Appendix A - Compiler Settings

The following are sample compiler configuration (in the Options → C/C++ Compilers settings). They are used only to run the preprocessor.

Note: eCv may be supplied with some predefined compiler configurations, so you may not need to set these up yourself.

Microsoft Visual C++ or Visual C++ Express

executable is "C:/Program Files/Microsoft Visual Studio ###/vc/bin/cl.exe" where ### depends on the version you installed (8 for 2005, 9.0 for 2008 and 10.0 for 2010)
additional path for executable files is "C:/Program Files/Microsoft Visual Studio ###/Common7/IDE"
language is C90 or C++ as desired (C99 is not supported)
char is signed unless the /J compiler option is used, in which case it is unsigned
wchar_t is unsigned
sizes for char, short, int, long, long long are 8, 16, 32, 32, 64 respectively
sizes for float, double, long double are 32, 64, 64 respectively
pointer size is 32 bits when using the 32-bit compilers, or 64 bits when using the 64-bit compilers
integer division rounds towards zero
include path intro is "/I" (that's capital i as in Include)
include path separator is " /I" (that's capital i as in Include; note the extra space at the start)
#define intro is "/D"
#define separator is " /D" (note the extra space)
preprocessor command for C90 is: "/P /nologo /Za /TC $d $i $x $f".
preprocessor command for C++ is: "/P /nologo /Za /TP $d $i $x $f".

Under 64-bit Windows, replace "Program Files" in all the above by "Program Files (x86)".

gcc

executable is "cpp" (this runs the preprocessor directly) - if you are running under Windows via MinGW or Cygwin, then use "cpp.exe" and provide the full path
additional path for executable files - under Windows this should be the folder containing file cc1.exe
language is C90, C99 or C++ as desired
for modern versions of gcc, the sizes for various types and the signedness of plain char and wchar_t are as defined by the Application Binary Interface for the platform you are targeting (the signedness of plain char can be overridden by compiler options -funsigned-char and -fsigned-char, and wchar_t can be forced to be equivalent to unsigned short int with -fshort-wchar)
integer division rounds towards zero
include path intro is "-I " (that's capital i as in Include)
include path separator is " -I " (that's capital i as in Include; note the extra space at the start)
#define intro is "-D "
#define separator is " -D " (note the extra space at the start)
preprocessor command for C90 is: "-x c -std=c90 -o $o $d $i $x $f".
preprocessor command for C99 is: "-x c -std=c99 -o $o $d $i $x $f".
preprocessor command for C++ is: "-x c -std=c++98 -o $o $d $i $x $f".

Important: some of the header files for gcc use non-standard syntax of the form __attribute__((...)). In order to hide this syntax from eCv, file eCv.h #defines __attribute__(_x) as a null macro when both __ECV__ and __GNUC__ are defined. However, certain gcc-related header files (e.g. _mingw.h) contain the line "#undef __attribute__". You will need to remove any such lines, or surround them with #ifndef __ECV__ ... #endif.

TOC