Re: [Groff] Overview, Sept. 2014

[Steffen Nurpmeso]

address@hidden wrote:
 |On Wed, 10 Sep 2014, Werner LEMBERG wrote:
 |>> The problem with global variables is their long range effect,
 |>> comparable with the infamous goto statement: considered harmful.
 |>
 |> I like `goto' a lot, and it is an invaluable instruction if used with
 |> care.  The same is true with global variables.  Sorry to say, but we
 |> are now going into hearsay and hollow statements, which isn't helpful.
 |
 |I may have to look into this C++ stuff. I have only written C and I have 
 |not figured out how to write multi-threaded applications without global 
 |variables. And I make good use of goto and longjmp. Apps would be a lot 
 |junkier without them.

_I_ usually collect such global data in a structure and
instantiate that; in BSS usually, but if i there is complete
control and it is doable then on the stack and all functions take
that as a "self" first argument (most likely i use this approach
for single compilation units).  This has good side-effects: i can
search for /_?g[.-] and get all global data matches (usually
without false hits, then), and i can layout the structure in a way
that minimizes useless alignment padding.  I can use the global
instance as a first-time initialization switch if i base it upon
a pointer, then only have a single global mutex to protect _all_
first time inits all through the entire library / whatever.  In
fact i wrote programs and libraries without any DATA section, but
text / rodata and a minimal bss, anything else was stack and
heap-bss (through the dynamic allocator a.k.a. mmap(2)).
This all was C++ (but -nostdlib -fno-rtti -fno-exceptions etc.).

--steffen