Creator builds acting oddly...

mzimmers

...not sure how to put this into words, so I'll just show you the files and the result:

main.cpp:

#include "testsha.h"
int main()
{
    SHA256Reset();
    return 0;
}

testsha.h:

extern int SHA256Reset();

testsha224-256.cpp:

int SHA256Reset()
{
  return 0;
}

When I build, I get this error:

C:\Users\MZimmers\Qt projects\test\main.cpp:5: error: undefined reference to `SHA256Reset()'

When I change the file testsha224-256.c to a .cpp file, do a clean, a qmake and a build, the error goes away.

Can someone explain this behavior to me?

Windows 10, newest version of Creator, MinGW 5.3.0.

Thanks...this one has me cross-eyed.

dheerendra

this is not a issue with qt build i feel. it issue with mixing c and cpp in same project.

mzimmers

Right you are. After sleeping on it, I did some googling and realized that the inclusion of the header file needs to be enclosed thusly:

extern "C"
{
#include testsha.h
}

(There are other ways of doing this, but this is cleanest for a C header file you don't wish to edit.)

This prevents the C++ compiler from altering (some say "mangling") the function name.

Thanks for looking.