digitalmars.D - Should Druntime and Phobos be built with -gs ?
- Vladimir Panteleev (34/34) Dec 03 2012 I've recently updated my watchdog wrapper script which starts D
- Jacob Carlborg (5/37) Dec 04 2012 Isn't it better to ship Phobos and druntime with debug versions of the
- Vladimir Panteleev (7/9) Dec 05 2012 Yes, providing something immediately usable with the -debuglib
- Brad Roberts (3/9) Dec 05 2012 If it's the right thing to be doing, the better question is 'why isn't i...
- Vladimir Panteleev (8/24) Dec 05 2012 That's a good question, but changing DMD switches is probably not
- deadalnix (4/20) Dec 06 2012 Some debugger allow you to change the value of variables when the
I've recently updated my watchdog wrapper script which starts D services to use gdb and disable rt_trapExceptions. My intention was to bypass D's standard exception handler and let gdb handle uncaught exceptions, and perhaps print better stack traces including function arguments and line numbers. However, this was the result: Program received signal SIGSEGV, Segmentation fault. 0x0000000000531f7c in rt.deh2.terminate() () No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. I assume that the stack frames under _d_throwc are not accessible because _d_throwc does not create a stack frame, as Druntime is built with -release but not -gs. (To clarify, stack frames are disabled by -release unless -gs is specified, in which case they're always emitted.) Should the Phobos and Druntime makefiles be changed to include -gs in the release DFLAGS? I haven't noticed any difference in performance from timing the Druntime unittests. In theory, enabling it should provide a better out-of-the-box debugging experience at a negligible performance/filesize cost.
Dec 03 2012
On 2012-12-04 08:47, Vladimir Panteleev wrote:I've recently updated my watchdog wrapper script which starts D services to use gdb and disable rt_trapExceptions. My intention was to bypass D's standard exception handler and let gdb handle uncaught exceptions, and perhaps print better stack traces including function arguments and line numbers. However, this was the result: Program received signal SIGSEGV, Segmentation fault. 0x0000000000531f7c in rt.deh2.terminate() () No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. No symbol table info available. I assume that the stack frames under _d_throwc are not accessible because _d_throwc does not create a stack frame, as Druntime is built with -release but not -gs. (To clarify, stack frames are disabled by -release unless -gs is specified, in which case they're always emitted.) Should the Phobos and Druntime makefiles be changed to include -gs in the release DFLAGS? I haven't noticed any difference in performance from timing the Druntime unittests. In theory, enabling it should provide a better out-of-the-box debugging experience at a negligible performance/filesize cost.Isn't it better to ship Phobos and druntime with debug versions of the libraries as well. -- /Jacob Carlborg
Dec 04 2012
On Tuesday, 4 December 2012 at 12:11:37 UTC, Jacob Carlborg wrote:Isn't it better to ship Phobos and druntime with debug versions of the libraries as well.Yes, providing something immediately usable with the -debuglib switch would be nice (I'd imagine a build without -O or -inline). However, if the performance impact of -gs is negligible, there's little reason not to enable it in the release version of Phobos. Those who want every 0.x% of performance can always build/write their own library.
Dec 05 2012
On 12/5/2012 10:32 AM, Vladimir Panteleev wrote:On Tuesday, 4 December 2012 at 12:11:37 UTC, Jacob Carlborg wrote:If it's the right thing to be doing, the better question is 'why isn't it the default' and not an option that has to be turned on?Isn't it better to ship Phobos and druntime with debug versions of the libraries as well.Yes, providing something immediately usable with the -debuglib switch would be nice (I'd imagine a build without -O or -inline). However, if the performance impact of -gs is negligible, there's little reason not to enable it in the release version of Phobos. Those who want every 0.x% of performance can always build/write their own library.
Dec 05 2012
"Vladimir Panteleev" <vladimir thecybershadow.net> On Thursday, 6 December 2012 at 03:31:42 UTC, Brad Roberts wrote:On 12/5/2012 10:32 AM, Vladimir Panteleev wrote:That's a good question, but changing DMD switches is probably not worth it at this point. I took a look at what GCC does: "-O also turns on -fomit-frame-pointer on machines where doing so does not interfere with debugging." That's interesting... so, at least in some situations, there is some way to get a proper stack trace without stack frames.On Tuesday, 4 December 2012 at 12:11:37 UTC, Jacob Carlborg wrote:If it's the right thing to be doing, the better question is 'why isn't it the default' and not an option that has to be turned on?Isn't it better to ship Phobos and druntime with debug versions of the libraries as well.Yes, providing something immediately usable with the -debuglib switch would be nice (I'd imagine a build without -O or -inline). However, if the performance impact of -gs is negligible, there's little reason not to enable it in the release version of Phobos. Those who want every 0.x% of performance can always build/write their own library.
Dec 05 2012
On Thursday, 6 December 2012 at 03:31:42 UTC, Brad Roberts wrote:On 12/5/2012 10:32 AM, Vladimir Panteleev wrote:Some debugger allow you to change the value of variables when the program is paused or some other similar stuffs. It require more information than simply the stack trace.On Tuesday, 4 December 2012 at 12:11:37 UTC, Jacob Carlborg wrote:If it's the right thing to be doing, the better question is 'why isn't it the default' and not an option that has to be turned on?Isn't it better to ship Phobos and druntime with debug versions of the libraries as well.Yes, providing something immediately usable with the -debuglib switch would be nice (I'd imagine a build without -O or -inline). However, if the performance impact of -gs is negligible, there's little reason not to enable it in the release version of Phobos. Those who want every 0.x% of performance can always build/write their own library.
Dec 06 2012