From f0e43e5c4634870b8ac7bf65d5ffa5f292d4c8a5 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 16 Apr 2010 19:30:02 +0000
Subject: [PATCH] Switch the checking of implicit casts for static_cast,
 C-style, and functional casts over to InitializationSequence, eliminating a
 caller of Sema::TryImplicitConversion. We also get access and ambiguity
 checking "for free".

More cleanups to come in this routine.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@101526 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaCXXCast.cpp | 32 +++++++++++++++-----------------
 lib/Sema/SemaInit.cpp    | 13 ++++++++-----
 2 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/lib/Sema/SemaCXXCast.cpp b/lib/Sema/SemaCXXCast.cpp
index a40bb62b17..716e51b7dd 100644
--- a/lib/Sema/SemaCXXCast.cpp
+++ b/lib/Sema/SemaCXXCast.cpp
@@ -953,26 +953,24 @@ TryStaticImplicitCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
     return TC_NotApplicable;
   }
 
-  // FIXME: To get a proper error from invalid conversions here, we need to
-  // reimplement more of this.
-  // FIXME: This does not actually perform the conversion, and thus does not
-  // check for ambiguity or access.
-  ImplicitConversionSequence ICS =
-    Self.TryImplicitConversion(SrcExpr, DestType,
-                               /*SuppressUserConversions=*/false,
-                               /*AllowExplicit=*/true,
-                               /*InOverloadResolution=*/false,
-                               /*one of user provided casts*/true);
-
-  if (ICS.isBad())
+  InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);
+  InitializationKind InitKind
+    = InitializationKind::CreateCast(/*FIXME:*/OpRange, CStyle);
+  InitializationSequence InitSeq(Self, Entity, InitKind, &SrcExpr, 1);
+  if (InitSeq.getKind() == InitializationSequence::FailedSequence)
     return TC_NotApplicable;
 
-  // The conversion is possible, so commit to it.
+  Sema::OwningExprResult Result
+    = InitSeq.Perform(Self, Entity, InitKind, 
+                      Action::MultiExprArg(Self, (void **)&SrcExpr, 1));
   Kind = CastExpr::CK_NoOp;
-  msg = 0;
-  return Self.PerformImplicitConversion(SrcExpr, DestType, ICS, Sema::AA_Casting,
-                                        /*IgnoreBaseAccess*/CStyle) ?
-      TC_Failed : TC_Success;
+  if (Result.isInvalid()) {
+    msg = 0;
+    return TC_Failed;
+  }
+  
+  SrcExpr = Result.takeAs<Expr>();
+  return TC_Success;
 }
 
 /// TryConstCast - See if a const_cast from source to destination is allowed,
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index b66c9805c3..edff4a5396 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3486,15 +3486,18 @@ InitializationSequence::Perform(Sema &S,
       CurInit = S.Owned(CurInitExpr);
       break;
         
-    case SK_ConversionSequence:
-        if (S.PerformImplicitConversion(CurInitExpr, Step->Type, Sema::AA_Converting, 
-                                      false, *Step->ICS))
+    case SK_ConversionSequence: {
+      bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
+
+      if (S.PerformImplicitConversion(CurInitExpr, Step->Type, *Step->ICS,
+                                      Sema::AA_Converting, IgnoreBaseAccess))
         return S.ExprError();
         
       CurInit.release();
-      CurInit = S.Owned(CurInitExpr);        
+      CurInit = S.Owned(CurInitExpr);
       break;
-
+    }
+        
     case SK_ListInitialization: {
       InitListExpr *InitList = cast<InitListExpr>(CurInitExpr);
       QualType Ty = Step->Type;
-- 
2.40.0