Re: Fwd: Link Problems With Borland C++ 4.52

Question

I have seen this problem before in another context, and I'll offer the
cause and solution in the hope that they will apply to the Crystal problem.
Many Windows based applications rely on PASCAL calling conventions, which
change the way parameters are handled in function/method calls. They
indicate this by placing one of the following immediately before the
function name in the prototype declarations:
- pascal_far (or something like that)
- WINAPI
- some other typedef of either of the above
For example:
int WINAPI AddTotal(int valueA, int valueB);
Unfortunately, v2.0 of Forte does not provide any mechanisms for changing
the calling conventions of the prototypes in the generated C++ wrapper
library, so when you compile that code, the linker fails. I think that the
compiler may generate different symbols depending on calling conventions,
so that's why it fails.
To fix this, don't autocompile your code, but generate the distribution, go
into the generated C++ files and look for the function prototypes (I think
you can search for FORTE_NO_PROTOTYPES), add WINAPI to the appropriate
places in the prototype definitions (see above) and use fcompile to build
the library. Instructions for fcompile are in the Interfacing With
External Systems manual.
Hope this helps,
James
At 11:05 AM 5/29/97 PDT, you wrote:
>
We are trying to wrapper Crystal Reports from Forte. I know that there
are a number of other people in this same boat, as I've seen messages
posted here at various points during the past few weeks. We are having
a particular problem with getting the compile to go through, which we
have sent in to Forte Tech Support. I'm forwarding the message I sent
Tech Support to this group in the hopes that someone here may have
already seen and resolved a similar problem.
Thanks in advance for any help you can offer!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
>
Date: Wed, 28 May 97 13:47:20 PDT
From: dg7077a
To: Forte Technical Support
Cc: Gardner, Steve
Subject: Link Problems With Borland C++ 4.52
Name of requestor: [Dale V. Georg / Alaiah Chandrashekar]
Company: [Indus Consultancy Services]
Phone for callback: [[phone]]
Customer Site: [Mack Trucks, Inc.]
Product: [Forte]
Version of Forte: [2.0.H.1]
Server OS: [SunOS 5.5.1]
Client OS: [Windows 3.1]
DBMS: [Oracle 7.2.3]
Reproducible?: [Yes]
Brief description: [Link Problems With Borland C++ 4.52]
Complete description of problem or question:
We are attempting to write a C-wrapper interface from Forte to Crystal
Reports' Report Engine. We are using Borland C++ version 4.52.
Unfortunately, we have been unable to get a clean compile after a day
and half of effort. We get as far as the link stage of the
compilation, and
the compiler aborts with an "Unknown symbol" error message for each
of the functions we are trying to wrapper. We have tried a number of
ideas to fix this problem, and are continuing to try to solve it on
our own,
but any help would be greatly appreciated. Please have someone call
Alaiah Chandrashekar at the number above as soon as possible.
Thanks!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
James Urquhart [email protected]
Product Manager phone: [phone]
Forte Software, Inc. fax: [phone]

Answer 1

James,
Thanks for your quick response. Yesterday we had been running down
the path of examining the calling conventions and trying to change them
to PASCAL, but without much success. After receiving your note, we
went back over it again, and this time we were able to finally to piece it
together. In addition to editing the Forte-generated .cc file to declare
the functions as PASCAL, we also had to turn off the compiler's case
sensitivity. (The Crystal .lib file had the function names in mixed case,
but the Borland compiler was generating all uppercase for the names.)
Now I had actually tried this yesterday and it didn't work (in fact it
generated a whole bunch of new errors) - because until we took a
second look at it today, I didn't realize that Borland's linker actually has
TWO flags that control case sensitivity. If you only turn one or the
other off, things can get pretty ugly looking. As soon as we turned
both of them off, the compile and link went beautifully. Again, thanks
for your help; hopefully we are over the worst of it now!
Dale
I have seen this problem before in another context, and I'll offer the
cause and solution in the hope that they will apply to the Crystalproblem.
>
Many Windows based applications rely on PASCAL callingconventions, which
change the way parameters are handled in function/method calls.They
indicate this by placing one of the following immediately before the
function name in the prototype declarations:
- pascal_far (or something like that)
- WINAPI
- some other typedef of either of the above
For example:
int WINAPI AddTotal(int valueA, int valueB);
Unfortunately, v2.0 of Forte does not provide any mechanisms forchanging
the calling conventions of the prototypes in the generated C++wrapper
library, so when you compile that code, the linker fails. I think thatthe
compiler may generate different symbols depending on callingconventions,
so that's why it fails.
To fix this, don't autocompile your code, but generate thedistribution, go
into the generated C++ files and look for the function prototypes (I think
you can search for FORTE_NO_PROTOTYPES), add WINAPI tothe appropriate
places in the prototype definitions (see above) and use fcompile tobuild
the library. Instructions for fcompile are in the Interfacing With
External Systems manual.
Hope this helps,
James
At 11:05 AM 5/29/97 PDT, you wrote:
We are trying to wrapper Crystal Reports from Forte. I know that
there
are a number of other people in this same boat, as I've seenmessages
posted here at various points during the past few weeks. We arehaving
a particular problem with getting the compile to go through, whichwe
have sent in to Forte Tech Support. I'm forwarding the message Isent
Tech Support to this group in the hopes that someone here mayhave
already seen and resolved a similar problem.
Thanks in advance for any help you can offer!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc.
[email protected]
>
>>
Date: Wed, 28 May 97 13:47:20 PDT
From: dg7077a
To: Forte Technical Support
Cc: Gardner, Steve
Subject: Link Problems With Borland C++ 4.52
Name of requestor: [Dale V. Georg / AlaiahChandrashekar
Company: [Indus Consultancy Services]
Phone for callback: [[phone]]
Customer Site: [Mack Trucks, Inc.]
Product: [Forte]
Version of Forte: [2.0.H.1]
Server OS: [SunOS 5.5.1]
Client OS: [Windows 3.1]
DBMS: [Oracle 7.2.3]
Reproducible?: [Yes]
Brief description: [Link Problems With Borland C++ 4.52]
Complete description of problem or question:
We are attempting to write a C-wrapper interface from Forte to
Crystal
>>
Reports' Report Engine. We are using Borland C++ version 4.52.
Unfortunately, we have been unable to get a clean compile after aday
and half of effort. We get as far as the link stage of the
compilation, and
the compiler aborts with an "Unknown symbol" error message foreach
of the functions we are trying to wrapper. We have tried a numberof
ideas to fix this problem, and are continuing to try to solve it on
our own,
but any help would be greatly appreciated. Please have someonecall
Alaiah Chandrashekar at the number above as soon as possible.
Thanks!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, [email protected]
James Urquhart [email protected]
Product Manager phone: [phone]
Forte Software, Inc. fax: [phone]-----------------------------------------------------------------------------------
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
[email protected]------------------