[fpc-pascal] Debug information
I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. What OS? Are you expecting a line number associated with code in the calling program or the .DLL/.so? What has caused the error- is the calling convention etc. correct? -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues] ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Am Tuesday 11 September 2012 12:05:02 schrieb Mark Morgan Lloyd: Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. What OS? Linux Are you expecting a line number associated with code in the calling program or the .DLL/.so? Expecting: line xxx of yyy.pas But when loading a library only adresses are shown. What has caused the error simple access violation - is the calling convention etc. correct? I hope so because the program runs 24/7 in some places in eurpoe. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Am Tuesday 11 September 2012 12:05:02 schrieb Mark Morgan Lloyd: Are you expecting a line number associated with code in the calling program or the .DLL/.so? By now only the main program if affected. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
On 11/09/2012 10:28, Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. This is about debug info written by DumpStack or similar (written by the exe itself, to the console)? Or debug info shown by gdb using bt? If the first, does the latter work? As from your other replies, the exception occurs in your pascal code. But is this code in a callback from the DLL? (This would mean that stackframes of the DLL exist, and they have no line info) Or could for any other reason (including compiled with optimization) there be a stackframe (just one) that has no line info? IIRC the line-info on stacktraces is only displayed until the very first time a line without info is discovered. That is: 1) If within the current stackdump a line without info is discovered, then no further line will be attempted to be resolved (even if info could be available) 2) If in a previous dump, such a line was discovered, then in any further dump (even though unrelated) no line info is printed. In Lazarus the leak view, can attempt to resolve such traces. It requires the exact exe with debug info. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Constant of 2D array
Hello, Can I write constants of a 2D array? I am trying to convert some C++ code which uses this ... so far I tryed: const number_return_map: array[0..7][0..7] of U8 = ( ( 15, 14, 13, 12, 11, 10, 9, 8 ), ( 14, 0, 1, 3, 6, 10, 10, 9 ), ( 13, 1, 2, 4, 7, 11, 11, 10 ), ( 12, 3, 4, 5, 8, 12, 12, 11 ), ( 11, 6, 7, 8, 9, 13, 13, 12 ), ( 10, 10, 11, 12, 13, 14, 14, 13 ), ( 9, 10, 11, 12, 13, 14, 15, 14 ), ( 8, 9, 10, 11, 12, 13, 14, 15 ) ); but it stops between the two [0..7] requesting a of, which indicates that it does not want a 2D array but expects a 1D array only. -- Felipe Monteiro de Carvalho ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Constant of 2D array
2012/9/11 Felipe Monteiro de Carvalho felipemonteiro.carva...@gmail.com: Hello, Can I write constants of a 2D array? I am trying to convert some C++ code which uses this ... so far I tryed: const number_return_map: array[0..7][0..7] of U8 = const number_return_map: array[0..7,0..7] of byte = Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Constant of 2D array
On Tue, Sep 11, 2012 at 2:58 PM, Vincent Snijders vincent.snijd...@gmail.com wrote: const number_return_map: array[0..7,0..7] of byte = Ah, nice, thanks =) Now it works... and the syntax is almost the same as in C++ which facilitates the conversion -- Felipe Monteiro de Carvalho ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Constant of 2D array
11.09.2012 16:51, Felipe Monteiro de Carvalho пишет: Hello, Can I write constants of a 2D array? I am trying to convert some C++ code which uses this ... so far I tryed: const number_return_map: array[0..7][0..7] of U8 = ( ( 15, 14, 13, 12, 11, 10, 9, 8 ), ( 14, 0, 1, 3, 6, 10, 10, 9 ), ( 13, 1, 2, 4, 7, 11, 11, 10 ), ( 12, 3, 4, 5, 8, 12, 12, 11 ), ( 11, 6, 7, 8, 9, 13, 13, 12 ), ( 10, 10, 11, 12, 13, 14, 14, 13 ), ( 9, 10, 11, 12, 13, 14, 15, 14 ), ( 8, 9, 10, 11, 12, 13, 14, 15 ) ); but it stops between the two [0..7] requesting a of, which indicates that it does not want a 2D array but expects a 1D array only. No of required by array syntax. But array may be multidimensional. Should be const number_return_map: array[0..7] of array [0..7] of U8 ... ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Am Tuesday 11 September 2012 14:16:35 schrieb Martin: On 11/09/2012 10:28, Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. This is about debug info written by DumpStack or similar (written by the exe itself, to the console)? Or debug info shown by gdb using bt? If the first, does the latter work? ? It is a console program with graphic output to the framebuffer. When loading succesfully the library (which depends on the x11 library) the framebuffer is written to an XWindow (Linux). The software runs with a plain (embedded) linux and also in an XWindow environment. I have only the information of what the exe program writes down in case of an error. No other debug tool is used by now. Specially when the program runs outside it will be not easy to use additional tools, I think. As from your other replies, the exception occurs in your pascal code. But is this code in a callback from the DLL? (Linux Library *.so) No. (This would mean that stackframes of the DLL exist, and they have no line info) Or could for any other reason (including compiled with optimization) there be a stackframe (just one) that has no line info? May be. IIRC the line-info on stacktraces is only displayed until the very first time a line without info is discovered. That is: 1) If within the current stackdump a line without info is discovered, then no further line will be attempted to be resolved (even if info could be available) With not loading the library it shows all lines correctly. 2) If in a previous dump, such a line was discovered, then in any further dump (even though unrelated) no line info is printed. But why are the lines not shown if there is only one line without info? In Lazarus the leak view, can attempt to resolve such traces. It requires the exact exe with debug info. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
