I am trying to compile the code for one of the projects and the source file uses autoreconf for generating the makefiles.
" autoreconf --verbose --force --make "
The problem is that this somehow generates the makefiles that uses the compiler as GCC. I want it to generate the configuration files with a different compiler. How can I do it?
I can issue the command as make CC= but this throws an error in the libtool that is used later on.
Thank You
Typically autoreconf just regenerates the configure script and the autoconf makefile templates, it doesn't create any actual makefiles.
Makefiles get created when configure is run, and that's when you want to override the compiler:
configure CC=clang CXX=clang++
that should create makefiles that use CC=clang and CXX=clang++
Related
I am trying to get intermediate .i .s file by CMake when compiling .cpp file, but cmake default only output .o file. Is there any command to manipulate cmake to keep these intermediate file, thanks a lot!
If you are using gcc, try adding this line.
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -save-temps=obj")
Which flag to use depends on the compiler you are using. Also, you should strongly prefer to inject such compiler-and-scenario-specific flags into the build externally, rather than set()-ing them inside the build.
For g++ or clang++, the following invocation would be appropriate:
$ cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug \
-DCMAKE_CXX_FLAGS="-save-temps=obj"
For MSVC it would be:
> cmake -S . -B build "-DCMAKE_CXX_FLAGS=/FA"
My goal is to add my Qt project to a Jenkins buildserver, for nightly builds. Therefore I want to compile my project from the command line. I copied the buildsteps located in the build configuration:
"/opt/fslc-x11/2.5/sysroots/x86_64-fslcsdk-linux/usr/bin/qt5/qmake" "/home/xxxx/repositories/xxx/xxx.pro" -spec linux-oe-g++ && /usr/bin/make qmake_all
"/usr/bin/make"
I execute these commands in the build directory. The problem lies in the qmake command. The qmake command generates the makefile, but this makefile is different when I generate it in the command line instead of in QtCreator. The binary result after make is ofcourse very different.
It seems that the qmake command from the command line creates a debug makefile instead of a release makefile:
CFLAGS = -pipe -02 -pipe -g -feliminate-unused-debug-types --sysroot=.........
The -02 -pipe -g -feliminate-unused-debug-types part is the only thing added when I run qmake in the command line (checked with diff).
I've tried the following:
Added CONFIG+=release to the qmake command
Added CONFIG-=DEBUG to the qmake command
Furthermore I've verified that the system environment and the terminal emulator is the same.
My question comes down to:
Why does qmake add the (debug) flags when running from the command line?
Does QtCreator add more to the environment that I might have missed?
Let me know if you need more information about the settings or the makefile that is generated.
Ok. So long story short: I've tried compiling for the local Linux distro with the standard qmake and my problem was solved.
It seems that problem lies at the custom qmake of the target (x86_64-fslcsdk-linux). I'm not gonna put more time in this issue, so feel free to add a more satisfying answer. I'll be happy to try it out :).
I am trying to build GNU Coreutils 8.23 using the LLVM 3.4 tool-chain. One very important aspect is that I also need the LLVM bytecode for all the coreutils. Therefore, I need to include -emit-llvm in the CFLAGS. Therefore, I removed the $(CFLAGS) from the LINK variable of the coreutils Makefile. Afterwards, I run the following command:
make CC=/home/user/llvm-3.4.2/build/Release+Asserts/bin/clang
CCLD=/home/user/llvm-3.4.2/build/Release+Asserts/bin/llvm-link
IGNORE_UNUSED_LIBRARIES_CFLAGS= CFLAGS="-emit-llvm -S"
VERBOSE=1 AM_CFLAGS= AM_LDFLAGS=
AR=/home/user/llvm-3.4.2/build/Release+Asserts/bin/llvm-ar
RANLIB=/home/user/llvm-3.4.2/build/Release+Asserts/bin/llvm-ranlib
and I get the following error:
/home/user/llvm-3.4.2/build/Release+Asserts/bin/llvm-link: src/libver.a:1:2: error: expected integer
!<arch>
^
/home/user/llvm-3.4.2/build/Release+Asserts/bin/llvm-link: error loading file 'src/libver.a'
Any ideas of how to get this to work?
Try this.
export CC="/home/user/llvm-3.4.2/build/Release+Asserts/bin/clang"
export CXX="/home/user/llvm-3.4.2/build/Release+Asserts/bin/clang++"
Make sure this is where your compiler toolchain is present.
Then in the the coreutils directory, run ./configure (before this run ./bootstrap if you havent already run it). Running ./configure checks if your clang can compile properly and creates a Makefile with the correct configuration.
Then do a make and make install as instructed.
Lib file '.a' here is not readable by llvm-link.
A possible informal hack to this probably is to find out the Makefile generating this lib, and let
AR = llvm-link, ar option = -o(i.e. change ar rv to llvm-link -o),
and disable ranlib command while compling(you don't need ranlib if using llvm-link).
Then the '.a' file generated is a stitched bc file, and this '.a' file should be accpetable by llvm-link command you are calling
My project is build using CMake and is compiled with DistCC + GCC.
I configure the compiler as follows:
SET(CMAKE_C_COMPILER "distcc variation-of-gcc")
To build the project, I simply run 'cmake' and then 'make -jXX'.
Although distcc really speeds up things, I sometimes want to build without distribution - I want it to build locally on the machine.
I know I can modify DISTCC_HOSTS to include only localhost - but this still has the overhead of distcc networking, although it is faster than the overhead for other machines...
I can also do that by rerunning cmake again and modifying the CMAKE_C_COMPILER using customization flags.
But I am looking for a way to do that by just adding a flag directly to 'make'.
I.e.
# This will use distcc:
make -jXX ...
# This will run locally:
make LOCAL_BUILD=1 -jX ...
Is there a CMake trick I can use?
We use the following to allow make time (rather than cmake time) switching on and off of the -Werror flag.
if(CMAKE_GENERATOR STREQUAL "Unix Makefiles")
# TODO: this approach for the WERROR only works with makefiles not Ninja
set(CMAKE_CXX_COMPILE_OBJECT "<CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> $(WERROR) -o <OBJECT> -c <SOURCE>")
endif()
Then we run
make WERROR=-Werror
to turn on warnings as error.
I expect you could do something similar to have whether to use distcc come from a make variable. Like this:
set(CMAKE_CXX_COMPILE_OBJECT "$(USE_DISTCC) <CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE>")
And then run either
make USE_DISTCC=distcc
or just
make
The simplest thing to do (IMO) is write a little script in your project that invokes the compiler, and change your CMake files to run that script instead of containing the name of the compiler directly:
SET(CMAKE_C_COMPILER "my-gcc-script")
Now you can have that script normally run distcc, but (based on an environment variable or something) also run without distcc. There isn't any need to change anything in your CMake files.
I have c and c++ project, and i would like to check for dead function (function that could not be called), for that i want to build a call graph and see which could not be accessed from the written code.
for that i want to use clang with the flag "-S -emit-llvm" so i could creat a dot file.
im using autoconf to compile the project and the autoconfig dont recognize the file that has been compiled as an executable.
tried using this line :
./configure --enable-debug --prefix=/opt/ibutils CC=clang CXX=clang++ CXXFLAGS="-S -emit-llvm"
and this
./configure --enable-debug --prefix=/opt/ibutils CC=clang CXX=clang++ CXXFLAGS="-S -emit-llvm"
LD="llvm-link"
does anyone know the reason? have a suggestions what could i do?
thanks