Merge branch 'rickard/runtime-dep/OTP-11773'

* rickard/runtime-dep/OTP-11773:
  Introduce system_information:sanity_check()
  Verify runtime_dependencies when running 'otp_build patch_app'
  Add test-case verifying runtime dependencies found by xref
  Introduce runtime_dependencies in .app files
  Bump versions and ensure that all are "normal" versions

2 files changed, 36 insertions, 3 deletions

diff --git a/lib/kernel/doc/src/app.xml b/lib/kernel/doc/src/app.xml
index 7c9d6eecec..b24a2bd7bd 100644
--- a/lib/kernel/doc/src/app.xml
+++ b/lib/kernel/doc/src/app.xml
@@ -61,7 +61,8 @@
    {applications, Apps},
    {env,          Env},
    {mod,          Start},
-   {start_phases, Phases}]}.
+   {start_phases, Phases},
+   {runtime_dependencies, RTDeps}]}.
 
              Value                Default
              -----                -------
@@ -77,8 +78,10 @@ Apps         [App]                []
 Env          [{Par,Val}]          []
 Start        {Module,StartArgs}   []
 Phases       [{Phase,PhaseArgs}]  undefined
+RTDeps       [ApplicationVersion] []
   Module = Name = App = Par = Phase = atom()
-  Val = StartArgs = PhaseArgs = term()</code>
+  Val = StartArgs = PhaseArgs = term()
+  ApplicationVersion = string()</code>
     <p><c>Application</c> is the name of the application.</p>
     <p>For the application controller, all keys are optional.
       The respective default values are used for any omitted keys.</p>
@@ -87,6 +90,8 @@ Phases       [{Phase,PhaseArgs}]  undefined
       <c>description</c>, <c>vsn</c>, <c>modules</c>, <c>registered</c>
       and <c>applications</c>. The other keys are ignored by
       <c>systools</c>.</p>
+      <warning><p>The <c>RTDeps</c> type was introduced in OTP 17.0 and
+      might be subject to changes during the OTP 17 release.</p></warning>
     <taglist>
       <tag><c>description</c></tag>
       <item>
@@ -185,6 +190,33 @@ Phases       [{Phase,PhaseArgs}]  undefined
           start phases must be a subset of the set of phases defined
           for the primary application. Refer to <em>OTP Design Principles</em> for more information.</p>
       </item>
+      <tag><marker id="runtime_dependencies"><c>runtime_dependencies</c></marker></tag>
+      <item><p>A list of application versions that the application
+      depends on. An example of such an application version is
+      <c>"kernel-3.0"</c>. Application versions specified as runtime
+      dependencies are minimum requirements. That is, a larger
+      application version than the one specified in the
+      dependency satisfies the requirement. For information on
+      how to compare application versions see
+      <seealso marker="doc/system_principles:versions">the
+      documentation of versions in the system principles
+      guide</seealso>. Note that that the application version
+      specifies a source code version. An additional indirect
+      requirement is that installed binary application of
+      the specified version has been built so that it is
+      compatible with the rest of the system.</p>
+      <p>Some dependencies might only be required in specific runtime
+      scenarios. In the case such optional dependencies exist, these are
+      specified and documented in the corresponding "App" documentation
+      of the specific application.</p>
+      <warning><p>The <c>runtime_dependencies</c> key was introduced in
+      OTP 17.0. The type of its value might be subject to changes during
+      the OTP 17 release.</p></warning>
+      <warning><p>All runtime dependencies specified in OTP applications
+      during the OTP 17 release might not be completely correct. This
+      is actively worked on. Declared runtime dependencies in OTP
+      applications are expected to be correct in OTP 18.</p></warning>
+      </item>
     </taglist>
   </section>
 
diff --git a/lib/kernel/src/kernel.app.src b/lib/kernel/src/kernel.app.src
index cb8c98ab06..5658c6b6cf 100644
--- a/lib/kernel/src/kernel.app.src
+++ b/lib/kernel/src/kernel.app.src
@@ -114,6 +114,7 @@
                 pg2]},
   {applications, []},
   {env, [{error_logger, tty}]},
-  {mod, {kernel, []}}
+  {mod, {kernel, []}},
+  {runtime_dependencies, ["erts-6.0", "stdlib-2.0", "sasl-2.4"]}
  ]
 }.