I followed Bart's suggestion and added the -al switch to the fpc.cfg file. This was probably the right move, as - after a new compile - I could see the wanted .s file beside the regular EXE.
I uploaded the .s file here: https://mega.nz/file/rlpyHa7b#fx0LYTjapmUdFRkzVGCCzFFogqYuEu7UvYQ5HtilLks I opened the new .s file with a text editor and had a new surprising result: the instruction i:=cmbYear.ItemIndex+2005; is nowhere to be found. I tried to find the figure 2005 both as 07D5 and as D507: no hit. I tried to find the string 'peppe' (that I correctly find in the EXE) in the S file: no hit. I tried to find the string 'peppe' in hex format (7065707065) in the S file: no hit. I tried to understand where the OnClick event could be written, but - with little surprise - I could not. I recompiled with no debug info + using the option 'no optimization'. The new .s file is stored here https://mega.nz/file/X1B2mJpL#smqDJOoDOBZOMoDUpeNutXw3C3YgqHurbdC6L7m2vf4 The new .s file gives no new information than the old one. With all this: the EXE works ok. This case shows that I have a lot of things to learn. Any help? Peppe PS: if interested: unit1.lfm https://mega.nz/file/O1IDhIwb#0SDAninq5yfTOKELksfTRnaXqpIocwh3ugthDzFK2G8 unit1.pas https://mega.nz/file/fgYjFQzJ#wuaS4A7CeTR0Ra35_E5gk8ggGlAFPBqaSJS_p_yi8Ss On Fri, Sep 3, 2021 at 11:07 PM duilio foschi <octopush...@gmail.com> wrote: > today I did an experiment that gave me surprising results (due to my > ignorance, > of course). > > I have an application written in Lazarus and I need to do one fix only. > > This line > > result:=EncodeDate( > cmbYear.ItemIndex+2005, > cmbMonth.ItemIndex+1, > 1); > > > needs to be changed into > > > result:=EncodeDate( > cmbYear.ItemIndex+2006, > cmbMonth.ItemIndex+1, > 1); > > > I thought it would be easy to use an hex editor like PSPad hex, find the > number > 2005 as 07D5 then fix it (maybe after the right guess in case of multiple > hits). > > To my surprise, I could not find the word 07D5. As I vaguely remember the > big endian/little endian question, I tried to look for D507: no hit. > > In order to dig into the question, I created a Lazarus windows application > made of a TCombobox and a TButton. I used v. 2.0.6 on windows 7. > > I added the following code: > > procedure TForm1.Button1Click(Sender: TObject); > var > a:string; > i:integer; > begin > cmbYear.Items.Add('2020'); > cmbYear.Items.Add('2021'); > Caption:='peppe'; > i:=cmbYear.ItemIndex+2005; > Caption:=inttostr(i); > end; > > I compiled/linked that application then opened the EXE using PsPad Hex. > > Looking for string 'peppe', I can easily spot the part that contains > the code of interest. > > Please see here for a screenshot of PsPad Hex: > https://i.ibb.co/2M054Qx/1.jpg > > (I encircled a few familiar names). > > I cannot understand how this instruction > > i:=cmbYear.ItemIndex+2005; > > is coded here. > > I am no assembly expert, but I expect that the compiler would translate > the instruction into something like > > move 2005 to register X > add register X to register Y (where register Y represents > cmbYear.ItemIndex) > move register Y to register Z (where register Z represents var i) > > In any case I would expect that the figure 2005 (07D5) be written > somewhere, > but facts prove me wrong. > > I am very curious: what really happens in the EXE? > > In which form gets this instruction compiled? > i:=cmbYear.ItemIndex+2005; > > Could someone explain? > > Thank you > > Peppe > >
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