[CursorInfo] Add ObjC location to generated symbol graph

Add the file for an imported ObjC-symbol to the generated symbol graph
when ObjC documentation is requested.

Skips line/column information for now since it's not needed. If we add
those we should extract location retrieval to a common method for both
cursor info and symbol graph gen.

Resolves rdar://91658873.

Author: bnbarham

lib/SymbolGraphGen/Symbol.cpp

@@ -21,6 +21,7 @@
 #include "swift/Basic/Unicode.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
+#include "clang/Basic/SourceManager.h"
 #include "AvailabilityMixin.h"
 #include "JSON.h"
 #include "Symbol.h"
@@ -409,6 +410,30 @@ void Symbol::serializeAccessLevelMixin(llvm::json::OStream &OS) const {
 }
 
 void Symbol::serializeLocationMixin(llvm::json::OStream &OS) const {
+  if (ClangNode ClangN = VD->getClangNode()) {
+    if (!Graph->Walker.Options.IncludeClangDocs)
+      return;
+
+    if (auto *ClangD = ClangN.getAsDecl()) {
+      clang::SourceManager &ClangSM =
+          ClangD->getASTContext().getSourceManager();
+
+      clang::PresumedLoc Loc = ClangSM.getPresumedLoc(ClangD->getLocation());
+      if (Loc.isValid()) {
+        // TODO: We should use a common function to fill in the location
+        // information for both cursor info and symbol graph gen, then also
+        // include position here.
+        OS.attributeObject("location", [&](){
+          SmallString<1024> FileURI("file://");
+          FileURI.append(Loc.getFilename());
+          OS.attribute("uri", FileURI.str());
+        });
+      }
+    }
+
+    return;
+  }
+
   auto Loc = VD->getLoc(/*SerializedOK=*/true);
   if (Loc.isInvalid()) {
     return;

test/SourceKit/CursorInfo/cursor_symbol_graph_objc.swift

@@ -1,5 +1,10 @@
 // REQUIRES: objc_interop
 
+// TODO: Add some way to specify extra options to symbolgraph-extract and then
+//       split this test into parts under the SymbolGraph directory. The SK
+//       tests should just check that we run the generation on 1. the correct
+//       symbol and 2. with the correct options.
+
 // RUN: %empty-directory(%t)
 // RUN: split-file --leading-lines %s %t
 
@@ -10,6 +15,9 @@ func test(s: ObjCStruct) {
   // RUN: %sourcekitd-test -req=cursor -pos=%(line+1):3 -req-opts=retrieve_symbol_graph=1 %t/use.swift -- -I %t/mod -target %target-triple %t/use.swift | %FileCheck -check-prefix=CHECK-FUNC %s
   someFunc()
 
+  // RUN: %sourcekitd-test -req=cursor -pos=%(line+1):3 -req-opts=retrieve_symbol_graph=1 %t/use.swift -- -I %t/mod -target %target-triple %t/use.swift | %FileCheck -check-prefix=CHECK-DIRECTIVE-FUNC %s
+  funcUnderDirective()
+
   // RUN: %sourcekitd-test -req=cursor -pos=%(line+1):9 -req-opts=retrieve_symbol_graph=1 %t/use.swift -- -I %t/mod -target %target-triple %t/use.swift | %FileCheck -check-prefix=CHECK-NO %s
   _ = s.noDoc
 
@@ -100,6 +108,9 @@ func test(s: ObjCStruct) {
 // CHECK-FUNC:         "displayName": "Function",
 // CHECK-FUNC:         "identifier": "swift.func"
 // CHECK-FUNC:       },
+// CHECK-FUNC:       "location": {
+// CHECK-FUNC:         "uri": "file://{{.*}}mod{{\\\\|/}}M.h"
+// CHECK-FUNC:       },
 // CHECK-FUNC:       "names": {
 // CHECK-FUNC:         "subHeading": [
 // CHECK-FUNC:           {
@@ -266,3 +277,9 @@ struct ObjCStruct {
   // CHECK-MIXED-DOC-NEXT:    ]
   // CHECK-MIXED-DOC-NEXT:  }
 };
+
+#line 10 "other.h"
+void funcUnderDirective(void);
+// CHECK-DIRECTIVE-FUNC:  "location": {
+// CHECK-DIRECTIVE-FUNC:    "uri": "file://{{.*}}other.h"
+// CHECK-DIRECTIVE-FUNC:  }