fxlibc/STATUS
Lephenixnoir cd7fe7a329
signal: simple implementation (DONE)
This version of signal (which does not rely on a notion of userland
processes and is thus excluded from Vhex) follows C99 semantics but does
not generate any signals by default.

Basically, the signal function sets up function pointers and the signal
function calls them. Termination signals call exit() while other signals
call _Exit(), which is a quicker program termination similar to abort().

C99 allows programs to long jump out of signal handlers (!) which is
unbelievably scary because it would bypass stack switching code in Vhex
as well as normal interrupt handler termination in gint.
2021-05-30 15:09:33 +02:00

179 lines
5.4 KiB
Text

This file describes the implementation status and some notes; information is
taken from the C99 standard (ISO/IEC 9899:1999), section 7 ("Library").
# Notes for implementers
7.1.2§6:
Use (extern) in all function prototypes
7.1.3§1:
Only expose standard identifiers; anything else might be defined as a macro.
Make sure every argument name, internal function name, etc. starts with
either "__" or "_X" (where X is any uppercase letter)
7.1.4§1:
Always give a function even if there is a macro definition, so that the
address of the function can be taken; don't rely on the macro being defined,
as the user can remove it except in some special cases
String functions (mainly in <string.h>) can use 4-byte accesses, and in doing
so read up to 3 bytes after the end of the string if it is not padded (which
malloc'd strings and literal strings both are, leaving only stack-allocated and
statically-allocated ones). This allows important speed optimizations. The
extra access cannot trigger memory protection because there is no valid memory
less than 4 bytes before the end of any protection region. The extra access
might trigger the UBC in very specific scenarios, but we don't really care.
# Status
In this file, every definition is classified in one of several implementation
statuses. There are 5 stages that every definition should go through.
TODO: Function/symbol/macro is not implemented/defined
BDEPS(...): Function/symbol/macro needs ... to build
LDEPS(...): Function/symbol/macro needs ... to link
TEST: Function/symbol/macro needs to be tested
DONE: Function/symbol/macro is defined, builds, links, and is tested
7.2 <assert.h>
! 7.2.1 assert: LDEPS(fprintf,stderr)
7.3 <complex.h> => OpenLibm
7.4 <ctype.h>
7.4.1 is*: DONE
7.4.2 to*: DONE
7.5 <errno.h>
7.5.2 EDOM EILSEQ ERANGE: DONE
7.6 <fenv.h> => OpenLibm
7.7 <float.h> => GCC
7.8 <inttypes.h>
! 7.8.1 PRI* macros: LDEPS(*printf)
! 7.8.1 SCN* macros: LDEPS(*scanf)
7.8.2.1 imaxabs: DONE
7.8.2.2 imaxdiv: DONE
7.8.2.3 strtoimax strtoumax: DONE
! 7.8.2.4 wcstoimax wcstoumax: TODO
7.9 <iso646.h> => GCC
7.10 <limits.h> => GCC
7.11 <locale.h>
! 7.11.1 setlocale: TEST
! 7.11.2 localeconv: TEST
7.12 <math.h> => OpenLibm
7.13 <setjmp.h>
7.13.1 setjmp: DONE
7.13.2 longjmp: DONE
7.14 <signal.h>
7.14 sig_atomic_t SIG_DFL SIG_ERR SIG_IGN: DONE
7.14 SIGABRT SIGFPE SIGILL SIGINT SIGSEGV SIGTERM: DONE
7.14.1.1 signal: DONE
7.14.1.2 raise: DONE
7.15 <stdarg.h> => GCC
7.16 <stdbool.h> => GCC
7.17 <stddef.h> => GCC
7.18 <stdint.h> => GCC
7.19 <stdio.h>
! 7.19.1 Introduction: TODO
! 7.19.4 Operations on files: TODO
! 7.19.5 File access functions: TODO
! 7.19.6 Formatted input/output functions: TODO
! 7.19.7 Character input/output functions: TODO
! 7.19.8 Direct input/output functions: TODO
! 7.19.9 File positioning functions: TODO
! 7.19.10 Error-handling functions: TODO
7.20 <stdlib.h>
7.20 RAND_MAX, MB_CUR_MAX: TODO
7.20.1.1 atof: DONE
7.20.1.2 atoi, atol, atoll: DONE
7.20.1.3 strtod, strtof, strtold: DONE
7.20.1.4 strtol, strtoul, strtoll, strtoull: DONE
! 7.20.2 Pseudo-random sequence generation functions: TODO
! 7.20.3 Memory management functions: TODO (check existing code first)
7.20.4.1 abort: DONE
! 7.20.4.2 atexit: TODO
7.20.4.3 exit: DONE (missing stream flushing/closing/etc)
7.20.4.4 _Exit: DONE (gint only)
! 7.20.4.5 getenv: TODO
! 7.20.4.6 system: TODO
! 7.20.5 Searching and sorting utilities: TODO
7.20.6.1 abs, labs, llabs: DONE
7.20.6.2 div, ldiv, lldiv: DONE
! 7.20.7 Multibyte/wide character conversion functions: TODO
! 7.20.8 Multibyte/wide string conversion functions: TODO
7.21 <string.h>
7.21.2.1 memcpy: DONE
7.21.2.2 memmove: DONE (Unoptimized: byte-by-byte)
7.21.2.3 strcpy: DONE
7.21.2.4 strncpy: DONE
7.21.3.1 strcat: DONE
7.21.3.2 strncat: DONE
7.21.4.1 memcmp: DONE
7.21.4.2 strcmp: DONE
7.21.4.3 strcoll: DONE
7.21.4.4 strncmp: DONE
7.21.4.5 strxfrm: DONE
7.21.5.1 memchr: DONE
7.21.5.2 strchr: DONE
7.21.5.3 strcspn: DONE
7.21.5.4 strpbrk: DONE
7.21.5.5 strrchr: DONE
7.21.5.6 strspn: DONE
7.21.5.7 strstr: DONE
7.21.5.8 strtok: DONE
7.21.6.1 memset: DONE
7.21.6.2 strerror: DONE
7.21.6.3 strlen: DONE
Extensions:
- strnlen: DONE
- strchrnul: DONE
- strcasestr: DONE
- strcasecmp: DONE
- strncasecmp: DONE
- strdup: DONE
- strndup: DONE
7.22 <tgmath.h> => GCC
7.23 <time.h>
! 7.23.1 Components of time: TODO
! 7.23.2.1 clock: TODO
! 7.23.2.2 difftime: TODO
! 7.23.2.3 mktime: TODO
! 7.23.2.4 time: TODO
! 7.23.3.1 asctime: TODO
! 7.23.3.2 ctime: TODO
! 7.23.3.3 gmtime: TODO
! 7.23.3.4 localtime: TODO
! 7.23.3.5 strftime: TODO
7.24 <wchar.h>
TODO (not a priority)
7.25 <wctype.h>
TODO (not a priority)
# Supporting locales
What if we wanted to support more locales?
-> Need to a mechanism to supply the raw information, similar to the text files
in /usr/share/i18n/locales
-> Implement setlocale() and localeconv() properly (not hard)
-> Probably support nl_langinfo(), which is much better than localeconv()
-> Fix the "TODO: locale: ..." messages wherever assumptions on the locale are
made in the code
-> Properly implement strcoll() and strxfrm()