add should_install module

1 files changed, 39 insertions, 0 deletions

diff --git a/xmake/modules/private/action/require/impl/utils/should_install.lua b/xmake/modules/private/action/require/impl/utils/should_install.lua
new file mode 100644
index 000000000..ca104787f
--- /dev/null
+++ b/xmake/modules/private/action/require/impl/utils/should_install.lua
@@ -0,0 +1,39 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki
+-- @file        should_install.lua
+--
+
+
+-- should install?
+function _should_install(instance)
+    if instance:parents() then
+        -- if all the packages that depend on it already exist, then there is no need to install it
+        for _, parent in pairs(instance:parents()) do
+            if _should_install(parent) and not parent:exists() then
+                return true
+            end
+        end
+    else
+        return not instance:exists()
+    end
+end
+
+-- the given package should be install?
+function main(instance)
+    return _should_install(instance)
+end