrote:
> These are mandatory for C23 and concern all types for which the
> platform has `int_leastN_t` and `uint_leastN_t`. For musl these types
> always coincide with `intN_t` and `uintN_t` and are always present for
> N equal 8, 16, 32 and 64.
> 
> They can be added for general use since all lowercase letters were
> previously reserved.
> 
> Nevertheless, users that use these modifiers will see a lot of
> warnings from compilers in the beginning. This is because the
> compilers have not yet integrated this form of a specifier into their
> correponding extensions (gcc attributes). So unfortunately also
> testing this feature may be a bit noisy for the moment.
> 
> The only architecture dependend choice is the type for N == 64, which
> may be `long` or `long long`. We just mimick the test that is done in
> other places to compare `UINTPTR_MAX` and `UINT64_MAX` to determine
> that.
> ---
>  src/stdio/vfprintf.c  | 28 +++++++++++++++++++++++++---
>  src/stdio/vfwprintf.c | 28 +++++++++++++++++++++++++---
>  2 files changed, 50 insertions(+), 6 deletions(-)
> 
> diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
> index cbc79783..265fb7ad 100644
> --- a/src/stdio/vfprintf.c
> +++ b/src/stdio/vfprintf.c
> @@ -33,7 +33,7 @@
>  
>  enum {
>  	BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
> -	ZTPRE, JPRE,
> +	ZTPRE, JPRE, WPRE,
>  	STOP,
>  	PTR, INT, UINT, ULLONG,
>  	LONG, ULONG,
> @@ -57,7 +57,7 @@ static const unsigned char states[]['z'-'A'+1] = {
>  		S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
>  		S('m') = NOARG,
>  		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
> -		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
> +		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE, S('w') = WPRE,
>  	}, { /* 1: l-prefixed */
>  		S('b') = ULONG, S('B') = ULONG,
>  		S('d') = LONG, S('i') = LONG,
> @@ -101,6 +101,12 @@ static const unsigned char states[]['z'-'A'+1] = {
>  		S('o') = UMAX, S('u') = UMAX,
>  		S('x') = UMAX, S('X') = UMAX,
>  		S('n') = PTR,
> +	}, { /* 8: w-prefixed */
> +		S('b') = UINT, S('B') = UINT,
> +		S('d') = INT, S('i') = INT,
> +		S('o') = UINT, S('u') = UINT,
> +		S('x') = UINT, S('X') = UINT,
> +		S('n') = PTR,
>  	}
>  };
>  
> @@ -447,7 +453,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
>  	int w, p, xp;
>  	union arg arg;
>  	int argpos;
> -	unsigned st, ps;
> +	unsigned st, ps, width=0;
>  	int cnt=0, l=0;
>  	size_t i;
>  	char buf[sizeof(uintmax_t)*CHAR_BIT+3+LDBL_MANT_DIG/4];
> @@ -527,9 +533,25 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
>  			if (OOB(*s)) goto inval;
>  			ps=st;
>  			st=states[st]S(*s++);
> + 			if (st == WPRE) {
> +				if (*s == '0') goto inval;
> +				width = getint(&s);
> +                        }
>  		} while (st-1<STOP);
>  		if (!st) goto inval;
>  
> +		if (ps == WPRE) switch (width) {
> +		case 8:   ps = HHPRE; st = (st == UINT) ? UCHAR  : ((st == INT) ? CHAR  : PTR); break;
> +		case 16:  ps = HPRE;  st = (st == UINT) ? USHORT : ((st == INT) ? SHORT : PTR); break;
> +		case 32:  ps = BARE;  break;
> +#if UINTPTR_MAX >= UINT64_MAX
> +		case 64:  ps = LPRE;  st = (st == UINT) ? ULONG  : ((st == INT) ? LONG  : PTR); break;
> +#else
> +		case 64:  ps = LLPRE; st = (st == UINT) ? ULLONG : ((st == INT) ? LLONG : PTR); break;
> +#endif

The logic here for whether w64 is LPRE or LLPRE is wrong. The
condition for whether [u]int64_t is long or long long is not whether
uintptr_t or long long would be too wide (they never are, in our ABIs)
but whether long is long enough. All our [u]intN_t are the lowest-rank
type of the desired size, and this seems to be consistent with what
other implementations like glibc do.

