Is there any way, without modifying Ruby/DL itself, to specify
a function that returns a 64-bit integer using Ruby/DL? And to pass
a 64-bit integer to a function?
Consider:
require 'dl/import'
module Test64
dlload "foo.so"
extern "long long int get_64bit_value()"
extern "void set_64bit_value(long long int)"
end
The above results in an error, currently, because Ruby/DL does not
support 64-bit integers as immediate values.
I thought of using a double (which is 64 bits, on my platform anyway):
Is there any way, without modifying Ruby/DL itself, to specify
a function that returns a 64-bit integer using Ruby/DL? And to pass
a 64-bit integer to a function?
As far as I know Ruby/DL does not yet work properly on 64 bit platforms. The author plans to fix that, but didn't have the time to do it when I last contacted him.
I think this would involve changes in lots of places because Ruby/DL seems to be using one-byte type tokens and .pack() internally. However if you want to use the native bit-width of the system you will need to use "L_" instead of "L" and so on in the pack arguments. So I think this would involve changing the semantics in quite a few code locations...
I don't know very much about Ruby/DL but can't you just define a struct that
has two 32-bit numbers in it, and manipulate and pass those?
"Jamis Buck" <jamis_buck@byu.edu> wrote in message
news:20041214220549.GA15605@serling.WorkGroup...
···
Okay, you C gurus out there. Here's a stumper.
Is there any way, without modifying Ruby/DL itself, to specify
a function that returns a 64-bit integer using Ruby/DL? And to pass
a 64-bit integer to a function?
Consider:
require 'dl/import'
module Test64
dlload "foo.so"
extern "long long int get_64bit_value()"
extern "void set_64bit_value(long long int)"
end
The above results in an error, currently, because Ruby/DL does not
support 64-bit integers as immediate values.
I thought of using a double (which is 64 bits, on my platform anyway):
Well, I'm actually on a 32-bit system. But gcc supports a 64-bit
integer (long long), as does MSVC++.
It's not critical, but it would certainly be nice. For now, I'm just
using unsigned longs, which will lose the most significant 32 bits of
each return value.
- Jamis
···
On 08:47 Wed 15 Dec , Florian Gross wrote:
Jamis Buck wrote:
>Is there any way, without modifying Ruby/DL itself, to specify
>a function that returns a 64-bit integer using Ruby/DL? And to pass
>a 64-bit integer to a function?
As far as I know Ruby/DL does not yet work properly on 64 bit platforms.
The author plans to fix that, but didn't have the time to do it when I
last contacted him.
I think this would involve changes in lots of places because Ruby/DL
seems to be using one-byte type tokens and .pack() internally. However
if you want to use the native bit-width of the system you will need to
use "L_" instead of "L" and so on in the pack arguments. So I think this
would involve changing the semantics in quite a few code locations...
I don't know very much about Ruby/DL but can't you just define a struct that
has two 32-bit numbers in it, and manipulate and pass those?
Well, structs in Ruby/DL are implemented as pointers to structs. You
can't create a "bare" structure in Ruby/DL (to my knowledge).
- Jamis
···
On 01:17 Thu 16 Dec , DaZoner wrote:
"Jamis Buck" <jamis_buck@byu.edu> wrote in message
news:20041214220549.GA15605@serling.WorkGroup...
> Okay, you C gurus out there. Here's a stumper.
>
> Is there any way, without modifying Ruby/DL itself, to specify
> a function that returns a 64-bit integer using Ruby/DL? And to pass
> a 64-bit integer to a function?
>
> Consider:
>
> require 'dl/import'
> module Test64
> dlload "foo.so"
> extern "long long int get_64bit_value()"
> extern "void set_64bit_value(long long int)"
> end
>
> The above results in an error, currently, because Ruby/DL does not
> support 64-bit integers as immediate values.
>
> I thought of using a double (which is 64 bits, on my platform anyway):
>
> require 'dl/import'
> module Test64
> dlload "foo.so"
> extern "double get_64bit_value()"
> extern "void set_64bit_value(double)"
> end
>
> result = Test64.get_64bit_value
> p [result].pack("D").unpack("LL")
>
> But the value that comes back is nothing like what the function itself
> is really returning...
>
> Any clever tricks I can try? Anyone? Please?
>
> - Jamis
>
> --
> Jamis Buck
> jgb3@email.byu.edu
> http://www.jamisbuck.org/jamis
>
>
>
