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Building
--------
First run configure to set up the standards conformance. It has help when run
with -h, which will always be more up-to-date than anything that could be put
in this document.
Then run make.
Code Organization
-----------------
Every identifier is placed in its own .c file. Every single one. Every function
(with two types of exceptions), every extern variable, every #define, every
typedef, every struct and union definition. This facilitates generating man
pages, 1 per, as well has header generation.
The two exceptions are math functions (in <math.h>, <complex.h>, and
<tgmath.h>) that are defined identically for all three floating point types,
and Curses functions (in <curses.h>) that include w and possible mv and mvw
prefixed versions. Those use macros inside those files to define the alternate
versions, and the man page and header file generation scripts treat them
specially.
As for paths, files are in src/<primary header name without.h>/<identifier>.c.
For example, printf() is at src/stdio/printf.c.
Compiler Requirements
---------------------
The compiler must define exactly one of __LP32__, __ILP32__, __ILP64__,
__LLP64__, or __LP64__, describing the relative sizes of int, long, long long,
and pointer types as described in this table (underscores remove for clarity):
LP32 ILP32 ILP64 LLP64 LP64
char 8 8 8 8 8
short 16 16 16 16 16
int 16 32 64 32 32
long 32 32 64 32 64
long long 64 64 64 64 64
pointer 32 32 64 64 64
The aformentioned symbol is used, among other places, for the proper definition
of size_t, ssize_t, and intptr_t.
The implementation of <complex.h> depends on the compilers representation of
_Complex types being the same as an array of two of the underlying floating
point type, with the first being the real part and the second being the
imaginary part. That is, for each type t in float, double, and long double,
the declaration union { _Complex t c; t f[2]; }; should be usable to directly
manipulate the real and imaginary members of the complex type.
Coding Style
------------
Start with K&R. Indents are tabs. Tabs are 8 spaces.
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