I have a very large project that I'm trying to migrate from GNU make to cmake. As such, I think having intermediary files containing various variables is a good way to go.
Since I'm just starting out, this is what I have for top_directory/vars/CMakeLists.txt:
cmake_minimum_required(VERSION 2.8)
set(VARIABLE "value")
This way, in another folder, I can add this line to that CMakeLists.txt:
add_subdirectory(top_directory/vars)
However, when trying to run cmake on top_directory/vars/CMakeLists.txt, I receive the following error:
me#host:/tmp>cmake .
-- The C compiler identification is unknown
-- The CXX compiler identification is GNU 7.3.1
-- Check for working C compiler: /usr/bin/g++
-- Check for working C compiler: /usr/bin/g++ -- broken
CMake Error at /usr/share/cmake/Modules/CMakeTestCCompiler.cmake:52 (message):
The C compiler
"/usr/bin/g++"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /tmp/CMakeFiles/CMakeTmp
Run Build Command:"/usr/bin/gmake" "cmTC_607e9/fast"
/usr/bin/gmake -f CMakeFiles/cmTC_607e9.dir/build.make CMakeFiles/cmTC_607e9.dir/build
gmake[1]: Entering directory '/tmp/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o
/usr/bin/g++ -o CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o -c /tmp/CMakeFiles/CMakeTmp/testCCompiler.c
/tmp/CMakeFiles/CMakeTmp/testCCompiler.c:2:3: error: #error "The CMAKE_C_COMPILER is set to a C++ compiler"
# error "The CMAKE_C_COMPILER is set to a C++ compiler"
^~~~~
gmake[1]: *** [CMakeFiles/cmTC_607e9.dir/build.make:66: CMakeFiles/cmTC_607e9.dir/testCCompiler.c.o] Error 1
gmake[1]: Leaving directory '/tmp/CMakeFiles/CMakeTmp'
gmake: *** [Makefile:126: cmTC_607e9/fast] Error 2
CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
CMakeLists.txt
-- Configuring incomplete, errors occurred!
See also "/tmp/CMakeFiles/CMakeOutput.log".
See also "/tmp/CMakeFiles/CMakeError.log".
Now I can force it by adding -DCMAKE_C_COMPILER=gcc, but that really defeats the portability aspect.
So my question is: is this the right way to be making "variable" CMake files and why does CMake incorrectly detect my C compiler?
Helpful Information:
cmake --version
cmake version 3.11.1
CMake suite maintained and supported by Kitware (kitware.com/cmake).
gcc --version
gcc (SUSE Linux) 7.3.1 20180323 [gcc-7-branch revision 258812]
Copyright (C) 2017 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.
If there is any additional information I can provide, then please let me know.
Related
I have been asked to compile C Source codes with g++ compiler in cMake environment.
I tried one of the solution from Stack Overflow:
Set CC,CXX before running cmake like in below steps.
export CC=/usr/bin/g++
export CXX=/usr/bin/g++
but I get below errors while running cmake
"cmake -DPLATFORM=x64 ../"
-- The C compiler identification is unknown
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/g++
-- Check for working C compiler: /usr/bin/g++ -- broken
CMake Error at /usr/share/cmake-3.10/Modules/CMakeTestCCompiler.cmake:52 (message):
The C compiler
"/usr/bin/g++"
is not able to compile a simple test program.
It fails with the following output:
For individual files you can set the language yourself independent of the file extension by setting the LANGUAGE source file property:
# compile foo.c and bar.c with the C++ compiler
set_source_files_properties(foo.c bar.c PROPERTIES LANGUAGE CXX)
This results in CMake using the C++ compiler for the .c files regardless of the compilers used for C / C++.
It may be possible to achieve the same effect for the whole project by listing only C++ as language, but I haven't tested this option:
# top level project
project(MyProject LANGUAGES CXX)
...
