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cc65/libsrc/common/_scanf.c
uz ed2767e65f Changed names of the pragmas to be identical to the corresponding command line
options. This should make use easier. The old names of the pragmas are still
available but will cause warnings.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4364 b7a2c559-68d2-44c3-8de9-860c34a00d81
2009-10-14 12:55:15 +00:00

871 lines
26 KiB
C

/*
* _scanf.c
*
* (c) Copyright 2001-2005, Ullrich von Bassewitz <uz@cc65.org>
* 2005-01-24, Greg King <gngking@erols.com>
*
* This is the basic layer for all scanf-type functions. It should be
* rewritten in assembly, at some time in the future. So, some of the code
* is not as elegant as it could be.
*/
#include <stddef.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <setjmp.h>
#include <limits.h>
#include <errno.h>
#include <ctype.h>
/* _scanf() can give EOF to these functions. But, the macroes can't
** understand it; so, they are removed.
*/
#undef isspace
#undef isxdigit
#include "_scanf.h"
extern void __fastcall__ _seterrno (unsigned char code);
#pragma static-locals(on)
/*****************************************************************************/
/* SetJmp return codes */
/*****************************************************************************/
enum {
RC_OK, /* setjmp() call */
RC_NOCONV, /* No conversion possible */
RC_EOF /* EOF reached */
};
/*****************************************************************************/
/* Data */
/*****************************************************************************/
static const char* format; /* Copy of function argument */
static const struct scanfdata* D_; /* Copy of function argument */
static va_list ap; /* Copy of function argument */
static jmp_buf JumpBuf; /* "Label" that is used for failures */
static char F; /* Character from format string */
static unsigned CharCount; /* Characters read so far */
static int C; /* Character from input */
static unsigned Width; /* Maximum field width */
static long IntVal; /* Converted int value */
static int Assignments; /* Number of assignments */
static unsigned char IntBytes; /* Number of bytes-1 for int conversions */
/* Flags */
static bool Converted; /* Some object was converted */
static bool Positive; /* Flag for positive value */
static bool NoAssign; /* Suppress assignment */
static bool Invert; /* Do we need to invert the charset? */
static unsigned char CharSet[(1+UCHAR_MAX)/CHAR_BIT];
static const unsigned char Bits[CHAR_BIT] = {
0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
};
/* We need C to be 16 bits since we cannot check for EOF otherwise.
* Unfortunately, this causes the code to be quite larger, even if for most
* purposes, checking the low byte would be enough, since if C is EOF, the
* low byte will not match any useful character anyway (at least for the
* supported platforms - I know that this is not portable). So the following
* macro is used to access just the low byte of C.
*/
#define CHAR(c) (*((unsigned char*)&(c)))
/*****************************************************************************/
/* Character sets */
/*****************************************************************************/
/* We don't want the optimizer to ruin our "perfect" ;-)
* assembly code!
*/
#pragma optimize (push, off)
static unsigned FindBit (void)
/* Locate the character's bit in the charset array.
