[5.5][SymbolGraph] add sourceOrigin field for symbols implementing remote protocol requirements

lib/SymbolGraphGen/Edge.cpp

@@ -15,9 +15,29 @@
 #include "Symbol.h"
 #include "SymbolGraphASTWalker.h"
 
+#include <queue>
+
 using namespace swift;
 using namespace symbolgraphgen;
 
+namespace {
+const ValueDecl *getForeignProtocolRequirement(const ValueDecl *VD, const ModuleDecl *M) {
+  std::queue<const ValueDecl *> requirements;
+  while (true) {
+    for (auto *req : VD->getSatisfiedProtocolRequirements()) {
+      if (req->getModuleContext()->getNameStr() != M->getNameStr())
+        return req;
+      else
+        requirements.push(req);
+    }
+    if (requirements.empty())
+      return nullptr;
+    VD = requirements.front();
+    requirements.pop();
+  }
+}
+} // end anonymous namespace
+
 void Edge::serialize(llvm::json::OStream &OS) const {
   OS.object([&](){
     OS.attribute("kind", Kind.Name);
@@ -66,6 +86,11 @@ void Edge::serialize(llvm::json::OStream &OS) const {
 
     if (!InheritingDecl && Source.getSynthesizedBaseTypeDecl())
       InheritingDecl = Source.getSymbolDecl();
+
+    if (!InheritingDecl) {
+      if (const auto *ID = getForeignProtocolRequirement(Source.getSymbolDecl(), &Graph->M))
+        InheritingDecl = ID;
+    }
 
     // If our source symbol is a inheriting decl, write in information about
     // where it's inheriting docs from.

test/SymbolGraph/Relationships/Synthesized/Inputs/RemoteP.swift

@@ -0,0 +1,14 @@
+/// Some Protocol
+public protocol P {
+    func someFunc()
+
+    /// This one has docs!
+    func otherFunc()
+
+    func bonusFunc()
+}
+
+public extension P {
+    /// Extra default docs!
+    func extraFunc() {}
+}

test/SymbolGraph/Relationships/Synthesized/RemoteInheritedDocs.swift

@@ -0,0 +1,71 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %S/Inputs/RemoteP.swift -module-name RemoteP -emit-module -emit-module-path %t/RemoteP.swiftmodule -emit-module-source-info-path %t/RemoteP.swiftsourceinfo -emit-module-doc-path %t/RemoteP.swiftdoc
+// RUN: %target-swift-frontend %s -module-name RemoteInheritedDocs -emit-module -emit-module-path %t/RemoteInheritedDocs.swiftmodule -emit-module-source-info-path %t/RemoteInheritedDocs.swiftsourceinfo -emit-module-doc-path %t/RemoteInheritedDocs.swiftdoc -I %t
+
+// RUN: %target-swift-symbolgraph-extract -module-name RemoteInheritedDocs -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix SOME
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix OTHER
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix BONUS
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix INHERIT
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix LOCAL
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix OVERRIDE
+
+// RUN: %target-swift-symbolgraph-extract -module-name RemoteInheritedDocs -I %t -pretty-print -output-dir %t -skip-inherited-docs
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix SOME
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix OTHER
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix BONUS
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix SKIP
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix LOCAL
+// RUN: %FileCheck %s --input-file %t/RemoteInheritedDocs.symbols.json --check-prefix OVERRIDE
+
+// SOME:           "source": "s:19RemoteInheritedDocs1SV8someFuncyyF"
+// SOME-NEXT:      "target": "s:19RemoteInheritedDocs1SV"
+// SOME-NEXT:      "sourceOrigin"
+// SOME-NEXT:        "identifier": "s:7RemoteP1PP8someFuncyyF"
+// SOME-NEXT:        "displayName": "P.someFunc()"
+
+// OTHER:           "source": "s:19RemoteInheritedDocs1SV9otherFuncyyF"
+// OTHER-NEXT:      "target": "s:19RemoteInheritedDocs1SV"
+// OTHER-NEXT:      "sourceOrigin"
+// OTHER-NEXT:        "identifier": "s:7RemoteP1PP9otherFuncyyF"
+// OTHER-NEXT:        "displayName": "P.otherFunc()"
+
+// BONUS:           "source": "s:19RemoteInheritedDocs1SV9bonusFuncyyF"
+// BONUS-NEXT:      "target": "s:19RemoteInheritedDocs1SV"
+// BONUS-NEXT:      "sourceOrigin"
+// BONUS-NEXT:        "identifier": "s:7RemoteP1PP9bonusFuncyyF"
+// BONUS-NEXT:        "displayName": "P.bonusFunc()"
+
+// INHERIT: This one has docs!
+// SKIP-NOT: This one has docs!
+
+// LOCAL: Local docs override!
+
+// OVERRIDE-NOT: Extra default docs!
+// OVERRIDE-NOT: Extension override!
+
+import RemoteP
+
+// The `RemoteP.P` protocol has three methods: `someFunc` and `bonusFunc` don't have docs upstream,
+// but `otherFunc` does. Regardless, each one needs a `sourceOrigin` field connecting it to
+// upstream.
+
+// `RemoteP.P` also has an extension with a default implementation for `extraFunc` that does have
+// docs, but overriding it here should prevent those from appearing
+
+public struct S: P {
+    public func someFunc() {}
+
+    public func otherFunc() {}
+
+    /// Local docs override!
+    public func bonusFunc() {}
+
+    public func extraFunc() {}
+}
+
+public extension P {
+    /// Extension override!
+    func someFunc() {}
+}
+