[8u] RFR: 8262864: No debug symbols in image for Windows --with-native-debug-symbols=external

[Simon Tooke]

(disclaimer, I am not an official reviewer, but I'm offering my opinion 
to those who are)

I tried this patch, and it does as it says; I see map and PDB files 
where I didn't before.

However (and this is not a fault of this PR; it's a preexisting bug) 
since java.exe and java.dll are both in the ./bin directory on Windows, 
only one set of debug information is present - in my testing, the 
map/pdb files corresponding to java.dll, not java.exe.

Another pre-existing issue is that the compressed debug ('.diz') file 
contains the full build path to the debug files, where it's probably 
tidier to have them relative to the image directory.  For example:

Archive: 
C:/tmp/build-8/jdk8u-dev/build/windows-x86_64-server-fastdebug/images/j2re-image/bin/java.diz
  Length   Method    Size  Cmpr    Date    Time   CRC-32   Name
--------  ------  ------- ---- ---------- ----- --------  ----
  1199104  Defl:N   215859  82% 03/09/2021 11:37 bf9b8804 
cygdrive/c/tmp/build-8/jdk8u-dev/build/windows-x86_64-server-fastdebug/jdk/objs/libjava/java.pdb
   141184  Defl:N    26367  81% 03/09/2021 11:37 a6a7fc16 
cygdrive/c/tmp/build-8/jdk8u-dev/build/windows-x86_64-server-fastdebug/jdk/objs/libjava/java.map
--------          -------  ---                            -------
  1340288           242226  82%                            2 files

instead of ./bin/java.pdb and ./bin/java.map.

I don't expect either of these issues to hold up this PR, though; this 
PR is fine.  These issue may even occur in later JDKs; I'll have to go 
check.

-Simon Tooke

On 2021-03-02 1:50 p.m., Andrew Leonard wrote:
> Hi,
> Please can I get reviews for this patch to fix the creation of jdk8u
> Windows debug files (.map, .pdb) when using
> --with-native-debug-symbols=external. A recent fix resolved this for
> non-Windows (https://bugs.openjdk.java.net/browse/JDK-8252395), this fixes
> Windows and also a minor issue with the other platforms that JDK-8252395
> didn't quite fix.
> webrev: https://cr.openjdk.java.net/~aleonard/8262864/webrev.00/
> bug: https://bugs.openjdk.java.net/browse/JDK-8262864
> Thanks
> Andrew
>