[Index] Handle more cases in reportRelatedTypeRef

Look through attributed/specifier/paren TypeReprs, avoid reporting
`RelBase` relations for suppressed conformances, and handle protocol
compositions for the `Type` code path.

rdar://146331982

Author: hamishknight

lib/Index/Index.cpp

@@ -1506,6 +1506,9 @@ bool IndexSwiftASTWalker::reportRelatedRef(ValueDecl *D, SourceLoc Loc, bool isI
 bool IndexSwiftASTWalker::reportInheritedTypeRefs(InheritedTypes Inherited,
                                                   Decl *Inheritee) {
   for (auto Base : Inherited.getEntries()) {
+    // Suppressed conformances aren't considered base types.
+    if (Base.isSuppressed())
+      continue;
     if (!reportRelatedTypeRef(Base, (SymbolRoleSet) SymbolRole::RelationBaseOf, Inheritee))
       return false;
   }
@@ -1516,6 +1519,25 @@ bool IndexSwiftASTWalker::reportRelatedTypeRepr(const TypeRepr *TR,
                                                 SymbolRoleSet Relations,
                                                 Decl *Related, bool Implicit,
                                                 SourceLoc ParentLoc) {
+  // Look through parens/specifiers/attributes.
+  while (true) {
+    if (TR->isParenType()) {
+      TR = TR->getWithoutParens();
+      continue;
+    }
+    if (auto *SPR = dyn_cast<SpecifierTypeRepr>(TR)) {
+      TR = SPR->getBase();
+      continue;
+    }
+    if (auto *ATR = dyn_cast<AttributedTypeRepr>(TR)) {
+      TR = ATR->getTypeRepr();
+      continue;
+    }
+    break;
+  }
+  // NOTE: We don't yet handle InverseTypeRepr since we don't have an inverse
+  // relation for inheritance.
+
   if (auto *composite = dyn_cast<CompositionTypeRepr>(TR)) {
     for (auto *Type : composite->getTypes()) {
       if (!reportRelatedTypeRepr(Type, Relations, Related, Implicit,
@@ -1561,6 +1583,15 @@ bool IndexSwiftASTWalker::reportRelatedTypeRepr(const TypeRepr *TR,
 bool IndexSwiftASTWalker::reportRelatedType(Type Ty, SymbolRoleSet Relations,
                                             Decl *Related, bool Implicit,
                                             SourceLoc Loc) {
+  // Try decompose a protocol composition.
+  if (auto *PCT = Ty->getAs<ProtocolCompositionType>()) {
+    for (auto member : PCT->getMembers()) {
+      if (!reportRelatedType(member, Relations, Related, Implicit, Loc))
+        return false;
+    }
+    return true;
+  }
+
   if (auto *nominal = Ty->getAnyNominal()) {
     if (!reportRelatedRef(nominal, Loc, Implicit, Relations, Related))
       return false;

test/Index/conformances.swift

@@ -10,6 +10,24 @@ struct DirectConf: P1 { // CHECK: [[@LINE]]:8 | struct/Swift | DirectConf | [[Di
     // CHECK-NEXT: RelChild | struct/Swift | DirectConf | [[DirectConf_USR]]
 }
 
