[cfe-commits] r71983 - in /cfe/trunk/lib/Sema: Sema.h SemaExprCXX.cpp

[Douglas Gregor]

On May 17, 2009, at 11:41 AM, Anders Carlsson wrote:

> Author: andersca
> Date: Sun May 17 13:41:29 2009
> New Revision: 71983
>
> URL: http://llvm.org/viewvc/llvm-project?rev=71983&view=rev
> Log:
> Implement Sema::ActOnFinishFullExpr and create a  
> CXXExprWithTemporaries node if necessary.
>
> Modified:
>    cfe/trunk/lib/Sema/Sema.h
>    cfe/trunk/lib/Sema/SemaExprCXX.cpp
>
> Modified: cfe/trunk/lib/Sema/Sema.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=71983&r1=71982&r2=71983&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/lib/Sema/Sema.h (original)
> +++ cfe/trunk/lib/Sema/Sema.h Sun May 17 13:41:29 2009
> @@ -162,7 +162,11 @@
>   /// in the top level function.  Clients should always use  
> getSwitchStack() to
>   /// handle the case when they are in a block.
>   llvm::SmallVector<SwitchStmt*, 8> FunctionSwitchStack;
> -
> +
> +  /// ExprTemporaries - This is the stack of temporaries that are  
> created by
> +  /// the current full expression.
> +  llvm::SmallVector<CXXTempVarDecl*, 8> ExprTemporaries;
> +
>   /// CurFunctionNeedsScopeChecking - This is set to true when a  
> function or
>   /// ObjC method body contains a VLA or an ObjC try block, which  
> introduce
>   /// scopes that need to be checked for goto conditions.  If a  
> function does
> @@ -1583,6 +1587,8 @@
>                                                TypeTy *Ty,
>                                                SourceLocation RParen);
>
> +  virtual OwningExprResult ActOnFinishFullExpr(ExprArg Expr);
> +
>   bool RequireCompleteDeclContext(const CXXScopeSpec &SS);
>
>   DeclContext *computeDeclContext(const CXXScopeSpec &SS);
>
> Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=71983&r1=71982&r2=71983&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Sun May 17 13:41:29 2009
> @@ -164,8 +164,11 @@
>       CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) {
>     exprs.release();
>
> -    // FIXME: Is this correct?
> +    // FIXME: Is this correct (I don't think so). Instead, we  
> should have an
> +    // CXXUnresolvedTemporaryObjectExpr node for this.
>     CXXTempVarDecl *Temp = CXXTempVarDecl::Create(Context,  
> CurContext, Ty);
> +    ExprTemporaries.push_back(Temp);
> +
>     return Owned(new (Context) CXXTemporaryObjectExpr(Context, Temp,  
> 0, Ty,
>                                                       TyBeginLoc,
>                                                       Exprs, NumExprs,
> @@ -190,6 +193,8 @@
>   if (const RecordType *RT = Ty->getAsRecordType()) {
>     CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
>
> +    // FIXME: We should always create a CXXTemporaryObjectExpr here  
> unless
> +    // both the ctor and dtor are trivial.
>     if (NumExprs > 1 || Record->hasUserDeclaredConstructor()) {
>       CXXConstructorDecl *Constructor
>         = PerformInitializationByConstructor(Ty, Exprs, NumExprs,
> @@ -203,7 +208,8 @@
>         return ExprError();
>
>       CXXTempVarDecl *Temp = CXXTempVarDecl::Create(Context,  
> CurContext, Ty);
> -
> +      ExprTemporaries.push_back(Temp);
> +
>       exprs.release();
>       return Owned(new (Context) CXXTemporaryObjectExpr(Context, Temp,
>                                                         Constructor,  
> Ty,
> @@ -1494,3 +1500,18 @@
>   }
>   return QualType();
> }
> +
> +Sema::OwningExprResult Sema::ActOnFinishFullExpr(ExprArg Arg) {
> +  Expr *FullExpr = Arg.takeAs<Expr>();
> +  assert(FullExpr && "Null full expr!");
> +
> +  if (!ExprTemporaries.empty()) {
> +    // Create a cleanup expr.
> +    FullExpr =
> +      new (Context) CXXExprWithTemporaries(FullExpr,  
> &ExprTemporaries[0],
> +                                           ExprTemporaries.size());
> +    ExprTemporaries.clear();
> +  }
> +
> +  return Owned(FullExpr);
> +}

This is coming along very nicely! Should we add some asserts() in  
various places to be sure that we've captured all of the temporaries?  
For example, at the end of a compound expression, we could

	assert(ExprTemporaries.empty() && " Temporaries node captured in  
compound expression");

    - Doug