Use headers and libraries from different folders - macos

I have two GTK builds on my Mac, an X11 one with headers and a Quartz one without. I can compile Vala code for X11 just fine, but how do I use the Quartz libraries?
This is probably a C question, but I only ever used that toolchain through valac.

When using valac, it gets the appropriate compile and link flags from pkg-config based on the --pkg flags. You can see what is being included with pkg-config --cflags --libs gtk+-2.0. If you wish to change this you have two opions:
Use valac -C to only produce C files and manage the compilation and linking yourself.
Set export PKG_CONFIG_PATH=/usr/lib/pkgconfig:/sw/lib/pkgconfig or whatever collection of directories to get your packages coming in the desired order.
I'm not quite sure where your GTK+ installs are located, presumably in a MacPorts tree.

Related

Modify default library search dirs that gcc passes to ld

I want to force new GCC 12 on my old debian (that only has GCC 6 by default) to use fresh libstdc++ headers with new header-only features, but link with old stdlibc++,gcc_s (and other system/compiler libs used by GCC6) to keep binary compatibility with native runtime of old debian (so that users of old GCC6 can link with my binaries without having GCC12).
Of course I know that some functionality in the old runtime will be missing, and ABI is also different, but I guess I can fight with that. Afterall RedHat seems to be using similar scheme for their devtoolset packages (they try to link missing functionality of new runtime statically to your binary if these symbols are not found in native old runtime)
So far I am stuck with -L arguments that GCC is passing to ld.
Here is complete output of /usr/local/gcc12/bin/x86_64-linux-gnu-gcc-12 main.cpp -Wl,-v -v command for simple hello-world main.cpp:
https://pastebin.com/JhYSfg4x
The question: Where does GCC take all these -L paths from, and how do I remove/modify them? I don't want to accidentally link with new version of libraries that were built with GCC12:
-L/usr/lib/gcc/x86_64-linux-gnu -L/usr/local/gcc12/lib/gcc/x86_64-linux-gnu/12 -L/usr/local/gcc12/lib/gcc/x86_64-linux-gnu/12/../../../../lib64 -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc -L/usr/local/gcc12/lib/gcc/x86_64-linux-gnu/12/../../.. /tmp/ccXfhCs4.o
System ld.conf does not mention any paths to /usr/local/gcc12 folder.
-nostdlib and -nodefaultlibs are removing some standard -l flags, but they are not doing anything to -L flags.
Update: I ended up just removing all *.a, .so, *.la files from include, lib and lib64 folders of gcc12, and I also added -L path to native libraries. This way I am sure gcc12 can't pickup one of its libraries for li nking. Not sure if this is good solution, but it works.

GCC built from source in different location is incorrectly using same shared libs as native GCC

I'm a student doing research involving extending the TM capabilities of gcc. My goal is to make changes to gcc source, build gcc from the modified source, and, use the new executable the same way I'd use my distro's vanilla gcc.
I built and installed gcc in a different location (not /usr/bin/gcc), specifically because the modified gcc will be unstable, and because our project goal is to compare transactional programs compiled with the two different versions.
Our changes to gcc source impact both /gcc and /libitm. This means we are making a change to libitm.so, one of the shared libraries that get built.
My expectation:
when compiling myprogram.cpp with /usr/bin/g++, the version of libitm.so that will get linked should be the one that came with my distro;
when compiling it with ~/project/install-dir/bin/g++, the version of libitm.so that will get linked should be the one that just got built when I built my modified gcc.
But in reality it seems both native gcc and mine are using the same libitm, /usr/lib/x86_64-linux-gnu/libitm.so.1.
I only have a rough grasp of gcc internals as they apply to our project, but this is my understanding:
Our changes tell one compiler pass to conditionally insert our own "function builtin" instead of one it would normally use, and this is / becomes a "symbol" which needs to link to libitm.
When I use the new gcc to compile my program, that pass detects those conditions and successfully inserts the symbol, but then at runtime my program gives a "relocation error" indicating the symbol is not defined in the file it is searching in: ./test: relocation error: ./test: symbol _ITM_S1RU4, version LIBITM_1.0 not defined in file libitm.so.1 with link time reference
readelf shows me that /usr/lib/x86_64-linux-gnu/libitm.so.1 does not contain our new symbols while ~/project/install-dir/lib64/libitm.so.1 does; if I re-run my program after simply copying the latter libitm over the former (backing it up first, of course), it does not produce the relocation error anymore. But naturally this is not a permanent solution.
So I want the gcc I built to use the shared libs that were built along with it when linking. And I don't want to have to tell it where they are every time - my feeling is that it should know where to look for them since I deliberately built it somewhere else to behave differently.
This sounds like the kind of problem any amateur gcc developer would have when trying to make a dev environment and still be able to use both versions of gcc, but I had difficulty finding similar questions. I am thinking this is a matter of lacking certain config options when I configure gcc before building it. What is the right configuration to do this?
My small understanding of the instructions for building and installing gcc led me to do the following:
cd ~/project/
mkdir objdir
cd objdir
../source-dir/configure --enable-languages=c,c++ --prefix=/home/myusername/project/install-dir
make -j2
make install
I only have those config options because they seemed like the ones closest related to "only building the parts I need" and "not overwriting native gcc", but I could be wrong. After the initial config step I just re-run make -j2 and make install every time I change the code. All these steps do complete without errors, and they produce the ~/project/install-dir/bin/ folder, containing the gcc and g++ which behave as described.
I use ~/project/install-dir/bin/g++ -fgnu-tm -o myprogram myprogram.cpp to compile a transactional program, possibly with other options for programs with threads.
(I am using Xubuntu 16.04.3 (64 bit), within VirtualBox on Windows. The installed /usr/bin/gcc is version 5.4.0. Our source at ~/project/source-dir/ is a modified version of 5.3.0.)
You’re running into build- versus run-time linking differences. When you build with -fgnu-tm, the compiler knows where the library it needs is found, and it tells the linker where to find it; you can see this by adding -v to your g++ command. However when you run the resulting program, the dynamic linker doesn’t know it should look somewhere special for the ITM library, so it uses the default library in /usr/lib/x86_64-linux-gnu.
Things get even more confusing with ITM on Ubuntu because the library is installed system-wide, but the link script is installed in a GCC-private directory. This doesn’t happen with the default GCC build, so your own GCC build doesn’t do this, and you’ll see libitm.so in ~/project/install-dir/lib64.
To fix this at run-time, you need to tell the dynamic linker where to find the right library. You can do this either by setting LD_LIBRARY_PATH (to /home/.../project/install-dir/lib64), or by storing the path in the binary using -Wl,-rpath=/home/.../project/install-dir/lib64 when you build it.

