RE: CFORTRAN for cygwin/egcs?

RE: CFORTRAN for cygwin/egcs?

[Billinghurst, David (RTD)]

Yes please.  I'd love an example of a DLL callable from Excel

> -----Original Message-----
> From:	Mumit Khan [SMTP:khan@xraylith.wisc.EDU]
> Sent:	Tuesday 16 March 1999 19:47
> To:	Richard Stanton
> Cc:	cygwin@sourceware.cygnus.com
> Subject:	Re: CFORTRAN for cygwin/egcs? 
> 
> "Richard Stanton" <stanton@haas.berkeley.edu> writes:
> > It IS trivial to use, I've found, as long as you use version 3.5 rather
> than
> > 2.8. The latter seems to be more easily found. As you say,
> > using -Df2cFortran, and linking with -lg2c, gets the sample program to
> > compile without warnings.
> 
> Thank you. That's very useful information, especially since it goes into
> the mailing list archive.
> 
> BTW, can I use your Excel DLL as an example (with proper attribution of
> course)?  I'd like to create some examples in C, C++ and F77 to create
> DLLs for VB/Excel etc like I've done for Java etc.
> 
> Regards,
> Mumit
> 
> 
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Excel-callable DLL [RE: CFORTRAN for cygwin/egcs?]

[Mumit Khan]

On Tue, 16 Mar 1999, Billinghurst, David (RTD) wrote:

> Yes please.  I'd love an example of a DLL callable from Excel

I won't get a chance to make an example for a while, but here's the
essential info:

1. You need to tell the compiler that the functions need to use the
   stdcall calling convention and not the default cdecl. There are two
   ways to do it:

   a. You can attach an __attribute__((stdcall)) (or WINAPI or STDCALL
   which are macros that expand to the attribute) to each exported
   function. This is not possible in g77, so you need to use b.

   b. Compile all the to-be-turned-into-DLL files with -mrtd, which tells
   the compiler to use stdcall calling convention for all the functions.

   In most cases, (b) is the simpler option since you don't need to modify
   the source code at all.
  
2. if you're using Cygwin GCC (no -mno-cygwin), then you need to do supply
   "special" entry point so that Cygwin DLL is initialized correctly when
   it's loaded by Excel etc. Also, you need to make sure cygwin1.dll is in
   your path when Excel loads your DLL.

   $ dllwrap --entry __cygwin_noncygwin_dll_entry@12 [rest of the options]

I believe the examples in the dllhelpers package describe the rest.

BTW, this is exactly the same mechanism for creating a Java JNI using
Cygwin DLL. (1) is taken care of automatically since Java headers define
a macro that essentially makes the calling convention stdcall. See my
java-jni-examples package for more info.

Regards,
mumit



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Excel-callable DLL [RE: CFORTRAN for cygwin/egcs?]

[Mumit Khan]

On Tue, 16 Mar 1999, Billinghurst, David (RTD) wrote:

> Yes please.  I'd love an example of a DLL callable from Excel

I won't get a chance to make an example for a while, but here's the
essential info:

1. You need to tell the compiler that the functions need to use the
   stdcall calling convention and not the default cdecl. There are two
   ways to do it:

   a. You can attach an __attribute__((stdcall)) (or WINAPI or STDCALL
   which are macros that expand to the attribute) to each exported
   function. This is not possible in g77, so you need to use b.

   b. Compile all the to-be-turned-into-DLL files with -mrtd, which tells
   the compiler to use stdcall calling convention for all the functions.

   In most cases, (b) is the simpler option since you don't need to modify
   the source code at all.
  
2. if you're using Cygwin GCC (no -mno-cygwin), then you need to do supply
   "special" entry point so that Cygwin DLL is initialized correctly when
   it's loaded by Excel etc. Also, you need to make sure cygwin1.dll is in
   your path when Excel loads your DLL.

   $ dllwrap --entry __cygwin_noncygwin_dll_entry@12 [rest of the options]

I believe the examples in the dllhelpers package describe the rest.

BTW, this is exactly the same mechanism for creating a Java JNI using
Cygwin DLL. (1) is taken care of automatically since Java headers define
a macro that essentially makes the calling convention stdcall. See my
java-jni-examples package for more info.

Regards,
mumit



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RE: CFORTRAN for cygwin/egcs?

[Billinghurst, David (RTD)]

Yes please.  I'd love an example of a DLL callable from Excel

> -----Original Message-----
> From:	Mumit Khan [SMTP:khan@xraylith.wisc.EDU]
> Sent:	Tuesday 16 March 1999 19:47
> To:	Richard Stanton
> Cc:	cygwin@sourceware.cygnus.com
> Subject:	Re: CFORTRAN for cygwin/egcs? 
> 
> "Richard Stanton" <stanton@haas.berkeley.edu> writes:
> > It IS trivial to use, I've found, as long as you use version 3.5 rather
> than
> > 2.8. The latter seems to be more easily found. As you say,
> > using -Df2cFortran, and linking with -lg2c, gets the sample program to
> > compile without warnings.
> 
> Thank you. That's very useful information, especially since it goes into
> the mailing list archive.
> 
> BTW, can I use your Excel DLL as an example (with proper attribution of
> course)?  I'd like to create some examples in C, C++ and F77 to create
> DLLs for VB/Excel etc like I've done for Java etc.
> 
> Regards,
> Mumit
> 
> 
> --
> Want to unsubscribe from this list?
> Send a message to cygwin-unsubscribe@sourceware.cygnus.com

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