/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/fmt/conv.h"
#include "libc/fmt/internal.h"
#include "libc/limits.h"
#include "libc/mem/internal.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/str/tab.internal.h"
#include "libc/str/tpdecodecb.internal.h"
#include "libc/str/utf16.h"
#include "libc/sysv/errfuns.h"
#include "third_party/gdtoa/gdtoa.h"
#define READ \
({ \
int c = callback(arg); \
if (c != -1) \
++consumed; \
c; \
})
#define FP_BUFFER_GROW 48
#define BUFFER \
({ \
int c = READ; \
if (fpbufcur >= fpbufsize - 1) { \
fpbufsize = fpbufsize + FP_BUFFER_GROW; \
fpbuf = realloc(fpbuf, fpbufsize); \
} \
if (c != -1) { \
fpbuf[fpbufcur++] = c; \
fpbuf[fpbufcur] = '\0'; \
} \
c; \
})
#define UNBUFFER \
({ \
if (c != -1) { \
fpbuf[--fpbufcur] = '\0'; \
} \
})
/**
* String / file / stream decoder.
*
* This scanf implementation is able to tokenize strings containing
* 8-bit through 128-bit integers (with validation), floating point
* numbers, etc. It can also be used to convert UTF-8 to UTF-16/32.
*
* - `%d` parses integer
* - `%ms` parses string allocating buffer assigning pointer
*
* @param callback supplies UTF-8 characters using -1 sentinel
* @param fmt is a computer program embedded inside a c string, written
* in a domain-specific programming language that, by design, lacks
* Turing-completeness
* @param va points to the variadic argument state
* @see libc/fmt/pflink.h (dynamic memory is not a requirement)
*/
int __vcscanf(int callback(void *), //
int unget(int, void *), //
void *arg, //
const char *fmt, //
va_list va) {
struct FreeMe {
struct FreeMe *next;
void *ptr;
} *freeme = NULL;
unsigned char *fpbuf = NULL;
size_t fpbufsize;
size_t fpbufcur;
const unsigned char *p = (const unsigned char *)fmt;
int *n_ptr;
int items = 0;
int consumed = 0;
unsigned i = 0;
int c = READ;
for (;;) {
switch (p[i++]) {
case '\0':
if (c != -1 && unget) {
unget(c, arg);
}
goto Done;
case ' ':
case '\t':
case '\n':
case '\r':
case '\v':
while (isspace(c)) {
c = READ;
}
break;
case '%': {
uint128_t number;
unsigned char *buf;
size_t bufsize;
double fp;
unsigned width = 0;
unsigned char bits = 32;
unsigned char charbytes = sizeof(char);
unsigned char diglet;
unsigned char base;
unsigned char prefix;
bool rawmode = false;
bool issigned = false;
bool ismalloc = false;
bool isneg = false;
bool thousands = false;
bool discard = false;
for (;;) {
switch (p[i++]) {
case '%': // %% → %
goto NonDirectiveCharacter;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
width *= 10;
width += p[i - 1] - '0';
break;
case '*':
discard = true;
break;
case 'm':
ismalloc = true;
break;
case 'c':
rawmode = true;
if (!width)
width = 1;
// fallthrough
case 's':
while (isspace(c)) {
c = READ;
}
goto DecodeString;
case '\'':
thousands = true;
break;
case 'j': // j=64-bit jj=128-bit
if (bits < 64) {
bits = 64;
} else {
bits = 128;
}
break;
case 'l': // long
case 'L': // loooong
charbytes = sizeof(wchar_t);
// fallthrough
case 't': // ptrdiff_t
case 'Z': // size_t
case 'z': // size_t
bits = 64;
break;
case 'h': // short and char
charbytes = sizeof(char16_t);
bits >>= 1;
break;
case 'b': // binary
base = 2;
prefix = 'b';
goto ConsumeBasePrefix;
case 'p': // pointer (NexGen32e)
bits = 48;
// fallthrough
case 'x':
case 'X': // hexadecimal
base = 16;
prefix = 'x';
goto ConsumeBasePrefix;
case 'o': // octal
base = 8;
goto HandleNumber;
case 'n':
goto ReportConsumed;
case 'd': // decimal
issigned = true;
// fallthrough
case 'u':
base = 10;
HandleNumber:
while (isspace(c)) {
c = READ;
}
