[CMake] Trouble with FindPNG module

[Robert Dailey]

Interestingly, the changes to my toolchain made below work:


set( CMAKE_SYSTEM_NAME Linux )
set( CMAKE_SYSTEM_VERSION 1 )
set( CMAKE_SYSTEM_PROCESSOR i386 )
set( CMAKE_C_COMPILER gcc-4.9 )
set( CMAKE_CXX_COMPILER g++-4.9 )
set( CMAKE_C_COMPILER_ARG1 -m32 )
set( CMAKE_CXX_COMPILER_ARG1 -m32 )


The only change here is that I'm using CMAKE_C_COMPILER_ARG1 and
CMAKE_CXX_COMPILER_ARG1. These are not documented anywhere. I only
found out about them from a post from Bill Hoffman (which I have lost
the URL to).

Is this the correct toolchain? At least find_package() is properly
finding 32-bit libraries now, so I am happy. Should
CMAKE_SYSTEM_PROCESSOR be i386 or i686?



On Mon, Apr 24, 2017 at 12:22 PM, Robert Dailey
<rcdailey.lists at gmail.com> wrote:
> The output is:
>
> x86_64-linux-gnu
>
> How can I tell CMake to look for 32-bit libraries? I would like to
> force this from my toolchain file (which I posted a few minutes ago)
>
> On Mon, Apr 24, 2017 at 10:16 AM, Andrew Fuller <afuller at teradici.com> wrote:
>> Where did the library get installed on your system?  What's the value of
>> CMAKE_<LANG>_LIBRARY_ARCHITECTURE?
>>
>>
>> Since you're on a 64-bit system, I'd expect CMake to be looking for 64-bit
>> libraries unless you've told it otherwise.
>>
>> ________________________________
>> From: CMake <cmake-bounces at cmake.org> on behalf of Robert Dailey
>> <rcdailey.lists at gmail.com>
>> Sent: April 24, 2017 7:54:18 AM
>> To: CMake; CMake Developers
>> Subject: Re: [CMake] Trouble with FindPNG module
>>
>> Sorry to bump; any info on this? I'm completely blocked :-(
>>
>> On Fri, Apr 21, 2017 at 4:48 PM, Robert Dailey <rcdailey.lists at gmail.com>
>> wrote:
>>> I'm running CMake 3.8.0 on Ubuntu 14. I invoke the following:
>>>
>>> find_package(PNG REQUIRED)
>>>
>>> Which gives me the output in CMake:
>>>
>>> Could NOT find PNG (missing: PNG_LIBRARY) (found version "1.2.50")
>>>
>>> The CMakeCache.txt file has these variables set:
>>>
>>> PNG_LIBRARY_DEBUG:FILEPATH=PNG_LIBRARY_DEBUG-NOTFOUND
>>> PNG_LIBRARY_RELEASE:FILEPATH=PNG_LIBRARY_RELEASE-NOTFOUND
>>> PNG_PNG_INCLUDE_DIR:PATH=/usr/include
>>>
>>> So it found the headers, but not the libs. Why did it not find the
>>> libs? Note that my version of Ubuntu is 64-bit, and I've installed the
>>> 32-bit libs like so:
>>>
>>> $ sudo apt-get install libpng12-dev:i386
>>>
>>> Would the find module be confused because it is trying to find the
>>> 64-bit library? What's the issue?
>> --
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