Dependency adapters for virtual targets

README.md

@@ -20,6 +20,7 @@ list.
 
 | Last updated | Title                                                                                                                                                     | Author(s) alias                                                              | Category              |
 | ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------- | --------------------- |
+|   2022-10-17 | [Dependency adapters for virtual targets](designs/2022-10-17-dependency-adapter.md) | [@vdye](https://github.com/vdye) | Bazel |
 |   2022-10-11 | [Renaming applicable_licenses](https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ) | [@aiuto](https://github.com/aiuto) | Configuration |
 |   2022-08-03 | [Platforms on Targets](designs/2022-08-03-platforms-on-targets.md) | [@katre](https://github.com/katre) | Configuration |
 |   2022-07-07 | [Enabling Global exec_groups](https://github.com/bazelbuild/proposals/new/main/designs/2022-07-07_global_exec_groups.md)                           | [@susinmotion](https://github.com/susinmotion)  |  Configurability     |

images/dependency-adapter/regular-deps.puml

@@ -0,0 +1,16 @@
+@startuml
+package "Local Repository" {
+    [ Executable A ] as A
+    [ Library B ] as B
+}
+
+package "External Repository (shared_libs)" {
+    [ Library C ] as C
+    [ Library D ] as D
+}
+
+A --> B: <back:white> //B:libB
+A -r-> C: <back:white>@shared_libs//C:libC
+C --> D: <back:white> //D:libD
+
+@enduml

images/dependency-adapter/virtual-deps-with-adapter.puml

@@ -0,0 +1,26 @@
+@startuml
+package "Local Repository" {
+    [ Executable A ] as A
+    node "dependency adapter" as adapter_local {
+        cloud "<color:grey>Library B" as B
+        [ Library B ] as B_concrete
+    }
+}
+
+package "External Repository (shared_libs)" {
+    node "dependency adapter" as adapter_shared {
+        cloud "<color:grey>Library C" as C
+        [ Library C ] as C_concrete
+    }
+    [ Library D ] as D
+}
+
+A -d-> adapter_local
+adapter_local --> B_concrete: <back:white> //B:libB
+B .[#grey]r.|> B_concrete: <color:grey>//convert to //\n<color:grey>//concrete //
+A -r-> adapter_shared
+C .[#grey]d.|> C_concrete: <color:grey>// convert to//\n<color:grey>// concrete//
+adapter_shared -r-> C_concrete: <back:white>//@shared_libs~//C:libC //
+C_concrete --> D: <back:white> //D:libD
+
+@enduml