Make handling of deprecated items and properties configurable

As of now, a newly deprecated property leads to users getting bombarded
with warnings, even though they did not yet have a chance to adapt their
project.
Now the warnings appear by default one minor version before removal,
which together with our convention of keeping deprecated properties for
at least two minor versions gives users enough time to adapt without
getting spammed.
There is also a mode for switching to the previous behavior (for early
detection), as well as the possibility to trigger errors instead of
warnings, which should be helpful in CI configurations.
To support the case where the user cannot do anything about them, the
warnings can also be suppressed altogether.

Change-Id: I295f816758f0f111fcb0351581a4328be3af5668
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Ivan Komissarov <ABBAPOH@gmail.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/doc/reference/cli/cli-options.qdocinc b/doc/reference/cli/cli-options.qdocinc
index db8eeae48..ecb8f5c3e 100644
--- a/doc/reference/cli/cli-options.qdocinc
+++ b/doc/reference/cli/cli-options.qdocinc
@@ -331,6 +331,27 @@
 
 //! [config-ui-system]
 
+//! [deprecation-warnings]
+
+    \section2 \c {--deprecation-warnings <mode>}
+
+    Uses the specified deprecation warning mode, which controls what to do when deprecated
+    items or properties are encountered in the project. By default, a warning is emitted
+    if the item or property is scheduled for removal in the next minor version of \QBS.
+    Warnings can also be switched on or off unconditionally, and it can be specified that
+    project resolving should abort if deprecated constructs are present.
+
+    Possible values of \c <mode> are:
+
+    \list
+        \li \c error
+        \li \c on
+        \li \c before-removal (default value)
+        \li \c off
+   \endlist
+
+//! [deprecation-warnings]
+
 //! [log-level]
 
     \section2 \c {--log-level <level>}