On 8/25/22 4:11 PM, some-java-user-99206970363698485...@vodafonemail.de
wrote:
Hello,
the JDK source code contains many Java classes which are specific to one
platform / operating system, for example
classes to interact with the file system or the AWT and Swing related classes
are different for Windows and Linux.
Is there a way to compile the Java source code for all platforms supported by
the JDK at once? My goal is not to build
a functional JDK, but to use the class files (or rather the compilation
process) for static code analysis, specifically
for analysis with CodeQL. I assume this might also be useful for other code
analysis tools, and maybe also in general
to detect Java compilation errors with the JDK source code.
It appears the OpenJDK building instructions are always for building for a
specific target platform and therefore
skip compiling the Java code for other platforms. Additionally the `configure`
command checks also check for tools
needed to compile native code (e.g. Xcode or Visual Studio), even though for
pure Java compilation they would not be
needed (?). Therefore when you try to use multiple configurations (as described
in the build instructions) it would
require you to install all the tools for all platforms (if that is even
possible on the same host operating system).
Ideally I am looking for a solution which satisfies the following:
- Compiles the Java source code for all supported platforms
- Compiles all the Java source code in one build command execution
- Or at least compiles the Java source code with separate build command
executions, but which can all be
run from the same host operating system (no need to use separate operating
systems)
- Does not require any of the tools for native compilation to be installed
Though I am happy about any solution which gets as close as possible to this.
Thanks already in advance!
This is not a usecase I have ever encountered before, and the build
system does not have anything close to supporting it. I don't think you
can achieve this without some serious effort.
Even if you were to include all the java source dirs, I'm pretty sure
you couldn't compile them straight into the same output dir. Different
versions of the same java class can appear in different platform
directories. We also have a lot of generated java code where some may
get generated differently depending on platform. For example in
make/modules/java.base/gensrc/GensrcMisc.gmk, we use the native
preprocessor to generate constants into a java class.
It's not possible to cross compile all platforms from any single OS, so
you can't provide native toolchains for separate builds on the same host.
Depending on how close to correct you need the java class files to be
produced, it could be possible to hack around in the build system to
achieve something that is perhaps close enough, but as I said already,
it won't be trivial. I doubt we would want to incorporate any such
change into the build permanently without some very strong motivation.
/Erik
