LINK_OPTIONS: Add new family of properties

This family enable to manage link flags

Three new properties:
* directory property: LINK_OPTIONS
* target properties: LINK_OPTIONS and INTERFACE_LINK_OPTIONS

Two new commands
* add_link_options(): to populate directory property
* target_link_options(): to populate target properties

Fixes: #16543

1 files changed, 9 insertions, 0 deletions

diff --git a/Help/command/OPTIONS_SHELL.txt b/Help/command/OPTIONS_SHELL.txt
new file mode 100644
index 0000000..530c012
--- /dev/null
+++ b/Help/command/OPTIONS_SHELL.txt
@@ -0,0 +1,9 @@
+The final set of compile or link options used for a target is constructed by
+accumulating options from the current target and the usage requirements of
+it dependencies.  The set of options is de-duplicated to avoid repetition.
+While beneficial for individual options, the de-duplication step can break
+up option groups.  For example, ``-D A -D B`` becomes ``-D A B``.  One may
+specify a group of options using shell-like quoting along with a ``SHELL:``
+prefix.  The ``SHELL:`` prefix is dropped and the rest of the option string
+is parsed using the :command:`separate_arguments` ``UNIX_COMMAND`` mode.
+For example, ``"SHELL:-D A" "SHELL:-D B"`` becomes ``-D A -D B``.