Compiler c: My OS is centos which has a

My OS is centos which has a default gcc in path /usr/bin/gcc. But it is old, I need a new version of gcc. So I install a new version in a new path /usr/local/bin/gcc. But when I run cmake, it stil... For GCC, copying from the full list of warnings provided by this tool for your compiler version appears to be the only way to ensure that all warnings are turned on, since (unlike Clang) GCC does not provide -Weverything. The tool appears to parse the actual c .opt file in the GCC source code, so its results should be definitive. A compiler is, more generally, a program that converts a program in one programming language into a program in another programming language (arguably, you can even have a compiler with the same input and output language if significant transformations are applied). gcc and g++ are compiler -drivers of the GNU Compiler Collection (which was once upon a time just the GNU C Compiler ). Even though they automatically determine which backends (cc1 cc1plus ...) to call depending on the file-type, unless overridden with -x language, they have some differences. The probably most important difference in their defaults is which libraries they link against automatically. According to GCC's online documentation link options and how g++ is invoked, g++ is roughly ...