Purpose of --enable-gold when configuring gcc - gcc

When building gcc 5.1 from source, the configure script lists the following option:
--enable-gold[=ARG] build gold [ARG={default,yes,no}]
What does this mean? Is it telling gcc to use gold as the linker if gold is installed on the box ? If so, does it expect gold to be the default linker or should I point to gold via the
--with-ld=<path/to/linker>
option?
I could not find a reference to --enable-gold in the online gcc configure docs.
Thanks!

GCC shares its top-level configure script with some other GNU projects, notably Binutils and GDB.
--enable-gold is an option for Binutils, which says to build the Gold linker as well as the older BFD linker. The option has absolutely no effect when building GCC.

Related

How to configure clang to use arm-none-eabi linker

I am trying to configure the last version of clang (6.0) to use the arm-none-eabi linker instead of the ld.lld but clang is always ignoring everything and keep asking for the ld.lld one. I am trying to build for cortex-m3 (lpx1769 board). How do I force clang to use the linker I want.
-fuse-ld=ld is also not working, so does clang no longer allow the use of any other linker?
So the answer was to use the flag:
-fuse-ld=path/to/linker-to-be-used
Remember that if you passing this flag to clang it will cause a warning that clang will not use this flag (only the linker stage will do). Thus if you compiling with -Werror, the warning will be turned into an error.
Moreover, because you are cross-compiling probably you will need to let the linker know where to find the target-specific libraries needed using the -L option. See this for more info:
https://clang.llvm.org/docs/CrossCompilation.html

GCC Compiler options supported for given version

I have an powerpc cross compiled gcc tool chain of version 3.4.3
I am getting certain error for options which are not supported by this compiler like (unrecognized command line option "-Wno-pointer-sign")
Is there a way i can print all supported compiler option for this gcc version. I dont have source code for this.
You can use gcc --help=warnings to get the full list of supported -Wsomething options. Regarding the rest, there're gcc --help=common, gcc --help=params etc, check gcc --help output

Does llvm/clang still need MinGW gcc after built?

I am new to llvm/clang and have successfully built clang with MinGW.
I have one simple question - is MinGW gcc still needed for clang to work as a c/c++ compiler?
Thanks,
jweiboman
Right now - unfortunately, yes. clang will use gcc to assemble / link the stuff. This is necessary to e.g. provide the proper cmdline for linker invocation adding CRT objects & libraries.
As soon as someone will provide the the complete "toolchain" definition for mingw in clang, this won't be necessary. Only assembler and linker (part of binutils) will be required.

custom built gcc 4.6.0 on ubuntu 11.04 links wrong libstdc++

my custom built gcc 4.6.0, installed in my home directory, on ubuntu 10.04, links the system libstdc++ instead of the custom built one, most of the time (as evidenced by ldd). to be more puzzling, using this newly built gcc, custom compiled openmpi libraries are linked correctly, and this is the only software i have compiled that behaves ok. does anybody have any explanation for this, or a workaround?
thanks
Isn't there an option to statically link the libstdc into the gcc when you configure it? --disable-shared if I understand how it works correctly. Worst case make another compile of gcc with that switch and see if you run into the issue.
I don't know why this isn't detailed more clearly on the GCC website for end-users. The GCC FAQ clearly states this is a common problem wrt libstdc++. Environment variables are troublesome. Wrapping the linker, nobody knows how to do that. Editing /etc/ld.so.conf isn't an option. Adding -Wl,-rpath everywhere, come on. The easiest solution is the specs file. For a typical 64-bit x86 Linux system, go into your custom gcc installation, in dirname `g++ -print-libgcc-file-name`and then run g++ -dumpspecs > specs. Edit that file, find the *link_command: section. After %(link_libgcc) add -rpath /home/user/bin/gcc-9/lib64 (of course use your own path). Or add the same rpath to end of *link: section. Alternatively, configure gcc with --with-specs='%{!static:%x{-rpath=/home/user/bin/gcc9/lib64} %x{-enable-new-dtags}}' . Enjoy your own C++ compiler that generates binaries that just work.
See also:
GCC specs file: how to get the installation path
Linking g++ 4.8 to libstdc++
How to configure libstdc++ with GCC 4.8?

Problem compiling gcc 4.4.0 on OpenSolaris 2009.6

I am attempting to compile gcc 4.4.0 on opensolaris 2009.6
Currently in the box (which is a AMD 64bit machine), I have the gcc 3.4.6 installed.
I unpacked the gcc 4.4.0 tarball.
I set the following env variables:
export CXX=/usr/local/bin/g++
export CC=/usr/local/bin/gcc
Then I ran "configure && make" and this is the error message that I got:
checking for i386-pc-solaris2.11-gcc... /export/home/me/wd/gcc/gcc-4.4.0/host-i386-pc-solaris2.11/gcc/xgcc -B/export/home/me/wd/gcc/gcc-4.4.0/host-i386-pc-solaris2.11/gcc/ -B/usr/local/i386-pc-solaris2.11/bin/ -B/usr/local/i386-pc-solaris2.11/lib/ -isystem /usr/local/i386-pc-solaris2.11/include -isystem /usr/local/i386-pc-solaris2.11/sys-include -m64
checking for suffix of object files... configure: error: in `/export/home/me/wd/gcc/gcc-4.4.0/i386-pc-solaris2.11/amd64/libgcc':
configure: error: cannot compute suffix of object files: cannot compile
See `config.log' for more details.
Anyone has any suggestion as to how to work around this error message?
/Edit:
Content of the config.log is posted here: link text
Normally the GCC build is bootstrapped, i.e. first it uses the system compiler to build GCC C compiler, and then it uses the freshly built compiler to recompile GCC once again (and then even once more time again). The configure line shows that it is not the system compiler but the already-built GCC compiler which is used for configure test there.
Since it fails, the problem is that the freshly-built GCC is somehow "stillborn" here. If config.log will not help you, I'd suggest to ask at gcc-help#gcc.gnu.org.
EDIT: Ah-ha, I think it is the assembler. You are using GNU assembler, but the unsupported options look like they were meant for Sun assembler. This should be solved by adding --with-gnu-as configure option (and then possibly having to specify its path explicitly with --with-as=/usr/gnu/bin/as)
You can also take a look at Solaris-specific GCC build instructions.
There's a readily available build for gcc4, which you can try updating. Its current version is 4.3.3. To get started, install pkg-get from OpenCSW and check out the build from the subversion repository:
svn co https://gar.svn.sourceforge.net/svnroot/gar/csw/mgar/pkg/gcc4/trunk/ gcc4
cd gcc4
gmake package

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