I am new to clang as I was using msvc before but I want my project to be cross-platform. When I try to build my project, the linker cant link with glfw for some reason.
I get a couple more errors like this for other functions.
error LNK2019: unresolved external symbol glfwInit referenced in function main
Project Structure:
Build.bat:
#echo off
set headerFiles=-Ilibs/headers -Isrc
set libraryFiles=-Llibs/lib/glfw3
set cppFiles=src/*.cpp
set outPutName=LearningVulkan
call clang++ %cppFiles% %headerFiles% %libraryFiles% -o bin/%outPutName%.exe
After some more digging I found that I have to put the file path with -L and then use -l for the actual library name.
Here's what I mean
#echo off
set headerFiles=-I libs/headers -Isrc
rem add the file path with -L and then add the library with -l
set libraryFiles=-Llibs/libs -lopengl32 -lglfw3
set cppFiles=src/*.cpp
set outPutName=LearningVulkan
call clang++ %cppFiles% -DMD %headerFiles% %libraryFiles% -o bin/%outPutName%.exe
start bin/%outPutName%.exe
Related
I use QtCreator 4.15.2, clang 12.0.1.
I have "generic project" with makefile. File src/test/main.cpp contains import test.StringUtil;. QtCreator complains that module is not found. (Project builds ok, but makefile uses gcc; I'm not familiar with clang.) I tried this:
Generated .pcm file in separate directory:
clang++ -std=c++20 -fmodules --precompile -x c++-module src/test/StringUtil.cpp -o target/clang/test.StringUtil.pcm
Edited myproject.cxxflags in project root so it contains:
-std=c++20 -fmodules -fprebuilt-module-path=/home/me/myproject/target/clang -Wall -Wextra -Wpedantic -fno-rtti
If I specify relative path -fprebuilt-module-path=target/clang then nothing changes; QtCreator still says that module not found. But with absolute path looks like ClangCodeModel gets disabled (crashes?): <No Symbols> in QtCreator's symbols combobox, no syntax errors reporting.
I also tried to compile in additiion to generating .pcm file, with no difference:
clang++ -std=c++20 -fmodules -c -x c++-module src/test/StringUtil.cpp -o target/build/clang/test.StringUtil.o
So: how do I make it work?
When I added support for modules in my own build system I found it easiest to specify each imported module with the flag -fmodule-file="path/to/other.pcm".
In the future I guess that the big build systems will do this aswell. since you need to preprocess the files anyway there is no extra cost. (It could be some extra work if you write your makefiles by hand though)
I don't think that qtcreators code model supports modules as of yet. I have tried but it does not work for me.
I have a sqlite extension file. The source is sqliteext/csv.c. When I build the lib with clang the output file is created at lib/csv.so.
cc -g -fPIC -I /usr/local/include -shared sqliteext/csv.c -o lib/csv.so
When I compile the lib using zig...
zig build-lib -I /usr/local/include -I /usr/include -I /usr/include/x86_64-linux-gnu --c-source sqliteext/csv.c -dynamic --output-dir lib
There are two problems.
zig prefixes the filename with a lib
zig add a version number thing in the suffix
so the output file is lib/libcsv.so.0.0.0
And what's interesting about this is that I need to change the filename in my extension loader (that's ok) but that I also need a symlink to handle the 0.0.0.
I'm still looking at the CLI help but I'm still not seeing the thing I need.
See https://github.com/ziglang/zig/issues/2230 and https://github.com/ziglang/zig/issues/2231
The former was fixed the same day as your post via https://github.com/ziglang/zig/pull/6315
I have been trying to enable the gold linker on FreeBSD to use the link time optimizations. I made gold from the binutils under /usr/ports. After building binutils using make -k install clean i got ld under /usr/bin and in the directory /usr/local/bin i got ld, ld.gold and ld.bfd.
Now while trying to use link time optimization for the simple example programs here http://llvm.org/docs/GoldPlugin.html (a.c and b.c under the heading 'Examples of Link Time Optimization') i entered the four commands as follows:
clang -flto a.c -c -o a.o
ar q a.a a.o
clang b.c -c -o b.o
clang -flto a.a b.o -o main
I got the following error:
usr/bin/ld: unrecogonized option '-plugin'
usr/bin/ld: use the --help option for usage information
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Is there the problem with the linker that ld.gold is not being called. Should I replace the ld with ld.gold? Does the linker looks in the right directiry for the .so plugins?
The LLVMgold.so and libLTO.so shared objects are in the directory /usr/local/llvm-devel/lib/.
I cannot find the directory where clang is installed. I am not sure where to make the bfd-plugins directory and add the symlinks to LLVMgold.so and libLTO.so.
I am using freebsd 10.1 release. How to enable the gold linker for link time optimizations?
also how can I enable it to be the default linker?
You may want to use ld.gold instead of ld. It is installed at /usr/local/bin/ld.gold. If you are using a Makefile, it would work by setting LD variable to ld.gold, either by modifying your Makefile or specifying it on command line. Example in case you are using lang/clang37:
gmake all CC=clang37 LD=ld.gold
EDIT:
It would be even more neat if you add -fuse-ld=gold to your LDFLAGS:
LDFLAGS=-fuse-ld=gold
I'm not sure ld.bfd allows plugins, but I could be wrong.
