Disable make builtin rules and variables from insi

Question

I want to disable builtin rules and variables as per passing the -r and -R options to GNU make, from inside the make file. Other solutions that allow me to do this implicitly and transparently are also welcome.

I've found several references to using MAKEFLAGS, and had similar problems.

Answer 1

Disabling of built-in rules by writing an empty rule for .SUFFIXES does not work if one then writes another .SUFFIXES rule to add previously known suffixes - the built-in rules are re-enabled. Example: One wants to define rules for .c.i and .i.o, and to disable the built-in rule .c.o. Writing

.SUFFIXES:
.SUFFIXES: .o .i .c

does not work - it does not prevent the built-in rule .c.o from being applied.

The solution is the one employed by Marc Eaddy and documented in the GNU make manual, 10.5.6 Canceling Implicit Rules:

You can override a built-in implicit rule (or one you have defined yourself) by defining a new pattern rule with the same target and prerequisites, but a different recipe. When the new rule is defined, the built-in one is replaced. The new rule’s position in the sequence of implicit rules is determined by where you write the new rule.

You can cancel a built-in implicit rule by defining a pattern rule with the same target and prerequisites, but no recipe. For example, the following would cancel the rule that runs the assembler:

    %.o : %.s