* < .A - Argument character
* > .X - Offset of the byte in the character-set mask
* > .A - Bit-mask
*/
{
asm ("pha");
asm ("lsr a"); /* Divide by CHAR_BIT */
asm ("lsr a");
asm ("lsr a");
asm ("tax"); /* Byte's offset */
asm ("pla");
asm ("and #%b", CHAR_BIT-1);
asm ("tay"); /* Bit's offset */
asm ("lda %v,y", Bits);
return (unsigned) __AX__;
}
#pragma optimize (pop)
static void __fastcall__ AddCharToSet (unsigned char /* C */)
/* Set the given bit in the character set */
{
FindBit();
asm ("ora %v,x", CharSet);
asm ("sta %v,x", CharSet);
}
#pragma optimize (push, off)
static unsigned char IsCharInSet (void)
/* Check if the char. is part of the character set. */
{
/* Get the character from C. */
asm ("lda #$00");
asm ("ldx %v+1", C);
asm ("bne L1"); /* EOF never is in the set */
asm ("lda %v", C);
FindBit();
asm ("and %v,x", CharSet);
asm ("L1:");
asm ("ldx #$00");
return (unsigned char) __AX__;
}
#pragma optimize (pop)
static void InvertCharSet (void)
/* Invert the character set */
{
asm ("ldy #%b", sizeof (CharSet) - 1);
asm ("L1:");
asm ("lda %v,y", CharSet);
asm ("eor #$FF");
asm ("sta %v,y", CharSet);
asm ("dey");
asm ("bpl L1");
}
/*****************************************************************************/
/* Code */
/*****************************************************************************/
static void PushBack (void)
/* Push back the last (unused) character, provided it is not EOF. */
{
/* Get the character from C. */
/* Only the high-byte needs to be checked for EOF. */
asm ("ldx %v+1", C);
asm ("bne %g", Done);
asm ("lda %v", C);
/* Put unget()'s first argument on the stack. */
asm ("jsr pushax");
/* Copy D into the zero-page. */
(const struct scanfdata*) __AX__ = D_;
asm ("sta ptr1");
asm ("stx ptr1+1");
/* Copy the unget vector to jmpvec. */
asm ("ldy #%b", offsetof (struct scanfdata, unget));
asm ("lda (ptr1),y");
asm ("sta jmpvec+1");
asm ("iny");
asm ("lda (ptr1),y");
asm ("sta jmpvec+2");
/* Load D->data into __AX__. */
asm ("ldy #%b", offsetof (struct scanfdata, data) + 1);
asm ("lda (ptr1),y");
asm ("tax");
asm ("dey");
asm ("lda (ptr1),y");
/* Call the unget routine. */
asm ("jsr jmpvec");
/* Take back that character's count. */
asm ("lda %v", CharCount);
asm ("bne %g", Yank);
asm ("dec %v+1", CharCount);
Yank:
asm ("dec %v", CharCount);
Done:
;
}
static void ReadChar (void)
/* Get an input character, count characters */
{
/* Move D to ptr1 */
asm ("lda %v", D_);
asm ("ldx %v+1", D_);
asm ("sta ptr1");
asm ("stx ptr1+1");
/* Copy the get vector to jmpvec */
asm ("ldy #%b", offsetof (struct scanfdata, get));
asm ("lda (ptr1),y");
asm ("sta jmpvec+1");
asm ("iny");
asm ("lda (ptr1),y");
asm ("sta jmpvec+2");
/* Load D->data into __AX__ */
asm ("ldy #%b", offsetof (struct scanfdata, data) + 1);
asm ("lda (ptr1),y");
asm ("tax");
asm ("dey");
asm ("lda (ptr1),y");
/* Call the get routine */
asm ("jsr jmpvec");
/* Assign the result to C */
asm ("sta %v", C);
asm ("stx %v+1", C);
/* If C is EOF, don't bump the character counter.
* Only the high-byte needs to be checked.
*/
asm ("inx");
asm ("beq %g", Done);
/* Must bump CharCount. */
asm ("inc %v", CharCount);
asm ("bne %g", Done);
asm ("inc %v+1", CharCount);
Done:
;
}
#pragma optimize (push, off)
static void __fastcall__ Error (unsigned char /* Code */)
/* Does a longjmp using the given code */
{
asm ("pha");
(char*) __AX__ = JumpBuf;
asm ("jsr pushax");
asm ("pla");
asm ("ldx #>0");
asm ("jmp %v", longjmp);
}
#pragma optimize (pop)
static void CheckEnd (void)
/* Stop a scan if it prematurely reaches the end of a string or a file. */
{
/* Only the high-byte needs to be checked for EOF. */
asm ("ldx %v+1", C);
asm ("beq %g", Done);
Error (RC_EOF);
Done:
;
}
static void SkipWhite (void)
/* Skip white space in the input and return the first non white character */
{
while ((bool) isspace (C)) {
ReadChar ();
}
}
#pragma optimize (push, off)
static void ReadSign (void)
/* Read an optional sign and skip it. Store 1 in Positive if the value is
* positive, store 0 otherwise.
