Looks good, though I am not an official (R)eviewer. Charlie
> On Nov 21, 2014, at 9:30 AM, Erik Helin <erik.he...@oracle.com> wrote: > > Hi all, > > this patch changes the debug symbols format on Solaris from STABS > [0] to DWARF [1] for libjvm.so. Since the supported compiler on Solaris > has been updated to Oracle Solaris Studio 12.3 [2], the STABS debug format > is now deprecated in the supported compiler [3]: > > -xdebugformat=stabs generates debugging information > using the stabs standard format. The stabs format is no > longer supported. > > Furthermore, in Oracle Solaris Studio 12.4, the release notes says [4]: > > The –xdebugformat=stabs for all compilers might be removed in a future > release. The only debugger format option will be –xdebugformat=dwarf, > which is currently the default. > > So, it seems to be a good time to change the debug format to DWARF when > compiling with Oracle Solaris Studio. I also changed the debug format for > GCC on Solaris to be DWARF, since the STABS support in GCC is in > maintenance mode [5]. > > More reasons for using DWARF instead of STABS are: > - Better support by Oracle Studio Performance Analyzer (the performance > team have requested that we use DWARF v2 or later instead of STABS). > - DWARF provides a better debugging experience for C++ compared to STABS. > > The one drawback of using DWARF compared to STABS is that the size of the > debuginfo increases. For a SPARC fastdebug build the size of > libjvm.debuginfo built with STABS is 782 MB and with DWARF 1002 MB. > > To summarize, we need to change from STABS to DWARF because STABS is > deprecated in 12.3 (even "more" deprecated 12.4 given the wording in the > release notes). I would suggest to change sooner rather than later, given > that the change to DWARF also brings Oracle Studio Performance Analyzer > support as well as a better C++ debugging experience in dbx. > > Webrev: > http://cr.openjdk.java.net/~ehelin/8065656/webrev.00/ > > Bug: > https://bugs.openjdk.java.net/browse/JDK-8065656 > > Testing: > - Compiled with Oracle Solaris Studio 12.3 on both Solaris 11.1 on SPARC > and Solaris 11.1 on x86-64 using JPRT. > - Verified that DWARF v2 symbols are produced with objdump. > > Thanks, > Erik > > [0]: http://www.sourceware.org/gdb/onlinedocs/stabs.html > [1]: http://www.dwarfstd.org/ > [2]: http://mail.openjdk.java.net/pipermail/jdk9-dev/2014-October/001489.html > [3]: https://docs.oracle.com/cd/E24457_01/html/E22003/cplusplus.1.html > [4]: https://docs.oracle.com/cd/E37069_01/html/E37070/gnxfn.html > [5]: https://sourceware.org/ml/binutils/2013-01/msg00028.html