On 11/09/2012 16:07, Rainer Stratmann wrote: Or could for any other reason (including compiled with optimization) there be a stackframe (just one) that has no line info? May be. IIRC the line-info on stacktraces is only displayed until the very first time a line without info is discovered. That is: 1) If within the current stackdump a line without info is discovered, then no further line will be attempted to be resolved (even if info could be available) With not loading the library it shows all lines correctly. You load the lib dynamically? e.g OpenLibrary? If it is hardlinked (procedure ... external) then this changes the exe, and the linker may move stuff around (including debug info, and maybe debug info gets broken). On some platform samrtlinking, also has a real risk of breaking debug info... If it is via OpenLibrary (e.g. you can control the usage via commandline switch, and therefore truly have the same exe, then I do not know... There may be other reasons, that I do not know of. You can always (not sure if it works for PIE / position independent) take the address, and have gdb check, if it can be resolved). 2) If in a previous dump, such a line was discovered, then in any further dump (even though unrelated) no line info is printed. But why are the lines not shown if there is only one line without info? Missing recovery in the implementation... Now this is from memory. double check it. I may well remember this wrong. Basically, if an error happens (exception) during a trace is printed, then this could lead to a new trace, a new error, a new trace ... a stackoverflow. So during a trace, the pointer to the trace prog, is set to the basic address only prog. Unfortunately there is no distinction between errors. So not finding a line is an error (IIRC it is handled the same as if dbg info is invalid/broken), and that is the end... ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Martin wrote: On 11/09/2012 10:28, Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. How is the library being loaded: using FPC's dynlibs unit? If using dynlibs, is the problem immediately after loading the library (.so) or is it on a call of an entry point in the library? This is about debug info written by DumpStack or similar (written by the exe itself, to the console)? Or debug info shown by gdb using bt? If the first, does the latter work? As from your other replies, the exception occurs in your pascal code. But is this code in a callback from the DLL? (This would mean that stackframes of the DLL exist, and they have no line info) Or could for any other reason (including compiled with optimization) there be a stackframe (just one) that has no line info? Is the DLL successfully called, does it exit predictably, and does the stack recover to the state it was on entry (i.e. without an extra or missing word)? -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues] ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Am Tuesday 11 September 2012 18:14:57 schrieb Mark Morgan Lloyd: Martin wrote: On 11/09/2012 10:28, Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. How is the library being loaded: using FPC's dynlibs unit? Yes. If using dynlibs, is the problem immediately after loading the library (.so) or is it on a call of an entry point in the library? Immediately after loading the library. This is about debug info written by DumpStack or similar (written by the exe itself, to the console)? Or debug info shown by gdb using bt? If the first, does the latter work? As from your other replies, the exception occurs in your pascal code. But is this code in a callback from the DLL? (This would mean that stackframes of the DLL exist, and they have no line info) Or could for any other reason (including compiled with optimization) there be a stackframe (just one) that has no line info? Is the DLL successfully called, does it exit predictably, and does the stack recover to the state it was on entry (i.e. without an extra or missing word)? The program restarts some times and there is no error. Stack recovery I don't know. I think it will be ok. How can I see that? I use loadlibrary and freelibrary. There are only 3 functions/procedures calling from the program. (init_proc, loop_proc, exit_proc). The library calls back a procedure (add a key to a keybuffer) but in this procedure there is no error. I tried safeloadlibrary but the same thing. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Am Tuesday 11 September 2012 17:38:44 schrieb Martin: But why are the lines not shown if there is only one line without info? Missing recovery in the implementation... Now this is from memory. double check it. I may well remember this wrong. Basically, if an error happens (exception) during a trace is printed, then this could lead to a new trace, a new error, a new trace ... a stackoverflow. So during a trace, the pointer to the trace prog, is set to the basic address only prog. Unfortunately there is no distinction between errors. So not finding a line is an error (IIRC it is handled the same as if dbg info is invalid/broken), and that is the end... For debugging the best would be to write down as much information as possible. Even if it causes (eventually) more (endless) errors. Would this be possible? May be with a switch? ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Debug information
Rainer Stratmann wrote: Am Tuesday 11 September 2012 18:14:57 schrieb Mark Morgan Lloyd: Martin wrote: On 11/09/2012 10:28, Rainer Stratmann wrote: I found out that there is no line information shown (-gl) if an error occurs (more or less shortly) after the program loads a dynamic library. This same behaviour happens with fpc version 2.4.2-0 and 2.6.0. If no library is loaded line information is shown. The error adresses are the same in both cases. How is the library being loaded: using FPC's dynlibs unit? Yes. If using dynlibs, is the problem immediately after loading the library (.so) or is it on a call of an entry point in the library? Immediately after loading the library. In which case I presume that you could comment out the calls to the entry points in the library and duplicate the problem (have you tried this?). Does the recently-added GetLoadError() function tell you anything useful? Is the DLL successfully called, does it exit predictably, and does the stack recover to the state it was on entry (i.e. without an extra or missing word)? The program restarts some times and there is no error. If it's specifically something that happens at load time then below probably isn't relevant. Stack recovery I don't know. I think it will be ok. How can I see that? Inline assembler to dump esp and ebp. I use loadlibrary and freelibrary. There are only 3 functions/procedures calling from the program. (init_proc, loop_proc, exit_proc). The library calls back a procedure (add a key to a keybuffer) but in this procedure there is no error. I tried safeloadlibrary but the same thing. -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues] ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
