[CodeComplete] Do not complete self-initializations

[ilya-biryukov]

Summary

Removes references to initialized variable from the following completions:

int x = ^;

Handles only the trivial cases where the variable name is completed
immediately at the start of initializer or assignment, more complicated
cases aren't covered, e.g. these completions still contain 'x':

// More complicated expressions.
int x = foo(^);
int x = 10 + ^;
// Other kinds of initialization.
int x{^};
int x(^);
// Constructor initializers.
struct Foo {
  Foo() : x(^) {}
  int x;
};

We should address those in the future, but they are outside of the scope of
this initial change.

[ilya-biryukov]

• Remove std::move, the target is const ref, so it does nothing (thanks, clang-tidy!)

[sammccall]

:-)

lib/Sema/SemaCodeComplete.cpp

 
 void Sema::CodeCompleteInitializer(Scope *S, Decl *D) {
   ValueDecl *VD = dyn_cast_or_null<ValueDecl>(D);
   if (!VD) {
     CodeCompleteOrdinaryName(S, PCC_Expression);
     return;
   }
 
-  CodeCompleteExpression(S, VD->getType());
+  CodeCompleteExpressionData Data;
+  Data.PreferredType = VD->getType();
+  // Ignore VD to avoid completing the variable itself, e.g. in 'int foo = ^'.
+  Data.IgnoreDecls.push_back(VD);
+
+  CodeCompleteExpression(S, Data);
 }
 
 void Sema::CodeCompleteReturn(Scope *S) {
   QualType ResultType;
   if (isa<BlockDecl>(CurContext)) {
     if (BlockScopeInfo *BSI = getCurBlock())
       ResultType = BSI->ReturnType;
   } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(CurContext))

test/CodeCompletion/ordinary-name-cxx11.cpp

void foo() {
   // CHECK-CC4-NEXT: COMPLETION: Pattern : typeof <#expression#>
   // CHECK-CC4-NEXT: COMPLETION: Pattern : typeof(<#type#>)
   // CHECK-CC4-NEXT: COMPLETION: union
   // CHECK-CC4-NEXT: COMPLETION: unsigned
   // CHECK-CC4-NEXT: COMPLETION: void
   // CHECK-CC4-NEXT: COMPLETION: volatile
   // CHECK-CC4-NEXT: COMPLETION: wchar_t
   // CHECK-CC4-NEXT: COMPLETION: X : X
-  // CHECK-CC4-NEXT: COMPLETION: y : [#int#]y
   // CHECK-CC4-NEXT: COMPLETION: z : [#void#]z(<#int#>)
 
   // RUN: %clang_cc1 -fsyntax-only -fno-rtti -code-completion-patterns -code-completion-at=%s:6:14 -std=gnu++11 %s -o - | FileCheck -check-prefix=CHECK-NO-RTTI %s
   // CHECK-NO-RTTI: COMPLETION: bool
   // CHECK-NO-RTTI-NEXT: COMPLETION: char
   // CHECK-NO-RTTI-NEXT: COMPLETION: char16_t
   // CHECK-NO-RTTI-NEXT: COMPLETION: char32_t
   // CHECK-NO-RTTI-NEXT: COMPLETION: class

test/CodeCompletion/ordinary-name.cpp

void foo() {
   // CHECK-CC4-NEXT: COMPLETION: Pattern : typeof <#expression#>
   // CHECK-CC4-NEXT: COMPLETION: Pattern : typeof(<#type#>)
   // CHECK-CC4-NEXT: COMPLETION: union
   // CHECK-CC4-NEXT: COMPLETION: unsigned
   // CHECK-CC4-NEXT: COMPLETION: void
   // CHECK-CC4-NEXT: COMPLETION: volatile
   // CHECK-CC4-NEXT: COMPLETION: wchar_t
   // CHECK-CC4-NEXT: COMPLETION: X : X
-  // CHECK-CC4-NEXT: COMPLETION: y : [#int#]y
   // CHECK-CC4-NEXT: COMPLETION: z : [#void#]z(<#int#>)
 