Short of a compelling reason not to, though, I plan to just go with
the fix-up of my v2 patch for this functionality. Its ordering avoids
duplication of logic (the ?: branches in the cases above) and the need
for maintaining extra side state (the width variable) thru the state
machine.

Rich

Re: [musl] [C23 printf 2/3] C23: implement the wN length specifiers for printf

[Jₑₙₛ Gustedt]

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Rich,

on Fri, 2 Jun 2023 10:38:00 -0400 you (Rich Felker <dalias@libc.org>)
wrote:

> The logic here for whether w64 is LPRE or LLPRE is wrong. The
> condition for whether [u]int64_t is long or long long is not whether
> uintptr_t or long long would be too wide (they never are, in our ABIs)
> but whether long is long enough. All our [u]intN_t are the lowest-rank
> type of the desired size, and this seems to be consistent with what
> other implementations like glibc do.

I probably copied that logic wrong from somewhere. Yes, right thing is
probably just to compare to the new `ULONG_WIDTH` macro or so.

One thing to think about could be to always map 64 to `long long`,
just for this function here. This would always have the right size and
representation. And since this is an implementation of the C library,
we make the rules ;-)

> Short of a compelling reason not to, though, I plan to just go with
> the fix-up of my v2 patch for this functionality. Its ordering avoids
> duplication of logic (the ?: branches in the cases above) and the need
> for maintaining extra side state (the width variable) thru the state
> machine.

I thought a bit of having the state only in the width variable, but
since we also need to track signedness and the extra cases for FP,
this becomes quickly quite messy.

So yes, looks good (with some minor remarks in up-thread).

Thanks
Jₑₙₛ

-- 
:: ICube :::::::::::::::::::::::::::::: deputy director ::
:: Université de Strasbourg :::::::::::::::::::::: ICPS ::
:: INRIA Nancy Grand Est :::::::::::::::::::::::: Camus ::
:: :::::::::::::::::::::::::::::::::::: ☎ +33 368854536 ::
:: https://icube-icps.unistra.fr/index.php/Jens_Gustedt ::

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Re: [musl] [C23 printf 2/3] C23: implement the wN length specifiers for printf

[Rich Felker]

On Fri, Jun 02, 2023 at 05:09:26PM +0200, Jₑₙₛ Gustedt wrote:
> Rich,
> 
> on Fri, 2 Jun 2023 10:38:00 -0400 you (Rich Felker <dalias@libc.org>)
> wrote:
> 
> > The logic here for whether w64 is LPRE or LLPRE is wrong. The
> > condition for whether [u]int64_t is long or long long is not whether
> > uintptr_t or long long would be too wide (they never are, in our ABIs)
> > but whether long is long enough. All our [u]intN_t are the lowest-rank
> > type of the desired size, and this seems to be consistent with what
> > other implementations like glibc do.
> 
> I probably copied that logic wrong from somewhere. Yes, right thing is
> probably just to compare to the new `ULONG_WIDTH` macro or so.
> 
> One thing to think about could be to always map 64 to `long long`,
> just for this function here. This would always have the right size and
> representation. And since this is an implementation of the C library,
> we make the rules ;-)

Well, in musl we generally want the code to have well-defined behavior
even if it's inlined via LTO, where the types would mismatch. Note
that this is kinda a problem for scanf where va_arg is used with
void*, except that POSIX, conveniently, explicitly requires the C
(compiler) implementation accept mismatched va_arg types when both
types are pointers. This is a big hammer but it seems to be a
necessary assumption to admit implementing the %n$ form of scanf,
which POSIX requires.

Rich

Re: [musl] [C23 printf 2/3] C23: implement the wN length specifiers for printf

[Jₑₙₛ Gustedt]

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Rich,

on Fri, 2 Jun 2023 11:16:40 -0400 you (Rich Felker <dalias@libc.org>)
wrote:

> Note that this is kinda a problem for scanf where va_arg is used
> with void*, except that POSIX, conveniently, explicitly requires the
> C (compiler) implementation accept mismatched va_arg types when both
> types are pointers.

I think that was a change for C23, we here have something similar in
7.16.1.1

  — one type is pointer to qualified or unqualified `void` and the
    other is a pointer to a qualified or unqualified character type;

Unfortunately, C can not go easily further than that, because other
than in POSIX there might be data pointers that have different
representations. (We could have said something like pointers with the
same width and representation, though.)

Also for the new `nullptr_t` type we now have

  — or, the type of the next argument is `nullptr_t` and type is a
    pointer type that has the same representation and alignment
    requirements as a pointer to a character type.

