Trouble compiling libpng (& zlib) using RVCT 4.0's armcc compiler - cygwin

I'm trying to compile libpng & zlib using the RVCT 4.0 armcc compiler. However armcc cannot find 'fcntl.h', which I assume is a standard C library. Cygwin has fcntl.h (and the associated files types.h and _types.h), but when I use those, I get various compilation errors.
Should I be using Cygwin's version of standard C libraries, or RVCT's? If the latter is correct, where do I get RVCT's versions of fcntl.h, types.h and _types.h?
Thanks!
Arjun

Which version of zlib/libpng are you trying to compile?
fcntl.h is POSIX standard, not ANSI/ISO C. RealView doesn't care about POSIX.
Compiling the zlib with RVCT 4.0 has always worked like a breeze.
I've tried libpng: well, it works if you define RISCOS, to prevent the sources from including sys/types.h (yet another POSIX file).
Here's my command line: armcc -c *.c -I/tmp/zlib/ -DRISCOS
Hope this helps

Related

cuda, gcc incompatible, downgrade [duplicate]

I am new to Cuda, and I am trying to compile this simple test_1.cu file:
#include <stdio.h>
__global__ void kernel(void)
{
}
int main (void)
{
kernel<<<1,1>>>();
printf( "Hello, World!\n");
return 0;
}
using this: nvcc test_1.cu
The output I get is:
In file included from /usr/local/cuda/bin/../include/cuda_runtime.h:59:0,
from <command-line>:0:
/usr/local/cuda/bin/../include/host_config.h:82:2: error: #error -- unsupported GNU version! gcc 4.5 and up are not supported!
my gcc --version:
gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
How can I install a second version of gcc (4.4 -) along with 4.6 without messing everything up?
I found this old topic:
CUDA incompatible with my gcc version
the answer was:
gcc 4.5 and 4.6 are not supported with CUDA - code won't compile and
the rest of the toolchain, including cuda-gdb, won't work properly.
You cannot use them, and the restriction is non-negotiable.
Your only solution is to install a gcc 4.4 version as a second
compiler (most distributions will allow that). There is an option to
nvcc --compiler-bindir which can be used to point to an alternative
compiler. Create a local directory and the make symbolic links to the
supported gcc version executables. Pass that local directory to nvcc
via the --compiler-bindir option, and you should be able to compile
CUDA code without effecting the rest of your system.
But I have no idea how to do it
In my case I didn't have root rights, so I couldn't fully replace the current gcc (4.7) with the older version 4.4 (which I think would be a bad alternative). Although I did have rights where CUDA was installed. My solution was to create an extra folder (e.g. /somepath/gccfornvcc/), wherever I had rights, then to create a link to an nvcc accepted compiler. I already had gcc 4.4 available (but you can install it, without removing your current version).
ln -s [path to gcc 4.4]/gcc-4.4 /somepath/gccfornvcc/gcc
Then, in the same folder where the nvcc binary lives, you should find a file called nvcc.profile . There you just need to add the following line:
compiler-bindir = /somepath/gccfornvcc
And that will make nvcc use the proper compiler. This helps keeping the system in a proper state, keeping the newest compiler, but nvcc (only nvcc) will use the old compiler version.
Doing some research online shows several methods for accomplishing this task. I just tested the method found here: http://www.vectorfabrics.com/blog/item/cuda_4.0_on_ubuntu_11.04 and it worked like a charm for me. It steps you through installing gcc 4.4 and creating scripts to run that version with nvcc. If you prefer trying the method mentioned in your post I'd recommend following that first link to install gcc4.4 and then create symbolic links as mentioned in your post. Creating symbolic links in Linux is accomplished by using the 'ln' command.
For example:
ln -s [source file/folder path] [linkpath]
This link gives a few examples of creating symbolic links on both Ubuntu and Windows: http://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/. Hopefully that points you in the right direction.
I guess you may try the new, beta, version, that based on LLVM.
Another way to make nvcc work with non-default compiler (unlike #Sluml's answer, it allows more flexibility):
At first, just like #Slump proposed, you need to create directory ~/local/gcc-4.4/, and then create there symlinks for right versions of gcc: for i in gcc gxx; do ln -s /usr/bin/${i}-4.4 ~/local/cudagcc/${i}; done. Now when you run nvcc -ccbin ~/local/gcc-4.4/ ... nvcc will use correct versions of gcc.
Here is small CMake snippet of forcing nvcc use specific host compiler.
option (CUDA_ENFORCE_HOST_COMPILER "Force nvcc to use the same compiler used to compile .c(pp) files insted of gcc/g++" OFF)
if (${CUDA_ENFORCE_HOST_COMPILER})
set (CMAKE_GCC_TEMP_DIR "CMakeGCC")
file(MAKE_DIRECTORY ${CMAKE_GCC_TEMP_DIR})
execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_C_COMPILER} ${CMAKE_GCC_TEMP_DIR}/gcc)
execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_CXX_COMPILER} ${CMAKE_GCC_TEMP_DIR}/g++)
set(CUDA_NVCC_FLAGS -ccbin ${CMAKE_GCC_TEMP_DIR} ${CUDA_NVCC_FLAGS})
endif()
Reference:
I update my gcc from 4.4 to 4.6. Then I could not use nvcc to compile my code. Luckily, by using the method provided by the following link. I set my default gcc compiler back to gcc 4.4. Now, I could compile file using either gcc4.4 or gcc4.6. quit cool
http://ubuntuguide.net/how-to-install-and-setup-gcc-4-1g4-1-in-ubuntu-10-0410-10

