diff options
Diffstat (limited to 'Help/command')
| -rw-r--r-- | Help/command/if.rst | 204 |
1 files changed, 102 insertions, 102 deletions
diff --git a/Help/command/if.rst b/Help/command/if.rst index 684c113..ed62695 100644 --- a/Help/command/if.rst +++ b/Help/command/if.rst @@ -58,30 +58,30 @@ Basic Expressions """"""""""""""""" ``if(<constant>)`` - True if the constant is ``1``, ``ON``, ``YES``, ``TRUE``, ``Y``, - or a non-zero number (including floating point numbers). - False if the constant is ``0``, ``OFF``, - ``NO``, ``FALSE``, ``N``, ``IGNORE``, ``NOTFOUND``, the empty string, - or ends in the suffix ``-NOTFOUND``. Named boolean constants are - case-insensitive. If the argument is not one of these specific - constants, it is treated as a variable or string (see `Variable Expansion`_ - further below) and one of the following two forms applies. + True if the constant is ``1``, ``ON``, ``YES``, ``TRUE``, ``Y``, + or a non-zero number (including floating point numbers). + False if the constant is ``0``, ``OFF``, + ``NO``, ``FALSE``, ``N``, ``IGNORE``, ``NOTFOUND``, the empty string, + or ends in the suffix ``-NOTFOUND``. Named boolean constants are + case-insensitive. If the argument is not one of these specific + constants, it is treated as a variable or string (see `Variable Expansion`_ + further below) and one of the following two forms applies. ``if(<variable>)`` - True if given a variable that is defined to a value that is not a false - constant. False otherwise, including if the variable is undefined. - Note that macro arguments are not variables. - :ref:`Environment Variables <CMake Language Environment Variables>` also - cannot be tested this way, e.g. ``if(ENV{some_var})`` will always evaluate - to false. + True if given a variable that is defined to a value that is not a false + constant. False otherwise, including if the variable is undefined. + Note that macro arguments are not variables. + :ref:`Environment Variables <CMake Language Environment Variables>` also + cannot be tested this way, e.g. ``if(ENV{some_var})`` will always evaluate + to false. ``if(<string>)`` - A quoted string always evaluates to false unless: + A quoted string always evaluates to false unless: - * The string's value is one of the true constants, or - * Policy :policy:`CMP0054` is not set to ``NEW`` and the string's value - happens to be a variable name that is affected by :policy:`CMP0054`'s - behavior. + * The string's value is one of the true constants, or + * Policy :policy:`CMP0054` is not set to ``NEW`` and the string's value + happens to be a variable name that is affected by :policy:`CMP0054`'s + behavior. Logic Operators """"""""""""""" @@ -89,23 +89,23 @@ Logic Operators .. _NOT: ``if(NOT <condition>)`` - True if the condition is not true. + True if the condition is not true. .. _AND: ``if(<cond1> AND <cond2>)`` - True if both conditions would be considered true individually. + True if both conditions would be considered true individually. .. _OR: ``if(<cond1> OR <cond2>)`` - True if either condition would be considered true individually. + True if either condition would be considered true individually. ``if((condition) AND (condition OR (condition)))`` - The conditions inside the parenthesis are evaluated first and then - the remaining condition is evaluated as in the other examples. - Where there are nested parenthesis the innermost are evaluated as part - of evaluating the condition that contains them. + The conditions inside the parenthesis are evaluated first and then + the remaining condition is evaluated as in the other examples. + Where there are nested parenthesis the innermost are evaluated as part + of evaluating the condition that contains them. Existence Checks """""""""""""""" @@ -113,17 +113,17 @@ Existence Checks .. _COMMAND: ``if(COMMAND command-name)`` - True if the given name is a command, macro or function that can be - invoked. + True if the given name is a command, macro or function that can be + invoked. ``if(POLICY policy-id)`` - True if the given name is an existing policy (of the form ``CMP<NNNN>``). + True if the given name is an existing policy (of the form ``CMP<NNNN>``). ``if(TARGET target-name)`` - True if the given name is an existing logical target name created - by a call to the :command:`add_executable`, :command:`add_library`, - or :command:`add_custom_target` command that has already been invoked - (in any directory). + True if the given name is an existing logical target name created + by a call to the :command:`add_executable`, :command:`add_library`, + or :command:`add_custom_target` command that