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-rw-r--r--src/core/vsprintf.c148
-rw-r--r--src/include/vsprintf.h57
2 files changed, 125 insertions, 80 deletions
diff --git a/src/core/vsprintf.c b/src/core/vsprintf.c
index 0e374e65e..ada1f13de 100644
--- a/src/core/vsprintf.c
+++ b/src/core/vsprintf.c
@@ -1,15 +1,35 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
#include <stddef.h>
#include <stdarg.h>
#include <console.h>
#include <errno.h>
#include <vsprintf.h>
-#define CHAR_LEN 1
-#define SHORT_LEN 2
-#define INT_LEN 3
-#define LONG_LEN 4
-#define LONGLONG_LEN 5
-#define SIZE_T_LEN 6
+/** @file */
+
+#define CHAR_LEN 0 /**< "hh" length modifier */
+#define SHORT_LEN 1 /**< "h" length modifier */
+#define INT_LEN 2 /**< no length modifier */
+#define LONG_LEN 3 /**< "l" length modifier */
+#define LONGLONG_LEN 4 /**< "ll" length modifier */
+#define SIZE_T_LEN 5 /**< "z" length modifier */
static uint8_t type_sizes[] = {
[CHAR_LEN] = sizeof ( char ),
@@ -20,8 +40,6 @@ static uint8_t type_sizes[] = {
[SIZE_T_LEN] = sizeof ( size_t ),
};
-/** @file */
-
/**
* A printf context
*
@@ -48,36 +66,80 @@ struct printf_context {
size_t max_len;
};
+/**
+ * Use lower-case for hexadecimal digits
+ *
+ * Note that this value is set to 0x20 since that makes for very
+ * efficient calculations. (Bitwise-ORing with @c LCASE converts to a
+ * lower-case character, for example.)
+ */
#define LCASE 0x20
+
+/**
+ * Use "alternate form"
+ *
+ * For hexadecimal numbers, this means to add a "0x" or "0X" prefix to
+ * the number.
+ */
#define ALT_FORM 0x02
-static char * format_hex ( char *buf, unsigned long long num, int width,
+/**
+ * Format a hexadecimal number
+ *
+ * @v end End of buffer to contain number
+ * @v num Number to format
+ * @v width Minimum field width
+ * @ret ptr End of buffer
+ *
+ * Fills a buffer in reverse order with a formatted hexadecimal
+ * number. The number will be zero-padded to the specified width.
+ * Lower-case and "alternate form" (i.e. "0x" prefix) flags may be
+ * set.
+ *
+ * There must be enough space in the buffer to contain the largest
+ * number that this function can format.
+ */
+static char * format_hex ( char *end, unsigned long long num, int width,
int flags ) {
- char *ptr = buf;
+ char *ptr = end;
int case_mod;
/* Generate the number */
case_mod = flags & LCASE;
do {
- *ptr++ = "0123456789ABCDEF"[ num & 0xf ] | case_mod;
+ *(--ptr) = "0123456789ABCDEF"[ num & 0xf ] | case_mod;
num >>= 4;
} while ( num );
/* Zero-pad to width */
- while ( ( ptr - buf ) < width )
- *ptr++ = '0';
+ while ( ( end - ptr ) < width )
+ *(--ptr) = '0';
/* Add "0x" or "0X" if alternate form specified */
if ( flags & ALT_FORM ) {
- *ptr++ = 'X' | case_mod;
- *ptr++ = '0';
+ *(--ptr) = 'X' | case_mod;
+ *(--ptr) = '0';
}
return ptr;
}
-static char * format_decimal ( char *buf, signed long num, int width ) {
- char *ptr = buf;
+/**
+ * Format a decimal number
+ *
+ * @v end End of buffer to contain number
+ * @v num Number to format
+ * @v width Minimum field width
+ * @ret ptr End of buffer
+ *
+ * Fills a buffer in reverse order with a formatted decimal number.
+ * The number will be space-padded to the specified width.
+ *
+ * There must be enough space in the buffer to contain the largest
+ * number that this function can format.
+ */
+static char * format_decimal ( char *end, signed long num, int width ) {
+ char *ptr = end;
int negative = 0;
/* Generate the number */
@@ -86,22 +148,21 @@ static char * format_decimal ( char *buf, signed long num, int width ) {
num = -num;
}
do {
- *ptr++ = '0' + ( num % 10 );
+ *(--ptr) = '0' + ( num % 10 );
num /= 10;
} while ( num );
/* Add "-" if necessary */
if ( negative )
- *ptr++ = '-';
+ *(--ptr) = '-';
/* Space-pad to width */
- while ( ( ptr - buf ) < width )
- *ptr++ = ' ';
+ while ( ( end - ptr ) < width )
+ *(--ptr) = ' ';
return ptr;
}
-
/**
* Write a formatted string to a printf context
*
@@ -114,11 +175,9 @@ int vcprintf ( struct printf_context *ctx, const char *fmt, va_list args ) {
int flags;
int width;
uint8_t *length;
- int character;
- unsigned long long hex;
- signed long decimal;
- char num_buf[32];
char *ptr;
+ char tmp_buf[32]; /* 32 is enough for all numerical formats.
