RFR: 8339355: Test build/AbsPathsInImage.java fails configure with --enable-ccache

[SendaoYan]

On Mon, 16 Jun 2025 06:57:35 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

> We do expect the debuginfo files to be reproducible and hence free of absolute paths. This was implemented in https://bugs.openjdk.org/browse/JDK-8284437, where `-fdebug-prefix-map` was one of the mitigations applied. I would start my investigation with trying to understand why that option isn't working, or being applied, when you build with `--enable-ccache`.

Thanks @erikj79 

I can not find the root cause how does the debuginfo files contains the absolute paths.

Take java.debuginfo example, this file generate by `objcopy --only-keep-debug build/ccache/support/modules_cmds/java.base/java build/ccache/support/modules_cmds/java.base/java.debuginfo`,  the source file `build/ccache/support/modules_cmds/java.base/java` contains absolute path string `DW_AT_comp_dir              /hygonjdk/yansendao/git/jdk` shows as below:


> dwarfdump build/ccache/support/modules_cmds/java.base/java | grep DW_AT_comp_dir
                    DW_AT_comp_dir              /hygonjdk/yansendao/git/jdk
                    DW_AT_comp_dir              /hygonjdk/yansendao/git/jdk


The file `build/ccache/support/modules_cmds/java.base/java` linked from libjli.so and main.o, and the main.o already contains `DW_AT_comp_dir` absolute path when enable ccache. I can't find the difference between with ccache and without ccache when generate main.o

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PR Comment: https://git.openjdk.org/jdk/pull/25811#issuecomment-2975666685