*/
{
/* We can ignore the high byte of C here, since if it is EOF, the lower
* byte won't match anyway.
*/
asm ("lda %v", C);
asm ("cmp #'-'");
asm ("bne %g", NotNeg);
/* Negative value */
asm ("sta %v", Converted);
asm ("jsr %v", ReadChar);
asm ("lda #$00"); /* Flag as negative */
asm ("beq %g", Store);
/* Positive value */
NotNeg:
asm ("cmp #'+'");
asm ("bne %g", Pos);
asm ("sta %v", Converted);
asm ("jsr %v", ReadChar); /* Skip the + sign */
Pos:
asm ("lda #$01"); /* Flag as positive */
Store:
asm ("sta %v", Positive);
}
#pragma optimize (pop)
static unsigned char __fastcall__ HexVal (char C)
/* Convert a digit to a value */
{
return (bool) isdigit (C) ?
C - '0' :
(char) tolower ((int) C) - ('a' - 10);
}
static void __fastcall__ ReadInt (unsigned char Base)
/* Read an integer, and store it into IntVal. */
{
unsigned char Val, CharCount = 0;
/* Read the integer value */
IntVal = 0L;
while ((bool) isxdigit (C) && ++Width != 0
&& (Val = HexVal ((char) C)) < Base) {
++CharCount;
IntVal = IntVal * (long) Base + (long) Val;
ReadChar ();
}
/* If we didn't convert anything, it's a failure. */
if (CharCount == 0) {
Error (RC_NOCONV);
}
/* Another conversion */
Converted = true;
}
static void AssignInt (void)
/* Assign the integer value in Val to the next argument. The function makes
* several non-portable assumptions, to reduce code size:
* - signed and unsigned types have the same representation.
* - short and int have the same representation.
* - all pointer types have the same representation.
*/
{
if (NoAssign == false) {
/* Get the next argument pointer */
(void*) __AX__ = va_arg (ap, void*);
/* Put the argument pointer into the zero-page. */
asm ("sta ptr1");
asm ("stx ptr1+1");
/* Get the number of bytes-1 to copy */
asm ("ldy %v", IntBytes);
/* Assign the integer value */
Loop: asm ("lda %v,y", IntVal);
asm ("sta (ptr1),y");
asm ("dey");
asm ("bpl %g", Loop);
/* Another assignment */
asm ("inc %v", Assignments);
asm ("bne %g", Done);
asm ("inc %v+1", Assignments);
Done: ;
}
}
static void __fastcall__ ScanInt (unsigned char Base)
/* Scan an integer including white space, sign and optional base spec,
* and store it into IntVal.
*/
{
/* Skip whitespace */
SkipWhite ();
/* Read an optional sign */
ReadSign ();
/* If Base is unknown (zero), figure it out */
if (Base == 0) {
if (CHAR (C) == '0') {
ReadChar ();
switch (CHAR (C)) {
case 'x':
case 'X':
Base = 16;
Converted = true;
ReadChar ();
break;
default:
Base = 8;
/* Restart at the beginning of the number because it might
* be only a single zero digit (which already was read).
*/
PushBack ();
C = '0';
}
} else {
Base = 10;
}
}
/* Read the integer value */
ReadInt (Base);
/* Apply the sign */
if (Positive == false) {
IntVal = -IntVal;
}
/* Assign the value to the next argument unless suppressed */
AssignInt ();
}
static char GetFormat (void)
/* Pick up the next character from the format string. */
{
/* return (F = *format++); */
(const char*) __AX__ = format;
asm ("sta regsave");
asm ("stx regsave+1");
++format;
asm ("ldy #0");
asm ("lda (regsave),y");
asm ("ldx #>0");
return (F = (char) __AX__);
}
int __fastcall__ _scanf (const struct scanfdata* D,
const char* format_, va_list ap_)
/* This is the routine used to do the actual work. It is called from several
* types of wrappers to implement the actual ISO xxscanf functions.
