briancroom · February 6, 2024 18:26 · May 17, 2016 · May 17, 2016 · May 17, 2016
diff --git a/Swift.md b/Swift.md
@@ -16,7 +16,7 @@ internal func fullLogString(_ message: String) -> String {
 }
 
 ```
-`./Greeter/Greeter.swift`
+`./Greeter/Greeter.swift`:
 
 ```swift
 import Logger
@@ -25,7 +25,7 @@ public func greet(_ name: String) {
     log("Hello \(name)!")
 }
 ```
-`./main.swift`
+`./main.swift`:
 
 ```swift
 import Greeter

diff --git a/gistfile1.txt → Swift.md b/gistfile1.txt → Swift.md
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,57 @@
+I am trying to determine if it is possible to build a Swift dynamic library which is itself composed of one of more private modules, without needing to expose to that fact to outside users. My hope was that I could build the private module as a static library, which would be linked into the primary (dynamic) library. The `dylib` could then be deployed together with its `swiftmodule` and `swiftdoc` and be imported, with the private module and its symbols not being exposed at all.
+
+Unfortunately, what I'm currently observing seems to indicate that the private module's `swiftmodule` also has to be available for the primary library to be successfully imported.
+
+This can be reproduced as follows. I have the following directory structure:
+
+`./Greeter/Logger/Logger.swift`:
+
+```swift
+public func log(_ message: String) {
+    print(fullLogString(message))
+}
+
+internal func fullLogString(_ message: String) -> String {
+    return "(Logger): \(message)"
+}
+
+```
+`./Greeter/Greeter.swift`
+
+```swift
+import Logger
+
+public func greet(_ name: String) {
+    log("Hello \(name)!")
+}
+```
+`./main.swift`
+
+```swift
+import Greeter
+
+greet("Swift")
+```
+
+I am building these as follows:
+
+```sh
+$ cd Greeter/Logger
+$ swiftc -emit-object -emit-module -force-single-frontend-invocation -parse-as-library Logger.swift
+$ ar -r libLogger.a Logger.o
+$ cd ../
+$ swiftc -emit-library -emit-module -parse-as-library -ILogger -lLogger -Xlinker -LLogger -Xlinker -install_name -Xlinker @rpath/libGreeter.dylib Greeter.swift
+$ cd ../
+$ swiftc -emit-executable -IGreeter -IGreeter/Logger -lGreeter -Xlinker -LGreeter -Xlinker -rpath -Xlinker Greeter main.swift
+```
+
+On the final command, if I omit the `-IGreeter/Logger` flag, compilation fails with the message: 
+
+```
+main.swift:1:8: error: missing required module 'Logger'
+```
+So I'm wondering...
+
+1. Why is the `Logger.swiftmodule` necessary to complete the build, even though `main.swift` does not import it or use any symbols from it?
+2. Is there a way I could perform the build differently such that it wouldn't be needed?
+3. Where could I have started looking to figure out these answers on my own?
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