I started to learn APUE* and compile the source code
Download the source code from Source Code
Extract it to
$ pwd
/Users/me/Desktop/PubRepo/C/APUE/apue.3e
Read readme
$ cat readme
Read the file called DISCLAIMER.
On Freebsd, type "gmake".
On other platforms, type "make" (as long as this is gnu make).
For FAQs, updated source code, and the lost chapter, see http://www.apuebook.com.
Please direct questions, suggestions, and bug reports to sar#apuebook.com.
Steve Rago
January 2013
I checked make version
$ make --version
GNU Make 3.81
Copyright (C) 2006 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.
This program built for i386-apple-darwin11.3.0
make but report error:
gcc -ansi -I../include -Wall -DMACOS -D_DARWIN_C_SOURCE -c -o sleep.o sleep.c
making intro
gcc -ansi -I../include -Wall -DMACOS -D_DARWIN_C_SOURCE getcputc.c -o getcputc -L../lib -lapue
ld: archive has no table of contents file '../lib/libapue.a' for architecture x86_64
clang: error: unable to execute command: Segmentation fault: 11
clang: error: linker command failed due to signal (use -v to see invocation)
make[1]: *** [getcputc] Error 254
make: *** [all] Error 1
I searched and found answer to add cp ./lib/error.c /usr/local/include/
$ cp ./lib/error.c /usr/local/include/
make clean and make
making intro
gcc -ansi -I../include -Wall -DMACOS -D_DARWIN_C_SOURCE getcputc.c -o getcputc -L../lib -lapue
ld: archive has no table of contents file '../lib/libapue.a' for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]: *** [getcputc] Error 1
make: *** [all] Error 1
The error is still there.
How could I apply apue.h?
* W Richard Stevens, Stephen A Rago
Advanced Programming in the Unix Environment, 3rd Edn, 2013.
I downloaded the APUE source to a Mac running macOS 10.14.1 Mojave with XCode 10.1 installed (see also Can't compile a C program on a Mac after upgrade to Mojave).
I then ran make CC=/usr/bin/clang (using /usr/bin/gcc is also OK) to use that instead of a home-built GCC 8.2.0, which failed in the db subdirectory. If you don't have any non-standard version of GCC installed on your PATH ahead of /usr/bin/gcc or /usr/bin/clang, you shouldn't need the CC=… argument.
This did a lot of building — all of it successfully (once I'd specified the compiler explicitly; I got an error on the -R. argument with the home-built GCC).
Make sure you have XCode properly installed. Worry about the Command Line Tools — see the "Can't compile" question for information on where to get them. You shouldn't need /usr/include for this, but it is likely to make life easier; again, see the "Can't compiler" question for how to install /usr/include.
There is an answer here from #makhlaghi that helped me a long time ago.
https://unix.stackexchange.com/questions/105483/compiling-code-from-apue.
Here is the answer that worked for me:
A short review of how to write and compile the programs in Advanced Programming in the UNIX® Environment, thanks to slm for helping me understand the steps. You can download the source code from here. I wish this information was included as part of appendix b of the book, where the header file is explained.
The uncompressed file contains directories with the names of the chapters and two others named include and lib. The ones with the names of the chapters have all the programs of that chapter in them.
The include directory contains the header file that is used in most of the programs in the book: apue.h. The lib directory has the source code of the implementations for the that header.
Lets assume the uncompressed file is located at: SCADDRESS/, for example it might be: /home/yourid/Downloads/apue.3e/
Once you uncompress the source code, go in the directory and run make:
$ cd SCADDRESS
$ make
make will compile all the programs in all the chapters. But the important thing is that before that, it will make the library that will contain the implementations of the functions in apue.h.
To compile an example program that you write from the book, run this GCC command (assuming your program's name is myls.c which is the first in the book):
gcc -o myls myls.c -I SCADDRESS/include/ -L SCADDRESS/lib/ -lapue
-I tells gcc which directory to look for the include file. -L tells it the location of the library directory, and -lapue, tells the name of the library file to look for in that directory. Such that -LXXX means to look for a file in the library directory with the name: libXXX.a or libXXX.so.
