Request for help

Request for help

[Srinivas Vangara (svangara)]

Hi 

Is the statement:

a[i]=a[i++]; a valid statement as per ANSI C standards or the behaviour
is undefined and the implementation is compiler dependent?

Looks like gcc is treating this as a[i]=a[i];i++; Where as the
programmers intention could be a[i+1]=a[i];i++;

Does the C language ANSI standard enforce any evaluation order or the
implementation is left to the compiler?

Thanks & Regards,
Srinivas.

Re: Request for help

[Andrew Bevitt]

> a[i]=a[i++]; 

I read this as saying assign to the array a's position i, the value stored
in array a's position i, and then increment i. In code this would be 

a[i] = a[i]; i++; 

> Looks like gcc is treating this as a[i]=a[i];i++; Where as the
> programmers intention could be a[i+1]=a[i];i++;

The programmers intention could never be that unless they really 
are not sure about prefix / postfix notation and the usage of arrays.

There are subtle differences: A) Assign to array a's position i, the
value stored in array a at position i, then increment i. B) Assign to
array a's position i+1 the value of array a at position i, then inc i.

> Does the C language ANSI standard enforce any evaluation order or the
> implementation is left to the compiler?

i++ will increase i after any other operation on the line is complete
++i will increase i and then perform the other operations.

Note you cannot just issue : a[i] = a[++i]; either though, as the new position
i (ie i+1) will be used for both the assigned value position and the read.

Re: Request for help

[Falk Hueffner]

"Srinivas Vangara \(svangara\)" <svangara@cisco.com> writes:

> Is the statement:
> 
> a[i]=a[i++]; a valid statement as per ANSI C standards or the behaviour
> is undefined and the implementation is compiler dependent?

It's undefined. See the documentation on -Wsequence-point.

-- 
	Falk

Re: Request for help

[Andrea 'Fyre Wyzard' Bocci]

>a[i]=a[i++];

IIRC it's undefined, as the standard doesn't say in which order the left 
nad right side of '=' have to be avaluated.

.fw.

Re: request for help

[llewelly]

Siddhartha S <sidharta@yahoo-inc.com> writes:

> Hi,
> 	Could you please point me to an authoritative document with changes in gcc3.0 
> with respect to gcc 2.95.*  especially with respect to c++ both in terms of 
> compatibility/performance?

First note that gcc 3.0 is quite old, and somewhat problematical
    compared to earlier and later releases of gcc. I strongly suggest
    you upgrade to gcc 3.3.3 instead. 

The new features for 3.0 are here:
    http://gcc.gnu.org/gcc-3.0/features.html
See also the caveats page:
    http://gcc.gnu.org/gcc-3.0/caveats.html

The new features for 3.3.3 are here:
    http://gcc.gnu.org/gcc-3.3/changes.html

Amoung other things, please note gcc 3+ requires proper using
    directives, using declarations, and/or std:: qualifications for
    standard C++ library components, as required by the 1998
    standard. 

request for help

[Siddhartha S]

Hi,
	Could you please point me to an authoritative document with changes in gcc3.0 
with respect to gcc 2.95.*  especially with respect to c++ both in terms of 
compatibility/performance? 
Thanks
Siddhartha S

Re: Request for help

[Wayne]

Note also that version 3.04 is several releases old.  
Dev-C++ for example uses version 3.2...

Wayne Keen

Re: Request for help

[Andrea 'fwyzard' Bocci]

You might prefere to download a precompiled (binary) version of GCC, 
instead of a source distribution.
See <http://www.mingw.org> for a Windows version.
You might also have a look at <http://www.bloodshed.net/devcpp.html> for an 
IDE wich support GCC.

.fw.

Request for help

[kiran kumar]

Respected Sir/Madam,
                   I am developing mobile games using
C,C++ and BREW. For Emulator I am generating Win32
dll. For target device I need ".mod" file which will
be in binary format. I downloaded the
"gcc-g++-3.0.4.tar.gz". But i am not able to get it
installed and use it for generating ".mod" file. Any
other files i have to download? How to install? how to
compile the code using GCC? please help me to get out
of this problem.


Thanks & Regards,
Kiran Kumar . T


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Re: Request for help

[Andrea 'Fyre Wyzard' Bocci]

At 23.14 04/02/2002 (GMT -0800), you wrote:
>Hi,
>   I'm Suraj Bhatt currently studying in degree course
>(computer engg.) & visitors of your site.
>   I'm currently working on 'SS7 over IP' project.For
>the development of this project i want compiler.
>
>   * Since for that project, Can GCC compiler use to
>develop ?

I think you can use GCC to COMPILE anything you want.

>   * If so, how can i get that compiler ?

See the GCC web pages, <http://gcc.gnu.org>.
There you'll find instructions on how to download, configure and install 
GCC from sources. To be able to do this, you will need a working C compiler.
If you don't already have one, or if you prefere not to do that, you can 
obtain precompiled versions of GCC for many architectures.
You won't find them on the GCC web site. Instead, try asking the provider 
of your OS.

>   * i came to know that GNU software will be used for
>development of SS7 project.So, please inform me by
>mail.
>   * Is this project available in India so, give name
>of supplier.
>
>Waiting for reply...
>Regards
>Suraj.

I hope this will help you. If you have problems regarding the installation 
of GCC, and you can't solve them after reading the web pages, feel free to 
ask help on this mailing list.

fwyzard

Request for help

[suraj bhatt]

Hi,
  I'm Suraj Bhatt currently studying in degree course
(computer engg.) & visitors of your site.
  I'm currently working on 'SS7 over IP' project.For
the development of this project i want compiler. 
  
  * Since for that project, Can GCC compiler use to
develop ?
  * If so, how can i get that compiler ?
  * i came to know that GNU software will be used for
development of SS7 project.So, please inform me by
mail.
  * Is this project available in India so, give name
of supplier.

Waiting for reply...
Regards
Suraj.

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