Solved

Building dll in Microsoft C++

Posted on 1999-01-28
8
247 Views
Last Modified: 2010-04-16
HI,

I have been trying to build DLL in MS C++ using extern "C".
Here is my simple code:

#include <stdio.h>^M
#include <math.h>^M
^M
/* extern "C" */^M
extern "C" _declspec(dllexport) void calc1(float,float);^M
^M
void calc1(float x,float y)^M
/* test subroutine for building library */^M
{^M
float z;^M
^M
z= x + y;^M
printf("x=%.2f y=%.2f z=%.2f\n",x,y,z);^M
^M
/* end calc1 */^M
}^M

I just want to compile this in command line mode.
To compile from command line, we used^M
^M
cl -c calc1.c^M
^M
We get the following error message:^M
^M
calc1.c(5) : error C2059: syntax error : 'string'^M

Why is this happening? What am I doing wrong?

Thank you!

JJ


0
Comment
Question by:jinjool
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
8 Comments
 
LVL 1

Expert Comment

by:peter_vc
ID: 1185448
JJ,

I thought you only had to use the extern "C" directive in cpp files.  I believe the compiler is smart enough to know that you are compiling a file with a .C extension, and therefore you should not require the "C".

Peter


0
 
LVL 22

Expert Comment

by:nietod
ID: 1185449
peter_vc, I think you found the problem, but you expained it backwards.  The problem is that with a ".c" extension it compiles the program as a C program not a C++ program.  But the solution is to change the file to have a ".cpp" extension.  That way it is compiled as a C++ program.  (I assume that jinjool intended for it to be a C++ program, or he wouldn't have C++ syntax.)
0
 
LVL 4

Expert Comment

by:pellep
ID: 1185450
Compiler error C2059 is usually a Syntax Error. line 5 is the printf() command. maybe it's not the extern "C" that's the problem...
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 22

Expert Comment

by:nietod
ID: 1185451
That line seems fine and is nowhere near 5.
0
 
LVL 23

Expert Comment

by:chensu
ID: 1185452
Are you using Microsoft C/C++ 7.0 or Microsoft Visual C++? Which version?

Line 5 is extern "C" _declspec(dllexport) void calc1(float,float);
0
 

Author Comment

by:jinjool
ID: 1185453
Thank you all for your comments.
Yes, nietod was right. The problem was-- the person who
did the program was running it without a .cpp extension.
I should have known it but somehow completely overlooked
the error.

Thanks again,
JJ
0
 
LVL 23

Expert Comment

by:chensu
ID: 1185454
So, the points should be given to nietod.
0
 
LVL 22

Accepted Solution

by:
nietod earned 50 total points
ID: 1185455
Answering as suggested by Chensu (Thanks).  (Sorry, for the delay, I was out of town.)
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Create string splitting user defined function in C++ 23 335
Arduino EDI - Programming language 3 114
Problem with SqlConnection 4 184
FMX TCameraComponent Problem 2 92
Introduction This article is the first in a series of articles about the C/C++ Visual Studio Express debugger.  It provides a quick start guide in using the debugger. Part 2 focuses on additional topics in breakpoints.  Lastly, Part 3 focuses on th…
  Included as part of the C++ Standard Template Library (STL) is a collection of generic containers. Each of these containers serves a different purpose and has different pros and cons. It is often difficult to decide which container to use and …
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question