r353571 - [CodeGen][NFC] Update comments in CGExprConstant.cpp.

[Eli Friedman via cfe-commits]

Author: efriedma
Date: Fri Feb  8 13:36:04 2019
New Revision: 353571

URL: http://llvm.org/viewvc/llvm-project?rev=353571&view=rev
Log:
[CodeGen][NFC] Update comments in CGExprConstant.cpp.


Modified:
    cfe/trunk/lib/CodeGen/CGExprConstant.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprConstant.cpp?rev=353571&r1=353570&r2=353571&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprConstant.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprConstant.cpp Fri Feb  8 13:36:04 2019
@@ -700,10 +700,12 @@ EmitArrayConstant(CodeGenModule &CGM, co
   return llvm::ConstantStruct::get(SType, Elements);
 }
 
-/// This class only needs to handle two cases:
-/// 1) Literals (this is used by APValue emission to emit literals).
-/// 2) Arrays, structs and unions (outside C++11 mode, we don't currently
-///    constant fold these types).
+// This class only needs to handle arrays, structs and unions. Outside C++11
+// mode, we don't currently constant fold those types.  All other types are
+// handled by constant folding.
+//
+// Constant folding is currently missing support for a few features supported
+// here: CK_ToUnion, CK_ReinterpretMemberPointer, and DesignatedInitUpdateExpr.
 class ConstExprEmitter :
   public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
   CodeGenModule &CGM;
@@ -1076,6 +1078,7 @@ public:
   }
 
   llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
+    // This is a string literal initializing an array in an initializer.
     return CGM.GetConstantArrayFromStringLiteral(E);
   }
 
@@ -1649,7 +1652,7 @@ private:
 llvm::Constant *ConstantLValueEmitter::tryEmit() {
   const APValue::LValueBase &base = Value.getLValueBase();
 
-  // Otherwise, the destination type should be a pointer or reference
+  // The destination type should be a pointer or reference
   // type, but it might also be a cast thereof.
   //
   // FIXME: the chain of casts required should be reflected in the APValue.