Implement the lvalue-to-rvalue conversion where needed. The

lvalue-to-rvalue conversion adjusts lvalues of qualified, non-class
type to rvalue expressions of the unqualified variant of that
type. For example, given:

  const int i;
  (void)(i + 17);

the lvalue-to-rvalue conversion for the subexpression "i" will turn it
from an lvalue expression (a DeclRefExpr) with type 'const int' into
an rvalue expression with type 'int'. Both C and C++ mandate this
conversion, and somehow we've slid through without implementing it. 

We now have both DefaultFunctionArrayConversion and
DefaultFunctionArrayLvalueConversion, and which gets used depends on
whether we do the lvalue-to-rvalue conversion or not. Generally, we do
the lvalue-to-rvalue conversion, but there are a few notable
exceptions:
  - the left-hand side of a '.' operator
  - the left-hand side of an assignment
  - a C++ throw expression
  - a subscript expression that's subscripting a vector

Making this change exposed two issues with blocks:
  - we were deducing const-qualified return types of non-class type
  from a block return, which doesn't fit well
  - we weren't always setting the known return type of a block when it
  was provided with the ^return-type syntax

Fixes the current Clang-on-Clang compile failure and PR6076.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95167 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/Sema/SemaCXXCast.cpp b/lib/Sema/SemaCXXCast.cpp
index 57c4f9bc2a..093700d9ef 100644
--- a/lib/Sema/SemaCXXCast.cpp
+++ b/lib/Sema/SemaCXXCast.cpp
@@ -388,7 +388,7 @@ void
 CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                const SourceRange &OpRange, const SourceRange &DestRange) {
   if (!DestType->isLValueReferenceType())
-    Self.DefaultFunctionArrayConversion(SrcExpr);
+    Self.DefaultFunctionArrayLvalueConversion(SrcExpr);
 
   unsigned msg = diag::err_bad_cxx_cast_generic;
   if (TryConstCast(Self, SrcExpr, DestType, /*CStyle*/false, msg) != TC_Success
@@ -407,7 +407,7 @@ CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                      const SourceRange &OpRange, const SourceRange &DestRange,
                      CastExpr::CastKind &Kind) {
   if (!DestType->isLValueReferenceType())
-    Self.DefaultFunctionArrayConversion(SrcExpr);
+    Self.DefaultFunctionArrayLvalueConversion(SrcExpr);
 
   unsigned msg = diag::err_bad_cxx_cast_generic;
   if (TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/false, OpRange,
@@ -434,7 +434,7 @@ CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
   }
 
   if (!DestType->isLValueReferenceType() && !DestType->isRecordType())
-    Self.DefaultFunctionArrayConversion(SrcExpr);
+    Self.DefaultFunctionArrayLvalueConversion(SrcExpr);
 
   unsigned msg = diag::err_bad_cxx_cast_generic;
   if (TryStaticCast(Self, SrcExpr, DestType, /*CStyle*/false, OpRange, msg,
@@ -1197,7 +1197,7 @@ bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr,
     return false;
 
   if (!CastTy->isLValueReferenceType() && !CastTy->isRecordType())
-    DefaultFunctionArrayConversion(CastExpr);
+    DefaultFunctionArrayLvalueConversion(CastExpr);
 
   // C++ [expr.cast]p5: The conversions performed by
   //   - a const_cast,