Add cbprintf(3) and vcbprintf(3).

Thanks to Owen Shepherd of the Public Domain C Library for helping design
and formalize these interfaces.

kernel/debugger.cpp

@@ -153,7 +153,7 @@ void Print(const char* format, ...)
 {
 	va_list ap;
 	va_start(ap, format);
-	vprintf_callback(PrintCallback, NULL, format, ap);
+	vcbprintf(NULL, PrintCallback, format, ap);
 	va_end(ap);
 }
 

kernel/include/sortix/kernel/log.h

@@ -28,6 +28,7 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <string.h>
 
 namespace Sortix {
@@ -95,15 +96,20 @@ inline size_t PrintF(const char* format, ...)
 {
 	va_list list;
 	va_start(list, format);
-	size_t result = vprintf_callback(device_callback, device_pointer, format, list);
+	int result = vcbprintf(device_pointer, device_callback, format, list);
 	va_end(list);
-	return result;
+	if ( result < 0 )
+		return SIZE_MAX;
+	return (size_t) result;
 }
 
 __attribute__((format(printf, 1, 0)))
 inline size_t PrintFV(const char* format, va_list list)
 {
-	return vprintf_callback(device_callback, device_pointer, format, list);
+	int result = vcbprintf(device_pointer, device_callback, format, list);
+	if ( result < 0 )
+		return SIZE_MAX;
+	return (size_t) result;
 }
 
 } // namespace Log

libc/Makefile

@@ -67,6 +67,7 @@ signal/sigorset.o \
 stdio/asprintf.o \
 stdio/clearerr.o \
 stdio/clearerr_unlocked.o \
+stdio/cbprintf.o \
 stdio/dprintf.o \
 stdio/fbufsize.o \
 stdio/fbufsize_unlocked.o \
@@ -142,11 +143,11 @@ stdio/sscanf.o \
 stdio/ungetc.o \
 stdio/ungetc_unlocked.o \
 stdio/vasprintf.o \
+stdio/vcbprintf.o \
 stdio/vdprintf.o \
 stdio/vfprintf_unlocked.o \
 stdio/vfscanf.o \
 stdio/vfscanf_unlocked.o \
-stdio/vprintf_callback.o \
 stdio/vscanf_callback.o \
 stdio/vsnprintf.o \
 stdio/vsprintf.o \

libc/include/stdio.h

@@ -320,12 +320,11 @@ void fpurge_unlocked(FILE* fp);
 size_t fpending_unlocked(FILE* fp);
 #endif
 
-/* The Sortix backends for *printf and *scanf. */
+/* The backends for printf and scanf. */
 #if __USE_SORTIX
-size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
-                        void* user,
-                        const char* __restrict format,
-                        __gnuc_va_list ap)
+int cbprintf(void*, size_t (*)(void*, const char*, size_t), const char*, ...)
+	__attribute__((__format__ (printf, 3, 4)));
+int vcbprintf(void*, size_t (*)(void*, const char*, size_t), const char*, __gnuc_va_list ap)
 	__attribute__((__format__ (printf, 3, 0)));
 int vscanf_callback(void* fp,
                     int (*fgetc)(void*),

libc/stdio/cbprintf.cpp

@@ -0,0 +1,39 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    stdio/cbprintf.cpp
+    Formats text and outputs it via callback functions.
+
+*******************************************************************************/
+
+#include <stdarg.h>
+#include <stdio.h>
+
+extern "C"
+int cbprintf(void* user,
+             size_t (*callback)(void*, const char*, size_t),
+             const char* format,
+             ...)
+{
+	va_list ap;
+	va_start(ap, format);
+	int result = vcbprintf(user, callback, format, ap);
+	va_end(ap);
+	return result;
+}

libc/stdio/vasprintf.cpp

@@ -72,9 +72,9 @@ int vasprintf(char** restrict result_ptr,
 	state.string_used = 0;
 	if ( !(state.string = (char*) malloc(state.string_length * sizeof(char))) )
 		return *result_ptr = NULL, -1;
-	vprintf_callback(vasprintf_callback, &state, format, list);
+	int result = vcbprintf(&state, vasprintf_callback, format, list);
 	if ( !state.string )
 		return *result_ptr = NULL, -1;
 	state.string[state.string_used] = '\0';
-	return *result_ptr = state.string, (int) state.string_used;
+	return *result_ptr = state.string, result;
 }

libc/stdio/vcbprintf.cpp

@@ -17,15 +17,13 @@
     You should have received a copy of the GNU Lesser General Public License
     along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
 
-    stdio/vprintf_callback.cpp
-    Provides printf formatting functions that uses callbacks.
+    stdio/vcbprintf.cpp
+    Formats text and outputs it via callback functions.
 