*/
{
register char* S;
bool HaveWidth; /* True if a width was given */
bool Match; /* True if a character-set has any matches */
char Start; /* Walks over a range */
/* Place copies of the arguments into global variables. This is not very
* nice, but on a 6502 platform it gives better code, since the values
* do not have to be passed as parameters.
*/
D_ = D;
format = format_;
ap = ap_;
/* Initialize variables */
Converted = false;
Assignments = 0;
CharCount = 0;
/* Set up the jump "label". CheckEnd() will use that label when EOF
* is reached. ReadInt() will use it when number-conversion fails.
*/
if ((unsigned char) setjmp (JumpBuf) == RC_OK) {
Again:
/* Get the next input character */
ReadChar ();
/* Walk over the format string */
while (GetFormat ()) {
/* Check for a conversion */
if (F != '%') {
/* Check for a match */
if ((bool) isspace ((int) F)) {
/* Special white space handling: Any whitespace in the
* format string matches any amount of whitespace including
* none(!). So this match will never fail.
*/
SkipWhite ();
continue;
}
Percent:
/* ### Note: The opposite test (C == F)
** would be optimized into buggy code!
*/
if (C != (int) F) {
/* A mismatch -- we will stop scanning the input,
* and return the number of assigned conversions.
*/
goto NoConv;
}
/* A match -- get the next input character, and continue. */
goto Again;
} else {
/* A conversion. Skip the percent sign. */
/* 0. Check for %% */
if (GetFormat () == '%') {
goto Percent;
}
/* 1. Assignment suppression */
NoAssign = (F == '*');
if (NoAssign) {
GetFormat ();
}
/* 2. Maximum field width */
Width = UINT_MAX;
HaveWidth = (bool) isdigit (F);
if (HaveWidth) {
Width = 0;
do {
/* ### Non portable ### */
Width = Width * 10 + (F & 0x0F);
} while ((bool) isdigit (GetFormat ()));
}
if (Width == 0) {
/* Invalid specification */
/* Note: This method of leaving the function might seem
* to be crude, but it optimizes very well because
* the four exits can share this code.
*/
_seterrno (EINVAL);
Assignments = EOF;
PushBack ();
return Assignments;
}
/* Increment-and-test makes better code than test-and-decrement
* does. So, change the width into a form that can be used in
* that way.
*/
Width = ~Width;
/* 3. Length modifier */
IntBytes = sizeof(int) - 1;
switch (F) {
case 'h':
if (*format == 'h') {
IntBytes = sizeof(char) - 1;
++format;
}
GetFormat ();
break;
case 'l':
if (*format == 'l') {
/* Treat long long as long */
++format;
}
/* FALLTHROUGH */
case 'j': /* intmax_t */
IntBytes = sizeof(long) - 1;
/* FALLTHROUGH */
case 'z': /* size_t */
case 't': /* ptrdiff_t */
/* Same size as int */
case 'L': /* long double - ignore this one */
GetFormat ();
}
/* 4. Conversion specifier */
switch (F) {
/* 'd' and 'u' conversions are actually the same, since the
* standard says that even the 'u' modifier allows an
* optionally signed integer.
*/
case 'd': /* Optionally signed decimal integer */
case 'u':
ScanInt (10);
break;
case 'i':
/* Optionally signed integer with a base */
ScanInt (0);
break;
case 'o':
/* Optionally signed octal integer */
ScanInt (8);
break;
case 'x':
case 'X':
/* Optionally signed hexadecimal integer */
ScanInt (16);
break;
case 's':
/* Whitespace-terminated string */
SkipWhite ();
CheckEnd (); /* Is it an input failure? */
Converted = true; /* No, conversion will succeed */
if (NoAssign == false) {
S = va_arg (ap, char*);
}
while (C != EOF
&& (bool) isspace (C) == false
&& ++Width) {
if (NoAssign == false) {
*S++ = C;
}
ReadChar ();
}
/* Terminate the string just read */
if (NoAssign == false) {
*S = '\0';
++Assignments;
}
break;
case 'c':
/* Fixed-length string, NOT zero-terminated */
if (HaveWidth == false) {
/* No width given, default is 1 */
Width = ~1u;
}
CheckEnd (); /* Is it an input failure? */
Converted = true; /* No, at least 1 char. available */
if (NoAssign == false) {
S = va_arg (ap, char*);
/* ## This loop is convenient for us, but it isn't
* standard C. The standard implies that a failure
* shouldn't put anything into the array argument.