Which then makes it defined behavior to pass in a `nullptr` sentinel,
where it previously was UB when `NULL` was for example `OL` or so, or
when the application passed in an explicit zero instead of `NULL`.

Jₑₙₛ

-- 
:: ICube :::::::::::::::::::::::::::::: deputy director ::
:: Université de Strasbourg :::::::::::::::::::::: ICPS ::
:: INRIA Nancy Grand Est :::::::::::::::::::::::: Camus ::
:: :::::::::::::::::::::::::::::::::::: ☎ +33 368854536 ::
:: https://icube-icps.unistra.fr/index.php/Jens_Gustedt ::

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[musl] [C23 printf 1/3] C23: implement the b and B printf specifiers

[Jens Gustedt]

The b specifier is mandatory for C23. It has been reserved previously,
so we may safely add it, even for older compilation modes.

The B specifier is optional, but recommended for those implementations
that didn't have it reserved previously for other purposes.

The PRIbXXX and PRIBXXX macros are mandatory if the specifiers are
supported and may serve as feature test macros for users.
---
 include/inttypes.h    | 34 ++++++++++++++++++++++++++++++++++
 src/stdio/vfprintf.c  | 19 ++++++++++++++++++-
 src/stdio/vfwprintf.c | 11 +++++++++--
 3 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/include/inttypes.h b/include/inttypes.h
index 61dcb727..73a42e32 100644
--- a/include/inttypes.h
+++ b/include/inttypes.h
@@ -120,12 +120,44 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIXFAST32 "X"
 #define PRIXFAST64 __PRI64 "X"
 
+#define PRIb8  "b"
+#define PRIb16 "b"
+#define PRIb32 "b"
+#define PRIb64 __PRI64 "b"
+
+#define PRIbLEAST8  "b"
+#define PRIbLEAST16 "b"
+#define PRIbLEAST32 "b"
+#define PRIbLEAST64 __PRI64 "b"
+
+#define PRIbFAST8  "b"
+#define PRIbFAST16 "b"
+#define PRIbFAST32 "b"
+#define PRIbFAST64 __PRI64 "b"
+
+#define PRIB8  "B"
+#define PRIB16 "B"
+#define PRIB32 "B"
+#define PRIB64 __PRI64 "B"
+
+#define PRIBLEAST8  "B"
+#define PRIBLEAST16 "B"
+#define PRIBLEAST32 "B"
+#define PRIBLEAST64 __PRI64 "B"
+
+#define PRIBFAST8  "B"
+#define PRIBFAST16 "B"
+#define PRIBFAST32 "B"
+#define PRIBFAST64 __PRI64 "B"
+
 #define PRIdMAX __PRI64 "d"
 #define PRIiMAX __PRI64 "i"
 #define PRIoMAX __PRI64 "o"
 #define PRIuMAX __PRI64 "u"
 #define PRIxMAX __PRI64 "x"
 #define PRIXMAX __PRI64 "X"
+#define PRIbMAX __PRI64 "b"
+#define PRIBMAX __PRI64 "B"
 
 #define PRIdPTR __PRIPTR "d"
 #define PRIiPTR __PRIPTR "i"
@@ -133,6 +165,8 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIuPTR __PRIPTR "u"
 #define PRIxPTR __PRIPTR "x"
 #define PRIXPTR __PRIPTR "X"
+#define PRIbPTR __PRIPTR "b"
+#define PRIBPTR __PRIPTR "B"
 
 #define SCNd8   "hhd"
 #define SCNd16  "hd"
diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index a712d80f..cbc79783 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -48,6 +48,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,6 +59,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -65,17 +67,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -85,11 +90,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -156,6 +163,12 @@ static char *fmt_x(uintmax_t x, char *s, int lower)
 	return s;
 }
 
