From: Ralf Habacker <ralf.habacker@freenet.de>
Date: Mon, 18 May 2020 10:51:03 +0000 (+0200)
Subject: cmake: Add macro check_auto_option() as an addition to add_auto_option()
X-Git-Tag: dbus-1.13.18~4^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb6d4a14399f880cee581fb1706e1f4ac85df158;p=thirdparty%2Fdbus.git

cmake: Add macro check_auto_option() as an addition to add_auto_option()

check_auto_option() checks the values given to an auto-option and prints
a fatal error in case of invalid combinations.
---

diff --git a/cmake/modules/Macros.cmake b/cmake/modules/Macros.cmake
index 741d0c1c3..9db3bfb0e 100644
--- a/cmake/modules/Macros.cmake
+++ b/cmake/modules/Macros.cmake
@@ -212,3 +212,24 @@ macro(add_auto_option _name _text _default)
     endif()
     set_property(CACHE ${_name} PROPERTY STRINGS AUTO ON OFF)
 endmacro()
+
+
+#
+# Ensure that if a tristate ON/OFF/AUTO feature is set to ON,
+# its requirements have been met. Fail with a fatal error if not.
+#
+# _name: name of a variable ENABLE_FOO representing a tristate ON/OFF/AUTO feature
+# _text: human-readable description of the feature enabled by _name, for the
+#        error message
+# _var: name of a variable representing a system property we checked for,
+#       such as an executable that must exist for the feature enabled by _name to work
+# _vartext: what we checked for, for the error message
+#
+macro(check_auto_option _name _text _var _vartext)
+    set(_nameval ${${_name}})
+    set(_varval ${${_var}})
+    #message("debug: _name ${_name} ${_nameval}  _var ${_var} ${_varval}")
+    if(${_nameval} AND NOT ${_nameval} STREQUAL "AUTO" AND NOT ${_varval})
+        message(FATAL_ERROR "${_text} requested but ${_vartext} not found")
+    endif()
+endmacro()
diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index 4ffe7779e..8239c8e86 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -23,9 +23,7 @@ if(DBUS_ENABLE_DOXYGEN_DOCS)
         set(INSTALL_QCH_DIR ${CMAKE_INSTALL_DATADIR}/doc/dbus)
     endif()
     find_program(QHELPGENERATOR_EXECUTABLE NAMES qhelpgenerator qhelpgenerator-qt5)
-    if(ENABLE_QT_HELP AND NOT ENABLE_QT_HELP STREQUAL "AUTO" AND NOT QHELPGENERATOR_EXECUTABLE)
-        message(FATAL_ERROR "Qt help requested but qhelpgenerator not found")
-    endif()
+    check_auto_option(ENABLE_QT_HELP "Qt help" QHELPGENERATOR_EXECUTABLE "qhelpgenerator")
     if(ENABLE_QT_HELP AND QHELPGENERATOR_EXECUTABLE)
         message(STATUS "${QHELPGENERATOR_EXECUTABLE} found")
         set(DOXYGEN_GENERATE_QHP YES)