Build error with CERN ROOT 5.34/21

[smueller]

When building Mars using the latest and recommended (November 2014) CERN ROOT version 5.34/21 on Ubuntu 14.04 64bit, there are build errors concerning mbase/MQuarternion.h and msim/MPhotonData.h. In both these header files the sqrt() is 'redefined' from 'sqrt' to 'sqrt ::sqrt'.

In the header files it looks like:

#ifndef ROOT_TQuaternion
#include <math.h>
#define sqrt ::sqrt
#include <TQuaternion.h>
#undef sqrt
#endif

The build error looks like:

In file included from MPhotonData.cc:43:0:
/usr/include/c++/4.8/bits/random.h: In member function ‘std::student_t_distribution<_RealType>::result_type std::student_t_distribution<_RealType>::operator()(_UniformRandomNumberGenerator&)’:
MPhotonData.h:20:14: error: expected unqualified-id before ‘::’ token
 #define sqrt ::sqrt
              ^

[smueller]

I found a possible solution. But for now I only know this is running with my CERN Root version 5.34/21. How ever a valid solution should work for them all.

I tried to use the ROOT_VERSION(XX,XX,XX) function to fix this. I use it like this:

#include "RVersion.h"

#ifndef ROOT_TQuaternion
    #if ROOT_VERSION_CODE < ROOT_VERSION(5,34,21)
        #include <math.h>
        #define sqrt ::sqrt
        #include <TQuaternion.h>
        #undef sqrt
    #else
        #include <math.h>
        #include <TQuaternion.h>
    #endif
#endif

The #include "RVersion.h" is needed when there is no CERN Root include before the ROOT_VERSION()

But Root would not be Root without its pitfalls. This solution causes a different rootCINT related error.

 Calling make in msim
 - Compiling SimCint.cc
SimCint.cc: In function ‘void G__set_cpp_environmentSimCint()’:
SimCint.cc:79:37: error: expected ‘}’ at end of input
   G__add_compiledheader("SimIncl.h");
                                     ^
make[1]: *** [SimCint.o] Error 1
make: *** [msim.a] Error 2

This latter turns out to be a 'well known bug'. See
​http://root.cern.ch/phpBB3/viewtopic.php?t=5795

So I put a -p option to the Mars Makefile.rules where the CINT is called:

$(CINT)Cint.cc: $(HEADERS) $(CINT)LinkDef.h
	@echo " - Generating dictionary $(CINT)Cint.cc"
	rootcint -f $(CINT)Cint.cc \
	-c -p $(INCLUDES) $(LIBNOVA_INCLUDE_PATH) $(DEFINES) $(HEADERS) $(CINT)Incl.h $(CINT)LinkDef.h 

Now it is working on my machine. But further tests with different CERN Root versions might be needed.