[fpc-pascal] getting cross with the cross compiler
pascalX at piments.com
pascalX at piments.com
Tue Oct 10 11:45:05 CEST 2017
On 10/10/17 10:08, Tony Whyman wrote:
> On 10/10/17 05:51, pascalX at piments.com wrote:
>> Were it not for the version restrictions in building fpc one could
>> arguably say this was a reasonable assumption. As it is, it leads to
>> a very confused and confusing state which has taken several days to
>> understand and untangle.
>> Maybe that could be addressed.
>> Thanks for the help along the way.
> I do make a lot of use of the cross-compiler and the cross-platform
> libraries capability of FPC and I am wondering if you might be looking
> at the problem in the wrong way, especially when you seem to be talking
> about using the cross-compiler for the Lazarus IDE. Here's how I use
> them and hopefully this will inform your own understanding.
> 1. When I develop a program using the Lazarus IDE, I am only working
> with the native (debug) libraries for the development platform. In my
> case, this is 64-bit Linux. Occasionally, I will run 64-bit Windows in a
> virtual machine and Lazarus (in native Windows mode) to test for Windows
> specific issues. During the development and test cycle I do not use
> cross-compilers or libraries and you would probably only need to do this
> when compiling for a target on which it is just not practical to run the
> Lazarus IDE.
> 2. The cross-compiler and libraries come into their own when I generate
> production executables and installation packages as they enable the
> whole process to be performed on the same platform (Linux 64-bit) for my
> required target platforms: Linux (32-bit and 64-bit) and Windows (32-bit
> and 64-bit), and automated using a single script - which then goes on to
> build the Debian packages and Windows installer packages.
> 3. I always compile FPC from source. For the development platform, a
> 64-bit compiler is needed and the FPC RTL and FCL libraries include
> debug symbols. The Lazarus IDE compiles its libraries (LCL and
> components) using this compiler and the FPC libraries, and works very
> nicely without the user needing to understand too much about what is
> going on - or even having to do much in the way of IDE configuration.
> 4. For the production platform, a 32-bit cross complier is also needed
> as are optimised RTL and FCL libraries and optimised Lazarus libraries.
> These libraries have to be built explicitly for each of the production
> platforms. I have a separate location in the filesystem for the
> production libraries (separate from development libraries) with
> sub-directories for x86_64-linux, x86_64-win64, i386-linux, i386-win32.
> Within the Lazarus parts of the libraries, the Linux libs have the gtk2
> interface libraries, while the Windows ones have the win32 interfaces
> libraries (both win32 and win64).
> 5. I then use FPC Makefiles to build for each target platform in turn
> which reference the production and not the development libraries. This
> includes Lazarus programs and the Lazarus IDE does not have anything to
> do with this part of the process. Indeed, it would complicate matters no
> end to try and use the IDE to build for each production target.
> If you have taken only a few days to dis-entangle all there is to know
> about cross compilation and cross platform libraries then I think you
> are doing very well. It has taken me far longer than that to work out
> the toolchain that I need and I am still learning the best way to do
> things. Indeed, there may be no "best way" to do things. The above works
> for me, but may not work for you. However, the advice that I would give
> is that as soon as you start to talk about cross-compilers, then you
> need to start thinking about the differences between development and
> production environments. Unless you are working with embedded systems,
> then my advice is don't try to work with cross-compilers for
> development. On the other hand, when you generate production executables
> then cross-compilers and cross platform libraries are very useful for
> automating the process and ensuring consistent quality across all target
> platforms. However, you do need to think through carefully how the
> toolchain works and explicitly generate optimised libraries for each
> target platform including the Lazarus interface appropriate for the
> target. Use the IDE for development but have a separate scripted
> environment for generating production executables.
Thanks for a very clear and detailed description of you workflow. That
is definitely very helpful coming form someone with hands-on experience
of going the whole way.
I'm not new to cross-platform work, so I'm not starting from zero, but
this is the first time I've attempted a cross-platform project on
It's not a project I intend to distribute, it's just a bit of fun for a
friend that I am using to evaluate the cross-compilation capabilities
that Lazarus claims.
It looks like it's 98% of the way there with a couple wrinkles that need
In view of the issues I've found, VM may be the best way to get a final
result. But I like the idea of full cross-platform development and if no
one tests it and feeds the problems back the gap will never get bridged.
Thanks very much for the info and advice.
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