[cfe-users] clang on cygwin fails to produce executable from c++ source

Gerst P├ęter via cfe-users cfe-users at lists.llvm.org
Thu Apr 4 01:01:07 PDT 2019


Hi,

I'm trying to use clang on cygwin to compile C++ files but the executable
it produces fails to run. I get runtime failures from cygwin:

    Cygwin runtime failure: a.exe: Invalid relocation.  Offset 0x2fd4bce73
at address 0x1004010e9 doesn't fit into 32 bits

sample code - proba.cpp:

    #include <iostream>
    using namespace std;

    int main(void)
    {
        cout << "Hello, World!";
        return 0;
    }

compiled with:

    clang++ proba.cpp

Compilation finishes without any error or warning.

clang was compiled from sources. I tried the latest release (8.0.0) as well
as git version (26.03.2019). Both produces the same error when running its
output.

clang installation procedure was the following:

    git clone https://github.com/llvm/llvm-project.git
    mkdir build
    cd build
    cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
-DLLVM_ENABLE_PROJECTS="clang;compiler-rt;lld;" -DLLVM_TARGETS_TO_BUILD=X86
../llvm/
    make -j4
    make install

cygwin also has a clang package (version 5.0.1) that compiles proba.cpp to
a working executable. The reason of not using that is it does not compile
SystemC libraries (https://www.accellera.org/downloads/standards/systemc)
correctly. There are few tests that fail during 'make check' in contrast
when compiling with gcc (7.4.0) all the tests pass.

I also noticed that clang drivers that compiled from sources use g++ as the
linker while the one comes with the cygwin package uses ld. I also did not
manage to force clang 9 to use lld instead of g++. (-fuse-ld=lld is not
recognized by g++)

clang comes with cygwin:

    $ clang++ -v proba.cpp -o a_clang5.exe
    clang version 5.0.1 (tags/RELEASE_501/final)
    Target: x86_64-unknown-windows-cygnus
    Thread model: posix
    InstalledDir: /usr/bin
     "/usr/bin/clang-5.0" -cc1 -triple x86_64-unknown-windows-cygnus
-emit-obj -mrelax-all -disable-free -disable-llvm-verifier
-discard-value-names -main-file-name proba.cpp -mre
    location-model pic -pic-level 2 -mthread-model posix -fmath-errno
-masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64
-momit-leaf-frame-pointer -v -dwarf-co
    lumn-info -debugger-tuning=gdb -resource-dir /usr/lib/clang/5.0.1
-internal-isystem /usr/x86_64-pc-cygwin/include/c++ -internal-isystem
/usr/x86_64-pc-cygwin/include/c++/x86_6
    4-pc-cygwin -internal-isystem
/usr/x86_64-pc-cygwin/include/c++/backward -internal-isystem
/usr/x86_64-pc-cygwin/include/c++/7.4.0 -internal-isystem
/usr/x86_64-pc-cygwin/incl
    ude/c++/7.4.0/x86_64-pc-cygwin -internal-isystem
/usr/x86_64-pc-cygwin/include/c++/7.4.0/backward -internal-isystem
/usr/include/c++/7.4.0 -internal-isystem /usr/include/c++/7
    .4.0/x86_64-pc-cygwin -internal-isystem /usr/include/c++/7.4.0/backward
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++
-internal-isystem /usr/lib/gcc/x86_64
    -pc-cygwin/7.4.0/include/c++/x86_64-pc-cygwin -internal-isystem
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++/backward -internal-isystem
/usr/local/include -internal-isystem
     /usr/lib/clang/5.0.1/include -internal-isystem
/usr/x86_64-pc-cygwin/include -internal-isystem /usr/include
-internal-isystem /usr/include/w32api -fdeprecated-macro -fdebug-c
    ompilation-dir /cygdrive/c/home/peter.gerst/tmp/clang_proba
-ferror-limit 19 -fmessage-length 175 -femulated-tls -fobjc-runtime=gcc
-fcxx-exceptions -fexceptions -fdiagnostics
    -show-option -fcolor-diagnostics -o /tmp/proba-e855cb.o -x c++ proba.cpp
    clang -cc1 version 5.0.1 based upon LLVM 5.0.1 default target
x86_64-unknown-windows-cygnus
    ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++"
    ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/x86_64-pc-cygwin"
    ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/backward"
    ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/7.4.0"
    ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/7.4.0/x86_64-pc-cygwin"
    ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/7.4.0/backward"
    ignoring nonexistent directory "/usr/include/c++/7.4.0"
    ignoring nonexistent directory "/usr/include/c++/7.4.0/x86_64-pc-cygwin"
    ignoring nonexistent directory "/usr/include/c++/7.4.0/backward"
    ignoring nonexistent directory "/usr/local/include"
    ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include"
    #include "..." search starts here:
    #include <...> search starts here:
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++/x86_64-pc-cygwin
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++/backward
     /usr/lib/clang/5.0.1/include
     /usr/include
     /usr/include/w32api
    End of search list.
     "/usr/bin/ld" -m i386pep --wrap _Znwm --wrap _Znam --wrap
_ZnwmRKSt9nothrow_t --wrap _ZnamRKSt9nothrow_t --wrap _ZdlPv --wrap _ZdaPv
--wrap _ZdlPvRKSt9nothrow_t --wrap _ZdaPv
    KSt9nothrow_t -Bdynamic --tsaware -o a_clang5.exe /usr/lib/crt0.o
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/crtbegin.o
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0 -L/usr/x86_64-pc-cygwin/
    lib -L/usr/lib /tmp/proba-e855cb.o -lstdc++ -liconv -lgcc_s -lgcc
-lcygwin -ladvapi32 -lshell32 -luser32 -lkernel32 -lgcc_s -lgcc -lcygwin
/usr/lib/default-manifest.o /usr/lib
    /gcc/x86_64-pc-cygwin/7.4.0/crtend.o