+static char *fmt_b(uintmax_t x, char *s)
+{
+	for (; x; x>>=1) *--s = '0' + (x&1);
+	return s;
+}
+
 static char *fmt_o(uintmax_t x, char *s)
 {
 	for (; x; x>>=3) *--s = '0' + (x&7);
@@ -437,7 +450,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 	unsigned st, ps;
 	int cnt=0, l=0;
 	size_t i;
-	char buf[sizeof(uintmax_t)*3+3+LDBL_MANT_DIG/4];
+	char buf[sizeof(uintmax_t)*CHAR_BIT+3+LDBL_MANT_DIG/4];
 	const char *prefix;
 	int t, pl;
 	wchar_t wc[2], *ws;
@@ -564,6 +577,10 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 			a = fmt_x(arg.i, z, t&32);
 			if (arg.i && (fl & ALT_FORM)) prefix+=(t>>4), pl=2;
 			if (0) {
+		case 'b': case 'B':
+			a = fmt_b(arg.i, z);
+			if (arg.i && (fl & ALT_FORM)) prefix = (t == 'b' ? "0b" : "0B"), pl=2;
+			} if (0) {
 		case 'o':
 			a = fmt_o(arg.i, z);
 			if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index 53697701..dbc93f74 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -41,6 +41,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -51,6 +52,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,17 +60,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -78,11 +83,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -145,7 +152,7 @@ static int getint(wchar_t **s) {
 
 static const char sizeprefix['y'-'a'] = {
 ['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
-['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
+['b'-'a']='j', ['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
 ['p'-'a']='j'
 };
 
@@ -321,7 +328,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 		case 'a': case 'e': case 'f': case 'g':
 			l = fprintf(f, charfmt, w, p, arg.f);
 			break;
-		case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
+		case 'b': case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
 			l = fprintf(f, charfmt, w, p, arg.i);
 			break;
 		}
-- 
2.34.1

[musl] [C23 printf 1/3] C23: implement the b and B printf specifiers

[Jens Gustedt]

The b specifier is mandatory for C23. It has been reserved previously,
so we may safely add it, even for older compilation modes.

The B specifier is optional, but recommended for those implementations
that didn't have it reserved previously for other purposes.

The PRIbXXX and PRIBXXX macros are mandatory if the specifiers are
supported and may serve as feature test macros for users.
---
 include/inttypes.h    | 34 ++++++++++++++++++++++++++++++++++
 src/stdio/vfprintf.c  | 19 ++++++++++++++++++-
 src/stdio/vfwprintf.c | 11 +++++++++--
 3 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/include/inttypes.h b/include/inttypes.h
index 61dcb727..73a42e32 100644
--- a/include/inttypes.h
+++ b/include/inttypes.h
@@ -120,12 +120,44 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIXFAST32 "X"
 #define PRIXFAST64 __PRI64 "X"
 
+#define PRIb8  "b"
+#define PRIb16 "b"
+#define PRIb32 "b"
+#define PRIb64 __PRI64 "b"
+
+#define PRIbLEAST8  "b"
+#define PRIbLEAST16 "b"
+#define PRIbLEAST32 "b"
+#define PRIbLEAST64 __PRI64 "b"
+
+#define PRIbFAST8  "b"
+#define PRIbFAST16 "b"
+#define PRIbFAST32 "b"
+#define PRIbFAST64 __PRI64 "b"
+
+#define PRIB8  "B"
+#define PRIB16 "B"
+#define PRIB32 "B"
+#define PRIB64 __PRI64 "B"
+
+#define PRIBLEAST8  "B"
+#define PRIBLEAST16 "B"
+#define PRIBLEAST32 "B"
+#define PRIBLEAST64 __PRI64 "B"
+
+#define PRIBFAST8  "B"
+#define PRIBFAST16 "B"
+#define PRIBFAST32 "B"
+#define PRIBFAST64 __PRI64 "B"
+
 #define PRIdMAX __PRI64 "d"
 #define PRIiMAX __PRI64 "i"
 #define PRIoMAX __PRI64 "o"
 #define PRIuMAX __PRI64 "u"
 #define PRIxMAX __PRI64 "x"
 #define PRIXMAX __PRI64 "X"
+#define PRIbMAX __PRI64 "b"
+#define PRIBMAX __PRI64 "B"
 
 #define PRIdPTR __PRIPTR "d"
 #define PRIiPTR __PRIPTR "i"
@@ -133,6 +165,8 @@ uintmax_t wcstoumax(const wchar_t *__restrict, wchar_t **__restrict, int);
 #define PRIuPTR __PRIPTR "u"
 #define PRIxPTR __PRIPTR "x"
 #define PRIXPTR __PRIPTR "X"
+#define PRIbPTR __PRIPTR "b"
+#define PRIBPTR __PRIPTR "B"
 
