I want to have code covergage in my application, so in premake.lua I added the following:
if options["coverage"] then
tinsert(package.buildoptions, {"-fprofile-arcs", "-ftest-coverage"})
tinsert(package.links, "gcov")
end
then I ran the following command:
premake --coverage --target gnu ; make
That did not work until I added the following :
if options["coverage"] then
tinsert(package.buildoptions, {"-fprofile-arcs", "-ftest-coverage"})
tinsert(package.linkoptions, {"-fprofile-arcs"})
tinsert(package.links, "gcov")
end
Which was a solution posed on the Internet. My problem is that I found 0 documentation on this -fprofile-arcs linker flag... What does it do? and where is it documented?
This option is not given to the linker. It is interpreted by the compiler driver(gcc, g++).
When compiling, this option is just passed to the compiler (cc1, cc1plus).
When linking, the effect of the options is that the compiler driver just includes the -lgcov on the linker command line.
Related
I am trying to add my llvm pass into Rustc. Rustc has one compiling option -C passes=val where we could add extra LLVM passes to run. However, as my try, this option can only accept the pass when the pass code is placed inside the LLVM code tree, but I want to add my pass out-of-tree into Rustc.
When I add my pass via this option:
RUSTFLAGS="-C passes=my-pass" cargo build
Compiler reports errors:
error: failed to run LLVM passes: unknown pass name 'my-pass'
Then I try to load my pass via -C llvm-args=-fpass-plugin=/opt/new-pass/mypass.so -C passes=my-pass in the clang way. It reports: rustc -Cllvm-args="..." with: Unknown command line argument '-fpass-plugin=/opt/new-pass/mypass.so'. Also tried to replace -fpass-plugin with other options like -load and -load-pass-plugin, but they still cannot be recognized by rustc.
How could I add my custom pass into Rustc?
I was trying to find a solution to this exact problem too. According to a rust developer on their Zulip Chat, it looks like you need to build a custom rustc with plugin support.
I'm trying to cross compile a rust project with cross. My project depends on libcurl. The linker can find the libcurl .so but not the libraries which it depends on:
I'm running:
cross build -vv --target=arm-unknown-linux-gnueabihf
which gives me:
= note: /usr/arm-linux-gnueabihf/bin/../lib/gcc/arm-linux-gnueabihf/8.3.0/../../../../arm-linux-gnueabihf/bin/ld: warning: libnghttp2.so.14, needed by /usr/lib/arm-linux-gnueabihf/libcurl.so, not found (try using -rpath or -rpath-link)
I've already confirmed that the library its looking for exists:
root#80a13d68ad84:/# find /usr/lib -name "libnghttp2.so.14"
/usr/lib/x86_64-linux-gnu/libnghttp2.so.14
/usr/lib/arm-linux-gnueabihf/libnghttp2.so.14
I've read about rust build scripts here, where I can add paths to the library search path, but that has not resolved the issue, this is what my build.rs looks like:
fn main() {
println!("cargo:rustc-link-search=native=/usr/lib/arm-linux-gnueabihf");
}
The error suggests using -rpath or -rpath-link, so how do I configure the rpath in rust? Or is there a different way to resolve this issue?
You might be able to specify linker arguments by using an environment variable like
RUSTFLAGS="-C link-arg=--rpath=..."
Cargo allows placing the same kind of flag in the configuration file (see here) but I'm not sure if cross has the same support for something like that.
while I am building glibc library using yocto project it is giving
error: missing attribute ((constructor)) support??
after adding the coverage flags:
TARGET_CFLAGS += "-fprofile-arcs -ftest-coverage"
TARGET_LDFLAGS += "-lgcov -fprofile-arcs -ftest-coverage"
still, I am getting an error for glibc.
Please find the link of config log file : https://drive.google.com/file/d/14tiQJ8JIFE_tDWt3H9tS8zBBQROcZDNa/view
It is not working even after adding the following line in conf/local.conf :
EXTRA_OECONF = "libc_cv_ctors_header=yes"
Even i tried this
EXTRA_OECONF_append = "libc_cv_ctors_header=yes"
please find the config log file generated during compilation : https://drive.google.com/open?id=1kxTu8pt7h_9ty55OywP9Ilmmp04T61Rr
So, How to resolve this error?
Log file error Point
poky-linux/gcc/i586-poky-linux/8.2.0/ld: /tmp/ccxetEc1.o: in function `_GLOBAL__sub_D_00100_1__start':
conftest.c:(.text.exit+0x40): undefined reference to `__gcov_exit'<br>
collect2: error: ld returned 1 exit status<br>
configure:5682: $? = 1<br>
configure:5702: error: missing __attribute__ ((constructor)) support??
