From 3ed024dcb2f874e9a6a1eac6142a0864eac33460 Mon Sep 17 00:00:00 2001 From: Jeff Johnston Date: Wed, 25 Mar 2009 21:16:04 +0000 Subject: 2009-03-25 Craig Howland * libc/include/math.h: (llround, llroundf): Declare. * libm/common/s_llround.c: New file, implementing llround(). * libm/common/sf_llround.c: New file, implementing llroundf(). * libm/common/sf_lround.c: Remove spurious cast in _DOUBLE_IS_32BITS version of function. * libm/common/sf_lrint.c: Ditto. * libm/common/sf_logb.c: Corrected return for subnormal argument by replacing existing function with a version created from sf_ilogb.c. * libm/common/s_logb.c: Ditto, except starting point s_ilogb.c. Also added documentation for logb() and logbf(). * libm/common/s_signbit.c: Add signbit() documentation. * libm/common/s_log2.c: Update return values to match what w_log2.c has, since log2 uses log(); add note about being derived instead of direct. * libm/common/sf_fma.c: Add casts to attempt to get correct results, as well as comments pointing out problems with the implementation. * libm/common/s_fma.c: Add fma() and fmaf() documentation. * libm/common/sf_remquo.c: Incorrect quotient returns for large values corrected by discarding existing function and replacing with Sun verion, with some enhancements. * libm/common/s_remquo.c: Ditto. Add remquo() and remquof() documentation. * libm/common/s_fmax.c: Add fmax() and fmaxf() documentation. * libm/common/s_fmin.c: Add fmin() and fminf() documentation. * libm/common/s_fdim.c: Return NAN for NAN arg, add fdim() and fdimf() documentation. * libm/common/sf_fdim.c: Return NAN for NAN arg, HUGE_VALF for inf arg. * libm/common/s_trunc.c: Add trunc() and truncf() documentation. * libm/common/s_rint.c: Add rint() and rintf() documentation. * libm/common/s_round.c: Add round() and roundf() documentation. * libm/common/s_scalbn.c: Add scalbln() and scalblnf() documentation. * libm/common/s_infinity.c: Add infinity() and infinityf() documentation. * libm/common/s_lround.c: Add lround(), lroundf(), llround(), and llroundf() documentation. * libm/common/s_lrint.c: Add lrint(), lrintf(), llrint(), and llrintf() documentation. * libm/common/isgreater.c: New file for documenting math.h function-like macros isgreater(), isgreaterequal(), isless(), islessequal(), islessgreater(), and isunordered(). * libm/common/s_isnan.c: Add documentation for function-like macros fpclassify(), isfinite(), isinf(), isnan(), and isnormal(). * libm/common/s_nearbyint.c: Add nearbyint() and nearbyintf() documentation. * libm/common/Makefile.am: Add s_llround.c (src); sf_llround.c (fsrc); s_fdim.def, s_fma.def, s_fmax.def, s_fmin.def, s_logb.def, s_lrint.def, s_lround.def, s_nearbyint.def, s_remquo.def, s_rint.def, s_round.def, s_signbit.def, s_trunc.def, and isgreater.def (chobj); re-name all existing chew files (chobj) to match source file base names (put in underscores), delete all special targets for chew files (leaving all to be generated by rule). * libm/common/Makefile.in: regenerate. * libm/math/w_exp2.c: Add "base 2" to documentation description (and delete TRAD_SYNOPSIS). * libm/math/w_gamma.c: Add tgamma() and tgammaf() documentation, along with some history behind the function names. * libm/math/math.tex: Add includes for newly-added documentation (see .def additions to common/Makefile.am and math/Makefile.am in this ChangeLog list), adjusted existing .def file names to match source file base names (added underscores); add mention of HUGE_VALF; rename "Version of library" section to "Error Handling" and add some text about floating-point exception; added section "Standards Compliance And Portability". * libm/math/Makefile.am: Add w_exp2.def (chobj); re-name all existing chew files (chobj) to match source file base names, delete all special targets for chew files (leaving all to be generated by rule). * libm/math/Makefile.in: regenerated * doc/makedoc.c: Change silent ignoring of commands < 5 characters to a failure when reading macro file for commands < 4 characters; add -v (verbose) option for printing some debugging information; get rid of spurious translation of "@*" to "*" (no source files used @*, so no existing doc pages were affected); clean up some compiler warnings. * doc/doc.str: add BUGS and SEEALSO sections (to match texi2pod.pl which has them); Remove ITEM command (redundant with makedoc built-in "o", not used in any present source file so nothing is lost, anyway). * HOWTO: New file to hold information for maintainers regarding how to do things. Initial sections on documentation and ELIX levels. --- newlib/HOWTO | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 newlib/HOWTO (limited to 'newlib/HOWTO') diff --git a/newlib/HOWTO b/newlib/HOWTO new file mode 100644 index 000000000..6a0f2a92f --- /dev/null +++ b/newlib/HOWTO @@ -0,0 +1,117 @@ +This HOWTO file contains notes for maintainers and contributors to Newlib. +For information on using Newlib (building, installing), see README. (In +particular, the "Regenerating Configuration Files" section in README is of +interest to both users and contributors.) + +(This file could probably use some other "sections" in addition to the +initially-provided sections. Please help by adding as appropriate.) + +DOCUMENTATION +============= + + All the documentation for Newlib comes as part of the machine-readable +distribution. Functions are documented in the source files, although not +every file contains documentation, as many functions share manual