clang 9 compiled from sources:

    $ clang++ -v proba.cpp -o a.exe
    clang version 9.0.0 (https://github.com/llvm/llvm-project.git
e24441aab03e393d591d9252612e8c0ac557b1c3)
    Target: x86_64-unknown-windows-cygnus
    Thread model: posix
    InstalledDir: /usr/local/bin
     "/usr/local/bin/clang-9" -cc1 -triple x86_64-unknown-windows-cygnus
-emit-obj -mrelax-all -disable-free -disable-llvm-verifier
-discard-value-names -main-file-name proba.cpp -mrelocation-model pic
-pic-level 2 -mthread-model posix -fmath-errno -masm-verbose
-mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info
-debugger-tuning=gdb -momit-leaf-frame-pointer -v -resource-dir
/usr/local/lib/clang/9.0.0 -fdeprecated-macro -fdebug-compilation-dir
/cygdrive/c/home/peter.gerst/tmp/clang_proba -ferror-limit 19
-fmessage-length 135 -fno-use-cxa-atexit -fobjc-runtime=gcc
-fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics
-o /tmp/proba-b6bf15.o -x c++ proba.cpp -faddrsig
    clang -cc1 version 9.0.0 based upon LLVM 9.0.0svn default target
x86_64-unknown-cygwin
    #include "..." search starts here:
    #include <...> search starts here:
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++/x86_64-pc-cygwin
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/include/c++/backward
     /usr/local/include
     /usr/local/lib/clang/9.0.0/include
     /usr/include/w32api
     /usr/include
    End of search list.
     "/usr/bin/g++" -v -m64 -o a.exe /tmp/proba-b6bf15.o
    Using built-in specs.
    COLLECT_GCC=/usr/bin/g++
    COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/lto-wrapper.exe
    Target: x86_64-pc-cygwin
    Configured with:
/cygdrive/i/szsz/tmpp/gcc/gcc-7.4.0-1.x86_64/src/gcc-7.4.0/configure
--srcdir=/cygdrive/i/szsz/tmpp/gcc/gcc-7.4.0-1.x86_64/src/gcc-7.4.0
--prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc
--docdir=/usr/share/doc/gcc --htmldir=/usr/share/doc/gcc/html -C
--build=x86_64-pc-cygwin --host=x86_64-pc-cygwin --target=x86_64-pc-cygwin
--without-libiconv-prefix --without-libintl-prefix --libexecdir=/usr/lib
--enable-shared --enable-shared-libgcc --enable-static
--enable-version-specific-runtime-libs --enable-bootstrap
--enable-__cxa_atexit --with-dwarf2 --with-tune=generic
--enable-languages=ada,c,c++,fortran,lto,objc,obj-c++ --enable-graphite
--enable-threads=posix --enable-libatomic --enable-libcilkrts
--enable-libgomp --enable-libitm --enable-libquadmath
--enable-libquadmath-support --disable-libssp --enable-libada
--disable-symvers --with-gnu-ld --with-gnu-as
--with-cloog-include=/usr/include/cloog-isl --without-libiconv-prefix
--without-libintl-prefix --with-system-zlib --enable-linker-build-id
--with-default-libstdcxx-abi=gcc4-compatible
--enable-libstdcxx-filesystem-ts
    Thread model: posix
    gcc version 7.4.0 (GCC)

