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multiconf.make

multiconf.make is a self-contained Makefile include that lets you build the same targets under many different flag sets. For example debug vs release, ASan vs UBSan, GCC vs Clang. Each different set of flags generates object files into its own dedicated cache directory, so objects compiled with one configuration are never reused by another. Object files from previous configurations are preserved, so swapping back to a previous configuration only requires compiling objects which have actually changed.

Benefits at a glance

Benefit	What `multiconf.make` does
Isolated configs	Stores objects into `cachedObjs/<hash>/`, one directory per unique flag set.
Fast switching	Reusing an old config is instant—link only, no recompilation.
Header deps	Edits to headers trigger only needed rebuilds.
One-liner targets	Macros (`c_program`, `cxx_program`, …) hide all rule boilerplate.
Parallel-ready	Safe with `make -j`, no duplicate compiles of shared sources.
Controlled verbosity	Default only lists objects, while `V=1` display full commands.
`clean` included	`make clean` deletes all objects, binaries and links.

Quick Start

1 · List your sources

C_SRCDIRS   := src src/cdeps    # all .c are in these directories
CXX_SRCDIRS := src src/cxxdeps  # all .cpp are in these directories

2 · Add and include

# root/Makefile
include multiconf.make

3 · Declare targets

app:
$(eval $(call c_program,app,app.o cdeps/obj.o))

test:
$(eval $(call cxx_program,test, test.o cxxdeps/objcxx.o))

lib.a:
$(eval $(call static_library,lib.a, lib.o cdeps/obj.o))

lib.so:
$(eval $(call c_dynamic_library,lib.so, lib.o cdeps/obj.o))

4 · Build any config you like

# Release with GCC
make CFLAGS="-O3"

# Debug with Clang + AddressSanitizer (new cache dir)
make CC=clang CFLAGS="-g -O0 -fsanitize=address"

# Switch back to GCC release (objects still valid, relink only)
make CFLAGS="-O3"

Objects for each command live in different sub-folders; nothing overlaps.