[9fans] porting linux program for beginners

[9fans] porting linux program for beginners

[Fernan Bolando]

Hi

I got the following errors when trying out ape on my old programs.
can anybody clarify it's meaning? Are there additional pointers when
porting programs to p9?

what is IND UCHAR and IND CONST CHAR?

dumb_input.c:249[stdin:1718] argument prototype mismatch "IND UCHAR"
for "IND CONST CHAR": strlen

,Fernan

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Re: [9fans] porting linux program for beginners

[andrey mirtchovski]

for a brief introduction to porting unix code to plan9 i suggest you
check out the config.h file for the links browser (available in
/contrib/andrey on sources). it handles many of the gotchas that
you're bound to encounter.

On 3/14/06, Fernan Bolando <fernanbolando@mailc.net> wrote:
> Hi
>
> I got the following errors when trying out ape on my old programs.
> can anybody clarify it's meaning? Are there additional pointers when
> porting programs to p9?
>
> what is IND UCHAR and IND CONST CHAR?
>
> dumb_input.c:249[stdin:1718] argument prototype mismatch "IND UCHAR"
> for "IND CONST CHAR": strlen
>
> ,Fernan
>
> --
> Public PGP/GnuPG key (http://www.fernski.com)
> pub 1024D/3576CA71 2006-02-02 Fernan Bolando
> Key fingerprint = FDFE C9A8 FFED C1A5 2F5C EFEB D595 AF1C 3576 CA71
>

Re: [9fans] porting linux program for beginners

[C H Forsyth]

the compiler shows the linear type representation it uses internally.
IND is `indirect', a pointer, or *
UCHAR is `unsigned char'
CONST is obviously `const'
so in

dumb_input.c:249[stdin:1718] argument prototype mismatch "IND UCHAR" for "IND CONST CHAR": strlen

	you're passing an unsigned char* to strlen, which expects const char* (or char*)

the compiler could possibly translate them back to normal C declarator form
from the internal one, but on the other hand, in more subtle cases,
seeing them written in linear form can be helpful if you've got
a * or () in the wrong place.

newer versions of gcc will object too,
so you might as well get the types right now.

Re: [9fans] porting linux program for beginners

[David Leimbach]

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On 3/14/06, C H Forsyth <forsyth@vitanuova.com> wrote:
>
> the compiler shows the linear type representation it uses internally.
> IND is `indirect', a pointer, or *
> UCHAR is `unsigned char'
> CONST is obviously `const'
> so in
>
> dumb_input.c:249[stdin:1718] argument prototype mismatch "IND UCHAR" for
> "IND CONST CHAR": strlen
>
>         you're passing an unsigned char* to strlen, which expects const
> char* (or char*)
>
> the compiler could possibly translate them back to normal C declarator
> form
> from the internal one, but on the other hand, in more subtle cases,
> seeing them written in linear form can be helpful if you've got
> a * or () in the wrong place.



The output is backwards from what I'd expect about the types though.

In C and C++ const always refers to the item on the left of the const,
unless thre isn't one, then you go to the right.

const int
and
int const

are identical

int const *

and

int * const

are not the same :)

So when I read:
"IND CONST CHAR"

my brain is already "wired up" to think of that as

char * const

not

char const *

or equivalently

const char *

Anyone else have this problem?  If it's just me I'll shut up and learn to
cope.

Dave


newer versions of gcc will object too,
> so you might as well get the types right now.



gcc 4.0 is a particularly painful experience when compiling open sourced
codes I've seen that didn't pay attention to pointer target signedness.

Dave

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Re: [9fans] porting linux program for beginners

[Fernan Bolando]

On 3/15/06, C H Forsyth <forsyth@vitanuova.com> wrote:
> the compiler shows the linear type representation it uses internally.
> IND is `indirect', a pointer, or *
> UCHAR is `unsigned char'
> CONST is obviously `const'
> so in
>
> dumb_input.c:249[stdin:1718] argument prototype mismatch "IND UCHAR" for "IND CONST CHAR": strlen
>
>         you're passing an unsigned char* to strlen, which expects const char* (or char*)
>
> the compiler could possibly translate them back to normal C declarator form
> from the internal one, but on the other hand, in more subtle cases,
> seeing them written in linear form can be helpful if you've got
> a * or () in the wrong place.
>
> newer versions of gcc will object too,
> so you might as well get the types right now.

thanks. it is ok now.
I will see if I can get some of my codes posted on my webpage this weekend
It will is mostly some simple ape ports and I am not sure if there is
any real advantage
to port it as a native plan9 program.

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