Handmade Hero»Forums»Code
2 posts
I seem to be unable to pass linker options as environment variable in build.bat
Edited by Lichinka on Reason: Initial post
I am on Day 17.
These are the contents of my build.bat:
1
2
3
4
5
6
7
@echo off
set CmnCompileFlags = -MT -Gm- -nologo -GR- -EHsc -EHa- -Oi -W4 -wd4201 -wd4100 -FC -Zi -Fmwin32_game.map 
set CmnLinkerFlags = -subsystem:windows,5.2 -opt:ref user32.lib Gdi32.lib Ole32.lib
IF NOT EXIST ..\build mkdir ..\build
pushd ..\build
cl %CmnCompileFlags% ..\code\win32_game.cpp /link %CmnLinkerFlags%
popd

When trying to run it I receive a bunch of LNK2019 erros such as this one:
win32_game.obj : error LNK2019: ссылка на неразрешенный внешний символ __imp_StretchDIBits в функции "void __cdecl Win32DisplayBufferInWin
However this compiles just fine:
1
2
3
4
5
6
7
@echo off
set CmnCompileFlags = -MT -Gm- -nologo -GR- -EHsc -EHa- -Oi -W4 -wd4201 -wd4100 -FC -Zi -Fmwin32_game.map 
set CmnLinkerFlags = -subsystem:windows,5.2 -opt:ref user32.lib Gdi32.lib Ole32.lib
IF NOT EXIST ..\build mkdir ..\build
pushd ..\build
cl %CmnCompileFlags% ..\code\win32_game.cpp /link -subsystem:windows,5.2 -opt:ref user32.lib Gdi32.lib Ole32.lib
popd

Yes, I checked if compiler flags were in effect.
I also tried moving -subsystem:windows,5.2 and -opt:ref ouside %CmnLinkerFlags% to see if that would help. It seems that linker just doesn't see any libraries inside of a variable.
I would really like to know what is going on here and whether there is a workaround.
Mārtiņš Možeiko
2198 posts / 1 project
I seem to be unable to pass linker options as environment variable in build.bat
Edited by Mārtiņš Možeiko on
The problem is that you setting environment variables with set CmnCompileFlags = xxx syntax. This actually sets CmnCompileFlags(space) environment variable.

So if you want to use it like that, you need to add space when using it with % symbols: %CmnCompileFlags % (notice space before closing % symbol. Or you can do set CmnCompileFlags=xxx without any spaces around = symbol.

You can check this easily by adding following lines to your .bat file:
1
2
echo CmnCompileFlags without space = %CmnCompileFlags%
echo CmnCompileFlags WITH space = %CmnCompileFlags %


Same thing with CmnLinkerFlags variable.
2 posts
I seem to be unable to pass linker options as environment variable in build.bat
Edited by Lichinka on
mmozeiko
So if you want to use it like that, you need to add space when using it with % symbols: %CmnCompileFlags %

Thanks, this solved the issue. Any ideas why CmnCompileFlags worked just fine? Cmd output for illustration:
1
2
3
4
CmnCompileFlags without space =  -MT -Gm- -nologo -GR- -EHsc -EHa- -Oi -W4 -wd4201 -wd4100 -FC -Zi -Fmwin32_game.map
CmnCompileFlags WITH space =  -MT -Gm- -nologo -GR- -EHsc -EHa- -Oi -W4 -wd4201 -wd4100 -FC -Zi -Fmwin32_game.map
CmnLinkerFlags without space =
CmnLinkerFlags WITH space =  -subsystem:windows,5.2 -opt:ref user32.lib Gdi32.lib Ole32.lib

Edit: I did a little bit more fidgeting with the bat file, and I can't reproduce this behaviour anymore. At this point I do need to add an extra space into %CmnCompileFlags % for it to work. I am not sure what change in particular caused it, but I do not think it is worth your attention to investigate what was probably user error on my part.