That fixed compilation issues and seems more semantically correct. Using array
of length 0 fails compilation because of -Werror=array-bounds in GCC 6.1.
We actually don't want a flexible array in this union, but rather a way
to access it byte by byte. This fixes the build for gcc >= 6
In file included from ../../libraries/AP_GPS/AP_GPS.cpp:24:0:
../../libraries/AP_GPS/AP_GPS_ERB.h:93:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
In file included from ../../libraries/AP_GPS/AP_GPS_ERB.cpp:22:0:
../../libraries/AP_GPS/AP_GPS_ERB.h:93:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
In file included from ../../libraries/AP_GPS/AP_GPS_MTK.cpp:25:0:
../../libraries/AP_GPS/AP_GPS_MTK.h:75:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
In file included from ../../libraries/AP_GPS/AP_GPS_MTK19.cpp:26:0:
../../libraries/AP_GPS/AP_GPS_MTK.h:75:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
In file included from ../../libraries/AP_GPS/AP_GPS_SIRF.cpp:22:0:
../../libraries/AP_GPS/AP_GPS_SIRF.h:101:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
In file included from ../../libraries/AP_GPS/AP_GPS_UBLOX.cpp:23:0:
../../libraries/AP_GPS/AP_GPS_UBLOX.h:387:23: error: flexible array member in union
uint8_t bytes[];
^
compilation terminated due to -Wfatal-errors.
Due to the way the headers are organized a single change in a
AP_GPS backend would trigger a rebuild for most of the files in the
project. Time could be saved by using ccache (since most of the things
didn't change) but we can do better, i.e. re-organize
the headers so we don't have to re-build everything.
This makes internal headers internal and then other libraries only
depend on the AP_GPS.h header.
This commit changes the way libraries headers are included in source files:
- If the header is in the same directory the source belongs to, so the
notation '#include ""' is used with the path relative to the directory
containing the source.
- If the header is outside the directory containing the source, then we use
the notation '#include <>' with the path relative to libraries folder.
Some of the advantages of such approach:
- Only one search path for libraries headers.
- OSs like Windows may have a better lookup time.
This is a complete rewrite of the GPS driver structure, with a static
main driver and separate backend drivers. This will allow proper
support for multiple GPSes, and will allow parameters to be set on the
GPS object