I am a beginner in programming with C and I get this error code if i start a project on CLion:
C:\Program Files\JetBrains\CLion 2017.2.2\bin\cmake\bin\cmake.exe" -DCMAKE_BUILD_TYPE=Debug -G "CodeBlocks - MinGW Makefiles" C:\Users\danie\CLionProjects\untitled2
-- The C compiler identification is GNU 5.3.0
-- The CXX compiler identification is unknown
-- Check for working C compiler: C:/MinGW/bin/gcc.exe
-- Check for working C compiler: C:/MinGW/bin/gcc.exe -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
CMake Error at CMakeLists.txt:2 (project):
The CMAKE_CXX_COMPILER:
g++.exe
is not a full path and was not found in the PATH.
Tell CMake where to find the compiler by setting either the environment
variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
to the compiler, or to the compiler name if it is in the PATH.
-- Configuring incomplete, errors occurred!
See also "C:/Users/danie/CLionProjects/untitled2/cmake-build-debug/CMakeFiles/CMakeOutput.log".
See also "C:/Users/danie/CLionProjects/untitled2/cmake-build-debug/CMakeFiles/CMakeError.log".
[Finished]
What can I do to get it working?
Thank you for your help.
By default, CMake expects that project needs support for both C and C++. If your project needs only C, specify that in project() call:
project(<project-name> C)
I am trying to build Trilinos on my OS X 10.11.6 laptop and keep encountering the following problem: CMake uses Apple's Clang instead of GCC
...
Probing the environment ...
-- USE_XSDK_DEFAULTS='FALSE'
-- CMAKE_BUILD_TYPE='RELEASE'
-- BUILD_SHARED_LIBS='FALSE'
-- CMAKE_C_COMPILER_ID='AppleClang'
-- CMAKE_C_COMPILER_VERSION='7.3.0.7030031'
-- CMAKE_CXX_COMPILER_ID='AppleClang'
-- CMAKE_CXX_COMPILER_VERSION='7.3.0.7030031'
...
Despite the fact that I passed gcc/g++ address as an argument in call:
cmake -D CMAKE_C_COMPILER=/usr/bin/gcc -D CMAKE_CXX_COMPILER=/usr/bin/g++ ..
I installed GCC and G++ separately:
$ gcc --version
gcc (GCC) 4.9.2 20141029 (prerelease)
Copyright (C) 2014 Free Software Foundation, Inc.
UPD If anybody's interested, I've given up and moved development to ubuntu. If you find a way to do this, please comment below
When compiler is set explicitely, CMake doesn't try to guess its identification (variables *_COMPILER_ID and *_COMPILER_VERSION.
If you want (and usually you do want) this identification to correctly reflect your compiler, you need to set these variables explicitely too.
For setup several variables describing building environment you may use toolchain files.
Fedora 15
cmake version 2.8.4
I am using the following CMakeLists.txt. However the status message doesn't display when I run cmake .
CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
PROJECT(proj2 C)
IF(CMAKE_COMPILER_IS_GNUCXX)
MESSAGE(STATUS "==== GCC detected - Adding compiler flags")
SET(CMAKE_C_FLAGS "-pthread -ggdb -Wextra -Wall")
ENDIF(CMAKE_COMPILER_IS_GNUCXX)
ADD_EXECUTABLE(crypto_app main.c)
TARGET_LINK_LIBRARIES(crypto_app crypt)
All I get is the following:
-- The C compiler identification is GNU
-- Check for working C compiler: /usr/lib64/ccache/gcc
-- Check for working C compiler: /usr/lib64/ccache/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/projects/proj1/
Many thanks for any suggestions about this.
You're telling cmake that it's a C project, and then checking for a CXX (i.e. C++) compiler. CMAKE_COMPILER_IS_GNUCXX will never be true in this case. That's why.