How to change make builtin rules

Question

I would like to know if there is a way to change the rules applied automatically by make when there is no makefile. To give an example, if you write make foo in a directory containing a file called foo.cpp it executes g++ foo.cpp -o foo even if there is no makefile in the directory.

I would like to change them to suit my needs, say something like g++ foo.cpp -o foo --std=c++11 -W -O2 -I .... but also to add new rules for other extensions such as .c, .java or .tex

I know how to define the new rules, but I don't know where to specify them other than creating a makefile in every directory. I suppose there is some file that holds all these builtin rules but I haven't been able to find it or how to overload it with one of my own.

I'm working mostly with Mingw and cygwin.

Answer 1

According to the manual, the rule is actually:

n.o is made automatically from n.cc, n.cpp, or n.C with a recipe of the form ‘$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c’. We encourage you to use the suffix ‘.cc’ for C++ source files instead of ‘.C’.

So that leaves with either adjusting your environment variables (for example, in ~/.bashrc) or just creating a Makefile which overrides that rule.

Use make -p in a directory with no Makefile to learn all the defaults and built-in rules.