[SOLVED] How to debug the *.inc files of the FPC?

[devEric69]

Hello,

I used this thread to successfully debug the LCL (Actnlist.pas, etc):

https://forum.lazarus.freepascal.org/index.php/topic,24319.msg146262.html#msg146262

To summarize:
- I have copied the directories (lazarus)/lcl, (fpc)/packages, (fpc)/rtl and (fpc)/utils that were installed by Fcpupdeluxe, into a directory of my /home, ie in /home/Me/lcl, /home/Me/packages and /home/Me/utils.
- I've renamed (lazarus)/lcl to (lazarus)/__lcl, (fpc)/packages to (fpc)/__packages and (fpc)/utils to (fpc)/__utils.
- I've created 4 soft symlinks. A soft symlink named "(lazarus)/lcl" pointing to /home/Me/lcl, a  soft symlink named "(lazarus)/packages" pointing to /home/Me/packages, a soft symlink named "(lazarus)/rtl" pointing to /home/Me/rtl, and a soft symlink named "(lazarus)/utils" pointing to /home/Me/utils.
- in /home/Me/Me/lcl, /home/Me/packages and /home/Me/Me/utils, I've deleted all *.ppu and *.o files.
- in the IDE environment options (which apply to all projects), I've added in "Debugger > Additional search path", the paths to the sources I want to debug. For example, when I add /home/Me/Me/lcl, I can debug the ActnList.pas file found there. I'm happy .

My problem occurs as soon as I want to debug a *.inc file (which belongs to fcp anectotically). I would like to debug TStringList. The declaration of this class is in the file /home/Me/rtl/objpas/classes/classeh.inc, and its implementation is in the file /home/Me/rtl/objpas/classes/stringl.inc. So, I added in "Debugger > Additional search path", the path /home/Me/rtl/objpas/classes.
However, when I put breakpoints in /home/Me/rtl/objpas/classes/stringl.inc (in methods like TStringList.InsertItem, or TStringList.Add), no blue dots appear, and so, I can't debug this class .

Any idea, or clarification on the particularity of *.inc versus *.pas in relation to the debugger, ... please?

[wp]

In order to debug the LCL I normally go to "Project Options" > "Compiler Options" > "Additions and overrides". Click on "Stored in session of project" > "Add" > "Custom option", then click in the appearing new "Custom" line and enter "-gw2" (without quotes). This activates Dwarf2 debugger info for the project and all required packages. When (after pressing "OK", of course) you compile the project all units including LCL and third party units (except for RTL and FCL units) will be recompiled with debugger info, and you can debug them.

In order to debug RTL and FCL I add the file that I want to debug to the project and confirm the prompt to add the related path to the search path. After some iterations all required paths will be in the search path, and the IDE will be able to compile also these units with debug info.

I'd recommend to make a backup copy of fpc and project folder - playing with fpc settings is always a bit risky.

I am not sure if -gw2 is still to best way, but Martin revealed to the me once and it is still working fine.

[devEric69]

Hello,

Thank you for the answer.

I tested with your method, but it is still impossible for me to debug the file stringl.inc (no blue dot; I've added the stringl.inc file in my project with the menu "Project>Project inspector>Add files from filesytem").
Have you ever managed to debug a *.inc file step by step (sorry for my paranoid bias)?

[wp]

I don't know whether adding the inc file to the project works. stringl.inc belongs to TStringlist, and this is in classes.pas, isn't it? Therefore, you should add classes (from the original fpc folder) to the project.

[Martin_fr]

You should not need  "Debugger > Additional search path" (at least not for LCL). The IDE already knows where those sources are. (That is, if you do not move them around yourself).

I do not understand all your moving and symlinking.... Should not be needed.

First in order to debug in any file, it needs debug info.
Files belonging to Lazarus (lcl, lazutils, other packages, that have sources in Lazarus/components folder)  can be recompiled with debug info:
- open the package, open the options of the package, specify "generate debug info"
- use "Additions and overrides" (project options / search wiki)

For fpc that is more complex.
The "copy a file" or "copy a folder" by wp, may sometimes work.... sometimes... If nothing else in fpc depends on the file.