 *******************************************************************************/
 
-// Number of bugs seemingly unrelated bugs that have been traced to here:
-// Countless + 2
-
 #include <errno.h>
+#include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -51,19 +49,19 @@ static size_t noop_callback(void*, const char*, size_t amount)
 	return amount;
 }
 
-static
-size_t callback_character(size_t (*callback)(void*, const char*, size_t),
-                          void* user,
+static inline
+size_t callback_character(void* user,
+                          size_t (*callback)(void*, const char*, size_t),
                           char c)
 {
 	return callback(user, &c, 1);
 }
 
 extern "C"
-size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
-                        void* user,
-                        const char* restrict format,
-                        va_list parameters)
+int vcbprintf(void* user,
+              size_t (*callback)(void*, const char*, size_t),
+              const char* format,
+              va_list parameters)
 {
 	if ( !callback )
 		callback = noop_callback;
@@ -80,7 +78,7 @@ size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
 			while ( format[amount] && format[amount] != '%' )
 				amount++;
 			if ( callback(user, format, amount) != amount )
-				return SIZE_MAX;
+				return -1;
 			format += amount;
 			written += amount;
 			continue;
@@ -311,32 +309,32 @@ size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
 
 			if ( use_left_pad )
 				for ( size_t i = length_with_precision; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 			if ( callback(user, prefix, prefix_length) != prefix_length )
-				return SIZE_MAX;
+				return -1;
 			written += prefix_length;
 			if ( use_zero_pad )
 				for ( size_t i = normal_length; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, '0') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, '0') != 1 )
+						return -1;
 					else
 						written++;
 			if ( use_precision )
 				for ( size_t i = digits_length; i < precision; i++ )
-					if ( callback_character(callback, user, '0') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, '0') != 1 )
+						return -1;
 					else
 						written++;
 			if ( callback(user, output, output_length) != output_length )
-				return SIZE_MAX;
+				return -1;
 			written += output_length;
 			if ( use_right_pad )
 				for ( size_t i = length_with_precision; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 		}
@@ -379,19 +377,19 @@ size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
 
 			if ( !field_width_is_negative && 1 < abs_field_width )
 				for ( size_t i = 1; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 
 			if ( callback(user, &c, 1) != 1 )
-				return SIZE_MAX;
+				return -1;
 			written++;
 
 			if ( field_width_is_negative && 1 < abs_field_width )
 				for ( size_t i = 1; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 		}
@@ -422,19 +420,19 @@ size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
 
 			if ( !field_width_is_negative && string_length < abs_field_width )
 				for ( size_t i = string_length; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 
 			if ( callback(user, string, string_length) != string_length )
-				return SIZE_MAX;
+				return -1;
 			written += string_length;
 
 			if ( field_width_is_negative && string_length < abs_field_width )
 				for ( size_t i = string_length; i < abs_field_width; i++ )
-					if ( callback_character(callback, user, ' ') != 1 )
-						return SIZE_MAX;
+					if ( callback_character(user, callback, ' ') != 1 )
+						return -1;
 					else
 						written++;
 
@@ -464,5 +462,8 @@ size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
 			goto incomprehensible_conversion;
 	}
 
+	if ( INT_MAX < written )
+		return INT_MAX;
+
 	return written;
 }

libc/stdio/vdprintf.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2013.
+    Copyright(C) Jonas 'Sortie' Termansen 2013, 2014.
 
     This file is part of the Sortix C Library.
 
@@ -30,10 +30,10 @@
 
 static size_t write_callback(void* user, const char* string, size_t stringlen)
 {
-	return writeall((int) (uintptr_t) user, string, stringlen * sizeof(char));
+	return writeall((int) (uintptr_t) user, string, stringlen);
 }
 
 extern "C" int vdprintf(int fd, const char* restrict format, va_list list)
 {
-	return vprintf_callback(write_callback, (void*) (uintptr_t) fd, format, list);
+	return vcbprintf((void*) (uintptr_t) fd, write_callback, format, list);
 }

libc/stdio/vfprintf_unlocked.cpp

@@ -38,8 +38,5 @@ int vfprintf_unlocked(FILE* fp, const char* restrict format, va_list list)
 	if ( !(fp->flags & _FILE_WRITABLE) )
 		return errno = EBADF, fp->flags |= _FILE_STATUS_ERROR, EOF;
 
-	size_t result = vprintf_callback(FileWriteCallback, fp, format, list);
-	if ( result == SIZE_MAX )
-		return -1;
-	return (int) result;
+	return vcbprintf(fp, FileWriteCallback, format, list);
 }

libc/stdio/vsnprintf.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 
-    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
 
     This file is part of the Sortix C Library.
 
@@ -58,8 +58,8 @@ int vsnprintf(char* restrict str, size_t size, const char* restrict format,
 	info.size = size ? size-1 : 0;
 	info.produced = 0;
 	info.written = 0;
-	vprintf_callback(StringPrintCallback, &info, format, list);
+	int result = vcbprintf(&info, StringPrintCallback, format, list);
 	if ( size )
 		info.str[info.written] = '\0';
-	return (int) info.produced;
+	return result;
 }