RFR: JDK-8199347 Always use -Z7 for debug symbols when compiling on Windows

[Erik Joelsson]

Looks good.

/Erik


On 2018-03-08 14:10, Magnus Ihse Bursie wrote:
> For some time, we have used two different ways of handling debug symbols on Windows. Hotspot has been built using -Z7, and the JDK libraries using -Zi. -Z7 is preferable, since it does not create separate .pdb files for each source file; instead debug data is embedded in the .obj file, just like all other compilers do. This aligns better with the rest of the platforms. It also means we get rid of the mspdbsrv process, which serializes access to pdb files, and which has proven to be a bottleneck in certain situations.
>
> This does not mean that the end product is different: the linker still generates a .pdb file for the library/executable, and strip the debug information from the library/executable.
>
> This will also allow for some well-needed cleanups. With this change, hotspot and JDK libs finally build with the same debug symbol flags, and we can remove the hack that was introduced with the new hotspot build to override the debug symbol flags. Also, now that -Zi is ditched, we don't need the special handling of per-source-file pdb’s.
>
> I have verified on our build system using COMPARE_BUILD that this does not affect the generated output.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8199347 <https://bugs.openjdk.java.net/browse/JDK-8199347>
> WebRev: http://cr.openjdk.java.net/~ihse/JDK-8199347-use-Z7-for-debug-symbols/webrev.01 <http://cr.openjdk.java.net/~ihse/JDK-8199347-use-Z7-for-debug-symbols/webrev.01>
>
> /Magnus