glibc/stdio/printf-parse.h

389 lines
9.7 KiB
C

/* Internal header for parsing printf format strings.
Copyright (C) 1995 Free Software Foundation, Inc.
This file is part of th GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ctype.h>
#include <printf.h>
#include <string.h>
#include <stddef.h>
#define NDEBUG 1
#include <assert.h>
#define MAX(a,b) ({typeof(a) _a = (a); typeof(b) _b = (b); \
_a > _b ? _a : _b; })
#define MIN(a,b) ({typeof(a) _a = (a); typeof(b) _b = (b); \
_a < _b ? _a : _b; })
struct printf_spec
{
/* Information parsed from the format spec. */
struct printf_info info;
/* Pointers into the format string for the end of this format
spec and the next (or to the end of the string if no more). */
const char *end_of_fmt, *next_fmt;
/* Position of arguments for precision and width, or -1 if `info' has
the constant value. */
int prec_arg, width_arg;
int data_arg; /* Position of data argument. */
int data_arg_type; /* Type of first argument. */
/* Number of arguments consumed by this format specifier. */
size_t ndata_args;
};
/* The various kinds off arguments that can be passed to printf. */
union printf_arg
{
unsigned char pa_char;
short int pa_short_int;
int pa_int;
long int pa_long_int;
long long int pa_long_long_int;
unsigned short int pa_u_short_int;
unsigned int pa_u_int;
unsigned long int pa_u_long_int;
unsigned long long int pa_u_long_long_int;
float pa_float;
double pa_double;
long double pa_long_double;
const char *pa_string;
void *pa_pointer;
};
/* Read a simple integer from a string and update the string pointer.
It is assumed that the first character is a digit. */
static inline unsigned int
read_int (const char * *pstr)
{
unsigned int retval = **pstr - '0';
while (isdigit (*++(*pstr)))
{
retval *= 10;
retval += **pstr - '0';
}
return retval;
}
/* Find the next spec in FORMAT, or the end of the string. Returns
a pointer into FORMAT, to a '%' or a '\0'. */
static inline const char *
find_spec (const char *format)
{
while (*format != '\0' && *format != '%')
{
int len;
if (isascii (*format) || (len = mblen (format, MB_CUR_MAX)) <= 0)
++format;
else
format += len;
}
return format;
}
/* This is defined in reg-printf.c. */
extern printf_arginfo_function **__printf_arginfo_table;
/* FORMAT must point to a '%' at the beginning of a spec. Fills in *SPEC
with the parsed details. POSN is the number of arguments already
consumed. At most MAXTYPES - POSN types are filled in TYPES. Return
the number of args consumed by this spec; *MAX_REF_ARG is updated so it
remains the highest argument index used. */
static inline size_t
parse_one_spec (const char *format, size_t posn, struct printf_spec *spec,
size_t *max_ref_arg)
{
unsigned int n;
size_t nargs = 0;
/* Skip the '%'. */
++format;
/* Clear information structure. */
spec->data_arg = -1;
spec->info.alt = 0;
spec->info.space = 0;
spec->info.left = 0;
spec->info.showsign = 0;
spec->info.group = 0;
spec->info.pad = ' ';
/* Test for positional argument. */
if (isdigit (*format))
{
const char *begin = format;
n = read_int (&format);
if (n > 0 && *format == '$')
/* Is positional parameter. */
{
++format; /* Skip the '$'. */
spec->data_arg = n - 1;
*max_ref_arg = MAX (*max_ref_arg, n);
}
else
/* Oops; that was actually the width and/or 0 padding flag.
Step back and read it again. */
format = begin;
}
/* Check for spec modifiers. */
while (*format == ' ' || *format == '+' || *format == '-' ||
*format == '#' || *format == '0' || *format == '\'')
switch (*format++)
{
case ' ':
/* Output a space in place of a sign, when there is no sign. */
spec->info.space = 1;
break;
case '+':
/* Always output + or - for numbers. */
spec->info.showsign = 1;
break;
case '-':
/* Left-justify things. */
spec->info.left = 1;
break;
case '#':
/* Use the "alternate form":
Hex has 0x or 0X, FP always has a decimal point. */
spec->info.alt = 1;
break;
case '0':
/* Pad with 0s. */
spec->info.pad = '0';
break;
case '\'':
/* Show grouping in numbers if the locale information
indicates any. */
spec->info.group = 1;
break;
}
if (spec->info.left)
spec->info.pad = ' ';
/* Get the field width. */
spec->width_arg = -1;
spec->info.width = 0;
if (*format == '*')
{
/* The field width is given in an argument.