has already been invoked + (in any directory). ``if(TEST test-name)`` .. versionadded:: 3.3 @@ -133,21 +133,21 @@ Existence Checks .. _DEFINED: ``if(DEFINED <name>|CACHE{<name>}|ENV{<name>})`` - True if a variable, cache variable or environment variable - with given ``<name>`` is defined. The value of the variable - does not matter. Note the following caveats: - - * Macro arguments are not variables. - * It is not possible to test directly whether a `<name>` is a non-cache - variable. The expression ``if(DEFINED someName)`` will evaluate to true - if either a cache or non-cache variable ``someName`` exists. In - comparison, the expression ``if(DEFINED CACHE{someName})`` will only - evaluate to true if a cache variable ``someName`` exists. Both expressions - need to be tested if you need to know whether a non-cache variable exists: - ``if(DEFINED someName AND NOT DEFINED CACHE{someName})``. - - .. versionadded:: 3.14 - Added support for ``CACHE{<name>}`` variables. + True if a variable, cache variable or environment variable + with given ``<name>`` is defined. The value of the variable + does not matter. Note the following caveats: + + * Macro arguments are not variables. + * It is not possible to test directly whether a `<name>` is a non-cache + variable. The expression ``if(DEFINED someName)`` will evaluate to true + if either a cache or non-cache variable ``someName`` exists. In + comparison, the expression ``if(DEFINED CACHE{someName})`` will only + evaluate to true if a cache variable ``someName`` exists. Both expressions + need to be tested if you need to know whether a non-cache variable exists: + ``if(DEFINED someName AND NOT DEFINED CACHE{someName})``. + + .. versionadded:: 3.14 + Added support for ``CACHE{<name>}`` variables. ``if(<variable|string> IN_LIST <variable>)`` .. versionadded:: 3.3 @@ -159,43 +159,43 @@ File Operations .. _EXISTS: ``if(EXISTS path-to-file-or-directory)`` - True if the named file or directory exists. Behavior is well-defined - only for explicit full paths (a leading ``~/`` is not expanded as - a home directory and is considered a relative path). - Resolves symbolic links, i.e. if the named file or directory is a - symbolic link, returns true if the target of the symbolic link exists. + True if the named file or directory exists. Behavior is well-defined + only for explicit full paths (a leading ``~/`` is not expanded as + a home directory and is considered a relative path). + Resolves symbolic links, i.e. if the named file or directory is a + symbolic link, returns true if the target of the symbolic link exists. - False if the given path is an empty string. + False if the given path is an empty string. ``if(file1 IS_NEWER_THAN file2)`` - True if ``file1`` is newer than ``file2`` or if one of the two files doesn't - exist. Behavior is well-defined only for full paths. If the file - time stamps are exactly the same, an ``IS_NEWER_THAN`` comparison returns - true, so that any dependent build operations will occur in the event - of a tie. This includes the case of passing the same file name for - both file1 and file2. + True if ``file1`` is newer than ``file2`` or if one of the two files doesn't + exist. Behavior is well-defined only for full paths. If the file + time stamps are exactly the same, an ``IS_NEWER_THAN`` comparison returns + true, so that any dependent build operations will occur in the event + of a tie. This includes the case of passing the same file name for + both file1 and file2. ``if(IS_DIRECTORY path)`` - True if ``path`` is a directory. Behavior is well-defined only - for full paths. + True if ``path`` is a directory. Behavior is well-defined only + for full paths. - False if the given path is an empty string. + False if the given path is an empty string. ``if(IS_SYMLINK file-name)`` - True if the given name is a symbolic link. Behavior is well-defined - only for full paths. + True if the given name is a symbolic link. Behavior is well-defined + only for full paths. ``if(IS_ABSOLUTE path)`` - True if the given path is an absolute path. Note the following special - cases: + True if the given path is an absolute path. Note the following special + cases: - * An empty ``path`` evaluates to false. - * On Windows hosts, any ``path`` that begins with a drive letter and colon - (e.g. ``C:``), a forward slash or a backslash will evaluate to true. - This means a path like ``C:no\base\dir`` will evaluate to true, even - though the non-drive part of the path is relative. - * On non-Windows hosts, any ``path`` that begins with a tilde (``~``) - evaluates to true. + * An empty ``path`` evaluates to