Stringlist is in the RTL. So that requires the entire rtl to be rebuild.

If you build your fpc, with fpcupdeluxe, there may be an option to specify options for building fpc. You need
 -gw -godwarfsets

Without fpcupdeluxe (or if that does not offer the option), you need the full fpc sources, with makefiles, and you need to run make and specify the options.

And you may want to change the settings for your project, and packages from "debug info type" = "default" to "dwarf with sets".

[wp]

I tried to follow my recipe with a simple project which creates a stringlist. So far I had to add these unit folder to the search path of the project:

C:\development\fpc\trunk\rtl\objpas;C:\development\fpc\trunk\rtl\win32;C:\development\fpc\trunk\rtl\inc

and these inc files to the include path:

$(ProjOutDir);C:\development\fpc\trunk\rtl\inc;C:\development\fpc\trunk\rtl\win;C:\development\fpc\trunk\rtl\win32;C:\development\fpc\trunk\rtl\i386;C:\development\fpc\trunk\rtl\win\wininc

(Note that my fpc is in folder "c:\development\fpc\trunk", and I am on Windows, obviously).

How I am stuck in unit InfoDwrf complaining about "lnfodwrf.pp(1412,23) Error: Incompatible types: got "<address of function(Pointer):AnsiString;Register>" expected "<procedure variable type of function(Pointer):ShortString;Register>". I've never seen this... Martin, any idea how to proceed?

[Martin_fr]

How I am stuck in unit InfoDwrf complaining about "lnfodwrf.pp(1412,23) Error: Incompatible types: got "<address of function(Pointer):AnsiString;Register>" expected "<procedure variable type of function(Pointer):ShortString;Register>". I've never seen this... Martin, any idea how to proceed?

{$H+} / {$H-} ?


But seriously the road you travel is slippery....

So you copied (and therefore recompile) all the files in rtl\objpas (and a few others)

Now if anything in your project (including any package used by it) uses anything of the rtl outside those folders that uses any code from inside those folders, then you have a problem. Those still are pre-compiled against the original ppu. So you get "checksum changed" errors.

Yes you can identify all the needed files. And fix the folder structure and what not.... It will be easier to recompile the entire rtl using make (or probably possible with fpcupdeluxe)

[BrunoK]

That's for wp, windows 10 / 32bit

First a call stack of what will be shown when compiled with a debug version using bits and pieces of my FPC build process. (see  makefpc-306_w32.txt attachement)

Code: Pascal  [Select][+][-]