Using libraries compiled with GCC in a VisualC++ project (and vice versa)

It's possible to use code (and libraries) compiled with VisualC++ (so with .lib extension) in a project that will use GCC as compiler (and vice versa)? Or I have to rebuild them?
I'm trying to use SOCI 3.1 libraries that I have compiled with VisualC++ in a project that has GCC as compiler, but I'm getting some errors, and I don't know why..
You have to produce binaries for GCC using MinGW tools: reimp and dlltool. Here is MinGW wiki with complete explanation of the procedures: MSVC and MinGW DLLs
Short example:
reimp -d libmysql.lib
dlltool -k --input-def libmysql.def --dllname libmysql.dll --output-lib libmysql.a
reimp libmysql.lib
By the way, here is related thread on SOCI users mailing list which: MySQL Build fails. Look for useful links given in the thread.

Cuda compiler not working with GCC 4.5 +

I am new to Cuda, and I am trying to compile this simple test_1.cu file:
#include <stdio.h>
__global__ void kernel(void)
{
}
int main (void)
{
kernel<<<1,1>>>();
printf( "Hello, World!\n");
return 0;
}
using this: nvcc test_1.cu
The output I get is:
In file included from /usr/local/cuda/bin/../include/cuda_runtime.h:59:0,
from <command-line>:0:
/usr/local/cuda/bin/../include/host_config.h:82:2: error: #error -- unsupported GNU version! gcc 4.5 and up are not supported!
my gcc --version:
gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
How can I install a second version of gcc (4.4 -) along with 4.6 without messing everything up?
I found this old topic:
CUDA incompatible with my gcc version
the answer was:
gcc 4.5 and 4.6 are not supported with CUDA - code won't compile and
the rest of the toolchain, including cuda-gdb, won't work properly.
You cannot use them, and the restriction is non-negotiable.
Your only solution is to install a gcc 4.4 version as a second
compiler (most distributions will allow that). There is an option to
nvcc --compiler-bindir which can be used to point to an alternative
compiler. Create a local directory and the make symbolic links to the
supported gcc version executables. Pass that local directory to nvcc
via the --compiler-bindir option, and you should be able to compile
CUDA code without effecting the rest of your system.
But I have no idea how to do it
In my case I didn't have root rights, so I couldn't fully replace the current gcc (4.7) with the older version 4.4 (which I think would be a bad alternative). Although I did have rights where CUDA was installed. My solution was to create an extra folder (e.g. /somepath/gccfornvcc/), wherever I had rights, then to create a link to an nvcc accepted compiler. I already had gcc 4.4 available (but you can install it, without removing your current version).
ln -s [path to gcc 4.4]/gcc-4.4 /somepath/gccfornvcc/gcc
Then, in the same folder where the nvcc binary lives, you should find a file called nvcc.profile . There you just need to add the following line:
compiler-bindir = /somepath/gccfornvcc
And that will make nvcc use the proper compiler. This helps keeping the system in a proper state, keeping the newest compiler, but nvcc (only nvcc) will use the old compiler version.
Doing some research online shows several methods for accomplishing this task. I just tested the method found here: http://www.vectorfabrics.com/blog/item/cuda_4.0_on_ubuntu_11.04 and it worked like a charm for me. It steps you through installing gcc 4.4 and creating scripts to run that version with nvcc. If you prefer trying the method mentioned in your post I'd recommend following that first link to install gcc4.4 and then create symbolic links as mentioned in your post. Creating symbolic links in Linux is accomplished by using the 'ln' command.
For example:
ln -s [source file/folder path] [linkpath]
This link gives a few examples of creating symbolic links on both Ubuntu and Windows: http://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/. Hopefully that points you in the right direction.
I guess you may try the new, beta, version, that based on LLVM.
Another way to make nvcc work with non-default compiler (unlike #Sluml's answer, it allows more flexibility):
At first, just like #Slump proposed, you need to create directory ~/local/gcc-4.4/, and then create there symlinks for right versions of gcc: for i in gcc gxx; do ln -s /usr/bin/${i}-4.4 ~/local/cudagcc/${i}; done. Now when you run nvcc -ccbin ~/local/gcc-4.4/ ... nvcc will use correct versions of gcc.
Here is small CMake snippet of forcing nvcc use specific host compiler.
option (CUDA_ENFORCE_HOST_COMPILER "Force nvcc to use the same compiler used to compile .c(pp) files insted of gcc/g++" OFF)
if (${CUDA_ENFORCE_HOST_COMPILER})
set (CMAKE_GCC_TEMP_DIR "CMakeGCC")
file(MAKE_DIRECTORY ${CMAKE_GCC_TEMP_DIR})
execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_C_COMPILER} ${CMAKE_GCC_TEMP_DIR}/gcc)
execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_CXX_COMPILER} ${CMAKE_GCC_TEMP_DIR}/g++)
set(CUDA_NVCC_FLAGS -ccbin ${CMAKE_GCC_TEMP_DIR} ${CUDA_NVCC_FLAGS})
endif()
Reference:
I update my gcc from 4.4 to 4.6. Then I could not use nvcc to compile my code. Luckily, by using the method provided by the following link. I set my default gcc compiler back to gcc 4.4. Now, I could compile file using either gcc4.4 or gcc4.6. quit cool
http://ubuntuguide.net/how-to-install-and-setup-gcc-4-1g4-1-in-ubuntu-10-0410-10