A negative field width indicates left justification. */
const char *begin = ++format;
if (isdigit (*format))
{
/* The width argument might be found in a positional parameter. */
n = read_int (&format);
if (n > 0 && *format == '$')
{
spec->width_arg = n - 1;
*max_ref_arg = MAX (*max_ref_arg, n);
++format; /* Skip '$'. */
}
}
if (spec->width_arg < 0)
{
/* Not in a positional parameter. Consume one argument. */
spec->width_arg = posn++;
++nargs;
format = begin; /* Step back and reread. */
}
}
else if (isdigit (*format))
/* Constant width specification. */
spec->info.width = read_int (&format);
/* Get the precision. */
spec->prec_arg = -1;
/* -1 means none given; 0 means explicit 0. */
spec->info.prec = -1;
if (*format == '.')
{
++format;
if (*format == '*')
{
/* The precision is given in an argument. */
const char *begin = ++format;
if (isdigit (*format))
{
n = read_int (&format);
if (n > 0 && *format == '$')
{
spec->prec_arg = n - 1;
*max_ref_arg = MAX (*max_ref_arg, n);
++format;
}
}
if (spec->prec_arg < 0)
{
/* Not in a positional parameter. */
spec->prec_arg = posn++;
++nargs;
format = begin;
}
}
else if (isdigit (*format))
spec->info.prec = read_int (&format);
else
/* "%.?" is treated like "%.0?". */
spec->info.prec = 0;
/* If there was a precision specified, ignore the 0 flag and always
pad with spaces. */
spec->info.pad = ' ';
}
/* Check for type modifiers. */
#define is_longlong is_long_double
spec->info.is_long_double = 0;
spec->info.is_short = 0;
spec->info.is_long = 0;
while (*format == 'h' || *format == 'l' || *format == 'L' ||
*format == 'Z' || *format == 'q')
switch (*format++)
{
case 'h':
/* int's are short int's. */
spec->info.is_short = 1;
break;
case 'l':
if (spec->info.is_long)
/* A double `l' is equivalent to an `L'. */
spec->info.is_longlong = 1;
else
/* int's are long int's. */
spec->info.is_long = 1;
break;
case 'L':
/* double's are long double's, and int's are long long int's. */
spec->info.is_long_double = 1;
break;
case 'Z':
/* int's are size_t's. */
assert (sizeof(size_t) <= sizeof(unsigned long long int));
spec->info.is_longlong = sizeof(size_t) > sizeof(unsigned long int);
spec->info.is_long = sizeof(size_t) > sizeof(unsigned int);
break;
case 'q':
/* 4.4 uses this for long long. */
spec->info.is_longlong = 1;
break;
}
/* Get the format specification. */
spec->info.spec = *format++;
if (__printf_arginfo_table != NULL &&
__printf_arginfo_table[spec->info.spec] != NULL)
/* We don't try to get the types for all arguments if the format
uses more than one. The normal case is covered though. */
spec->ndata_args = (*__printf_arginfo_table[spec->info.spec])
(&spec->info, 1, &spec->data_arg_type);
else
{
/* Find the data argument types of a built-in spec. */
spec->ndata_args = 1;
switch (spec->info.spec)
{
case 'i':
case 'd':
case 'u':
case 'o':
case 'X':
case 'x':
if (spec->info.is_longlong)
spec->data_arg_type = PA_INT|PA_FLAG_LONG_LONG;
else if (spec->info.is_long)
spec->data_arg_type = PA_INT|PA_FLAG_LONG;
else if (spec->info.is_short)
spec->data_arg_type = PA_INT|PA_FLAG_SHORT;
else
spec->data_arg_type = PA_INT;
break;
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
if (spec->info.is_long_double)
spec->data_arg_type = PA_DOUBLE|PA_FLAG_LONG_DOUBLE;
else
spec->data_arg_type = PA_DOUBLE;
break;
case 'c':
spec->data_arg_type = PA_CHAR;
break;
case 's':
spec->data_arg_type = PA_STRING;
break;
case 'p':
spec->data_arg_type = PA_POINTER;
break;
case 'n':
spec->data_arg_type = PA_INT|PA_FLAG_PTR;
break;
case 'm':
default:
/* An unknown spec will consume no args. */
spec->ndata_args = 0;
break;
}
if (spec->data_arg == -1 && spec->ndata_args > 0)
{
/* There are args consumed, but no positional spec.
Use the next sequential arg position. */
spec->data_arg = posn;
posn += spec->ndata_args;
nargs += spec->ndata_args;
}
}
if (spec->info.spec == '\0')
/* Format ended before this spec was complete. */
spec->end_of_fmt = spec->next_fmt = format - 1;
else
{
/* Find the next format spec. */
spec->end_of_fmt = format;
spec->next_fmt = find_spec (format);
}
return nargs;
}