allow variable names in cmake version checks

Question

allow variable names in cmake version checks

Closed this issue 6 years ago · 3 comments

catkin_lint suggests to change
if(rviz_QT_VERSION VERSION_LESS "5")
into
if("${rviz_QT_VERSION}" VERSION_LESS "5")

with the following notice: operands for operator VERSION_LESS should be quoted strings.

However, using a variable name directly, without quoting and resolving is perfectly valid and IMHO much more readable. Could you improve this check, please?

Answer 1 · 2019-01-11T16:04:14.000Z

I improved the check, because the main goal was to prevent constructs like

set(var1 OFF)
set(var2 var1)
# ...
if(${var2})
    # ...
endif()

In this case, ${var2} resolves to var1, and var1 is then treated as variable and resolved again.

Answer 2 · 2019-01-14T07:09:41.000Z

Isn't that something we would like to happen?

Answer 3 · 2019-01-14T12:19:59.000Z

If you are very adept with CMake, maybe. Most people I know are surprised by this behavior, which is exactly why catkin_lint warns about it in the first place.