[CMake] CMAKE_C_COMPILE_OBJECT <FLAGS> vs <INCLUDES>

[Sam Cristall]

Hi Robert,

Yes, we are adding the Keil C8051 compiler, which is very old and uses a very unique command line syntax compared to the others supported by CMake.  Also, it's Windows only but Wine works -- so we optionally add Wine on non-Windows platforms.  An example would be:

wine C51.exe INCDIR(/path/to/dir/1/, /path/to/dir/2/) DEBUG DEFINE(FOO_FLAG) OBJECT(/path/to/output.obj) /path/to/source.c

To achieve this, we use a wrapper cmake script with the following:

set(CMAKE_C_COMPILE_OBJECT
"cmake\
-DWINE=${WINE}\
-DCOMPILER=<CMAKE_C_COMPILER>\
-DSOURCE=<SOURCE>\
-DINCLUDES=\"<INCLUDES>\"\
-DFLAGS=\"<DEFINES> <FLAGS>\"\
-DOBJECT=<OBJECT>\
-P \"${CMAKE_CURRENT_LIST_DIR}/C8051Compile.cmake\""
)

It was important that <INCLUDES> be separate, as its form is significantly different than most compilers.  Prior to cmake 3.4, it would be very difficult to handle this, since <FLAGS> would append the includes as a list of directories, and there is no CMAKE_INCLUDE_FLAG suffix variable (need a closing bracket for INCDIR).

> On Jun 30, 2016, at 2:23 PM, Robert Maynard <robert.maynard at kitware.com> wrote:
> 
> Hi,
> 
> Can you explain what the goal of your compilation wrappers are? Are
> you trying to add a new compiler?
> 
> 
> 
> On Wed, Jun 29, 2016 at 1:41 PM, Sam Cristall <cristall at eleveneng.com> wrote:
>> Looks like this was just a change in CMake 3.4.  Updated to latest, and everything is working.
>>> On Jun 28, 2016, at 5:19 PM, Sam Cristall <cristall at eleveneng.com> wrote:
>>> 
>>> I'm trying to implement a cross compilation wrapper and hit a snag with CMAKE_C_COMPILE_OBJECT.  I've found that on OSX / Linux (Makefile Generator), <INCLUDES> and <FLAGS> work as expected, however on Windows (MinGW Makefile Generator), <FLAGS> has both the flags and includes, whereas <INCLUDES> is undefined.  Is this expected?
>>> 
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