On Fri, 17 Dec 2021 11:27:43 GMT, Gilles Duboscq <g...@openjdk.org> wrote:
> When running `configure`, using `--with-devkit=` to point to a typical linux > devkit along with `--with-toolchain-path=` and `--with-toolchain-type=clang` > to point to a clang-based toolchain results in: > > configure:75064: checking whether the C compiler works > configure:75086: /dl/tools/clang -m64 -isysroot > /dl/x86_64-linux-gnu-to-x86_64-linux-gnu/x86_64-linux-gnu/sysroot -isysroot > /dl/x86_64-linux-gnu-to-x86_64-linux-gnu/x86_64-linux-gnu/sysroot -m64 > -isysroot /dl/x86_64-linux-gnu-to-x86_64-linux-gnu/x86_64-linux-gnu/sysroot > conftest.c >&5 > d.lld: error: cannot open crt1.o: No such file or directory > ld.lld: error: cannot open crti.o: No such file or directory > ld.lld: error: cannot open crtbegin.o: No such file or directory > ld.lld: error: unable to find library -lgcc > ld.lld: error: unable to find library -lgcc_s > ld.lld: error: unable to find library -lc > ld.lld: error: unable to find library -lgcc > ld.lld: error: unable to find library -lgcc_s > ld.lld: error: cannot open crtend.o: No such file or directory > ld.lld: error: cannot open crtn.o: No such file or directory > clang-12: error: linker command failed with exit code 1 (use -v to see > invocation) > ``` > This is because clang is unable to locate the gcc installation from the > devkit. > The gcc toolchain is not in the location clang expects in the sysroot (that's > not how our devkits are structured). > Note that it might go unnoticed on machines that have gcc installed because > clang will fallback to system-global locations. > > We can help clang by letting it now about the gcc location in the devkit with > `--gcc-toolchain=`. > However that's not enough and we then get: > > ld.lld: error: cannot open crt1.o: No such file or directory > ld.lld: error: cannot open crti.o: No such file or directory > ld.lld: error: unable to find library -lc > ld.lld: error: cannot open crtn.o: No such file or directory > > clang was able to locate the gcc support libraries but is not able to locate > required system libraries. > That's because `-isysroot` is not intended for libraries (only headers) but > also because `-isysroot` has no effect for clang on linux (see > [llvm#11503](https://bugs.llvm.org/show_bug.cgi?id=11503)). > Using `--sysroot=` in this case (clang on linux) resolves this issue. This pull request has now been integrated. Changeset: b17f8d5b Author: Gilles Duboscq <g...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/b17f8d5b6c4d4ec75bb57f1d2009e30332bdb3ce Stats: 15 lines in 1 file changed: 13 ins; 0 del; 2 mod 8278954: Using clang together with devkit on linux doesn't work for building Reviewed-by: erikj ------------- PR: https://git.openjdk.java.net/jdk/pull/6880
