Bug 86304
| Summary: | [PATCH] graphics/jpeg does not have 'extern "C"' for C++ | ||||||
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| Product: | Ports & Packages | Reporter: | Craig Rodrigues <rodrigc> | ||||
| Component: | Individual Port(s) | Assignee: | Dirk Meyer <dinoex> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Only Me | ||||||
| Priority: | Normal | ||||||
| Version: | Latest | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| Attachments: |
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Responsible Changed From-To: freebsd-ports-bugs->dinoex Assigning to port maintainer. State Changed From-To: open->closed committed, thanks. |
If jpeglib.h is included in a C++ program, the functions in libjpeg cannot be linked against, because the function prototypes are not decorated with 'extern "C"' Fix: The fix is to re define the EXTERN macro if you are compiling with a C++ compiler. How-To-Repeat: If you put the following code snippet: #include <stdio.h> #include "jpeglib.h" int main(int argc, char *argv[]) { jpeg_std_error(NULL); } in a C file (test.c), and compile with: gcc -I/usr/local/include test.c -L/usr/local/lib -ljpeg it will compile and link fine. If you rename the file to test.cpp, and compile with: g++ -I/usr/local/include test.cpp -L/usr/local/lib -ljpeg You will get a link error: : undefined reference to `jpeg_std_error(jpeg_error_mgr*)'