build: Clean up flag handling for examples

Fix ability to build examples from 32-bit builds.  Remove the implicit
rule usage, so that we know what flags are being used.  Make the override
of the FLAGS variables additive so that we don't wipe out FLAGS variables
set in the environment.

Signed-off-by: Brian Barrett <bbarrett@amazon.com>

examples/Makefile

@@ -22,15 +22,12 @@
 # $HEADER$
 #
 
-# Use the Open MPI-provided wrapper compilers.  Note that gmake
-# requires the CXX macro, while other versions of make (such as Sun's
-# make) require the CCC macro.
+# Use the Open MPI-provided wrapper compilers.
 
-CC = mpicc
-CXX = mpic++
-CCC = mpic++
-FC = mpifort
-JAVAC = mpijavac
+MPICC = mpicc
+MPICXX = mpic++
+MPIFC = mpifort
+MPIJAVAC = mpijavac
 SHMEMCC = shmemcc
 SHMEMCXX = shmemc++
 SHMEMFC = shmemfort
@@ -40,10 +37,10 @@ SHMEMFC = shmemfort
 # gmake requires the CXXFLAGS macro, while other versions of make
 # (such as Sun's make) require the CCFLAGS macro.
 
-CFLAGS = -g
-CXXFLAGS = -g
-CCFLAGS = -g
-FCFLAGS = -g
+CFLAGS += -g
+CXXFLAGS += -g
+CCFLAGS += -g
+FCFLAGS += -g
 
 # Example programs to build
 
@@ -129,49 +126,61 @@ clean:
 
 # Don't rely on default rules for the Fortran and Java examples
 
+hello_c: hello_c.c
+	$(MPICC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
+ring_c: ring_c.c
+	$(MPICC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
+connectivity_c: connectivity_c.c
+	$(MPICC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
+
+hello_cxx: hello_cxx.cc
+	$(MPICXX) $(CXXFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
+ring_cxx: ring_cxx.cc
+	$(MPICXX) $(CXXFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
+
 hello_mpifh: hello_mpifh.f
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 ring_mpifh: ring_mpifh.f
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 hello_usempi: hello_usempi.f90
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 ring_usempi: ring_usempi.f90
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 hello_usempif08: hello_usempif08.f90
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 ring_usempif08: ring_usempif08.f90
-	$(FC) $(FCFLAGS) $? -o $@
+	$(MPIFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 Hello.class: Hello.java
-	$(JAVAC) Hello.java
+	$(MPIJAVAC) Hello.java
 Ring.class: Ring.java
-	$(JAVAC) Ring.java
+	$(MPIJAVAC) Ring.java
 
 hello_oshmem: hello_oshmem_c.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 hello_oshmemcxx: hello_oshmem_cxx.cc
-	$(SHMEMCXX) $(CXXFLAGS) $? -o $@
+	$(SHMEMCXX) $(CXXFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 hello_oshmemfh: hello_oshmemfh.f90
-	$(SHMEMFC) $(FCFLAGS) $? -o $@
+	$(SHMEMFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 ring_oshmem: ring_oshmem_c.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 ring_oshmemfh: ring_oshmemfh.f90
-	$(SHMEMFC) $(FCFLAGS) $? -o $@
+	$(SHMEMFC) $(FCFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 oshmem_shmalloc: oshmem_shmalloc.c
-	$(SHMEMCC) $(CCFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 oshmem_circular_shift: oshmem_circular_shift.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 oshmem_max_reduction: oshmem_max_reduction.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 oshmem_strided_puts: oshmem_strided_puts.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@
 
 oshmem_symmetric_data: oshmem_symmetric_data.c
-	$(SHMEMCC) $(CFLAGS) $? -o $@
+	$(SHMEMCC) $(CFLAGS) $(LDFLAGS) $? $(LDLIBS) -o $@