Dynamic top-level targets

[Timothy Reilly]

Hello-

I've got a program that I'd like to compile with varying
sets of options.  All of these options are completely independent, and
the actual dependencies of the targets are the same- they differ only
in options passed to the commands.  My idea was to have each set of
flags be a pattern match rule and an explicit rule.  The pattern match
rule would match the option-set to the suffix, strip the suffix, and
depend on the prefix, which would repeat the process until only a
single option-set remained, which would match the explicit rule. 
Here's the relevant portion of the makefile :

debug: CXXFLAGS := $(CXXFLAGS) -Wall -g
debug: all

benchmark: CXXFLAGS := $(CXXFLAGS) -DBENCHMARK
benchmark: all

openmp: CXXFLAGS := $(CXXFLAGS) $(OMP)
openmp: all

release: CXXFLAGS := $(CXXFLAGS) -DNDEBUG -O2

release: all

vector: CXXFLAGS := $(CXXFLAGS) -DUSE_SIMD $(VECTOR_FLAGS)
vector: all


%_debug: CXXFLAGS := $(CXXFLAGS) -Wall -g
%_debug: %

%_benchmark: CXXFLAGS := $(CXXFLAGS) -DBENCHMARK
%_benchmark: %

%_openmp: CXXFLAGS := $(CXXFLAGS) $(OMP)
%_openmp: %

%_release: CXXFLAGS := $(CXXFLAGS) -DNDEBUG -O2
%_release: %

%_vector: CXXFLAGS := $(CXXFLAGS) -DUSE_SIMD $(VECTOR_FLAGS)
%_vector: %


The idea was to be able to do something as such: 

make vector_debug_openmp_benchmark 

and have CXXFLAGS expand to all of the relevant flags.

The
pattern match rules do not do what I'd like them to do, and I do not
understand why.  Is what I'm trying to do feasible/possible?


Thanks in advance for your time,
Timothy Reilly