 #define SCNd8   "hhd"
 #define SCNd16  "hd"
diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index a712d80f..cbc79783 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -48,6 +48,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,6 +59,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -65,17 +67,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -85,11 +90,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -156,6 +163,12 @@ static char *fmt_x(uintmax_t x, char *s, int lower)
 	return s;
 }
 
+static char *fmt_b(uintmax_t x, char *s)
+{
+	for (; x; x>>=1) *--s = '0' + (x&1);
+	return s;
+}
+
 static char *fmt_o(uintmax_t x, char *s)
 {
 	for (; x; x>>=3) *--s = '0' + (x&7);
@@ -437,7 +450,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 	unsigned st, ps;
 	int cnt=0, l=0;
 	size_t i;
-	char buf[sizeof(uintmax_t)*3+3+LDBL_MANT_DIG/4];
+	char buf[sizeof(uintmax_t)*CHAR_BIT+3+LDBL_MANT_DIG/4];
 	const char *prefix;
 	int t, pl;
 	wchar_t wc[2], *ws;
@@ -564,6 +577,10 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 			a = fmt_x(arg.i, z, t&32);
 			if (arg.i && (fl & ALT_FORM)) prefix+=(t>>4), pl=2;
 			if (0) {
+		case 'b': case 'B':
+			a = fmt_b(arg.i, z);
+			if (arg.i && (fl & ALT_FORM)) prefix = (t == 'b' ? "0b" : "0B"), pl=2;
+			} if (0) {
 		case 'o':
 			a = fmt_o(arg.i, z);
 			if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index 53697701..dbc93f74 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -41,6 +41,7 @@ enum {
 
 static const unsigned char states[]['z'-'A'+1] = {
 	{ /* 0: bare types */
+		S('b') = UINT, S('B') = UINT,
 		S('d') = INT, S('i') = INT,
 		S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -51,6 +52,7 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
 		S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
 	}, { /* 1: l-prefixed */
+		S('b') = ULONG, S('B') = ULONG,
 		S('d') = LONG, S('i') = LONG,
 		S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
 		S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
@@ -58,17 +60,20 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('c') = INT, S('s') = PTR, S('n') = PTR,
 		S('l') = LLPRE,
 	}, { /* 2: ll-prefixed */
+		S('b') = ULLONG, S('B') = ULLONG,
 		S('d') = LLONG, S('i') = LLONG,
 		S('o') = ULLONG, S('u') = ULLONG,
 		S('x') = ULLONG, S('X') = ULLONG,
 		S('n') = PTR,
 	}, { /* 3: h-prefixed */
+		S('b') = USHORT, S('B') = USHORT,
 		S('d') = SHORT, S('i') = SHORT,
 		S('o') = USHORT, S('u') = USHORT,
 		S('x') = USHORT, S('X') = USHORT,
 		S('n') = PTR,
 		S('h') = HHPRE,
 	}, { /* 4: hh-prefixed */
+		S('b') = UCHAR, S('B') = UCHAR,
 		S('d') = CHAR, S('i') = CHAR,
 		S('o') = UCHAR, S('u') = UCHAR,
 		S('x') = UCHAR, S('X') = UCHAR,
@@ -78,11 +83,13 @@ static const unsigned char states[]['z'-'A'+1] = {
 		S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
 		S('n') = PTR,
 	}, { /* 6: z- or t-prefixed (assumed to be same size) */
+		S('b') = SIZET, S('B') = SIZET,
 		S('d') = PDIFF, S('i') = PDIFF,
 		S('o') = SIZET, S('u') = SIZET,
 		S('x') = SIZET, S('X') = SIZET,
 		S('n') = PTR,
 	}, { /* 7: j-prefixed */
+		S('b') = UMAX, S('B') = UMAX,
 		S('d') = IMAX, S('i') = IMAX,
 		S('o') = UMAX, S('u') = UMAX,
 		S('x') = UMAX, S('X') = UMAX,
@@ -145,7 +152,7 @@ static int getint(wchar_t **s) {
 
 static const char sizeprefix['y'-'a'] = {
 ['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
-['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
+['b'-'a']='j', ['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
 ['p'-'a']='j'
 };
 
@@ -321,7 +328,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
 		case 'a': case 'e': case 'f': case 'g':
 			l = fprintf(f, charfmt, w, p, arg.f);
 			break;
-		case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
+		case 'b': case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
 			l = fprintf(f, charfmt, w, p, arg.i);
 			break;
 		}
-- 
2.34.1