page +information. For example, lround(), lroundf(), llround(), and llroundf() +share a single man page, which is in the source for lround(). The documentation +is written partially in a custom format and partially in Texinfo format. + + The custom part comprises makedoc.c and doc.str, both of which are in the +doc directory. doc.str is a macro file that can be used to define things to +be done by makedoc, using building blocks that are built into makedoc.c. +The basic function of makedoc is two-fold. First, it recognizes comments in +the proper format to pull out of source files. Second, it adds some Texinfo +commands as well as translating certain sequences into the appropriate +Texinfo commands. Refer to makedoc.c and doc.str for what these are. +(makedoc.c is not particularly-well commented.) Another way to see how they +work is to simply examine the source files with documentation comments. + +(A couple of examples that use some of the fancier options: + libm/common/s_isnan.c ("o+" variable-"bullet" list), + libc/stdio/sprintf.c ("O+" bullet list; "." for example code).) + + In addition to the makedoc.c stuff, Texinfo commands can be directly +used. Texinfo is a documentation system that uses a single source file to +produce both on-line information and a printed manual. You can use one of the +Info formatting commands to create the on-line version of the documentation +and TeX (or `texi2roff') to typeset the printed version. While Newlib contains +a copy of the texinfo package (texinfo.tex), the manual for it is not +included. The latest one may be found at + +http://www.gnu.org/software/texinfo/manual/texinfo/texinfo.html + +(which could be for a newer version of texinfo.tex than is included in Newlib). + + In addition to Texinfo commands, straight TeX commands can also be used, +but these, however, should be carefully limited and be given alternates for +when a non-printed manual is produced--such as when info pages are produced. +For an example of this kind of usage, see libm/common/s_logb.c. + + Please note that most files with documentation contain both an +ANSI_SYNOPSIS and a TRAD_SYNOPSIS section. The TRAD_SYNOPSIS section gets +deleted (since at least 2000) by makedoc, so when working on files these +can safely be deleted and if you're making a new file, there is no need +to add the TRAD_SYNOPSIS section. + + If writing a new function that requires documentation, the required +sections are FUNCTION, INDEX, ANSI_SYNOPSIS (or SYNOPSIS), DESCRIPTION, RETURNS, +and PORTABILITY. BUGS and SEEALSO should be added as appropriate. + + Source files which contain documentation are processed into ".def" +files with the extracted information. These .def files are noted in the +makefiles as either CHEWOUT_FILES in the libc makefiles or chobj in the libm +makefiles. These .def files need to be included into an appropriate .tex +file for inclusion in the manuals (one each for libc and libm). Pay special +attention under libc, as the manual is arranged by header file name, but not +all header files are represented by directories (e.g. wcsftime.c is found +under libc/time, but goes under wchar.h in the manual.) + +In summary, to add new documentation: + +1. Add properly-formatted comments to source file (e.g. src.c); +2. add "chewout" file to list in Makefile.am (CHEWOUT_FILES in libc or chobj in + libm) (e.g. src.def), re-generate Makefile.in; +3. add file to something.tex; +4. make ChangeLog entry and generate patch. + +EL/IX (ELIX_LEVEL_n, ELIX_n_SOURCES) +==================================== + + Some of the Makefiles contain definitions of ELIX_LEVEL_1 ... ELIX_LEVEL_4, +and corresponding definitions for ELIX_1_SOURCES ... ELIX_4_SOURCES. +These are referring to the EL/IX standards created by Red Hat for the +purpose of Linux-based open standards for embedded development. In brief, +the intent is to define multiple levels for API functions that allows the +user to size the library appropriately for their application--at least in +terms of the predefined lists. For full details, refer to the EL/IX home +page at http://sources.redhat.com/elix/. The likely best way to tell how to +classify any new functions in terms of needing an ELIX level qualification +is to ask Jeff Johnston. To see how it works and try classification on your +own, refer to the API specification on the web site, + +http://sources.redhat.com/elix/api/current/api.pdf. + +(Unfortunately, it is not complete with respect to either the C99 or POSIX +standards, so particular C and POSIX functions may or may not be found.) + + The following definitions of the levels are from the (draft) standard. + +Level 1 + RTOS compatible layer. Functions available in both Linux and a +typical deeply embedded operating system (eCos, RTEMS, VxWorks, pSOS, VRTX32, +etc.). Some functions may have reduced or modified semantics. + +Level 2 + Linux single process only. Includes level 1 plus any functions from Linux +that are not easily implemented on an RTOS. Also full implementations of +reduced functions in Level 1. + +Level 3 + Linux multiprocess for embedded applications. This is basically POSIX.1 +with some of the functions that are obviously not for embedded applications +(such as job control) removed. + +Level 4 + Full POSIX or Linux compliance. Essentially these are functions that are +present in a standard Linux kernel but are irrelevant to an embedded system. +These functions do not form part of the EL/IX API. -- cgit v1.2.3