if (c == '+' || (isneg = c == '-')) {
c = READ;
}
goto DecodeNumber;
case 'i': // flexidecimal
while (isspace(c)) {
c = READ;
}
if (c == '+' || (isneg = c == '-')) {
c = READ;
}
if (c == '0') {
c = READ;
if (c == 'x' || c == 'X') {
c = READ;
base = 16;
} else if (c == 'b' || c == 'B') {
c = READ;
base = 2;
} else if ('0' <= c && c <= '7') {
base = 8;
} else {
number = 0;
goto GotNumber;
}
} else {
base = 10;
}
goto DecodeNumber;
case 'a':
case 'A':
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G': // floating point number
if (!(charbytes == sizeof(char) ||
charbytes == sizeof(wchar_t))) {
items = -1;
goto Done;
}
while (isspace(c)) {
c = READ;
}
fpbufsize = FP_BUFFER_GROW;
if ((fpbuf = malloc(fpbufsize))) {
fpbufcur = 0;
fpbuf[fpbufcur++] = c;
fpbuf[fpbufcur] = '\0';
goto ConsumeFloatingPointNumber;
} else {
items = -1;
goto Done;
}
default:
items = einval();
goto Done;
}
}
ConsumeBasePrefix:
while (isspace(c)) {
c = READ;
}
if (c == '+' || (isneg = c == '-')) {
c = READ;
}
if (c == '0') {
c = READ;
if (c == prefix || c == prefix + ('a' - 'A')) {
c = READ;
} else if (c == -1) {
number = 0;
goto GotNumber;
}
}
DecodeNumber:
if (c != -1 && (1 <= kBase36[(unsigned char)c] &&
kBase36[(unsigned char)c] <= base)) {
number = 0;
width = !width ? bits : width;
do {
diglet = kBase36[(unsigned char)c];
if (1 <= diglet && diglet <= base) {
width -= 1;
number *= base;
number += diglet - 1;
} else if (thousands && diglet == ',') {
// ignore
} else {
break;
}
} while ((c = READ) != -1 && width > 0);
GotNumber:
if (!discard) {
uint128_t bane = (uint128_t)1 << (bits - 1);
if (!(number & ~((bane - 1) | (issigned ? 0 : bane))) ||
(issigned && number == bane)) {
++items;
} else {
items = erange();
goto Done;
}
if (issigned && isneg) {
number = ~number + 1;
}
void *out = va_arg(va, void *);
switch (bits) {
case sizeof(uint128_t) * CHAR_BIT:
*(uint128_t *)out = number;
break;
case 48:
case 64:
*(uint64_t *)out = (uint64_t)number;
break;
case 32:
*(uint32_t *)out = (uint32_t)number;
break;
case 16:
*(uint16_t *)out = (uint16_t)number;
break;
case 8:
default:
*(uint8_t *)out = (uint8_t)number;
break;
}
} else if (!items && c == -1) {
items = -1;
goto Done;
}
} else if (c == -1 && !items) {
items = -1;
goto Done;
} else {
if (c != -1 && unget) {
unget(c, arg);
}
goto Done;
}
continue;
ConsumeFloatingPointNumber:
if (c == '+' || c == '-') {
c = BUFFER;
}
bool hexadecimal = false;
if (c == '0') {
c = BUFFER;
if (c == 'x' || c == 'X') {
c = BUFFER;
hexadecimal = true;
goto BufferFloatingPointNumber;
} else if (c == -1) {
goto GotFloatingPointNumber;
} else {
goto BufferFloatingPointNumber;
}
} else if (c == 'n' || c == 'N') {
c = BUFFER;
if (c == 'a' || c == 'A') {
c = BUFFER;
if (c == 'n' || c == 'N') {
c = BUFFER;
if (c == '(') {
c = BUFFER;
do {
bool isdigit = c >= '0' && c <= '9';
bool isletter =
(c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
if (!(c == '_' || isdigit || isletter)) {
goto Done;
}
} while ((c = BUFFER) != -1 && c != ')');
if (c == ')') {
c = READ;
}
goto GotFloatingPointNumber;
} else {
UNBUFFER;
goto GotFloatingPointNumber;
}
} else {
goto Done;
}
} else {
goto Done;
}
} else if (c == 'i' || c == 'I') {
c = BUFFER;
if (c == 'n' || c == 'N') {
c = BUFFER;
if (c == 'f' || c == 'F') {
c = BUFFER;
if (c == 'i' || c == 'I') {
c = BUFFER;
if (c == 'n' || c == 'N') {
c = BUFFER;
if (c == 'i' || c == 'I') {
c = BUFFER;
if (c == 't' || c == 'T') {
c = BUFFER;
if (c == 'y' || c == 'Y') {
c = BUFFER;
} else {
goto Done;
}
} else {
goto Done;
}
} else {
goto Done;
}
} else {
goto Done;
