Difference between revisions of "Logging exceptions"
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'''Stacktrace''' is sometimes called '''Backtrace''' or '''Call stack''' and have meaning of list of stack frames placed on stack containing return address and local variables. Stacktrace is useful to trace back path of execution of nesting procedures. | '''Stacktrace''' is sometimes called '''Backtrace''' or '''Call stack''' and have meaning of list of stack frames placed on stack containing return address and local variables. Stacktrace is useful to trace back path of execution of nesting procedures. | ||
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| + | Compiler have to be directed to get debug information by switches. | ||
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| + | *-g - generate debug informations | ||
| + | *-gl - generate line numbers for debug informations | ||
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function ExceptFrameCount: Longint; | function ExceptFrameCount: Longint; | ||
function ExceptFrames: PPointer;</delphi> | function ExceptFrames: PPointer;</delphi> | ||
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| + | Unit System contains some stack related routines: | ||
| + | <delphi>function SysBackTraceStr(Addr:Pointer): ShortString; // Default address to string converter assigned to BackTraceStrFunc | ||
| + | procedure Dump_Stack(var f : text;bp:pointer); // Dump stack to text file | ||
| + | procedure DumpExceptionBackTrace(var f:text); // Dump backtrace to text file</delphi> | ||
| + | |||
| + | FPC help: | ||
| + | * [http://www.freepascal.org/docs-html/rtl/system/dumpexceptionbacktrace.html DumpExceptionBackTrace] | ||
| + | * [http://www.freepascal.org/docs-html/rtl/system/dump_stack.html dump_stack] | ||
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==Using map file== | ==Using map file== | ||
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| + | Use compiler switch -Xm to generate map file. | ||
==Exceptions in DLL== | ==Exceptions in DLL== | ||
=Getting stacktrace= | =Getting stacktrace= | ||
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* [[Profiling]] | * [[Profiling]] | ||
* [[Creating a Backtrace with GDB]] | * [[Creating a Backtrace with GDB]] | ||
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| + | =External links= | ||
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| + | * [http://www.ciuly.com/tools/programming/esprinter/index.html esprinter] - tool to get stacktrace from running FreePascal program specified by process id and thread id (for Win32) | ||
[[Category:Debugging]] | [[Category:Debugging]] | ||
Revision as of 21:02, 2 September 2010
Introduction
Stacktrace is sometimes called Backtrace or Call stack and have meaning of list of stack frames placed on stack containing return address and local variables. Stacktrace is useful to trace back path of execution of nesting procedures.
Compiler have to be directed to get debug information by switches.
- -g - generate debug informations
- -gl - generate line numbers for debug informations
Unit SysUtils contains some routines useful for debugging exceptions.
<delphi>{ Exception handling routines } function ExceptObject: TObject; function ExceptAddr: Pointer; function ExceptFrameCount: Longint; function ExceptFrames: PPointer;</delphi>
Unit System contains some stack related routines: <delphi>function SysBackTraceStr(Addr:Pointer): ShortString; // Default address to string converter assigned to BackTraceStrFunc procedure Dump_Stack(var f : text;bp:pointer); // Dump stack to text file procedure DumpExceptionBackTrace(var f:text); // Dump backtrace to text file</delphi>
FPC help:
Handling exceptions
Application.OnException
<delphi>procedure TMainForm.CustomExceptionHandler(Sender: TObject; E: Exception); const
NewLine = #13#10;
var
I: Integer; Frames: PPointer; Report: string;
begin
Report := 'Program exception! ' + NewLine + 'Stacktrace:' + NewLine + NewLine; if E <> nil then begin Report := Report + 'Exception class: ' + E.ClassName + NewLine + 'Message: ' + E.Message + NewLine; end; Report := Report + BackTraceStrFunc(ExceptAddr); Frames := ExceptFrames; for I := 0 to ExceptFrameCount - 1 do Report := Report + NewLine + BackTraceStrFunc(Frames); ShowMessage(Report); Halt; // End of program execution
end;
procedure TMainForm.FormCreate(Sender: TObject); begin
Application.OnException := @CustomExceptionHandler;
end;
procedure TMainForm.ButtonClick(Sender: TObject); begin
raise Exception.Create('Test');
end;</delphi>
Using map file
Use compiler switch -Xm to generate map file.
Exceptions in DLL
Getting stacktrace
See also
External links
- esprinter - tool to get stacktrace from running FreePascal program specified by process id and thread id (for Win32)
