Give InitListChecker a verification-only mode, where it neither emits diagnostics nor

builds a semantic (structured) initializer list, just reports on whether it can match
the given list to the target type.
Use this mode for doing init list checking in the initial step of initialization, which
will eventually allow us to do overload resolution based on the outcome.

llvm-svn: 140457

1 files changed, 19 insertions, 15 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 9a802226e2f..513990e177f 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -909,20 +909,22 @@ Sema::TryImplicitConversion(Expr *From, QualType ToType,
 /// explicit user-defined conversions are permitted.
 ExprResult
 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
-                                AssignmentAction Action, bool AllowExplicit) {
+                                AssignmentAction Action, bool AllowExplicit,
+                                bool Diagnose) {
   ImplicitConversionSequence ICS;
-  return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
+  return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS,
+                                   Diagnose);
 }
 
 ExprResult
 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                                 AssignmentAction Action, bool AllowExplicit,
-                                ImplicitConversionSequence& ICS) {
+                                ImplicitConversionSequence& ICS,
+                                bool Diagnose) {
   // Objective-C ARC: Determine whether we will allow the writeback conversion.
   bool AllowObjCWritebackConversion
     = getLangOptions().ObjCAutoRefCount && 
       (Action == AA_Passing || Action == AA_Sending);
-  
 
   ICS = clang::TryImplicitConversion(*this, From, ToType,
                                      /*SuppressUserConversions=*/false,
@@ -930,6 +932,8 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
                                      /*InOverloadResolution=*/false,
                                      /*CStyle=*/false,
                                      AllowObjCWritebackConversion);
+  if (!Diagnose && ICS.isFailure())
+    return ExprError();
   return PerformImplicitConversion(From, ToType, ICS, Action);
 }
 
@@ -8386,18 +8390,18 @@ Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
   // BuildRecoveryCallExpr diagnoses the error itself, so we just bail
   // out if it fails.
   if (CandidateSet.empty()) {
-    // In Microsoft mode, if we are inside a template class member function then

-    // create a type dependent CallExpr. The goal is to postpone name lookup

+    // In Microsoft mode, if we are inside a template class member function then
+    // create a type dependent CallExpr. The goal is to postpone name lookup
     // to instantiation time to be able to search into type dependent base
-    // classes.

-    if (getLangOptions().MicrosoftExt && CurContext->isDependentContext() && 

-        isa<CXXMethodDecl>(CurContext)) {

-      CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs,

-                                          Context.DependentTy, VK_RValue,

-                                          RParenLoc);

-      CE->setTypeDependent(true);

-      return Owned(CE);

-    }

+    // classes.
+    if (getLangOptions().MicrosoftExt && CurContext->isDependentContext() && 
+        isa<CXXMethodDecl>(CurContext)) {
+      CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs,
+                                          Context.DependentTy, VK_RValue,
+                                          RParenLoc);
+      CE->setTypeDependent(true);
+      return Owned(CE);
+    }
     return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs,
                                  RParenLoc, /*EmptyLookup=*/true);
   }