ccmake: Check for curses more robustly before enabling

Compute a default for `BUILD_CursesDialog` by building a small test
project that uses curses.  Disable `ccmake` by default if it fails,
and do not search for Curses as part of the main build.  This avoids
creating FindCurses cache entries when we are not considering ccmake.

If `BUILD_CursesDialog` is enabled (e.g. by the user) then warn if
curses cannot be found.

1 files changed, 41 insertions, 0 deletions

diff --git a/Source/Checks/Curses.cmake b/Source/Checks/Curses.cmake
new file mode 100644
index 0000000..46dc770
--- /dev/null
+++ b/Source/Checks/Curses.cmake
@@ -0,0 +1,41 @@
+message(STATUS "Checking for curses support")
+
+# Try compiling a simple project using curses.
+# Pass in any cache entries that the user may have set.
+set(CMakeCheckCurses_ARGS "")
+foreach(v
+    CURSES_INCLUDE_PATH
+    CURSES_CURSES_LIBRARY
+    CURSES_NCURSES_LIBRARY
+    CURSES_EXTRA_LIBRARY
+    CURSES_FORM_LIBRARY
+    )
+  if(${v})
+    list(APPEND CMakeCheckCurses_ARGS -D${v}=${${v}})
+  endif()
+endforeach()
+file(REMOVE_RECURSE "${CMake_BINARY_DIR}/Source/Checks/Curses-build")
+try_compile(CMakeCheckCurses_COMPILED
+  ${CMake_BINARY_DIR}/Source/Checks/Curses-build
+  ${CMake_SOURCE_DIR}/Source/Checks/Curses
+  CheckCurses # project name
+  CheckCurses # target name
+  CMAKE_FLAGS
+    "-DCMAKE_C_FLAGS:STRING=${CMAKE_C_FLAGS}"
+    ${CMakeCheckCurses_ARGS}
+  OUTPUT_VARIABLE CMakeCheckCurses_OUTPUT
+  )
+
+# Covnert result from cache entry to normal variable.
+set(CMakeCheckCurses_COMPILED "${CMakeCheckCurses_COMPILED}")
+unset(CMakeCheckCurses_COMPILED CACHE)
+
+if(CMakeCheckCurses_COMPILED)
+  message(STATUS "Checking for curses support - Success")
+  file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+    "Checking for curses support passed with the following output:\n${CMakeCheckCurses_OUTPUT}\n\n")
+else()
+  message(STATUS "Checking for curses support - Failed")
+  file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+    "Checking for curses support failed with the following output:\n${CMakeCheckCurses_OUTPUT}\n\n")
+endif()