+ * Insane width fields could overflow this buffer. */
/* Initialise context */
ctx->len = 0;
@@ -166,22 +225,21 @@ int vcprintf ( struct printf_context *ctx, const char *fmt, va_list args ) {
}
}
/* Process conversion specifier */
+ ptr = tmp_buf + sizeof ( tmp_buf ) - 1;
+ *ptr = '\0';
if ( *fmt == 'c' ) {
- character = va_arg ( args, unsigned int );
- ctx->handler ( ctx, character );
+ *(--ptr) = va_arg ( args, unsigned int );
} else if ( *fmt == 's' ) {
ptr = va_arg ( args, char * );
- for ( ; *ptr ; ptr++ ) {
- ctx->handler ( ctx, *ptr );
- }
} else if ( *fmt == 'p' ) {
- hex = ( intptr_t ) va_arg ( args, void * );
- ptr = format_hex ( num_buf, hex, width,
+ intptr_t ptrval;
+
+ ptrval = ( intptr_t ) va_arg ( args, void * );
+ ptr = format_hex ( ptr, ptrval, width,
( ALT_FORM | LCASE ) );
- do {
- ctx->handler ( ctx, *(--ptr) );
- } while ( ptr != num_buf );
} else if ( ( *fmt & ~0x20 ) == 'X' ) {
+ unsigned long long hex;
+
flags |= ( *fmt & 0x20 ); /* LCASE */
if ( *length >= sizeof ( unsigned long long ) ) {
hex = va_arg ( args, unsigned long long );
@@ -190,22 +248,22 @@ int vcprintf ( struct printf_context *ctx, const char *fmt, va_list args ) {
} else {
hex = va_arg ( args, unsigned int );
}
- ptr = format_hex ( num_buf, hex, width, flags );
- do {
- ctx->handler ( ctx, *(--ptr) );
- } while ( ptr != num_buf );
+ ptr = format_hex ( ptr, hex, width, flags );
} else if ( *fmt == 'd' ) {
+ signed long decimal;
+
if ( *length >= sizeof ( signed long ) ) {
decimal = va_arg ( args, signed long );
} else {
decimal = va_arg ( args, signed int );
}
- ptr = format_decimal ( num_buf, decimal, width );
- do {
- ctx->handler ( ctx, *(--ptr) );
- } while ( ptr != num_buf );
+ ptr = format_decimal ( ptr, decimal, width );
} else {
- ctx->handler ( ctx, *fmt );
+ *(--ptr) = *fmt;
+ }
+ /* Write out conversion result */
+ for ( ; *ptr ; ptr++ ) {
+ ctx->handler ( ctx, *ptr );
}
}
diff --git a/src/include/vsprintf.h b/src/include/vsprintf.h
index 3683fba16..99d6683e1 100644
--- a/src/include/vsprintf.h
+++ b/src/include/vsprintf.h
@@ -3,44 +3,31 @@
/** @file
*
- * printf and friends.
+ * printf() and friends
*
- * Etherboot's printf() functions understand the following format
- * specifiers:
+ * Etherboot's printf() functions understand the following subset of
+ * the standard C printf()'s format specifiers:
*
- * - Hexadecimal integers
- * - @c %[#]x - 4 bytes int (8 hex digits, lower case)
- * - @c %[#]X - 4 bytes int (8 hex digits, upper case)
- * - @c %[#]lx - 8 bytes long (16 hex digits, lower case)
- * - @c %[#]lX - 8 bytes long (16 hex digits, upper case)
- * - @c %[#]hx - 2 bytes int (4 hex digits, lower case)
- * - @c %[#]hX - 2 bytes int (4 hex digits, upper case)
- * - @c %[#]hhx - 1 byte int (2 hex digits, lower case)
- * - @c %[#]hhX - 1 byte int (2 hex digits, upper case)
- * .
- * If the optional # prefix is specified, the output will
- * be prefixed with 0x (or 0X).
+ * - Flag characters
+ * - '#' - Alternate form (i.e. "0x" prefix)
+ * - '0' - Zero-pad
+ * - Field widths
+ * - Length modifiers
+ * - 'hh' - Signed / unsigned char
+ * - 'h' - Signed / unsigned short
+ * - 'l' - Signed / unsigned long
+ * - 'll' - Signed / unsigned long long
+ * - 'z' - Signed / unsigned size_t
+ * - Conversion specifiers
+ * - 'd' - Signed decimal
+ * - 'x','X' - Unsigned hexadecimal
+ * - 'c' - Character
+ * - 's' - String
+ * - 'p' - Pointer
*
- * - Other integers
- * - @c %d - decimal int
- * .
- * Note that any width specification (e.g. the @c 02 in @c %02x)
- * will be accepted but ignored.
- *
- * - Strings and characters
- * - @c %c - char
- * - @c %s - string
- * - @c %m - error message text (i.e. strerror(errno))
- *
- * - Etherboot-specific specifiers
- * - @c %@ - IP address in ddd.ddd.ddd.ddd notation
- * - @c %! - MAC address in xx:xx:xx:xx:xx:xx notation
- *
- *
- * @note Unfortunately, we cannot use <tt> __attribute__ (( format (
- * printf, ... ) )) </tt> to get automatic type checking on arguments,
- * because we use non-standard format characters such as @c %! and
- * @c %@.
+ * Hexadecimal numbers are always zero-padded to the specified field
+ * width (if any); decimal numbers are always space-padded. Decimal
+ * long longs are not supported.
*
*/
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