On Tue, 11 Feb 2025 06:26:19 GMT, David Holmes <dhol...@openjdk.org> wrote:
> I am at a loss to understand how the initial change built and tested with no > problem even though `-ldl` was missing. Maybe there is some way to set a > default set of libraries to check and the toolchain include libdl.so in that. > ?? @dholmes-ora I just added a comment at https://bugs.openjdk.org/browse/JDK-8349752?focusedId=14751058&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-14751058, duplicating below: I had to refresh my memory on this (I now recall that I've run into related issue in the past), but I know the reason now why the build is successfully even without `-ldl`. `--allow-shlib-undefined` is the default on gnu linker. I linked "binutils/docs-2.18/ld/" below. Is `--no-allow-shlib-undefined` or `--no-undefined` specified for the linker in the closed test environment? https://sourceware.org/binutils/docs-2.18/ld/Options.html#:~:text=The%20reason%20that%20%2D%2Dallow,be%20resolvable%20at%20load%20time: > --allow-shlib-undefined > --no-allow-shlib-undefined > > Allows (the default) or disallows undefined symbols in shared libraries. This > switch is similar to --no-undefined except that it determines the behaviour > when the undefined symbols are in a shared library rather than a regular > object file. It does not affect how undefined symbols in regular object files > are handled. > The reason that --allow-shlib-undefined is the default is that the shared > library being specified at link time may not be the same as the one that is > available at load time, so the symbols might actually be resolvable at load > time. Plus there are some systems, (eg BeOS) where undefined symbols in > shared libraries is normal. (The kernel patches them at load time to select > which function is most appropriate for the current architecture. This is used > for example to dynamically select an appropriate memset function). Apparently > it is also normal for HPPA shared libraries to have undefined symbols. Following is the `gcc` & `ld` from the github build machine (https://github.com/jianglizhou/jdk/actions/runs/13124407248/job/36617644281). The linker is `2.38 [GNU ld (GNU Binutils for Ubuntu) 2.38]`. configure: Using gcc C compiler version 10.5.0 [gcc (Ubuntu 10.5.0-1ubuntu1~22.04) 10.5.0] ... checking resolved symbolic links for CXX... /usr/bin/x86_64-linux-gnu-g++-10 configure: Using gcc C++ compiler version 10.5.0 [g++ (Ubuntu 10.5.0-1ubuntu1~22.04) 10.5.0] ... configure: Using gcc linker version 2.38 [GNU ld (GNU Binutils for Ubuntu) 2.38] configure: comparing linker version to minimum version 2.25 ------------- PR Comment: https://git.openjdk.org/jdk/pull/23544#issuecomment-2651314171
