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User forums => Using Code::Blocks => Topic started by: nji on May 03, 2020, 02:02:23 pm

Title: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: nji on May 03, 2020, 02:02:23 pm

I recently installed 64bit build of v.20.03, bundled with mingw (on Window7 64bit).

Building a simple console app it builds it to 64bit without problems.

When I have a look at the project's build options
Compiler Settings/ Compiler Flags / General
there are Targets 32 and 64 bit, both deselected.

But in the command line there is -m64. Why?

If I choose 32bit target in the compiler settings (-m32)
both -m32 and -m64 are used for the command line.
What is the effect by that?

Also the linker gives lots of errors then like

Code

...ld.exe: cannot find -lstdc++

What do I have to do additionally to build 32bit apps?

Simple questions, but maybe may be answered in short
and of help not only for me but for other new users.

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: BlueHazzard on May 03, 2020, 03:13:15 pm

If you have compiling problems, post a full rebuild log as described here:
http://wiki.codeblocks.org/index.php?title=FAQ-Compiling_(general)#Q:_How_do_I_report_a_compilation_problem_on_the_forums.3F

There are essentially 3 places where compiler options are set:
1) Global compiler settings: Settings->Compiler -> Select your compiler from the drop down at the top->Compiler settings
2) Project level: Project->Build options->Select the project name on the left->Compiler
3) Target level: Project->Build options->Select the target name on the left->Compiler

All this options stack together...

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: nji on May 03, 2020, 05:04:25 pm

Better I'll try again:

I do the most sophisticated task of building a console app.
(All settings are as of installed C:B/ mingw).

Let it build ...

"Hello world!"

Then change the project's/ target's build options to -m32.
Do a rebuild ... and get the linker errors above.
What is missing?

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: sodev on May 03, 2020, 06:53:38 pm

Mingw-w64 toolchains are not multilib, they can compile only for one architecture. To build for 32 bit you have to download a 32 bit toolchain and either update the GCC compiler configuration of CodeBlocks to use that one instead, or, if you want to build for both architectures, add a new compiler configuration and use that one in the project.

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: nji on May 03, 2020, 07:02:03 pm

Thank you.

So I misunderstood the 2nd note of
http://www.codeblocks.org/downloads/26 (http://www.codeblocks.org/downloads/26)
I thought 32/64 bit would mean the target.

(Still I wonder why the compiler allows to produce 32bit code, just the linker fails (see posts above)).

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: BlueHazzard on May 03, 2020, 08:31:46 pm

Again... post a build log...
Again, i posted the location where the linker or compiler options are (replace compiler with linker in my uper direction) and look if there is a stray -m64 ....

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: huycan on May 03, 2020, 08:45:18 pm

If you want multilib... you can download from here: https://sourceforge.net/projects/mingw-w64/files/Multilib%20Toolchains%28Targetting%20Win32%20and%20Win64%29/ray_linn/gcc-9.x-with-ada/ (https://sourceforge.net/projects/mingw-w64/files/Multilib%20Toolchains%28Targetting%20Win32%20and%20Win64%29/ray_linn/gcc-9.x-with-ada/) then you can use the switch -m32 and -m64

Title: Re: 32 and 64 builds with mingw on Windows (NEWBIE question)
Post by: nji on May 03, 2020, 09:19:42 pm

Well, my tiny newbie question does seem not to be as "newbie" as I thought :-)

As I already wrote in my former post the bundled mingw does only 64bit.

(@BlueHazzard: Please notice that there is no sense in posting a log etc.)

If the multilib bundle works, it should be a fine thing...
and this thread of a help not only for me.

Thank you all of you!