LIST

list命令共包含 Reading, Search, Modification, Ordering四部分：

• Reading: LENGTH, GET, JOIN, SUBLIST;
• Search: FIND;
• Modification: APPEND, FILTER, INSERT, POP_BACK, POP_FRONT, PREPEND, REMOVE_ITEM, REMOVE_AT, REMOVE_DUPLICATES, TRANSFORM;
• Ordering: REVERSE, SORT

参考list-CMake Documentation, CMake 中的list操作。

Reading

LENGTH

# 返回list的长度
list(LENGTH <list> <output variable>)

cmake_minimum_required(VERSION 2.8)
set(mylist xxx yyy zzz aaa bbb ccc)
MESSAGE("mylist: ${mylist}")
list(LENGTH mylist ll)
MESSAGE("mylist: ${ll}")

OUTPUT: mylist: xxx;yyy;zzz;aaa;bbb;ccc mylist: 6

GET

# 返回列表<list>指定位置<element index>的值<output variable>
list(GET <list> <element index> [<element index> ...] <output variable>)

JOIN

# New in version 3.12.
# 使用连接符<glue>连接列表<list>中所有元素，最终返回一个字符串<output variable>
list(JOIN <list> <glue> <output variable>)

SUBLIST

# 获取列表<list>中从<beigin>处起，长度为<length>的元素组
list(SUBLIST <list> <begin> <length> <output variable>)

Search

FIND

# 在列表<list>中搜索值<value>，如果找到与<value>相同的元素则返回其对应的索引<output variable>，如果未发现则返回-1
list(FIND <list> <value> <output variable>)

Modification

APPEND

# 在<list>中（尾部）添加元素<element>，若<list>不存在，则视其为空表，并将该元素添加到空表中
list(APPEND <list> [<element> ...])

cmake_minimum_required(VERSION 2.8)
set(mylist aaa bbb ccc)
MESSAGE("mylist: ${mylist}")
list(APPEND mylist xxx yyy zzz)
MESSAGE("mylist: ${mylist}")
set(mylist2 111 222 333)
MESSAGE("mylist2: ${mylist2}")
list(APPEND mylist ${mylist2})
MESSAGE("mylist: ${mylist}")

OUTPUT: mylist: aaa;bbb;ccc mylist: aaa;bbb;ccc;xxx;yyy;zzz mylist2: 111;222;333 mylist: aaa;bbb;ccc;xxx;yyy;zzz;111;222;333

FILTER

# New in version 3.6.
# 包括或删除列表<list>中符合该模式的项目。在REGEX模式下，项目将与给定的正则表达式匹配。
list(FILTER <list> <INCLUDE|EXCLUDE> REGEX <regular_expression>)

INSERT

# 在列表<list>的指定索引<element_index>处插入元素<element>
# 有效的索引是[0,N](包括N，N是列表的长：list(LENGTH <LIST> N))
# 如果<list>不存在，将被视为空表将元素插入
list(INSERT <list> <element_index> <element> [<element> ...])

cmake_minimum_required(VERSION 2.8)
set(mylist aaa)
list(APPEND mylist bbb ccc)
MESSAGE("${mylist}")
#insert with index
list(INSERT mylist 2 xxx)
MESSAGE("${mylist}")

OUTPUT: aaa;bbb;ccc aaa;bbb;xxx;ccc

POP_BACK

# New in version 3.15
# 将列表中最后出现的变量<out-var>（<out-var-2>, <out-var-3>..）删除
# 如果没有提供<out-var>，则删除最后一个元素？（If no variable name is given, removes exactly one element）
list(POP_BACK <list> [<out-var>...])

POP_FRONT

# New in version 3.15
# 将列表中首次出现的变量<out-var>（<out-var-2>, <out-var-3>..）删除
# 如果没有提供<out-var>，则删除第一个元素？
list(POP_FRONT <list> [<out-var>...])

PREPEND

# New in version 3.15
# 将元素插入到列表<list>的最前方
# 应该可以理解为 list(INSERT <list> 0 [<element> ...])
list(PREPEND <list> [<element> ...])

REMOVE_ITEM

# 从列表<list>中删除指定值<value>对应的的元素
list(REMOVE_ITEM <list> <value> [<value> ...])

cmake_minimum_required(VERSION 2.8)
set(mylist aaa)
list(APPEND mylist bbb ccc)
MESSAGE("${mylist}")
#remove item from list
list(REMOVE_ITEM mylist ccc)
MESSAGE("${mylist}")

OUTPUT: aaa;bbb;ccc aaa;bbb

REMOVE_AT

# 从列表<list>中删除索引<index>指定位置的元素
list(REMOVE_AT <list> <index> [<index> ...])

cmake_minimum_required(VERSION 2.8)
set(mylist aaa)
list(APPEND mylist bbb ccc)
MESSAGE("${mylist}")
#remove item from list
list(REMOVE_ITEM mylist 2)
MESSAGE("${mylist}")

OUTPUT: aaa;bbb;ccc aaa;bbb

REMOVE_DUPLICATES

# 删除列表<list>中重复的元素，第一次出现的元素会被保留
list(REMOVE_DUPLICATES <list>)

cmake_minimum_required(VERSION 2.8)
set(mylist aaa)
list(APPEND mylist bbb ccc ccc bbb aaa)
MESSAGE("${mylist}")
#REMOVE_DUPLICATES
list(REMOVE_DUPLICATES mylist)
MESSAGE("${mylist}")

OUTPUT: aaa;bbb;ccc;ccc;bbb;aaa aaa;bbb;ccc

TRANSFORM？

# New in version 3.12
# Transforms the list by applying an action to all or, by specifying a <SELECTOR>, to the selected elements of the list, storing the result in-place or in the specified output variable.
list(TRANSFORM <list> <ACTION> [<SELECTOR>]
                      [OUTPUT_VARIABLE <output variable>])

Ordering

REVERSE

# 列表<list>反转
list(REVERSE <list>)

cmake_minimum_required(VERSION 2.8)
set(mylist aaa bbb ccc)
MESSAGE("mylist: ${mylist}")
list(REVERSE mylist)
MESSAGE("mylist: ${mylist}")

OUTPUT: mylist: aaa;bbb;ccc mylist: ccc;bbb;aaa

SORT

# 按字母顺序为排序
list(SORT )

cmake_minimum_required(VERSION 2.8)
set(mylist xxx yyy zzz aaa bbb ccc)
MESSAGE("mylist: ${mylist}")
list(SORT mylist)
MESSAGE("mylist: ${mylist}")

OUTPUT: mylist: xxx;yyy;zzz;aaa;bbb;ccc mylist: aaa;bbb;ccc;xxx;yyy;zzz