[cfe-dev] Strange type of an argument in CXXConstructExpr

[Richard Smith via cfe-dev]

Expressions in C++ never have reference type. You can use getValueKind() to
find if the expression is an lvalue or an rvalue. What is the problem
you're trying to solve here?
On Nov 8, 2015 6:30 AM, "victor via cfe-dev" <cfe-dev at lists.llvm.org> wrote:

> Hi everyone,
>
> Today I noticed an unusual behavior when using Clang. I found that the
> type of one of the arguments in a CXXConstructExpr was different from the
> type that I expected.
>
> This is the fragment of code:
>
> void QDomAttrPrivate::setNodeValue(const QString& v)
> {
>     *QDomTextPrivate *t = new QDomTextPrivate(0, this, v);*
>     ....
> }
>
> The invoked constructor is:
> *QDomTextPrivate(QDomDocumentPrivate*, QDomNodePrivate* parent, const
> QString& val);*
>
> and this is the related AST:
>
> |   |-DeclStmt 0x7f67b329cdb8 <line:4108:5, col:57>
> |   | `-VarDecl 0x7f67b329c7f0 <col:5, col:56> t 'class QDomTextPrivate *'
> |   |   `-CXXNewExpr 0x7f67b329cd60 <col:26, col:56> 'class
> QDomTextPrivate *'
> |   |     `-CXXConstructExpr 0x7f67b329cd18 <col:30, col:56> 'class
> QDomTextPrivate' 'void (class QQDomDocumentPrivate *, class QDomNodePrivate
> *, const class QString &)'
> |   |       |-ImplicitCastExpr 0x7f67b329cce0 <col:46> 'class
> QQDomDocumentPrivate *' <NullToPointer>
> |   |       | `-IntegerLiteral 0x7f67b329c848 <col:46> 'int' 0
> |   |       |-ImplicitCastExpr 0x7f67b329ccf8 <col:49> 'class
> QDomNodePrivate *' <DerivedToBase (QDomNodePrivate)>
> |   |       | `-CXXThisExpr 0x7f67b329c868 <col:49> 'class QDomAttrPrivate
> *' this
> |   |       `-DeclRefExpr 0x7f67b329c880 <col:55> '*const class QString*'
> lvalue ParmVar 0x7f67b329c560 'v' '*const class QString &*'
>
> What I find strange is that the type of the ParmVar 'v' loses the '&'.
> The problem is that, when I compare the "getType()" of the third argument
> in the CXXConstructExpr (1) and the "getType()" of the third parameter of
> the constructor (2), the types do not match:
>
> (1) const class QString
> (2) const class QString &
>
> Why is this happening? And what's more important, how do I sort out this
> issue?
>
> Thanks.
>
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20151108/cf12858c/attachment.html>