Always try to fold array sizes, and warn if we could fold something that isn't an ICE. This makes us compatible with GCC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65140 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 44 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 08b5a8c2ab..b69453d447 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3398,36 +3398,6 @@ void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) {
   Consumer.HandleTagDeclDefinition(Tag);
 }
 
-/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array
-/// types into constant array types in certain situations which would otherwise
-/// be errors (for GCC compatibility).
-static QualType TryToFixInvalidVariablyModifiedType(QualType T,
-                                                    ASTContext &Context,
-                                                    bool &SizeIsNegative) {
-  // This method tries to turn a variable array into a constant
-  // array even when the size isn't an ICE.  This is necessary
-  // for compatibility with code that depends on gcc's buggy
-  // constant expression folding, like struct {char x[(int)(char*)2];}
-  SizeIsNegative = false;
-  
-  const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
-  if (!VLATy) return QualType();
-  
-  Expr::EvalResult EvalResult;
-  if (!VLATy->getSizeExpr() ||
-      !VLATy->getSizeExpr()->Evaluate(EvalResult, Context))
-    return QualType();
-    
-  assert(EvalResult.Val.isInt() && "Size expressions must be integers!");
-  llvm::APSInt &Res = EvalResult.Val.getInt();
-  if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned()))
-    return Context.getConstantArrayType(VLATy->getElementType(),
-                                        Res, ArrayType::Normal, 0);
-
-  SizeIsNegative = true;
-  return QualType();
-}
-
 bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName, 
                           QualType FieldTy, const Expr *BitWidth) {
   // FIXME: 6.7.2.1p4 - verify the field type.
@@ -3473,20 +3443,9 @@ Sema::DeclTy *Sema::ActOnField(Scope *S, DeclTy *TagD,
   // C99 6.7.2.1p8: A member of a structure or union may have any type other
   // than a variably modified type.
   if (T->isVariablyModifiedType()) {
-    bool SizeIsNegative;
-    QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context,
-                                                           SizeIsNegative);
-    if (!FixedTy.isNull()) {
-      Diag(Loc, diag::warn_illegal_constant_array_size);
-      T = FixedTy;
-    } else {
-      if (SizeIsNegative)
-        Diag(Loc, diag::err_typecheck_negative_array_size);
-      else
-        Diag(Loc, diag::err_typecheck_field_variable_size);
-      T = Context.IntTy;
-      InvalidDecl = true;
-    }
+    Diag(Loc, diag::err_typecheck_field_variable_size);
+    T = Context.IntTy;
+    InvalidDecl = true;
   }
   
   if (BitWidth) {