diff options
Diffstat (limited to 'Help/command/if.rst')
| -rw-r--r-- | Help/command/if.rst | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/Help/command/if.rst b/Help/command/if.rst index 4781f35..1cd9965 100644 --- a/Help/command/if.rst +++ b/Help/command/if.rst @@ -187,10 +187,11 @@ Possible conditions are: ``if(<variable|string> IN_LIST <variable>)`` True if the given element is contained in the named list variable. -``if(DEFINED <variable>)`` - True if the given variable is defined. It does not matter if the - variable is true or false just if it has been set. (Note macro - arguments are not variables.) +``if(DEFINED <name>|ENV{<name>})`` + True if a variable or environment variable + with given ``<name>`` is defined. + The value of the variable does not matter. + Note that macro arguments are not variables. ``if((condition) AND (condition OR (condition)))`` The conditions inside the parenthesis are evaluated first and then @@ -231,7 +232,7 @@ which is true because ``var2`` is defined to "var1" which is not a false constant. Automatic evaluation applies in the other cases whenever the -above-documented signature accepts ``<variable|string>``: +above-documented condition syntax accepts ``<variable|string>``: * The left hand argument to ``MATCHES`` is first checked to see if it is a defined variable, if so the variable's value is used, otherwise the @@ -269,3 +270,8 @@ specified in a :ref:`Quoted Argument` or a :ref:`Bracket Argument`. A quoted or bracketed variable or keyword will be interpreted as a string and not dereferenced or interpreted. See policy :policy:`CMP0054`. + +There is no automatic evaluation for environment or cache +:ref:`Variable References`. Their values must be referenced as +``$ENV{<name>}`` or ``$CACHE{<name>}`` wherever the above-documented +condition syntax accepts ``<variable|string>``. |