[alsa-devel] SALSA-Lib versus C++
Dear List,
It -appears- to me that the source file headers generated by SALSA-Lib-0.0.5 (for example SALSA:asoundlib.h) are not generally usable from within a C++ program compiled with g++.
The first problem that I encountered was a failure in IOC_TYPECHECK from asm-generic/ioctl.h. After much searching, I concluded that this is a component of continuing struggles related to "sanitized linux-kernel-headers". Some of the Debian folks have supplied patches to disable this particular check when the ioctl.h file is included from userland, but these patched headers are not present in my cross-compile environment. This behavior apparently is not a problem with gcc or g++ < 2.3.3 - but shows up in later versions of g++. ... a real mess as best I can tell ...
The next problem is that when warnings are enabled, g++ complains vigorously about void pointers that are implicitly cast to typed pointers through-out all of the SALSA-Lib supplied header files.
Perhaps SALSA-Lib was never intended from usable from C++ programs - and indeed it could argued that its intended application (embedded systems) should avoid the use of C++. If this is the case, perhaps a mention of this restriction might be appropriate on the SALSA-Lib Website and/or in its README file ?
Thanks again for all of your help in trying to get this working.
Best regards, Scott.
At Sun, 1 Jul 2007 19:33:24 -0400, J. Scott Merritt wrote:
Dear List,
It -appears- to me that the source file headers generated by SALSA-Lib-0.0.5 (for example SALSA:asoundlib.h) are not generally usable from within a C++ program compiled with g++.
The first problem that I encountered was a failure in IOC_TYPECHECK from asm-generic/ioctl.h. After much searching, I concluded that this is a component of continuing struggles related to "sanitized linux-kernel-headers". Some of the Debian folks have supplied patches to disable this particular check when the ioctl.h file is included from userland, but these patched headers are not present in my cross-compile environment. This behavior apparently is not a problem with gcc or g++ < 2.3.3 - but shows up in later versions of g++. ... a real mess as best I can tell ...
The next problem is that when warnings are enabled, g++ complains vigorously about void pointers that are implicitly cast to typed pointers through-out all of the SALSA-Lib supplied header files.
Perhaps SALSA-Lib was never intended from usable from C++ programs - and indeed it could argued that its intended application (embedded systems) should avoid the use of C++. If this is the case, perhaps a mention of this restriction might be appropriate on the SALSA-Lib Website and/or in its README file ?
Did you try to include it from extern "C" { .. } block?
Takashi
At Mon, 02 Jul 2007 15:06:44 +0200, I wrote:
At Sun, 1 Jul 2007 19:33:24 -0400, J. Scott Merritt wrote:
Dear List,
It -appears- to me that the source file headers generated by SALSA-Lib-0.0.5 (for example SALSA:asoundlib.h) are not generally usable from within a C++ program compiled with g++.
The first problem that I encountered was a failure in IOC_TYPECHECK from asm-generic/ioctl.h. After much searching, I concluded that this is a component of continuing struggles related to "sanitized linux-kernel-headers". Some of the Debian folks have supplied patches to disable this particular check when the ioctl.h file is included from userland, but these patched headers are not present in my cross-compile environment. This behavior apparently is not a problem with gcc or g++ < 2.3.3 - but shows up in later versions of g++. ... a real mess as best I can tell ...
The next problem is that when warnings are enabled, g++ complains vigorously about void pointers that are implicitly cast to typed pointers through-out all of the SALSA-Lib supplied header files.
Perhaps SALSA-Lib was never intended from usable from C++ programs - and indeed it could argued that its intended application (embedded systems) should avoid the use of C++. If this is the case, perhaps a mention of this restriction might be appropriate on the SALSA-Lib Website and/or in its README file ?
Did you try to include it from extern "C" { .. } block?
... looks like C++ really doesn't like the conversion. So, don't use C++. I hate it :)
Takashi
participants (2)
-
J. Scott Merritt -
Takashi Iwai