Re: temp obj created by compiler
Hi Jonathan & Everyone, Thanks for your reply. Yes, as you pointed out, it will create only 2 temporaries as below: X a(1); sub r3, fp, #16 mov r0, r3 mov r1, #1 bl X::X[in-charge](int) a = f(a); sub r3, fp, #24 sub r2, fp, #16 mov r0, r3 mov r1, r2 bl X::X[in-charge](X const&) sub r2, fp, #24 sub r3, fp, #20 mov r0, r3 mov r1, r2 bl f(X) sub r3, fp, #20 mov r0, r3 bl X::~X [in-charge]()=>dtor for temp1 sub r3, fp, #24 mov r0, r3 bl X::~X [in-charge]()=>dtor for temp2 sub r3, fp, #16 mov r0, r3 bl X::~X [in-charge]()=>dtor for a What i want to know is how to find what are the temporaries inserted by the compl. I tried looking into the ABI but couldn't get much help. Is there any way i can figure out the temporaries inserted by the compl. Looking forward for more help. :) Best regards, San --- Jonathan Wakely <[EMAIL PROTECTED]> wrote: > On Thu, Feb 10, 2005 at 01:49:44PM +, Jonathan > Wakely wrote: > > > > a = f(a); //this will create 4 temorary objects > > > > Why? I think this will only create two > temporaries. > > > > One when a is copied to the "x" parameter of f() > and one when "x" is > > copied to the return value; > > to be clear, "x" isn't a true temporary as it has a > name, but it is > created and destroyed during the execution of f(), > which is what I > assume you meant. > > jon > > -- > "Keep away from people who try to belittle your > ambitions. Small people > always do that, but the really great make you feel > that you, too, can > become great." > - Mark Twain > __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Re: temp obj created by compiler
Hi Jon, Thanks again for replying. Let me clarify my problem: I have an assembly file of a .cpp file, from the assembly file i want to figure out where the compl has created temp objects. For this i thought of looking for copy-ctor becuase temp obj. are created using copy-ctors. I am not sure if there is any other way by which i can figure out that. I hope i am clear this time :). Regards, San --- Jonathan Wakely <[EMAIL PROTECTED]> wrote: > On Fri, Feb 11, 2005 at 05:44:52AM -0800, san san > wrote: > > > Hi Jonathan & Everyone, > > Hello again San, > > > What i want to know is how to find what are the > > temporaries inserted by the compl. > > I don't think I understand your question properly. > > > I tried looking into the ABI but couldn't get much > > help. Is there any way i can figure out the > > temporaries inserted by the compl. > > The compiler creates and destroys objects as > dictated by the C++ > standard. If the language rules require a temporary > object to be > created then the compiler will create one. > > Your code passes objects by value, not by reference, > which causes > objects to be created and destroyed. > > Apologies if I've misunderstood you, > > jon > > -- > "Political satire became obsolete when Henry > Kissinger was awarded the > Nobel Prize." > - Tom Lehrer > __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Re: temp obj created by compiler
Thanks Jon,
Can anyone throw more light on this.
Regards,
Sanjiv
--- Jonathan Wakely <[EMAIL PROTECTED]> wrote:
> On Fri, Feb 11, 2005 at 06:08:55AM -0800, san san
> wrote:
>
> > Hi Jon,
> >
> > Thanks again for replying. Let me clarify my
> problem:
> > I have an assembly file of a .cpp file, from the
> > assembly file i want to figure out where the compl
> has
> > created temp objects.
>
> Ah, I see what you mean now - but I probably can't
> help you with that.
>
> > For this i thought of looking for copy-ctor
> becuase
> > temp obj. are created using copy-ctors. I am not
> sure
> > if there is any other way by which i can figure
> out
> > that.
>
> Not necessarily true, temporaries might be created
> by any non-explicit
> constructor, consider
>
> struct A {
> A(int);
> };
>
> void f(const A&);
>
> f(0); // creates a temporary A using A::A(int)
>
> jon
>
> --
> "It is always the best policy to tell the truth,
> unless, of course, you
> are an exceptionally good liar."
> - Jerome K. Jerome
>
__
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