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Re: How to identify the type of the object being created using the new operator?
- From: Marc Glisse <marc dot glisse at inria dot fr>
- To: Swati Rathi <swatirathi at cse dot iitb dot ac dot in>
- Cc: GCC Development <gcc at gcc dot gnu dot org>
- Date: Mon, 6 Oct 2014 10:58:52 +0200 (CEST)
- Subject: Re: How to identify the type of the object being created using the new operator?
- Authentication-results: sourceware.org; auth=none
- References: <543256B6 dot 10807 at cse dot iitb dot ac dot in>
- Reply-to: GCC Development <gcc at gcc dot gnu dot org>
On Mon, 6 Oct 2014, Swati Rathi wrote:
Statement : A *a = new B;
gets translated in GIMPLE as
1. void * D.2805;
2. struct A * a;
3. D.2805 = operator new (20);
4. a = D.2805;
A is the base class and B is the derived class.
In statement 3, new operator is creating an object of derived class B.
By analyzing the RHS of the assignment statement 3, how can we identify the
type (in this case B) of the object being created?
I strongly doubt you can. It is calling B's constructor that will turn
this memory region into a B, operator new is the same as malloc, it
only returns raw memory.
(If A and B don't have the same size, the argument 20 can be a hint)