You are trying to build glibc with -fprofile-arcs -ftest-coverage in CFLAGS. That will not work. The errors you see are a result of these incorrect compiler flags.
A profiling glibc requires fairly substantial changes throughout the library and needs to be created by building with --enable-profile (which is not the default).
I had this error while I tried to enable coverage on a C project using a C++ test harness (CppUTest). Build system was handled by CMake.
Compilers and gcov were aligned on the same version (gcc --version, g++ --version and gcov --version gave the same version) but it seems that my build system was generated with a gcc 5 (resulting to an additional included directory by the linker: usr/lib/gcc/x86_64-linux-gnu/5). I clean the build tree and generated it again thanks to CMake which fixed the error.
While building a DLL under Windows I get the following output:
Linking main.exe ...
Warning: resolving _findPeaksWrapper by linking to _findPeaksWrapper#16
Use --enable-stdcall-fixup to disable these warnings
Creating library file: HSdll.dll.a
Use --disable-stdcall-fixup to disable these fixups
It’s not clear to me where I should be placing the --enable-stdcall-fixup flag. Putting it into the ghc-options field of my .cabal file gives a GHC error, while putting it into cc-options or ld-options seems not to do anything (the warnings are still displayed). Where should this flag go?
Googling indicates that --enable-stdcall-fixup is an option to ld. There are a few different pathways by which cabal's final link step can happen, but in your case it is apparently
Cabal -> ghc (link step) -> gcc -> ld
so to match this you must specify
ghc-options: -optl-Wl,--enable-stdcall-fixup
I am porting an application from Solaris to Linux
The object files which are linked do not have a main() defined. But compilation and linking is done properly in Solaris and executable is generated. In Linux I get this error
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../lib64/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
My problem is, I cannot include new .c/.o files since its a huge application and has been running for years. How can I get rid of this error?
Code extractes of makefile:
RPCAPPN = api
LINK = cc
$(RPCAPPN)_server: $(RPCAPIOBJ)
$(LINK) -g $(RPCAPIOBJ) -o $(RPCAPPN)_server $(IDALIBS) $(LIBS) $(ORALIBS) $(COMMONLIB) $(LIBAPI) $(CCLIB) $(THREADLIB) $(DBSERVERLIB) $(ENCLIB)
Try adding -nostartfiles to your linker options, i.e.
$(LINK) -nostartfiles -g ...
From the gcc documentation:
-nostartfiles
Do not use the standard system startup files when linking. The standard system libraries are used normally, unless -nostdlib or -nodefaultlibs is used.
This causes crt1.o not to be linked (it's normally linked by default) - normally only used when you implement your own _start code.
-shared link option must be used when you compile a .so
The issue for me was, I by mistake put int main() in a namespace. Make sure don't do that otherwise you will get this annoying link error.
Hope this helps anyone :)
I had similar result when trying to build a new test project with boost, and it turned out that I was missing one declaration :
#define BOOST_TEST_MODULE <yourtestName>
I had this same problem when creating my c project, and I forgot to save my main.c file, so there was no main function.
I had a similar result when compiling a Fortran program that had C++ components linked in. In my case, CMake failed to detect that Fortran should be used for the final linking. The messages returned by make then ended with
[100%] Linking CXX executable myprogram
/lib/../lib64/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
make[3]: *** [myprogram] Error 1
make[2]: *** [CMakeFiles/myprogram.dir/all] Error 2
make[1]: *** [CMakeFiles/myprogram.dir/rule] Error 2
make: *** [myprogram] Error 2
The solution was to add
set_target_properties(myprogram PROPERTIES LINKER_LANGUAGE Fortran)
to the CMakeLists.txt, so that make prints out:
[100%] Linking Fortran executable myprogram
[100%] Built target myprogram
I had the same issue with a large CMake project, after I moved some functions from one code file to another. I deleted the build folder, recreated it and rebuilt. Then it worked.
Generally, with suddenly appearing linker errors, try completely deleting your build folder and rebuilding first. That can save you the headaches from trying to hunt down an error that actually simply shouldn't be there: There might be CMake cache variables floating around that have the wrong values, or something was renamed and not deleted, ...
I had the same issue as to OP but on on FreeBSD 13.1.
What solved the issue was simply adding:
int main()
{
}
Since the .cpp file was only an object file containing definitions and declarations using:
extern "C"
{
<all definitions and declarations code goes here>
}
Every time I tried compiling this, the compiler kept throwing the same error as to OP.
So all I did was add an empty main() function all the way at the bottom and code compiled with no errors.