+struct LookThroughReprs: (@unchecked (Sendable)) {}
+// CHECK:      [[@LINE-1]]:39 | protocol/Swift | Sendable | s:s8SendableP | Ref,RelBase | rel: 1
+// CHECK-NEXT:   RelBase | struct/Swift | LookThroughReprs | s:14swift_ide_test16LookThroughReprsV
+
+// No RelBase relation here since `Copyable` isn't a base type. Also make sure
+// we don't put a reference at the `~`.
+struct NonCopyable: ~Copyable {}
+// CHECK-NOT: [[@LINE-1]]:21
+// CHECK:     [[@LINE-2]]:22 | protocol/Swift | Copyable | s:s8CopyableP | Ref | rel: 0
+// CHECK-NOT: [[@LINE-3]]:21
+
+protocol NonCopyableProto: ~Copyable {}
+
+struct AlsoNonCopyable: NonCopyableProto & ~Copyable {}
+// CHECK:      [[@LINE-1]]:25 | protocol/Swift | NonCopyableProto | s:14swift_ide_test16NonCopyableProtoP | Ref,RelBase | rel: 1
+// CHECK-NEXT:   RelBase | struct/Swift | AlsoNonCopyable | s:14swift_ide_test15AlsoNonCopyableV
+// CHECK-NEXT: [[@LINE-3]]:45 | protocol/Swift | Copyable | s:s8CopyableP | Ref | rel: 0
+
 struct ConfFromExtension {}
 extension ConfFromExtension: P1 { // CHECK: [[@LINE]]:11 | extension/ext-struct/Swift | ConfFromExtension | [[ConfFromExtension_ext_USR:.*]] | Def
   func foo() {} // CHECK: [[@LINE]]:8 | instance-method/Swift | foo() | [[ConfFromExtension_ext_foo_USR:.*]] | Def,RelChild,RelOver | rel: 2

test/Index/index_imported.swift

@@ -0,0 +1,43 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file --leading-lines %s %t
+
+// RUN: %target-swift-frontend -emit-module -o %t/Lib.swiftmodule %t/Lib.swift -module-name Lib
+// RUN: %target-swift-ide-test -print-indexed-symbols -source-filename %t/main.swift -module-to-print Lib -I %t | %FileCheck %s --check-prefix LIB
+// RUN: %target-swift-ide-test -print-indexed-symbols -source-filename %t/main.swift -I %t | %FileCheck %s
+
+//--- Lib.swift
+
+public protocol P {}
+public protocol Q {}
+public protocol R {}
+
+public typealias X = Q & R
+
+public struct S: X & P {}
+// LIB:      0:0 | protocol/Swift | Q | s:3Lib1QP | Ref,RelBase | rel: 1
+// LIB-NEXT:   RelBase | struct/Swift | S | s:3Lib1SV
+// LIB-NEXT: 0:0 | protocol/Swift | R | s:3Lib1RP | Ref,RelBase | rel: 1
+// LIB-NEXT:   RelBase | struct/Swift | S | s:3Lib1SV
+// LIB-NEXT: 0:0 | protocol/Swift | P | s:3Lib1PP | Ref,RelBase | rel: 1
+// LIB-NEXT:   RelBase | struct/Swift | S | s:3Lib1SV
+
+public protocol NonCopyableProto: ~Copyable {}
+public struct NonCopyable: NonCopyableProto & ~Copyable {}
+// LIB:      0:0 | protocol/Swift | NonCopyableProto | s:3Lib16NonCopyableProtoP | Ref,RelBase | rel: 1
+// LIB-NEXT:   RelBase | struct/Swift | NonCopyable | s:3Lib11NonCopyableV
+
+// We don't currently have a relation for Copyable.
+// LIB-NOT: s:s8CopyableP
+
+//--- main.swift
+
+import Lib
+
+struct K: P & X {}
+// CHECK:      [[@LINE-1]]:11 | protocol/Swift | P | s:3Lib1PP | Ref,RelBase | rel: 1
+// CHECK-NEXT:   RelBase | struct/Swift | K | s:14swift_ide_test1KV
+// CHECK-NEXT: [[@LINE-3]]:15 | type-alias/Swift | X | s:3Lib1Xa | Ref | rel: 0
+// CHECK-NEXT: [[@LINE-4]]:15 | protocol/Swift | Q | s:3Lib1QP | Ref,Impl,RelBase | rel: 1
+// CHECK-NEXT:   RelBase | struct/Swift | K | s:14swift_ide_test1KV
+// CHECK-NEXT: [[@LINE-6]]:15 | protocol/Swift | R | s:3Lib1RP | Ref,Impl,RelBase | rel: 1
+// CHECK-NEXT:   RelBase | struct/Swift | K | s:14swift_ide_test1KV