Building cmake with non-default GCC uses system libstdc++

I'm trying to compile CMake using a non-default GCC installed in /usr/local/gcc530, on Solaris 2.11.
I have LD_LIBRARY_PATH=/usr/local/gcc530/lib/sparcv9
Bootstrap proceeds fine, bootstrapped cmake successfully compiles various object files, but when it tries to link the real cmake (and other executables), I get pages of "undefined reference" errors to various standard library functions, because, as running the link command manually with -Wl,-verbose shows, the linker links with /usr/lib/64/libstdc++.so of the system default, much older GCC.
This is because apparently CMake tries to find curses/ncurses libraries (even if I tell it BUILD_CursesDialog:BOOL=OFF), finds them in /usr/lib/64, and adds -L/usr/lib/64 to build/Source/CMakeFiles/cmake.dir/link.txt, which causes the linker to use libstdc++.so from there, and not my actual GCC's own.
I found a workaround: I can get the path to proper libraries from $CC -m64 -print-file-name=libstdc++.so then put it with -L into LDFLAGS when running ./configure, and all works well then.
Is there a less hacky way? It's really weird that I can't tell GCC to prioritize its own libraries.
Also, is there some way to have CMake explain where different parts of a resulting command line came from?

Force CMake to use static libraries

[Shamelessly cross-posted from the CMake help list]
I'm trying to create binaries as statically as possible. The fortran code I've got has got X11 and quadmath as dependencies, and I've come across a number of issues (maybe each of these issues should be in a different question?):
My variables are currently
set(CMAKE_LIBRARY_PATH /usr/X11/lib /usr/X11/include/X11 ${CMAKE_LIBRARY_PATH})
find_package(X11 REQUIRED)
find_library(X11 NAMES X11.a PATHS /usr/X11/include/X11/ /usr/X11/lib)
find_library(X11_Xaw_LIB NAMES Xaw Xaw /usr/X11/include/X11/ /usr/X11/lib ${X11_LIB_SEARCH_PATH})
find_library(Xaw Xaw7 PATHS ${X11_LIB_SEARCH_PATH})
set(CMAKE_LIBRARY_PATH /usr/lib/gcc/x86_64-linux-gnu/4.7 /usr/lib/gcc/x86_64-linux-gnu/4.7/x32 /usr/lib/gcc/x86_64-linux-gnu/4.7/32 ${CMAKE_LIBRARY_PATH})
find_library(quadmath NAMES quadmath.a)
set(BUILD_SHARED_LIBS ON)
set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
set(LINK_SEARCH_START_STATIC TRUE)
set(LINK_SEARCH_END_STATIC TRUE)
set(SHARED_LIBS OFF)
set(STATIC_LIBS ON)
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
Using these, CMake attempts to build every program statically (as expected) - however, it fails because I don't have Xaw.a - I can't find out whether this actually should exist. I have installed the latest libxaw7-dev which I was expecting to fix it. One option would be to compile the X11 libraries myself, but I don't really want to do that...
if I comment out only set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static"), then CMake compiles everything, but uses shared libraries for every program, even though I specify the location of .a X11 libraries in my find_library() calls. I was expecting CMake to use the .a files where it could and then only use shared libraries - is there a way to force this behaviour?
does anyone know yet of a fix for the bug described here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46539; whereby gfortran seemingly can't statically link libquadmath? I tried the fix using gcc but I can't get CMake to recognise the libgfortran flag:
cmake -DCMAKE_Fortran_COMPILER=gcc -DCMAKE_Fortran_FLAGS=-gfortran
results in
-- The Fortran compiler identification is unknown
-- Check for working Fortran compiler: /usr/bin/gcc
-- Check for working Fortran compiler: /usr/bin/gcc -- broken
CMake Error at /usr/share/cmake-2.8/Modules/CMakeTestFortranCompiler.cmake:54 (message):
The Fortran compiler "/usr/bin/gcc" is not able to compile a simple test program.
However, as you might have noticed, I set the location of the libquadmath.a; when I build a program which doesn't use X11 but does use quadmath when I use
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