COMPILER_PATH=/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/:/usr/lib/gcc/x86_64-pc-cygwin/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/:/usr/lib/gcc/x86_64-pc-cygwin/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../x86_64-pc-cygwin/bin/

LIBRARY_PATH=/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../x86_64-pc-cygwin/lib/../lib/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../x86_64-pc-cygwin/lib/:/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../:/lib/:/usr/lib/
    COLLECT_GCC_OPTIONS='-v' '-m64' '-o' 'a.exe' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
     /usr/lib/gcc/x86_64-pc-cygwin/7.4.0/collect2.exe -plugin
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/cyglto_plugin.dll
-plugin-opt=/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/lto-wrapper.exe
-plugin-opt=-fresolution=/tmp/ccM89KcB.res
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lcygwin -plugin-opt=-pass-through=-ladvapi32
-plugin-opt=-pass-through=-lshell32 -plugin-opt=-pass-through=-luser32
-plugin-opt=-pass-through=-lkernel32 -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc --build-id -m i386pep --wrap _Znwm --wrap
_Znam --wrap _ZdlPv --wrap _ZdaPv --wrap _ZnwmRKSt9nothrow_t --wrap
_ZnamRKSt9nothrow_t --wrap _ZdlPvRKSt9nothrow_t --wrap _ZdaPvRKSt9nothrow_t
-Bdynamic --dll-search-prefix=cyg --tsaware -o a.exe
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../lib/crt0.o
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/crtbegin.o
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../x86_64-pc-cygwin/lib/../lib
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../lib -L/lib/../lib
-L/usr/lib/../lib
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../x86_64-pc-cygwin/lib
-L/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../.. /tmp/proba-b6bf15.o -lstdc++
-lgcc_s -lgcc -lcygwin -ladvapi32 -lshell32 -luser32 -lkernel32 -lgcc_s
-lgcc
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/../../../../lib/default-manifest.o
/usr/lib/gcc/x86_64-pc-cygwin/7.4.0/crtend.o
    COLLECT_GCC_OPTIONS='-v' '-m64' '-o' 'a.exe' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'

Compiling and executing the C equivalent of proba.cpp works fine with clang
9. I tried the tests suggested by the documentation (
https://clang.llvm.org/get_started.html):

    clang --help
    clang file.c -fsyntax-only
    clang file.c -S -emit-llvm -o -
    clang file.c -S -emit-llvm -o - -O3
    clang file.c -S -O3 -o -

They seemed to work correctly to me.

I also tried the following without success

    clang++ -c proba.cpp -o proba.o
    ld.lld proba.o -o proba.exe
    ld.lld: error: proba.o: unknown file type

Does anybody have any idea what could go wrong with the C++ compilation
using clang 9 on cygwin?

Did anybody manage to use lld linker along with clang under cygwin?

Any hint on how can clang + lld toolchain setup correctly under cygwin will
be also appreciated. Thank you!

Note:
This issue is also reported on superuser:
https://superuser.com/questions/1421240/clang-on-cygwin-fails-to-produce-executable-from-c-source
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