[CursorInfo] De-duplicate reported cursor info results

The constraint system might produce multiple solutions that all reference the same declaration. We should only report the declaration once in those cases instead of multiple times.

rdar://111814276

Author: ahoppen

lib/IDE/CursorInfo.cpp

@@ -277,6 +277,12 @@ class CursorInfoTypeCheckSolutionCallback : public TypeCheckCompletionCallback {
     bool IsDynamicRef;
     /// The declaration that is being referenced. Will never be \c nullptr.
     ValueDecl *ReferencedDecl;
+
+    bool operator==(const CursorInfoDeclReference &Other) const {
+      return nullableTypesEqual(BaseType, Other.BaseType) &&
+             IsDynamicRef == Other.IsDynamicRef &&
+             ReferencedDecl == Other.ReferencedDecl;
+    }
   };
 
 private:
@@ -326,8 +332,16 @@ class CursorInfoTypeCheckSolutionCallback : public TypeCheckCompletionCallback {
                             [&S](Expr *E) { return S.getResolvedType(E); });
     }
 
-    Results.push_back(
-        {OverloadInfo.BaseTy, IsDynamicRef, OverloadInfo.getValue()});
+    CursorInfoDeclReference NewResult = {OverloadInfo.BaseTy, IsDynamicRef,
+                                         OverloadInfo.getValue()};
+
+    if (llvm::any_of(Results, [&](const CursorInfoDeclReference &R) {
+          return R == NewResult;
+        })) {
+      return;
+    }
+
+    Results.push_back(NewResult);
   }
 
 public:

test/SourceKit/CursorInfo/cursor_ambiguous.swift

@@ -2,16 +2,35 @@ func testAmbiguousFunctionReference() {
   func foo(a: Int) {}
   func foo(a: String) {}
 
-  // RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):7 %s -- %s | %FileCheck %s
+  // RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):7 %s -- %s | %FileCheck %s --check-prefix LOCAL_FUNC
   _ = foo
 
-  // RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):7 %s -- %s | %FileCheck %s
+  // RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):7 %s -- %s | %FileCheck %s --check-prefix LOCAL_FUNC
   _ = foo(a: UInt(1))
+
+  // LOCAL_FUNC: source.lang.swift.ref.function.free
+  // LOCAL_FUNC: <Declaration>func foo(a: <Type usr="s:Si">Int</Type>)</Declaration>
+  // LOCAL_FUNC: SECONDARY SYMBOLS BEGIN
+  // LOCAL_FUNC: source.lang.swift.ref.function.free
+  // LOCAL_FUNC: <Declaration>func foo(a: <Type usr="s:SS">String</Type>)</Declaration>
+  // LOCAL_FUNC: SECONDARY SYMBOLS END
 }
 
-// CHECK: source.lang.swift.ref.function.free (2:8-2:19)
-// CHECK: <Declaration>func foo(a: <Type usr="s:Si">Int</Type>)</Declaration>
-// CHECK: SECONDARY SYMBOLS BEGIN
-// CHECK: source.lang.swift.ref.function.free (3:8-3:22)
-// CHECK: <Declaration>func foo(a: <Type usr="s:SS">String</Type>)</Declaration>
-// CHECK: SECONDARY SYMBOLS END
+
+
+struct TestDeduplicateResults {
+  // The constraints system produces multiple solutions here for the argument type but
+  // all reference the same declaration. Check that we de-duplicate them and that we
+  // don’t report any secondary sybmols.
+  static func staticFunc(_ duration: Int) {}
+
+  func test() {
+    // RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):10 %s -- %s | %FileCheck %s --check-prefix STATIC_FUNC
+    Self.staticFunc(1 * 1e9)
+  }
+
+  // STATIC_FUNC: source.lang.swift.ref.function.method.static
+  // STATIC_FUNC: <Declaration>static func staticFunc(_ duration: <Type usr="s:Si">Int</Type>)</Declaration>
+  // STATIC_FUNC: SECONDARY SYMBOLS BEGIN
+  // STATIC_FUNC-NEXT: SECONDARY SYMBOLS END
+}