[CodeCompletion] Block property setters: Use dynamic priority heuristic

[arphaman]

Summary

This patch implements a heuristic that I mentioned in https://reviews.llvm.org/D25520. When completing blocks properties that return void the default property completion result shows up before the setter, otherwise the setter completion now shows up before the default property completion. We normally want to use the result of the block call, so one typically wouldn't call a block that returns a non-void type in a standalone statement.

[arphaman]

I've rebased the patch

[manmanren]

LGTM.

Manman

lib/Sema/SemaCodeComplete.cpp

if (!P->isReadOnly() && IsBaseExprStatement &&
 
         std::string PlaceholderStr = formatBlockPlaceholder(
             getCompletionPrintingPolicy(Results.getSema()), P, BlockLoc,
             BlockProtoLoc, /*SuppressBlockName=*/true);
         // Add the placeholder string.
         Builder.AddPlaceholderChunk(
             Builder.getAllocator().CopyString(PlaceholderStr));
 
+        // When completing blocks properties that return void the default
+        // property completion result should show up before the setter,
+        // otherwise the setter completion should show up before the default
+        // property completion, as we normally want to use the result of the
+        // call.
         Results.MaybeAddResult(
             Result(Builder.TakeString(), P,
-                   Results.getBasePriority(P) + CCD_BlockPropertySetter),
+                   Results.getBasePriority(P) +
+                       (BlockLoc.getTypePtr()->getReturnType()->isVoidType()
+                            ? CCD_BlockPropertySetter
+                            : -CCD_BlockPropertySetter)),
             CurContext);
       }
     }
   }
 
   // Add nullary methods
   if (AllowNullaryMethods) {
     ASTContext &Context = Container->getASTContext();

test/Index/complete-block-property-assignment.m

 @interface Obj
 @property (readwrite, nonatomic, copy) void (^onAction)(Obj *object);
 @property (readwrite, nonatomic) int foo;
 @end
 
 @interface Test : Obj
 @property (readwrite, nonatomic, copy) FooBlock onEventHandler;
 @property (readonly, nonatomic, copy) void (^onReadonly)(int *someParameter);
+@property (readwrite, nonatomic, copy) int (^processEvent)(int eventCode);
 @property (readonly, nonatomic, strong) Obj *obj;
 @end
 
 @implementation Test
 
 #define SELFY self
 
 - (void)test {
   self.foo = 2;
   [self takeInt: 2]; self.foo = 2;
   /* Comment */ self.foo = 2;
   SELFY.foo = 2
 }
 
-// RUN: c-index-test -code-completion-at=%s:26:8 %s | FileCheck -check-prefix=CHECK-CC1 %s
-// RUN: c-index-test -code-completion-at=%s:27:27 %s | FileCheck -check-prefix=CHECK-CC1 %s
-// RUN: c-index-test -code-completion-at=%s:28:22 %s | FileCheck -check-prefix=CHECK-CC1 %s
-// RUN: c-index-test -code-completion-at=%s:29:9 %s | FileCheck -check-prefix=CHECK-CC1 %s
+// RUN: c-index-test -code-completion-at=%s:27:8 %s | FileCheck -check-prefix=CHECK-CC1 %s
+// RUN: c-index-test -code-completion-at=%s:28:27 %s | FileCheck -check-prefix=CHECK-CC1 %s
+// RUN: c-index-test -code-completion-at=%s:29:22 %s | FileCheck -check-prefix=CHECK-CC1 %s
+// RUN: c-index-test -code-completion-at=%s:30:9 %s | FileCheck -check-prefix=CHECK-CC1 %s
 // CHECK-CC1: ObjCPropertyDecl:{ResultType int}{TypedText foo} (35)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType Obj *}{TypedText obj} (35)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType void (^)(Obj *)}{TypedText onAction} (35)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType void (^)(Obj *)}{TypedText onAction}{Equal  = }{Placeholder ^(Obj *object)} (38)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType FooBlock}{TypedText onEventHandler} (35)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType FooBlock}{TypedText onEventHandler}{Equal  = }{Placeholder ^(Foo *someParameter)} (38)
 // CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType void (^)(int *)}{TypedText onReadonly} (35)
+// CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType int (^)(int)}{TypedText processEvent} (35)
+// CHECK-CC1-NEXT: ObjCPropertyDecl:{ResultType int (^)(int)}{TypedText processEvent}{Equal  = }{Placeholder ^int(int eventCode)} (32)
 
 - (void) takeInt:(int)x { }
 
 - (int) testFailures {
   (self.foo);
   int x = self.foo;
   [self takeInt: self.foo];
   if (self.foo) {
     func(self.foo);
   }
   return self.foo;
 }
 
-// RUN: c-index-test -code-completion-at=%s:47:9 %s | FileCheck -check-prefix=CHECK-NO %s
-// RUN: c-index-test -code-completion-at=%s:48:16 %s | FileCheck -check-prefix=CHECK-NO %s
-// RUN: c-index-test -code-completion-at=%s:49:23 %s | FileCheck -check-prefix=CHECK-NO %s
-// RUN: c-index-test -code-completion-at=%s:50:12 %s | FileCheck -check-prefix=CHECK-NO %s
-// RUN: c-index-test -code-completion-at=%s:51:15 %s | FileCheck -check-prefix=CHECK-NO %s
-// RUN: c-index-test -code-completion-at=%s:53:15 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:50:9 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:51:16 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:52:23 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:53:12 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:54:15 %s | FileCheck -check-prefix=CHECK-NO %s
+// RUN: c-index-test -code-completion-at=%s:56:15 %s | FileCheck -check-prefix=CHECK-NO %s
 // CHECK-NO: ObjCPropertyDecl:{ResultType int}{TypedText foo} (35)
 // CHECK-NO-NEXT: ObjCPropertyDecl:{ResultType Obj *}{TypedText obj} (35)
 // CHECK-NO-NEXT: ObjCPropertyDecl:{ResultType void (^)(Obj *)}{TypedText onAction} (35)
 // CHECK-NO-NEXT: ObjCPropertyDecl:{ResultType FooBlock}{TypedText onEventHandler} (35)
 // CHECK-NO-NEXT: ObjCPropertyDecl:{ResultType void (^)(int *)}{TypedText onReadonly} (35)
+// CHECK-NO-NEXT: ObjCPropertyDecl:{ResultType int (^)(int)}{TypedText processEvent} (35)
 
 @end