Re: [Mingw-users] for a c file g++ emits c++ warnings

[Clive M. <cli...@ms...>]

g++ --help emits this:

 

Usage: g++ [options] file...
Options:
  -pass-exit-codes         Exit with highest error code from a phase
  --help                   Display this information
    .

    .

    .
  -E                       Preprocess only; do not compile, assemble or link
  -S                       Compile only; do not assemble or link
  -c                       Compile and assemble, but do not link
  -o <file>                Place the output into <file>
  -x <language>            Specify the language of the following input files
                           Permissible languages include: c c++ assembler none
                           'none' means revert to the default behavior of
                           guessing the language based on the file's extension

 

So Roman, it looks as if the man page has a discrepancy with the command-line help. I have just tried -x (the 'none' mentioned above) but it too does not "guess" correctly that it is dealing with a c file. All of this wouldn't be an issue if were not using an IDE. The IDE can only use a common set of flags for all the files in the project. I think my best work around will be to compile the c++ module and make a library out of it, then link with the library from my c code. Will I run into c++ symbol naming issues if I use gcc to link to a c++ derived library?

 

Clive.


 

> To: min...@li...
> From: DXD...@ya...
> Date: Wed, 16 Sep 2009 00:18:32 +0400
> Subject: Re: [Mingw-users] for a c file g++ emits c++ warnings
> 
> Keith Marshall 
> <kei...@us...> писал в 
> своём письме Tue, 15 Sep 2009 17:04:01 +0400:
> 
> > This is a GCC feature[*], rather than MinGW specific; I see exactly
> > the same with the native compiler:
> >
> > $ g++ --version
> > g++ (GCC) 4.2.4 (Ubuntu 4.2.4-1ubuntu4)
> > Copyright (C) 2007 Free Software Foundation, Inc.
> > [...]
> >
> > $ g++ -W -Wall test.c
> > test.c: In function `int main()':
> > test.c:6: error: invalid conversion from `void*' to `char*'
> >
> > while again:
> >
> > $ g++ -W -Wall -x c test.c
> >
> > is silent. (It would seem to be a GCC bug, that `-x c' is required
> > to inform g++ that test.c is a C source file; as I read `info gcc',
> > the .c extension on the file name is specific to C, (not C++), and
> > is therefore _supposed_ to deliver the same effect).
> 
> It's not even a bug, as the man page says:
> 
> g++ is a program that calls GCC and treats .c, .h and .i files as C++ 
> source files instead of C source files unless −x is used, and 
> automatically specifies linking against the C++ library.
> 
> > [*] Of course, this "feature" is simply C++'s more pedantic attitude
> > to type coercions; if you must use a C++ compiler for C code, use an
> > explicit cast. Better still, set up your project makefiles with the
> > appropriate definitions for $(CC) and $(CXX), to use the correct GCC
> > front end for each language, (and use $(CXX) for linking any mixed
> > source application).
> >
> 
> Roman.
> 


g++ --help emits this:

 

Usage: g++ [options] file...
Options:
  -pass-exit-codes         Exit with highest error code from a phase
  --help                   Display this information
    .

    .

    .
  -E                       Preprocess only; do not compile, assemble or link
  -S                       Compile only; do not assemble or link
  -c                       Compile and assemble, but do not link
  -o <file>                Place the output into <file>
  -x <language>            Specify the language of the following input files
                           Permissible languages include: c c++ assembler none
                           'none' means revert to the default behavior of
                           guessing the language based on the file's extension

 

So Roman, it looks as if the man page has a discrepancy with the command-line help. I have just tried -x (the 'none' mentioned above) but it too does not "guess" correctly that it is dealing with a c file. All of this wouldn't be an issue if were not using an IDE. The IDE can only use a common set of flags for all the files in the project. I think my best work around will be to compile the c++ module and make a library out of it, then link with the library from my c code. Will I run into c++ symbol naming issues if I use gcc to link to a c++ derived library?

 

Clive.

 

 

_________________________________________________________________
Hotmail: Free, trusted and rich email service.
http://clk.atdmt.com/GBL/go/171222984/direct/01/