*/
while (++Width) {
CheckEnd (); /* Is it a matching failure? */
*S++ = C;
ReadChar ();
}
++Assignments;
} else {
/* Just skip as many chars as given */
while (++Width) {
CheckEnd (); /* Is it a matching failure? */
ReadChar ();
}
}
break;
case '[':
/* String using characters from a set */
/* Clear the set */
memset (CharSet, 0, sizeof (CharSet));
/* Skip the left-bracket, and test for inversion. */
Invert = (GetFormat () == '^');
if (Invert) {
GetFormat ();
}
if (F == ']') {
/* Empty sets aren't allowed; so, a right-bracket
* at the beginning must be a member of the set.
*/
AddCharToSet (F);
GetFormat ();
}
/* Read the characters that are part of the set */
while (F != '\0' && F != ']') {
if (*format == '-') { /* Look ahead at next char. */
/* A range. Get start and end, skip the '-' */
Start = F;
++format;
switch (GetFormat ()) {
case '\0':
case ']':
/* '-' as last char means: include '-' */
AddCharToSet (Start);
AddCharToSet ('-');
break;
default:
/* Include all characters
* that are in the range.
*/
while (1) {
AddCharToSet (Start);
if (Start == F) {
break;
}
++Start;
}
/* Get next char after range */
GetFormat ();
}
} else {
/* Just a character */
AddCharToSet (F);
/* Get next char */
GetFormat ();
}
}
/* Don't go beyond the end of the format string. */
/* (Maybe, this should mean an invalid specification.) */
if (F == '\0') {
--format;
}
/* Invert the set if requested */
if (Invert) {
InvertCharSet ();
}
/* We have the set in CharSet. Read characters and
* store them into a string while they are part of
* the set.
*/
Match = false;
if (NoAssign == false) {
S = va_arg (ap, char*);
}
while (IsCharInSet () && ++Width) {
if (NoAssign == false) {
*S++ = C;
}
Match = Converted = true;
ReadChar ();
}
/* At least one character must match the set. */
if (Match == false) {
goto NoConv;
}
if (NoAssign == false) {
*S = '\0';
++Assignments;
}
break;
case 'p':
/* Pointer, general format is 0xABCD.
* %hhp --> zero-page pointer
* %hp --> near pointer
* %lp --> far pointer
*/
SkipWhite ();
if (CHAR (C) != '0') {
goto NoConv;
}
Converted = true;
ReadChar ();
switch (CHAR (C)) {
case 'x':
case 'X':
break;
default:
goto NoConv;
}
ReadChar ();
ReadInt (16);
AssignInt ();
break;
case 'n':
/* Store the number of characters consumed so far
* (the read-ahead character hasn't been consumed).
*/
IntVal = (long) (CharCount - (C == EOF ? 0u : 1u));
AssignInt ();
/* Don't count it. */
if (NoAssign == false) {
--Assignments;
}
break;
case 'S':
case 'C':
/* Wide characters */
case 'a':
case 'A':
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
/* Optionally signed float */
/* Those 2 groups aren't implemented. */
_seterrno (ENOSYS);
Assignments = EOF;
PushBack ();
return Assignments;
default:
/* Invalid specification */
_seterrno (EINVAL);
Assignments = EOF;
PushBack ();
return Assignments;
}
}
}
} else {
NoConv:
/* Coming here means a failure. If that happens at EOF, with no
* conversion attempts, then it is considered an error; otherwise,
* the number of assignments is returned (the default behaviour).
*/
if (C == EOF && Converted == false) {
Assignments = EOF; /* Special case: error */
}
}
/* Put the read-ahead character back into the input stream. */
PushBack ();
/* Return the number of conversion-and-assignments. */
return Assignments;
}