stdio: simplify output size management in scanf

This commit is contained in:
Lephenixnoir 2024-01-14 20:18:24 +01:00
parent 69eadb67d2
commit 55ae7df318
No known key found for this signature in database
GPG key ID: 1BBA026E13FC0495
2 changed files with 65 additions and 122 deletions

View file

@ -37,21 +37,6 @@ void __scanf_end(struct __scanf_input *in)
in->str--;
}
enum
{
MODSKIP,
MODCHAR,
MODSHORT,
MODNORMAL,
MODLONG,
MODLONGLONG,
MODLONGDOUBLE,
MODINTMAXT,
MODSIZET,
MODPTRDIFFT,
};
void __purge_space( struct __scanf_input * __restrict__ in )
{
while (isspace(__scanf_peek(in))) __scanf_in(in);
@ -59,34 +44,24 @@ void __purge_space( struct __scanf_input * __restrict__ in )
void __scanf_store_i(int64_t value, int size, va_list *args)
{
if(size == MODSKIP) return;
if(size == MODCHAR)
if(size == 1)
*va_arg(*args, int8_t *) = value;
else if(size == MODSHORT)
else if(size == 2)
*va_arg(*args, int16_t *) = value;
else if(size == MODLONGLONG)
else if(size == 4)
*va_arg(*args, int32_t *) = value;
else if(size == 8)
*va_arg(*args, int64_t *) = value;
else if(size == MODINTMAXT)
*va_arg(*args, intmax_t *) = value;
else if(size == MODSIZET)
*va_arg(*args, size_t *) = value;
else if(size == MODPTRDIFFT)
*va_arg(*args, ptrdiff_t *) = value;
else
*va_arg(*args, int *) = value;
}
void __scanf_store_d(long double value, int size, va_list *args)
{
if (size==MODSKIP) return;
if(size == MODLONG)
*va_arg(*args, double *) = value;
else if(size == MODLONGDOUBLE)
*va_arg(*args, long double *) = value;
else
if(size == sizeof(float))
*va_arg(*args, float *) = value;
else if(size == sizeof(double))
*va_arg(*args, double *) = value;
else if(size == sizeof(long double))
*va_arg(*args, long double *) = value;
}
/* STATUS OF __scanf DEVELOPMENT */
@ -239,11 +214,9 @@ int __scanf(
{
bool skip = false;
int MOD = sizeof(int);
int MOD = MODNORMAL;
in->readsofar = 0; // we haven't started to read char from the input stream
in->readmaxlength = -1; // no specific maximum length to read is defined yet
in->bytes_read = 0; // we haven't started to read char from the input stream
int validrets = 0; // to be incremented each time we successfully read and store an input as per the format
int err = 0; // err control on __strto_xx( ) functions
@ -255,9 +228,8 @@ int __scanf(
// TODO: No __scanf_end() in any of the "return validrets"!!
while( format[pos] != 0 ) {
in->readmaxlength = -1;
user_length = 0;
MOD = MODNORMAL;
MOD = sizeof(int);
skip = false;
__allow_all_set();
@ -268,7 +240,9 @@ int __scanf(
// we will have to manage a given format
else if( format[pos] == '%' ) {
in->readmaxlength = INT_MAX;
int readmaxlength = INT_MAX;
char size_letter = 0;
// main loop
loopagain:
@ -282,7 +256,7 @@ int __scanf(
int currentlength = 0;
// we need to assign the read char to the corresponding pointer
char *c = skip ? NULL : va_arg(*args, char *);
for(unsigned int u=0; u<in->readmaxlength; u++) {
for(int u=0; u<readmaxlength; u++) {
int temp = __scanf_peek(in);
if(__is_allowed(temp)) {
__scanf_in(in);
@ -301,10 +275,9 @@ int __scanf(
}
// return the number of char read so far (cannot be skipped %*n is not valid)
case 'n': {
*(int*) va_arg( *args, int* ) = in->readsofar;
case 'n':
*va_arg(*args, int *) = in->bytes_read;
break;
}
// we are expecting the char '%' to be in the input stream, if not err and return
case '%': {
@ -314,69 +287,36 @@ int __scanf(
}
// the next read, even if valid, will not be stored
case '*': {
case '*':
skip = true;
goto loopagain;
break;
}
case 'h': {
if (MOD==MODNORMAL || MOD==MODSHORT) {
MOD--;
case 'h':
MOD = (size_letter == 'h') ? sizeof(char) : sizeof(short);
size_letter = 'h';
goto loopagain;
}
else return validrets; // we cannot have %hhh format modifier --> err
break;
}
case 'l': {
if (MOD==MODNORMAL || MOD==MODLONG) {
MOD++;
case 'l':
MOD = (size_letter == 'l') ? sizeof(long long) : sizeof(long);
