On 4/20/21, Tadeus Prastowo <tadeus.prastowo@xxxxxxxx> wrote: > On Tue, Apr 20, 2021 at 9:29 PM Peng Yu via Gcc-help > <gcc-help@xxxxxxxxxxx> wrote: >> >> Hi, >> >> As I understand gcc is just a front-end of ld. > > Yes. > >> Is there a way let gcc >> print out what ld commands are actually called? > > Use the compiler option: -Wl,-v > >> Is gcc also a frontend to another program for compiling an object from >> a source file? > > Yes. > >> Or it does this work on its own? If it servers as a >> front for compiling as well, how to let gcc print the underlying >> commands as well? > > Use the compiler option: -v I tried with hola.s below. https://cs.lmu.edu/~ray/notes/gasexamples/ It seems that gcc -v -Wl,-v gives quite complex underlying commands. But most of the options are not useful. The minimal commands should be just the following (on Linux). Why are there so many irrelevant command line options passed down to ld? What do crt1.o, crti.o and crtn.o do in details? Thanks. tmpfile=$(mktemp -u) as -o "$tmpfile" hola.s cmd=( ld -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o /usr/lib/x86_64-linux-gnu/crtn.o -lc "$tmpfile" ) "${cmd[@]}" $ gcc -Wl,-v -v -no-pie hola.s Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 10.2.1-6' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-10 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-10-Km9U7s/gcc-10-10.2.1/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-Km9U7s/gcc-10-10.2.1/debian/tmp-gcn/usr,hsa --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-mutex Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.2.1 20210110 (Debian 10.2.1-6) COLLECT_GCC_OPTIONS='-v' '-no-pie' '-mtune=generic' '-march=x86-64' as -v --64 -o /tmp/mktemp/ccETAQ7Y.o hola.s GNU assembler version 2.35.2 (x86_64-linux-gnu) using BFD version (GNU Binutils for Debian) 2.35.2 COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-no-pie' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-linux-gnu/10/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/10/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper -plugin-opt=-fresolution=/tmp/mktemp/ccBVaooZ.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/10/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/10 -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/10/../../.. -v /tmp/mktemp/ccETAQ7Y.o -lgcc --push-state --as-needed -lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/10/crtend.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crtn.o collect2 version 10.2.1 20210110 /usr/bin/ld -plugin /usr/lib/gcc/x86_64-linux-gnu/10/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper -plugin-opt=-fresolution=/tmp/mktemp/ccBVaooZ.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/10/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/10 -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/10/../../.. -v /tmp/mktemp/ccETAQ7Y.o -lgcc --push-state --as-needed -lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/10/crtend.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crtn.o GNU ld (GNU Binutils for Debian) 2.35.2 COLLECT_GCC_OPTIONS='-v' '-no-pie' '-mtune=generic' '-march=x86-64' -- Regards, Peng