then the program does compile successfully (running ldd reports 'not a dynamic executable') - does this mean that the bug has been fixed, or does it only work because I set the location in CMake?
I was having a similar problem. Turns out that cmake was implicitly linking against libgfortran and libquadmath. To fix this I put the following in my top level CMakeLists.txt:
unset(CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES)
I could then explicitly link again the libraries using:
SET_TARGET_PROPERTIES(main_f PROPERTIES LINKER_LANGUAGE "C"
LINK_FLAGS
"/usr/local/Cellar/gcc/7.1.0/lib/gcc/7/libgfortran.a
/usr/local/Cellar/gcc/7.1.0/lib/gcc/7/libquadmath.a -lm -lgcc"
)
The static version of libgfortran is necessary because the shared library also depends on libquadmath. The added "-lm" and "-lgcc" bring in the system dynamic versions of these libraries. On a mac system, you would want to use the full path to your libm.a as well.
I guess your questions are not that much related, I don't know the answer for all of them.
For your static linking problems, since you're using GCC, you can pass multiple -static and -dynamic flags to it:
set(CMAKE_EXE_LINKER_FLAGS "-static ${STATIC_LIBS} -dynamic ${EVERYTHING ELSE} -static ${MORE_STATIC_LIBS}")
I don't know why Xaw.a isn't available on your system, probably because the package maintainer of your Linux distribution didn't really make them available.
Also, compiling everything static might make things not compatible between all distros out there and you cripple the ability for others to use improved, up-to-date libraries with your program, it might not be what you want.
If you intend to make a self-contained package of your program, it might be better just to include the shared libraries you used together, like Dropbox and many other proprietary applications do (Humble Bundle games are other example).

using agg (antigrain) library and getting gsl shell working

My main aim is to get the GSL Shell working on my OSX 10.7 system. So far I have the correct version of lua with the correct patches running. I also have a working version of GSL which compiles and runs example programs. I can build agg perfectly and also run their example programs by running make in the macosx_sdl folder.
My first question is how on earth do I create my own project with agg? I know that you are supposed to simply add the files to your project file and go, but this does not seem to want to compile for me. Is it simply a case of adding the include directory and the libagg.a?
Finally, how do I build gsl shell? Currently it complains about the agg-plot folder a lot, so where do I put the agg files to make this build, then when i've done it where do I place the agg files so that the lua scripts can get to them?!
Hope someone can help!
In general to use the AGG library you need to make sure that the compiler is able to find the headers files and, during the linking, the libraries, either in form of a static or dynamic libraries.
To make the headers files and the libraries available you need to take into account the system that is used to build the software. If a traditional makefile sistem is used you need to add some flags to make sure that the headers file can be found. This can be achieved by adding into the makefile something like:
CFLAGS += -I/path/to/agg/headers
and for the linker:
LIBS += -L/path/to/agg/library -lagg -lm
In the specific case of GSL Shell 1.1 the file "make-packages" is used in the Makefile to configure the required packages. You can add here the flags required to locate the AGG library:
AGG_INCLUDES = -I/usr/include/agg2
AGG_LIBS = -lagg -lX11 -lpthread -lsupc++
you should just modify the path provided with the "-I" option and, in AGG_LIBS, add an option "-L/path/to/agg/library" to specify the path where the AGG libraries are located.
Please note also that the agg libraries depends on other libraries. For example on linux it needs at least the X11 library. The libraries supc++ may be needed if the linking is made by invoking gcc instead of g++ because if gcc is used the C++ runtime libraries are not included.

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