[CMake] Determining debug & release configurations

[Andreas Mohr]

Hi,

On Fri, Dec 07, 2012 at 04:01:27AM -0500, cmake-request at cmake.org wrote:
> Date: Thu, 6 Dec 2012 11:54:42 -0600
> From: Robert Dailey <rcdailey.lists at gmail.com>

> Does anyone have any code that can detect if a given configuration (by
> name) is a debug or release configuration? This should work in both
> single-configuration and multi-configuration generators.
> 
> For example, in Visual Studio:
> 
> Release -> Release
> MinSizeRel -> Release
> RelWithDebInfo -> Release
> Debug -> Debug
> 
> Also any custom-added configurations should also work.
> 
> For single configuration generators, it should also work. Example:
> 
> CMAKE_BUILD_TYPE -> MinSizeRel -> should evaluate to "Release".
> CMAKE_BUILD_TYPE -> Debug -> should evaluate to "Debug".

That's quite exactly what I'm doing right now (*dynamic*, *build-time*
calculation of required, *random-content* flag strings).

My solution (workaround?) is to provide functions to return a Win32 batch scriptlet
to automatically map those config names to their equivalents,
then continue filling batch file with what I actually want to do,
making use of the %var% helpers which were nicely defined by the prepended scriptlet code.

And of course that unfortunately means having to generate batch files to be executed
rather than possibly adding custom targets with direkt cmake -E copy.... handling.


But of course with a complex mapping of *dynamic* Debug/Release switching at *build-time*
you most likely do need to have a build-executable foundation to get this figured out properly.
Unless you write completely differing *static-content* scripts,
located in completely differing build tree prefixes of Debug/Release configurations.
That's possibly a better solution since with dynamic switching
within an existing tree of payload files
you may end up getting unwanted build configuration conflicts.

Actual possible implementation: add a scripts_[BUILD_CONFIGURATION] dir
somewhere in binary dir, for all configurations that you of course know of at configure time
(CMAKE_CONFIGURATION_TYPES).
Then configure-time generate
only-so-slightly differing scripts there, and invoke them using some

${CMAKE_SOME_BINARY_SUB_DIR}/scripts_${CMAKE_CFG_INTDIR}/my_script.bat

expression.



Helper functions suitable for *dynamic* (i.e., non-configure-time-generated)
evaluation of build-configuration-related values:


function(sbuild_configure_batch_var_name_debug_release_string_lower_get _out)
  set(${_out} "cfg_build_string_debug_release" PARENT_SCOPE)
endfunction(sbuild_configure_batch_var_name_debug_release_string_lower_get _out)
function(sbuild_configure_batch_var_name_debug_yes_no_get _out)
  set(${_out} "cfg_build_debug_yes_no" PARENT_SCOPE)
endfunction(sbuild_configure_batch_var_name_debug_yes_no_get _out)

function(sbuild_configure_batch_scriptlet_debug_flag_get _out_debug_flag_content)
  # Provide DOS batch syntax to support dynamic Debug/Release switching in multi-configuration generators (Visual Studio) [see CMAKE_CONFIGURATION_TYPES]

  # Within local handling, *always* query the authoritative helper for batch variable names,
  # to prevent any variable renaming issues from appearing.
  sbuild_configure_batch_var_name_debug_yes_no_get(var_name_debug_yes_no)
  sbuild_configure_batch_var_name_debug_release_string_lower_get(var_name_debrel_string_lower)
  set(sbuild_configure_batch_debug_flag_content "
set build_config=%1
echo \"%0: build config: %build_config%\"

if \"%build_config%\" == \"Release\" goto cfg_release
if \"%build_config%\" == \"Debug\" goto cfg_debug
if \"%build_config%\" == \"RelWithDebInfo\" goto cfg_release
if \"%build_config%\" == \"MinSizeRel\" goto cfg_release

echo \"Unknown build configuration (%build_config%), please add support!\"

rem fall-through to default Release setting (default should always be non-debug! don't leak debug symbols...)

rem Provide several very different variables, to satisfy any and all potential flag requirements
rem of various build environments

:cfg_release
set ${var_name_debug_yes_no}=no
set cfg_build_debug_enabled_int=0
set cfg_build_release_yes_no=yes
set cfg_build_release_enabled_int=1
set ${var_name_debrel_string_lower}=release
goto cfg_build_flags_done

:cfg_debug
set ${var_name_debug_yes_no}=yes
set cfg_build_debug_enabled_int=1
set cfg_build_release_yes_no=no
set cfg_build_release_enabled_int=0
set ${var_name_debrel_string_lower}=debug
goto cfg_build_flags_done

:cfg_build_flags_done

"
  )

  set(${_out_debug_flag_content} "${sbuild_configure_batch_debug_flag_content}" PARENT_SCOPE)
endfunction(sbuild_configure_batch_scriptlet_debug_flag_get _out_debug_flag_content)



HTH,

Andreas Mohr

-- 
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