Your /usr/bin/ld should be a symlink to whatever linker you want. You can change which linker is used by using binutils-config. Check the man-page here: http://www.linuxhowtos.org/manpages/8/binutils-config.htm. I realise this is a Linux link, but it's directed at binutils itself rather than linux-specifically.
It should be something along the lines binutils-config --gold.
On my Gentoo box it is binutils --linker=gold
EDIT: As pointed out, binutils-config doesn't work on BSD it seems. You can still manually update the symlinks though, the downside is that there might be a few of them.
You can find out which ld is used by your compiler by using gcc -print-prog-name=ld or clang -print-prog-name=ld. The file printed should be a symlink you can re-create to point to ld.gold as oposed to ld.bfd.
When I try to build Assimp by running build_ios.sh, it tells me:
CMake Error: your C compiler: "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/llvm-gcc" was not found. Please set CMAKE_C_COMPILER to a valid compiler path or name.
CMake Error: your CXX compiler: "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/llvm-g++" was not found. Please set CMAKE_CXX_COMPILER to a valid compiler path or name.
What I need the path to be is:
/Applications/XCode.app/Contents/Developer/Platforms/...
I've tried changing DEVROOT in build_ios.sh and IPHONE_xxxx_TOOLCHAIN.cmake, because that's what CMAKE_C_COMPILER etc seem to get generated from, but it still gives me the same errors.
Option 1:
You can set CMake variables at command line like this:
cmake -D CMAKE_C_COMPILER="/path/to/your/c/compiler/executable" -D CMAKE_CXX_COMPILER "/path/to/your/cpp/compiler/executable" /path/to/directory/containing/CMakeLists.txt
See this to learn how to create a CMake cache entry.
Option 2:
In your shell script build_ios.sh you can set environment variables CC and CXX to point to your C and C++ compiler executable respectively, example:
export CC=/path/to/your/c/compiler/executable
export CXX=/path/to/your/cpp/compiler/executable
cmake /path/to/directory/containing/CMakeLists.txt
Option 3:
Edit the CMakeLists.txt file of "Assimp": Add these lines at the top (must be added before you use project() or enable_language() command)
set(CMAKE_C_COMPILER "/path/to/your/c/compiler/executable")
set(CMAKE_CXX_COMPILER "/path/to/your/cpp/compiler/executable")
See this to learn how to use set command in CMake. Also this is a useful resource for understanding use of some of the common CMake variables.
Here is the relevant entry from the official FAQ: https://gitlab.kitware.com/cmake/community/wikis/FAQ#how-do-i-use-a-different-compiler
The cc and cxx is located inside /Applications/Xcode.app. This should find the right paths
export CXX=`xcrun -find c++`
export CC=`xcrun -find cc`
SOLUTIONS
Sometimes the project is created before installing g++. So install g++ first and then recreate your project. This worked for me.
Paste the following line in CMakeCache.txt:
CMAKE_CXX_COMPILER:FILEPATH=/usr/bin/c++
Note the path to g++ depends on OS. I have used my fedora path obtained using which g++
I am trying to configure util-linux to cross compile using arm-none-linux-gnueabi from CodeSourcery. My only problem so far is that it can't find my ncurses library which I compiled.
How can I add a directory to the ld search path? I've tried adding to my LIBRARY_PATH and LD_LIBRARY_PATH variables, but neither does anything. I know that I can add the -L flag to gcc and it will add to the linker path, but is there any way to do this globally, so that I can do it once, and not have to worry about it again?
Here is the output of arm-none-linux-gnueabi-gcc -print-search-dirs | grep libraries | sed 's/:/\n/g':
libraries
=/tools/bin/../lib/gcc/arm-none-linux-gnueabi/4.6.1/
/tools/bin/../lib/gcc/
/tools/bin/../lib/gcc/arm-none-linux-gnueabi/4.6.1/../../../../arm-none-linux-gnueabi/lib/arm-none-linux-gnueabi/4.6.1/
/tools/bin/../lib/gcc/arm-none-linux-gnueabi/4.6.1/../../../../arm-none-linux-gnueabi/lib/
/tools/bin/../arm-none-linux-gnueabi/libc/lib/arm-none-linux-gnueabi/4.6.1/
/tools/bin/../arm-none-linux-gnueabi/libc/lib/
/tools/bin/../arm-none-linux-gnueabi/libc/usr/lib/arm-none-linux-gnueabi/4.6.1/
/tools/bin/../arm-none-linux-gnueabi/libc/usr/lib/
I would like to add /arm/usr/lib and /arm/usr/local/lib to my ld search path.
If you need output from any other commands, just ask!
EDIT: I just found out about the CFLAGS environment variable--do all configure scripts/makefiles honor it?
Thank you!
If the ncurses library you compiled are going to be linked to the ARM binary you are cross-compiling you can not use LD_LIBRARY_PATH! LD_LIBRARY_PATH is only used by the current run-time and is in no way used by the compiler or linker when building your application.
The use of CFLAGS depends on creator of Makefile. CFLAGS are not automatically used even if they are defined as an environment variable. Only tools like the autoconf tools can pick them up from the environment and use them automagically. In the Makefiles find something like:
$(CC) $(CFLAGS) ....
if this fragment exists then the Makefile uses the CFLAGS variable. LDFLAGS is the more appropriate environment variable to use for link-time options.