false. + * On Windows hosts, any ``path`` that begins with a drive letter and colon + (e.g. ``C:``), a forward slash or a backslash will evaluate to true. + This means a path like ``C:no\base\dir`` will evaluate to true, even + though the non-drive part of the path is relative. + * On non-Windows hosts, any ``path`` that begins with a tilde (``~``) + evaluates to true. Comparisons """"""""""" @@ -203,29 +203,29 @@ Comparisons .. _MATCHES: ``if(<variable|string> MATCHES regex)`` - True if the given string or variable's value matches the given regular - expression. See :ref:`Regex Specification` for regex format. + True if the given string or variable's value matches the given regular + expression. See :ref:`Regex Specification` for regex format. - .. versionadded:: 3.9 - ``()`` groups are captured in :variable:`CMAKE_MATCH_<n>` variables. + .. versionadded:: 3.9 + ``()`` groups are captured in :variable:`CMAKE_MATCH_<n>` variables. .. _LESS: ``if(<variable|string> LESS <variable|string>)`` - True if the given string or variable's value is a valid number and less - than that on the right. + True if the given string or variable's value is a valid number and less + than that on the right. .. _GREATER: ``if(<variable|string> GREATER <variable|string>)`` - True if the given string or variable's value is a valid number and greater - than that on the right. + True if the given string or variable's value is a valid number and greater + than that on the right. .. _EQUAL: ``if(<variable|string> EQUAL <variable|string>)`` - True if the given string or variable's value is a valid number and equal - to that on the right. + True if the given string or variable's value is a valid number and equal + to that on the right. .. _LESS_EQUAL: @@ -244,20 +244,20 @@ Comparisons .. _STRLESS: ``if(<variable|string> STRLESS <variable|string>)`` - True if the given string or variable's value is lexicographically less - than the string or variable on the right. + True if the given string or variable's value is lexicographically less + than the string or variable on the right. .. _STRGREATER: ``if(<variable|string> STRGREATER <variable|string>)`` - True if the given string or variable's value is lexicographically greater - than the string or variable on the right. + True if the given string or variable's value is lexicographically greater + than the string or variable on the right. .. _STREQUAL: ``if(<variable|string> STREQUAL <variable|string>)`` - True if the given string or variable's value is lexicographically equal - to the string or variable on the right. + True if the given string or variable's value is lexicographically equal + to the string or variable on the right. .. _STRLESS_EQUAL: @@ -279,26 +279,26 @@ Version Comparisons .. _VERSION_LESS: ``if(<variable|string> VERSION_LESS <variable|string>)`` - Component-wise integer version number comparison (version format is - ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). - Any non-integer version component or non-integer trailing part of a version - component effectively truncates the string at that point. + Component-wise integer version number comparison (version format is + ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). + Any non-integer version component or non-integer trailing part of a version + component effectively truncates the string at that point. .. _VERSION_GREATER: ``if(<variable|string> VERSION_GREATER <variable|string>)`` - Component-wise integer version number comparison (version format is - ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). - Any non-integer version component or non-integer trailing part of a version - component effectively truncates the string at that point. + Component-wise integer version number comparison (version format is + ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). + Any non-integer version component or non-integer trailing part of a version + component effectively truncates the string at that point. .. _VERSION_EQUAL: ``if(<variable|string> VERSION_EQUAL <variable|string>)`` - Component-wise integer version number comparison (version format is - ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). - Any non-integer version component or non-integer trailing part of a version - component effectively truncates the string at that point. + Component-wise integer version number comparison (version format is + ``major[.minor[.patch[.tweak]]]``, omitted components are treated as zero). + Any non-integer version component or non-integer trailing part of a version + component effectively truncates the string at that point. .. _VERSION_LESS_EQUAL: |