RFR (S): JDK-8150201 Restore missing -g flags to files with OPT_CFLAGS/per-file

[Erik Joelsson]

Looks ok to me. Thanks for fixing this.

/Erik

On 2016-02-19 00:16, Magnus Ihse Bursie wrote:
> There seems to be a bit of confusion as to OPT_CFLAGS meant "CFLAGS 
> for optimization" or "CFLAGS for optimized/product build". Some usages 
> seems to suggest the first interpretation, while other usages seems to 
> have made the second (where OPT_CFLAGS align with 
> DEBUG_CFLAGS/FASTDEBUG_CFLAGS).
>
> The first interpretation seems to have been used for the code that 
> make it possible to override OPT_CFLAGS on a per-file basis by setting 
> e.g. OPT_CFLAGS/foo.o is set. In this case, the general value of 
> OPT_CFLAGS is discarded, including any -O flags.
>
> However, the second interpretation seems to have been used for FDS, 
> where -g (or -g0 -xs on solaris) are added to OPT_CFLAGS.
>
> The end result is that whenever the OPT_CFLAGS/foo.o mechanism is 
> used, the FDS -g flag is lost. :-(
>
> This patch is a minimal fix to restore the -g flag to these files.
>
> A more general approach to fix this was originally suggested as part 
> of JDK-8142909, but was deemed inadequate. After some discussion, the 
> entire problem with the missing -g flags was dropped from that bug. 
> However, one of the key points in the discussion was that an explicit 
> add of -g would be a better solution, which is what I have adopted 
> here (short of a major rewrite of the flag handling in the old build 
> system, which is not going to happen). I have also made a more 
> thorough check this time to really catch all such issues (at least for 
> default Oracle builds).
>
> The main reason for bringing this change in now is to make it possible 
> to compare the build results between the upcoming new hotspot build, 
> and the old. Since the new build always adds -g to all files (if we 
> need debug symbols, that is), there will be huge discrepances between 
> the two build system in the affected files.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8150201
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8150201-restore-missing-g-flag/webrev.01
>
> /Magnus