how to turn off ansi C++ when compiling?

hedpe · 11-28-2006, 02:12 PM

Hi,

I am getting these errors when trying to compile a specific extern "C" section of code with g++ to link it with a larger C++ project.

How can i turn off ANSI C++ during compilation to avoid this?

Code:

g++ -W -Wall -fno-exceptions -fno-rtti  -DHAVE_CONFIG_H -I../include -I../include -I. -I..  -DCLICK_USERLEVEL -g -O2 -MD -c ../elements/local/adddf3.cc
../elements/local/adddf3.cc: In function `DFtype __adddf3(DFtype, DFtype)':
../elements/local/adddf3.cc:33: warning: left shift count is negative
../elements/local/adddf3.cc:34: warning: left shift count is negative
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: left shift count is negative
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: left shift count >= width of type
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: left shift count >= width of type
../elements/local/adddf3.cc:35: warning: left shift count is negative
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: right shift count is negative
../elements/local/adddf3.cc:35: warning: left shift count is negative
../elements/local/adddf3.cc:36: warning: right shift count is negative
../elements/local/adddf3.cc:35: error: ISO C++ forbids cast to non-reference type used as lvalue
../elements/local/adddf3.cc:35: error: ISO C++ forbids cast to non-reference type used as lvalue

Thanks!
George

nadroj · 11-28-2006, 02:22 PM

Quote:

../elements/local/adddf3.cc:35: error: ISO C++ forbids cast to non-reference type used as lvalue

i dont know the answer to your specific question but can you just edit the source to fix this? if you pass an option to g++ to Ignore this error then the program may have a bug and unexpected results.

grezly · 11-28-2006, 04:22 PM

Normally it isn't a good idea to compile with less arguments.
But the one you maybe looking for is '-Wall'.
That switch shows all the warnings that will occur meanwhile compiling.

studioj · 11-28-2006, 10:30 PM

it's been a long time so forgive if i get this wrong but there is a way to deal with this.
i think you can just make your function a non member of your class.
declare it in the .hh file at the bottom outside of the class definition and then just put it in the .cc file as a function without a class just like it would be if you wer writing in c.