}
} else {
UNBUFFER;
goto GotFloatingPointNumber;
}
} else {
goto Done;
}
} else {
goto Done;
}
}
BufferFloatingPointNumber:
enum { INTEGER, FRACTIONAL, SIGN, EXPONENT } state = INTEGER;
do {
bool isdecdigit = c >= '0' && c <= '9';
bool ishexdigit = (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
bool ispoint = c == '.' || c == ',';
bool isdecexp = c == 'e' || c == 'E';
bool ishexp = c == 'p' || c == 'P';
bool issign = c == '+' || c == '-';
switch (state) {
case INTEGER:
case FRACTIONAL:
if (isdecdigit || (hexadecimal && ishexdigit)) {
goto Continue;
} else if (state == INTEGER && ispoint) {
state = FRACTIONAL;
goto Continue;
} else if (isdecexp || (hexadecimal && ishexp)) {
state = SIGN;
goto Continue;
} else {
goto Break;
}
case SIGN:
if (issign) {
state = EXPONENT;
goto Continue;
}
state = EXPONENT;
// fallthrough
case EXPONENT:
if (isdecdigit) {
goto Continue;
} else {
goto Break;
}
default:
goto Break;
}
Continue:
continue;
Break:
UNBUFFER;
break;
} while ((c = BUFFER) != -1);
GotFloatingPointNumber:
/* An empty buffer can't be a valid float; don't even bother parsing. */
bool valid = fpbufcur > 0;
if (valid) {
char *ep;
fp = strtod((char *)fpbuf, &ep);
/* We should have parsed the whole buffer. */
valid = ep == (char *)fpbuf + fpbufcur;
}
free(fpbuf);
fpbuf = NULL;
fpbufcur = fpbufsize = 0;
if (!valid) {
goto Done;
}
if (!discard) {
++items;
void *out = va_arg(va, void *);
if (charbytes == sizeof(char)) {
*(float *)out = (float)fp;
} else {
*(double *)out = (double)fp;
}
}
continue;
ReportConsumed:
n_ptr = va_arg(va, int *);
if (c != -1) {
*n_ptr = consumed - 1; // minus lookahead
} else {
*n_ptr = consumed;
}
continue;
DecodeString:
bufsize = !width ? 32 : rawmode ? width : width + 1;
if (discard) {
buf = NULL;
} else if (ismalloc) {
if ((buf = malloc(bufsize * charbytes))) {
struct FreeMe *entry;
if (buf && (entry = calloc(1, sizeof(struct FreeMe)))) {
entry->ptr = buf;
entry->next = freeme;
freeme = entry;
}
} else {
items = -1;
goto Done;
}
} else {
buf = va_arg(va, void *);
}
if (buf) {
size_t j = 0;
for (;;) {
if (ismalloc && !width && j + 2 + 1 >= bufsize &&
!__grow(&buf, &bufsize, charbytes, 0)) {
width = bufsize - 1;
}
if (c != -1 && j + !rawmode < bufsize && (rawmode || !isspace(c))) {
if (charbytes == 1) {
buf[j++] = (unsigned char)c;
c = READ;
} else if (tpdecodecb((wint_t *)&c, c, (void *)callback, arg) !=
-1) {
if (charbytes == sizeof(char16_t)) {
unsigned w = EncodeUtf16(c);
do {
if ((j + 1) * 2 < bufsize) {
((char16_t *)buf)[j++] = w;
}
} while ((w >>= 16));
} else {
((wchar_t *)buf)[j++] = (wchar_t)c;
}
c = READ;
}
} else {
if (!j && c == -1 && !items) {
items = -1;
goto Done;
} else if (rawmode && j != width) {
/* The C standard says that %c "matches a sequence of characters
* of
* **exactly** the number specified by the field width". If we
* have fewer characters, what we've just read is invalid. */
goto Done;
} else if (!rawmode && j < bufsize) {
if (charbytes == sizeof(char)) {
buf[j] = '\0';
} else if (charbytes == sizeof(char16_t)) {
((char16_t *)buf)[j] = u'\0';
} else if (charbytes == sizeof(wchar_t)) {
((wchar_t *)buf)[j] = L'\0';
}
}
break;
}
}
++items;
if (ismalloc) {
*va_arg(va, char **) = (void *)buf;
}
buf = NULL;
} else {
do {
if (isspace(c))
break;
} while ((c = READ) != -1);
}
break;
}
default:
NonDirectiveCharacter:
c = (c == p[i - 1]) ? READ : -1;
break;
}
}
Done:
while (freeme) {
struct FreeMe *entry = freeme;
freeme = entry->next;
if (items == -1)
free(entry->ptr);
free(entry);
}
if (fpbuf)
free(fpbuf);
return items;
}