1. #0 _INTERNALCREATE(0x196a3b8, 0) at ..\win\fstobjcr.pp:60
2. #1 CREATE(0x1962420, 0x0, 0x196a3b8) at ..\objpas\classes\action.inc:91
3. #2 CREATE(0x1962420, 0x1, 0x196a3b8) at include\customaction.inc:14
4. #3 SETHINT(0x196a3b8, 0x65f4edc 'Displays the map') at include\application.inc:1521
5. #4 UPDATEMOUSEHINT(0x196a3b8, 0x19774e8) at include\application.inc:478
6. #5 UPDATEMOUSECONTROL(0x196a3b8, 0x19774e8) at include\application.inc:623
7. #6 DOBEFOREMOUSEMESSAGE(0x196a3b8, 0x19774e8) at include\application.inc:2098
8. #7 DOBEFOREMOUSEMESSAGE(0x19774e8) at include\control.inc:1435
9. #8 WNDPROC(0x19774e8, {MSG = 512, WPARAM = 0, LPARAM = 1048807, RESULT = 0, WPARAMLO = 0, WPARAMHI = 0, WPARAMFILLER = {}, LPARAMLO = 231, LPARAMHI = 16, LPARAMFILLER = {}, RESULTLO = 0, RESULTHI = 0, RESULTFILLER = {}}) at include\wincontrol.inc:5431
10. #9 DELIVERMESSAGE(0x19774e8, ) at lclmessageglue.pas:112
11. #10 DOWINDOWPROC({WINDOW = 396222, MSG = 512, WPARAM = 0, LPARAM = 1048807, LMESSAGE = {MSG = 0, WPARAM = 0, LPARAM = 0, RESULT = 0, WPARAMLO = 0, WPARAMHI = 0, WPARAMFILLER = {}, LPARAMLO = 0, LPARAMHI = 0, LPARAMFILLER = {}, RESULTLO = 0, RESULTHI = 0, RESULTFILLER = {}}, PLMSG = 0x162faf4, LWINCONTROL = 0x19774e8, WINPROCESS = false, NOTIFYUSERINPUT = true, WINDOWINFO = 0x19e8f20, BACKUPBUFFER = {DC = 0, BITMAP = 0, BITMAPWIDTH = 0, BITMAPHEIGHT = 0}, WINDOWWIDTH = 0, WINDOWHEIGHT = 0, PAINTMSG = {MSG = 0, DC = 0, PAINTSTRUCT = 0x0, RESULT = 0}, RTLLAYOUT = false, ORGCHARCODE = 0, LMSCROLL = {MSG = 0, SCROLLCODE = 0, SMALLPOS = 0, SCROLLBAR = 0, RESULT = 0, POS = 0}, LMKEY = {MSG = 0, CHARCODE = 0, UNUSED = 0, KEYDATA = 0, RESULT = 0}, LMCHAR = {MSG = 0, CHARCODE = 0, UNUSED = 0, KEYDATA = 0, RESULT = 0}, LMMOUSE = {MSG = 0, KEYS = 0, XPOS = 0, YPOS = 0, POS = {X = 0, Y = 0}, DUMMY = 0, RESULT = 0}, LMCONTEXTMENU = {MSG = 0, HWND = 0, XPOS = 0, YPOS = 0, POS = {X = 0, Y = 0}, DUMMY = 0, RESULT = 0}, LMMOUSEMOVE = {MSG = 512, KEYS = 0, XPOS = 231, YPOS = 16, POS = {X = 231, Y = 16}, DUMMY = 1048807, RESULT = 0}, LMMOUSEEVENT = {MSG = 0, BUTTON = 0, WHEELDELTA = 0, X = 0, Y = 0, RESULT = 0, USERDATA = 0x0, STATE = []}, LMMOVE = {MSG = 0, MOVETYPE = 0, XPOS = 0, YPOS = 0, POS = {X = 0, Y = 0}, DUMMY = 0, RESULT = 0}, LMNOTIFY = {MSG = 0, IDCTRL = 0, NMHDR = 0x0, RESULT = 0}, DRAWLISTITEMSTRUCT = {ITEMID = 0, AREA = {LEFT = 0, TOP = 0, RIGHT = 0, BOTTOM = 0, TOPLEFT = {X = 0, Y = 0}, BOTTOMRIGHT = {X = 0, Y = 0}, VECTOR = {0, 0, 0, 0}}, DC = 0, ITEMSTATE = []}, NMHDR = 0x1000e7}) at win32\win32callback.inc:3005
12. #11 WINDOWPROC(396222, 512, 0, 1048807) at win32\win32callback.inc:3171
13. #12 USER32!AddClipboardFormatListener at :0
14. #13 USER32!CallWindowProcW at :0
15. #14 USER32!DispatchMessageW at :0
16. #15 USER32!DispatchMessageW at :0
17. #16 APPPROCESSMESSAGES(0x19ba398) at win32\win32object.inc:553
18. #17 HANDLEMESSAGE(0x196a3b8) at include\application.inc:1282
19. #18 RUNLOOP(0x196a3b8) at include\application.inc:1419
20. #19 APPRUN(0x19ba398, {Proc = {procedure (POINTER)} 0x162fdf8, Self = 0x196a3b8}) at include\interfacebase.inc:54
21. #20 RUN(0x196a3b8) at include\application.inc:1407
22. #21 main at MapViewer_Demo.lpr:55
23.  