What is libg2c library?

I have found the code which links against of 'g2c' library. Why do I need it? Just would like to understand why it might be important and what it does in general.
Thanks!
What is GNU Fortran?
g77 consists of several components:
A modified version of the gcc command, which also might be installed as the system's cc command. (In many cases, cc refers to the system's “native” C compiler, which might be a non-GNU compiler, or an older version of gcc considered more stable or that is used to build the operating system kernel.)
The g77 command itself, which also might be installed as the system's f77 command.
The libg2c run-time library. This library contains the machine code needed to support capabilities of the Fortran language that are not directly provided by the machine code generated by the g77 compilation phase.
libg2c is just the unique name g77 gives to its version of libf2c to distinguish it from any copy of libf2c installed from f2c (or versions of g77 that built libf2c under that same name) on the system.
You may think of it as, libg2c is to g77 as libc is to gcc.
Note that as of the GCC 4.x series, g77 has been discontinued, replaced by gfortran, which produces programs that do not require an extra libg2c runtime library.
"This library contains the machine code needed to support capabilities of the Fortran language that are not directly provided by the machine code generated by the g77 compilation phase."
from this link
Installing compat-gcc-34-g77 solves this requirement.
(gcc-34 must be replaced by your gcc version)

How to GCC compile without _alloca?

For some reason, I should use gcc to compile a C file, then link against Visual C++ 2008 project.
(I used the current latest gcc version: cygwin gcc 4.3.4 20090804.)
But there is one problem: gcc always allocate a big array with _alloca,
and VC linker can't resolve the symbol __alloca.
for example,
int func()
{
int big[10240];
....
}
this code makes the _alloca dependency although I didn't call the _alloca function explicitly.
(array size matters. if i change 10240 -> 128, everything ok)
I tried gcc option -fno-builtin-alloca or -fno-builtin, but no luck.
Is it possible to make gcc not to use _alloca ? (or adjust the threshold?)
Best thing to do would be to compile all code with VC++. If that's not possible..
You should use the mingw gcc instead of the cygwin one. It's designed to output code that will be linked against the VC++ runtime, not the cygwin libraries. In particular, it will call the VC++ runtime function __chkstk instead of __alloca.
You could just write your own _alloca routine and link against that. Look at the gcc library source to see what it's supposed to do.
It looks like _alloca has been deprecated by Microsoft and is no longer in their runtime libraries after VS2005. Newer runtime libraries support _malloca.
Your options don't look good. You can try to build with VS2005 instead. Perhaps cygwin has an option where you can tell it you are using a newer runtime library (and if they don't support that yet, you could file it as a feature request).
some related discussions:
cygwin: gcc and alloca
GNU Compiler Collection (GCC) Internals
gcc and alloca

Resources