error: conflicting types for 'sac_keyword_to_header'

[florentdemartin]

Using Cmake External Project to compile sacio, I end up with the following conflicting types error:

sacio.h : struct hid * sac_keyword_to_header(register const char *str, register unsigned int len);
header_map.c : struct hid * sac_keyword_to_header (register const char *str, register size_t len)

It seems to come from Makefile lines:
header_map.c: header_map.txt
gperf $< > $@
enums.c: enums.txt
gperf $< > $@

The error is not present if Cmake is not used, so it might be a Cmake issue rather than sacio issue. But any tips are welcome :-)