libc-top-half/musl/src/stdlib/strtod.c

   1 #include <stdlib.h>
   2 #ifdef __wasilibc_unmodified_upstream // Changes to optimize printf/scanf when long double isn't needed
   3 #else
   4 #include "printscan.h"
   5 #define __NEED_locale_t
   6 #include <bits/alltypes.h>
   7 #endif
   8 #include "shgetc.h"
   9 #include "floatscan.h"
  10 #include "stdio_impl.h"
  11
  12 #if defined(__wasilibc_printscan_no_long_double)
  13 static long_double strtox(const char *s, char **p, int prec)
  14 #else
  15 static long double strtox(const char *s, char **p, int prec)
  16 #endif
  17 {
  18         FILE f;
  19         sh_fromstring(&f, s);
  20         shlim(&f, 0);
  21 #if defined(__wasilibc_printscan_no_long_double)
  22         long_double y = __floatscan(&f, prec, 1);
  23 #else
  24         long double y = __floatscan(&f, prec, 1);
  25 #endif
  26         off_t cnt = shcnt(&f);
  27         if (p) *p = cnt ? (char *)s + cnt : (char *)s;
  28         return y;
  29 }
  30
  31 float strtof(const char *restrict s, char **restrict p)
  32 {
  33         return strtox(s, p, 0);
  34 }
  35
  36 double strtod(const char *restrict s, char **restrict p)
  37 {
  38         return strtox(s, p, 1);
  39 }
  40
  41 long double strtold(const char *restrict s, char **restrict p)
  42 {
  43 #if defined(__wasilibc_printscan_no_long_double)
  44         long_double_not_supported();
  45 #else
  46         return strtox(s, p, 2);
  47 #endif
  48 }
  49
  50 #ifdef __wasilibc_unmodified_upstream // WASI doesn't support signature-changing aliases
  51 weak_alias(strtof, strtof_l);
  52 weak_alias(strtod, strtod_l);
  53 weak_alias(strtold, strtold_l);
  54 weak_alias(strtof, __strtof_l);
  55 weak_alias(strtod, __strtod_l);
  56 weak_alias(strtold, __strtold_l);
  57 #else
  58 // WebAssembly doesn't permit signature-changing aliases, so use wrapper
  59 // functions instead.
  60 weak float strtof_l(const char *restrict s, char **restrict p, locale_t loc) {
  61         return strtof(s, p);
  62 }
  63 weak double strtod_l(const char *restrict s, char **restrict p, locale_t loc) {
  64         return strtod(s, p);
  65 }
  66 weak long double strtold_l(const char *restrict s, char **restrict p, locale_t loc) {
  67         return strtold(s, p);
  68 }
  69 #endif