include information about synthesized symbols' sources

rdar://75741632

Author: QuietMisdreavus

lib/SymbolGraphGen/Edge.cpp

@@ -57,5 +57,21 @@ void Edge::serialize(llvm::json::OStream &OS) const {
         });
       }
     }
+    
+    // If our source symbol is a synthesized decl, write in information about
+    // where it's inheriting docs from.
+    if (Source.getSynthesizedBaseTypeDecl()) {
+      Symbol inheritedSym(Graph, Source.getSymbolDecl(), nullptr);
+      SmallString<256> USR, Display;
+      llvm::raw_svector_ostream DisplayOS(Display);
+      
+      inheritedSym.getUSR(USR);
+      inheritedSym.printPath(DisplayOS);
+      
+      OS.attributeObject("sourceOrigin", [&](){
+        OS.attribute("identifier", USR.str());
+        OS.attribute("displayName", Display.str());
+      });
+    }
   });
 }

lib/SymbolGraphGen/FormatVersion.h

@@ -15,6 +15,6 @@
 
 #define SWIFT_SYMBOLGRAPH_FORMAT_MAJOR 0
 #define SWIFT_SYMBOLGRAPH_FORMAT_MINOR 5
-#define SWIFT_SYMBOLGRAPH_FORMAT_PATCH 2
+#define SWIFT_SYMBOLGRAPH_FORMAT_PATCH 3
 
 #endif // SWIFT_SYMBOLGRAPHGEN_FORMATVERSION_H

test/SymbolGraph/Relationships/Synthesized/InheritedDocs.swift

@@ -0,0 +1,24 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name InheritedDocs -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name InheritedDocs -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/InheritedDocs.symbols.json
+
+// CHECK:            "source": "s:13InheritedDocs1PPAAE8someFuncyyF::SYNTHESIZED::s:13InheritedDocs1SV"
+// CHECK-NEXT:       "target": "s:13InheritedDocs1SV"
+// CHECK-NEXT:       "sourceOrigin": {
+// CHECK-NEXT:         "identifier": "s:13InheritedDocs1PPAAE8someFuncyyF"
+// CHECK-NEXT:         "displayName": "P.someFunc()"
+// CHECK-NEXT:       }
+
+/// Protocol P
+public protocol P {
+    /// Some Function
+    func someFunc()
+}
+
+public extension P {
+    func someFunc() {}
+}
+
+public struct S: P {
+}