   // RUN: %clang_cc1 -fsyntax-only -fno-rtti -code-completion-patterns -code-completion-at=%s:6:14 -std=gnu++98 %s -o - | FileCheck -check-prefix=CHECK-NO-RTTI %s
   // CHECK-NO-RTTI: COMPLETION: bool
   // CHECK-NO-RTTI-NEXT: COMPLETION: char
   // CHECK-NO-RTTI-NEXT: COMPLETION: class
   // CHECK-NO-RTTI-NEXT: COMPLETION: const
   // CHECK-NO-RTTI-NEXT: COMPLETION: Pattern : const_cast<<#type#>>(<#expression#>)

test/CodeCompletion/self-inits.cpp

+int foo = 10;
+// RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:1:11 %s -o - | FileCheck --check-prefix=CC1 %s
+// CC1-NOT: foo

test/Index/complete-type-factors.m

 
 // RUN: c-index-test -code-completion-at=%s:16:11 -Xclang -code-completion-patterns %s | FileCheck -check-prefix=CHECK-CC1 %s
 // CHECK-CC1: EnumConstantDecl:{ResultType enum Color}{TypedText Blue} (32)
 // CHECK-CC1: ParmDecl:{ResultType enum Color}{TypedText color} (17)
 // CHECK-CC1: FunctionDecl:{ResultType int}{TypedText func1}{LeftParen (}{Placeholder enum Color}{RightParen )} (12)
 // CHECK-CC1: FunctionDecl:{ResultType enum Priority}{TypedText func2}{LeftParen (}{Placeholder int}{RightParen )} (25)
 // CHECK-CC1: EnumConstantDecl:{ResultType enum Color}{TypedText Green} (32)
 // CHECK-CC1: EnumConstantDecl:{ResultType enum Priority}{TypedText High} (32)
-// CHECK-CC1: VarDecl:{ResultType int}{TypedText i} (8)
 // CHECK-CC1: ParmDecl:{ResultType int}{TypedText integer} (8)
 // CHECK-CC1: EnumConstantDecl:{ResultType enum Priority}{TypedText Low} (32)
 // CHECK-CC1: ParmDecl:{ResultType enum Priority}{TypedText priority} (17)
 // CHECK-CC1: EnumConstantDecl:{ResultType enum Color}{TypedText Red} (32)
 // CHECK-CC1: NotImplemented:{ResultType size_t}{TypedText sizeof}{LeftParen (}{Placeholder expression-or-type}{RightParen )} (40)
 // CHECK-CC1: FunctionDecl:{ResultType enum Priority}{TypedText test1}{LeftParen (}{Placeholder enum Priority priority}{Comma , }{Placeholder enum Color color}{Comma , }{Placeholder int integer}{RightParen )} (25)
 // RUN: c-index-test -code-completion-at=%s:17:18 -Xclang -code-completion-patterns %s | FileCheck -check-prefix=CHECK-CC2 %s
 // CHECK-CC2: EnumConstantDecl:{ResultType enum Color}{TypedText Blue} (16)
-// CHECK-CC2: VarDecl:{ResultType enum Color}{TypedText c} (8)
 // CHECK-CC2: ParmDecl:{ResultType enum Color}{TypedText color} (8)
 // CHECK-CC2: FunctionDecl:{ResultType int}{TypedText func1}{LeftParen (}{Placeholder enum Color}{RightParen )} (25)
 // CHECK-CC2: FunctionDecl:{ResultType enum Priority}{TypedText func2}{LeftParen (}{Placeholder int}{RightParen )} (50)
 // CHECK-CC2: EnumConstantDecl:{ResultType enum Color}{TypedText Green} (16)
 // CHECK-CC2: EnumConstantDecl:{ResultType enum Priority}{TypedText High} (65)
 // CHECK-CC2: VarDecl:{ResultType int}{TypedText i} (17)
 // CHECK-CC2: ParmDecl:{ResultType int}{TypedText integer} (17)
 // CHECK-CC2: EnumConstantDecl:{ResultType enum Priority}{TypedText Low} (65)