Full paths in diagnostic output?

[Rick Mann]

Is there any way to tell GCC/Binutils to output full paths in its  
diagnostic output? For example, if gcc encounters a syntax error when  
compiling a .c file, it will tell me the filename in the output  
locating the error. Some external tools can function better if the  
full path is supplied, allowing them to find the file (which is much  
harder for it to track down when gcc is invoked with relative paths).

Is there a command-line option to enable something like this?

TIA,
-- 
Rick