How to compile the minrtl304 example for 64bit windows ?
lazarus / 62-General

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440bx · 2018-11-05 23:49

Hello,

I'm trying to compile (and run) the test program found in
"minrtl304.zip" of the following thread
https://forum.lazarus.freepascal.org/index.php/topic,41722.msg290584.h
tml#msg290584

I've left everything exactly the way it was, with two exceptions.  I
changed the command found in a.bat as shown below:

Code: [Select]Original command line (found in a.bat)

fpc.exe -va -Xs -XX -Os1 .\test.pas

changed to compile for 64bit to

fpc.exe -va -Xs -XX -Os1 -TWin64 -Px86_64 .\test.pas

The other "change" is that I copied ppcrossx64.exe into the directory
where test.pas is (thereby matching the 32bit setup/configuration.)

When compiling for 32bit, everything works great.  When compiling for
64bit, I get the following:

Code: [Select]lots and lots of information above...

[0.266] Reading object system.o
[0.269] Number of unresolved externals in objects 3
[0.270] Number of unresolved externals after static libraries 3
[0.271] Number of unresolved externals after defining symbols provided
by link script 3
[0.274] Number of unresolved externals after defining COMMON symbols 3

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

[0.276] test.pas(3,1) Error: Entrypoint _mainCRTStartup not defined
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[0.277] Number of unresolved externals after DLL imports 0
[0.278] test.pas(3,1) Fatal: There were 1 errors compiling module,
stopping
[0.280] Fatal: Compilation aborted
Error: Z:\Training\freepascal - minrtl304\minrtl304\ppcrossx64.exe
returned an error exitcode

When compiling for 32bit, the compiler (and linker) seems to find
_mainCRTStartup just fine.

When compiling for 64bit, the compiler/linker complains about not
finding _mainCRTStartup even though it is defined in sysinitpas.pas.

My question is: what do I have to do to make the linker find
_mainCRTStartup so, the linker and I can both be happy ;-)

Thank you for your help.

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engkin · 2018-11-06 19:45

Warning: I don't use 64bit.

Quote from: 440bx on November 06, 2018, 12:49:02 amWhen compiling for
64bit, the compiler/linker complains about not finding _mainCRTStartup
even though it is defined in sysinitpas.pas.
Regarding sysinitpas, let me quote the compiler source code (for
Windows):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
//compiler\systems\t_win.pas  Procedure
GlobalInitSysInitUnitName(Linker : TLinker);...      if cs_profile in
current_settings.moduleswitches then       
linker.sysinitunit:='sysinitgprof'      else if linkcygwin or
(Linker.SharedLibFiles.Find('cygwin')<>nil) or
(Linker.StaticLibFiles.Find('cygwin')<>nil) then       
linker.sysinitunit:='sysinitcyg'      else       
linker.sysinitunit:='sysinitpas';    end;
As you can see, the name of the unit that contains _mainCRTStartup (or
its equivalent) is not necessarily sysinitpas.

I guess you can find the name of the unit if you check the produced
compiler script (adding -s, I believe). Probably the last unit in the
INPUT section. If my guess is right, then giving sysinitpas the
expected name should solve finding _mainCRTStartup issue.

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440bx · 2018-11-06 21:15

Quote from: engkin on November 06, 2018, 08:45:41 pmI guess you can
find the name of the unit if you check the produced compiler script
(adding -s, I believe). Probably the last unit in the INPUT section.
If my guess is right, then giving sysinitpas the expected name should
solve finding _mainCRTStartup issue.
Engkin, thank you!  ... that looks like enough information for me to
make it work.  I appreciate it.