For example you'll see that #2 CREATE is TCustomAction.Create in D:\fpc-laz-asus\Lazarus\laz-svn-trunk\lcl\include\customaction.inc and the current debugger will happily accept break points there.

The structure of my folders is
  D:\fpc-laz-asus\FPC -> where all my versions of FPC reside
  D:\fpc-laz-asus\FPC\3.0.6 ->  Current development folder with optimized make units
  D:\fpc-laz-asus\FPC\3.0.6-dbg-bak ->  Debug units/*.o and *.ppu + some others
  D:\fpc-laz-asus\FPC\3.0.6-dbg ->  units/*.o and *.ppu for which we want to trace code from Lazarus

Add -FuD:\fpc-laz-asus\FPC\3.0.6-dbg/units/i386-win32/* as last of the -Fu of the fpc.cfg

For debugging parts of FPC, copy the desired *.o's and matching *.ppu's  from D:\fpc-laz-asus\FPC\3.0.6-dbg-bak to D:\fpc-laz-asus\FPC\3.0.6-dbg respecting the folder tree hierarchy, when no debugging required for the selected unit, delete the ppu and o from the 3.0.6-dbg.

Lazarus program MUST be compiled Type of debug info : Dwarf with sets. (-gw -godwarfsets)

How to do a build :
  Adjust the .txt batch to your own requirement.
  Start command line
  Paste the top of the file to REM END OF SETTING UP COMPILE ENVIRONMENT
Then depending on what you want to build, select the desired build commands.

An important note, to avoid a complete cycle build, first do
CD rtl + make
then
CD packages + make
because otherwise there may be trouble.

Most of the time, except of course when things go wrong ;-), it works.

Ah yes, backups maybe of some use ...

[devEric69]

The debugging path of a simple TStringList. Add() method written as follows...:

Code: Pascal  [Select][+][-]

1. procedure TForm1.btnTestClick(Sender: TObject);
2. var oStrList: TStringList;
3.     s1, s2: string;
4. begin
5.     s1:='Hello'; s1:='Koukou';
6.     oStrList:= TStringList.Create;
7.     oStrList.Add(s1); oStrList.Add(s2);
8.     FreeAndNil(oStrList);
9. end;

... ➔ by adding files, one by one, in the project inspector, starting with Classes.pp, then each *.inc file that says it is "not found" (until it has been added in the project inspector and its directory has been added in the -Fi of the project options) is slippery, certainly, but especially very long: the *.inc of FPC are fiting like "Russian dolls" between the *begin* and the final *end.* of this unit .../.../fcp/rtl/unix/classes.pp. All this end, for my part, with a global deprecated procedure that says that it is "already declared forward" (?).

➔ so, I tried the "raw" method: a shell script that returns to me, on the one hand the list of all paths of the .../.../fpc/rtl that contain *.inc, and on the other hand the list of the .../...fpc/rtl directory paths that contain *.p*, of which I only kept those that end with .../unix, .../linux, and .../inc. I included them in their repective tags (-Fu and -Fi) of the project's *.lpi. @BrunoK: Well, a compiler is smart, but very complicated and downright obscure when, like me, we haven't read "Compilers: Principles, Techniques, and Tools", commonly known as the "Dragon Book" ==> In short, I encountered completely obscure messages (possible that I put target-croos-compile paths instead of others...) .

- finally, I came across this post (https://forum.lazarus.freepascal.org/index.php/topic,41706.msg290002.html#msg290002), where GetMem and wp each give their own solution.

@wp: your solution works perfectly with just a few *.p* units added. But I see that just like me, in the case of a "container" unit of many *.inc like Classes.pp, that it becomes random to be able to debug an FPC class of the RTL, because they are exploded into too many pieces of file-codes-*.inc.

@Martin_fr: the solution that works in any case is effectively to reinstall with FCPUPdeluxe, which is very fast, with some compiler options for, and FCP, and Lazarus. I've used this options (button "Setup+ > Options override > FPC options && Lazarus options"): -O1 -gw2 -godwarfsets -gl ==> I can now debug step by step, anything I want (RTL, ...) :