gcc 9.3 complains about redundant function declarations:

[rhaschke]

Please fix the following warnings. Interestingly, gcc doesn't silence those warnings, even if the qhull includes are declared as
-isystem. I consider that a gcc bug...

In file included from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
394/usr/include/libqhull_r/libqhull_r.h:1057:9: warning: redundant redeclaration of ‘void qh_printsummary(qhT*, FILE*)’ in same scope [-Wredundant-decls]
395 1057 | void    qh_printsummary(qhT *qh, FILE *fp);
396      |         ^~~~~~~~~~~~~~~
397/usr/include/libqhull_r/libqhull_r.h:1024:9: note: previous declaration of ‘void qh_printsummary(qhT*, FILE*)’
398 1024 | void    qh_printsummary(qhT *qh, FILE *fp);
399      |         ^~~~~~~~~~~~~~~
400/usr/include/libqhull_r/libqhull_r.h:1099:6: warning: redundant redeclaration of ‘void qh_meminit(qhT*, FILE*)’ in same scope [-Wredundant-decls]
401 1099 | void qh_meminit(qhT *qh, FILE *ferr);
402      |      ^~~~~~~~~~
403In file included from /usr/include/libqhull_r/libqhull_r.h:31,
404                 from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
405/usr/include/libqhull_r/mem_r.h:218:6: note: previous declaration of ‘void qh_meminit(qhT*, FILE*)’
406  218 | void qh_meminit(qhT *qh, FILE *ferr);
407      |      ^~~~~~~~~~
408In file included from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
409/usr/include/libqhull_r/libqhull_r.h:1100:6: warning: redundant redeclaration of ‘void qh_memfreeshort(qhT*, int*, int*)’ in same scope [-Wredundant-decls]
410 1100 | void qh_memfreeshort(qhT *qh, int *curlong, int *totlong);
411      |      ^~~~~~~~~~~~~~~
412In file included from /usr/include/libqhull_r/libqhull_r.h:31,
413                 from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
414/usr/include/libqhull_r/mem_r.h:217:6: note: previous declaration of ‘void qh_memfreeshort(qhT*, int*, int*)’
415  217 | void qh_memfreeshort(qhT *qh, int *curlong, int *totlong);
416      |      ^~~~~~~~~~~~~~~
417In file included from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
418/usr/include/libqhull_r/libqhull_r.h:1123:9: warning: redundant redeclaration of ‘void qh_collectstatistics(qhT*)’ in same scope [-Wredundant-decls]
419 1123 | void    qh_collectstatistics(qhT *qh);
420      |         ^~~~~~~~~~~~~~~~~~~~
421In file included from /usr/include/libqhull_r/libqhull_r.h:121,
422                 from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
423/usr/include/libqhull_r/stat_r.h:515:9: note: previous declaration of ‘void qh_collectstatistics(qhT*)’
424  515 | void    qh_collectstatistics(qhT *qh);
425      |         ^~~~~~~~~~~~~~~~~~~~
426In file included from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
427/usr/include/libqhull_r/libqhull_r.h:1124:9: warning: redundant redeclaration of ‘void qh_printallstatistics(qhT*, FILE*, const char*)’ in same scope [-Wredundant-decls]
428 1124 | void    qh_printallstatistics(qhT *qh, FILE *fp, const char *string);
429      |         ^~~~~~~~~~~~~~~~~~~~~
430In file included from /usr/include/libqhull_r/libqhull_r.h:121,
431                 from /opt/ws_moveit/src/geometric_shapes/src/bodies.cpp:44:
432/usr/include/libqhull_r/stat_r.h:519:9: note: previous declaration of ‘void qh_printallstatistics(qhT*, FILE*, const char*)’
433  519 | void    qh_printallstatistics(qhT *qh, FILE *fp, const char *string);
434      |         ^~~~~~~~~~~~~~~~~~~~~

[cbbarber]

-Wredundant-decls should distinguish function redeclarations from variable redeclarations. Variable redeclarations change the code and should be avoided. Function redeclarations have no effect as far as I know.

Will leave open for the next release.