/* FP conversions will adjust to sizeof(double) later */
size_letter = 'l';
goto loopagain;
}
else return validrets; // we cannot have %ll format modifier --> err
break;
}
case 'L': {
if (MOD==MODNORMAL) {
MOD=MODLONGDOUBLE;
case 'L':
MOD = sizeof(long double);
size_letter = 'L';
goto loopagain;
}
else return validrets; // we cannot have %LL format modifier --> err
break;
}
case 'j': {
if (MOD==MODNORMAL) {
MOD=MODINTMAXT;
case 'j':
MOD = sizeof(intmax_t);
goto loopagain;
}
else return validrets; // we cannot have %LL format modifier --> err
break;
}
case 'z': {
if (MOD==MODNORMAL) {
MOD=MODSIZET;
case 'z':
MOD = sizeof(size_t);
goto loopagain;
}
else return validrets; // we cannot have %LL format modifier --> err
break;
}
case 't': {
if (MOD==MODNORMAL) {
MOD=MODPTRDIFFT;
case 't':
MOD = sizeof(ptrdiff_t);
goto loopagain;
}
else return validrets; // we cannot have %LL format modifier --> err
break;
}
case '0' ... '9': {
user_length = user_length * 10 + (int) ( format[pos] - '0' );
in->readmaxlength = user_length;
readmaxlength = user_length;
goto loopagain;
break;
}
@ -395,10 +335,10 @@ int __scanf(
long long int temp;
err = __strto_int(in, base, NULL, &temp, use_unsigned,
in->readmaxlength);
readmaxlength);
if (err == EOF && validrets == 0) return EOF;
if (err != 0) return validrets;
if (skip) __scanf_store_i( temp, MODSKIP, args );
if (skip) __scanf_store_i( temp, 0, args );
else __scanf_store_i( temp, MOD, args );
validrets++;
break;
@ -412,14 +352,20 @@ int __scanf(
case 'F':
case 'g':
case 'G': {
/* Adjust interpretation of no size / 'l' size */
if(size_letter == 0)
MOD = sizeof(float);
if(size_letter == 'l')
MOD = sizeof(double);
// read a double from the current input stream
// and store in the corresponding arg as a char by reference
long double temp;
err = __strto_fp( in, NULL, NULL, &temp,
in->readmaxlength);
readmaxlength);
if (err == EOF && validrets == 0) return EOF;
if (err != 0) return validrets;
if (skip) __scanf_store_d( temp, MODSKIP, args );
if (skip) __scanf_store_d( temp, 0, args );
else __scanf_store_d( temp, MOD, args );
validrets++;
break;
@ -430,10 +376,10 @@ int __scanf(
if (!skip) {
void *p = (void *) va_arg( *args, void** ); // get the adress of the target pointer (void**)
err = __strto_int( in, 0, p, NULL, true,
in->readmaxlength);
readmaxlength);
}
else err = __strto_int( in, 0, &temp, NULL, true,
in->readmaxlength);
readmaxlength);
if (err == 0) validrets++;
else return validrets;
skip = false;
@ -441,11 +387,11 @@ int __scanf(
}
case 'c': {
if(in->readmaxlength == INT_MAX)
in->readmaxlength = 1;
if(readmaxlength == INT_MAX)
readmaxlength = 1;
char *c = skip ? NULL : va_arg(*args, char *);
for(unsigned int u = 0; u < in->readmaxlength; u++) {
for(int u = 0; u < readmaxlength; u++) {
int temp = __scanf_in(in);
if(temp==EOF) return EOF;
else if(c) *c++ = temp;
@ -460,7 +406,7 @@ int __scanf(
__purge_space(in);
char *c = skip ? NULL : va_arg(*args, char *);
for(unsigned int u = 0; u < in->readmaxlength; u++) {
for(int u = 0; u < readmaxlength; u++) {
temp = __scanf_peek(in);
if(temp==EOF && curstrlength==0) return validrets;
if(isspace(temp) || ((temp==EOF && curstrlength!=0))) {

View file

@ -18,15 +18,12 @@ struct __scanf_input {
char const * __restrict__ str;
FILE *fp;
// max char to read from the input stream as per user length modifier
unsigned int readmaxlength;
// total number of char read so far in the current call of a XYscanf() function (to return a %n when required)
int readsofar;
/* Single-character lookahead buffer */
int buffer;
};
/* Total numbers of bytes read in a scall to *scanf() */
int bytes_read;
};
/* Generic formatted scaning. */
extern int __scanf(
@ -46,7 +43,7 @@ static inline int __scanf_in(struct __scanf_input *__in)
{
int c = __in->buffer;
__in->buffer = __scanf_fetch(__in);
__in->readsofar++;
__in->bytes_read++;
return c;
}