[CMake] debug/optimized include directories

[Michael Wild]

On 11/01/2011 09:49 PM, Robert Dailey wrote:
> Well if you need any help coding the feature let me know. I'm already
> liking the idea of adding features I want myself into CMake :)
> 
> Thanks!
> 
> ---------
> Robert Dailey
> 
> 
> On Tue, Nov 1, 2011 at 3:47 PM, David Cole <david.cole at kitware.com
> <mailto:david.cole at kitware.com>> wrote:
> 
>     On Tue, Nov 1, 2011 at 4:33 PM, Robert Dailey <rcdailey at gmail.com
>     <mailto:rcdailey at gmail.com>> wrote:
>     > On Tue, Nov 1, 2011 at 3:32 PM, David Cole <david.cole at kitware.com
>     <mailto:david.cole at kitware.com>> wrote:
>     >>
>     >> Not yet
>     >
>     > Meaning there are plans in the works to add such functionality in
>     the near
>     > future?
>     > For now I guess I could actually hard code VS environment
>     variables in my
>     > include directory strings, such as $(Configuration).
> 
>     There is a feature planned to add per-target include directories (as a
>     target property). As part of that work, we will probably naturally
>     also add per-configuration values of that new target property. It is
>     not yet added as a feature request in the bug tracker, but there are
>     related ones that I may "borrow" for the purpose. Stay tuned for more
>     info, but it is not coming in the next week or two. Hopefully, in time
>     for 2.8.7, but it depends on timing at this point.... so no promises.
> 
>     For now, your $(Configuration) idea is probably your best bet. (And
>     would continue to work even after we implement this feature...)
> 
> 
>     HTH,
>     David

Alternatively, if you want to keep it cross-platform and generator
independent, you could use a proxy header which #include's the correct
header using relative or absolute paths using #ifdef's. Probably that
proxy header would need to be generated by configure_file(). You then
would pass the configuration name by setting the
COMPILE_DEFINITIONS_<CONFIG> property on the directory, target or source
file affected.


Say you have the following layout:

project/
|-- CMakeLists.txt
|-- src/
|   |-- frobnicate.c
`-- include/
    |-- Debug/
    |   |-- foo.h
    |   `-- bar.h
    `-- Optimized/
        |-- foo.h
        `-- bar.h

Now, you want to include the configuration dependent foo.h and bar.h in
frobnicate.c without having to change frobnicate.c itself and might look
like this:

frobnicate.c
<<<<<<<<<<<<
#include "foo.h"
#include "bar.h"

int main(int argc, char** argv)
{
  foo();
  bar();
  return 0;
}
>>>>>>>>>>>>

To get around the issue of needing a configuration-dependent include
path, you could do the following in your CMakeLists.txt file:

CMakeLists.txt:
<<<<<<<<<<<<<<<
cmake_minimum_required(VERSION 2.6)
project(frobnicate C)

# loads of stuff ....

# generate wrapper headers for foo.h and bar.h
foreach(hdr foo.h bar.h)
  # find a good include guard name
  string(TOUPPER "${hdr}" incguard)
  string(REGEX REPLACE "[^a-zA-Z0-9_]" "_" incguard
    "PROXY_HDR_${incguard}")
  # write the proxy header
  file(WRITE "${PROJECT_BINARY_DIR}/include/${hdr}"
"
/* AUTOMATICALLY GENERATED BY CMAKE -- DO NOT EDIT! */
#pragma once
#ifndef ${incguard}
#define ${incguard}

/* if building debug configuration, include Debug/${hdr},
   otherwise Optimized/${hdr} */
#if defined(CONFIG_DEBUG)
#  include \"Debug/${hdr}\"
#else
#  include \"Optimized/${hdr}\"
#endif

#endif
")
endforeach()

# set up the definitions for the switch yard
set_directory_properties(PROPERTIES
  COMPILE_DEFINITIONS_DEBUG CONFIG_DEBUG
  COMPILE_DEFINITIONS_RELEASE CONFIG_RELEASE
  COMPILE_DEFINITIONS_RELWITHDEBINFO CONFIG_RELWITHDEBINFO
  COMPILE_DEFINITIONS_MINSIZEREL CONFIG_MINSIZE_REL)

# set up the include directories so our proxy headers and the actual
# headers can be found by the preprocessor
include_directories(
  ${PROJECT_BINARY_DIR}/include
  ${PROJECT_SOURCE_DIR}/include)

add_executable(frobnicate frobnicate.c)

>>>>>>>>>>>>>>>


HTH

Michael