Peter's email id corrected, this time... ysr1729
> On Nov 21, 2014, at 13:42, Srinivas Ramakrishna <ysr1...@gmail.com> wrote: > > > What does Peter think? For those too young to remember, Peter invented stabs > way back when he was a young grad student at Berkeley :-) > It has given admirable service, like so much else he has touched! > > -- Ramki > > ysr1729 > >> On Nov 21, 2014, at 08:30, charlie hunt <charlie.h...@oracle.com> wrote: >> >> 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
