Add makefile rules to compile and link c++ sources

build/Makefile

@@ -59,14 +59,16 @@ REF := ifos3D_reference.pdf
 ###############################################################################
 ### GNU compiler with OpenMPI
 CC             := export OMPI_CC=gcc-13 ; mpicc
+CXX            := export OMPI_CXX=gcc-13 ; mpicxx
 CPPFLAGS        = -D_GNU_SOURCE -DLOG_COLOR -DKISSFFT_DATATYPE=float
 EXTRA_CPPFLAGS := -DUSE_MPI
 CFLAGS          = -O3 -Wall -Wextra -g -std=c99 -fopenmp-simd -flto -march=znver4
+CXXFLAGS       := -O3 -Wall -Wextra -g -std=c++23 -fopenmp-simd -flto -march=znver4
 # -fopt-info-optimized-vec -fopt-info-optimized-loop
 # -fopenmp-simd -pthread -fopt-info-optimized-omp
 # -fopt-info-missed-vec -fopt-info-missed-loop
 CDEPEND         = -MMD -MP -MF .dep-$(subst /,-,$@)
-LD             := $(CC)
+LD             := $(CXX)
 LDFLAGS         = -lm
 EXTRA_LDFLAGS  := 
 
@@ -176,7 +178,7 @@ MERGE_FILES := json_parser.cpp \
                merge.cpp \
                readdsk.cpp \
                read_par_json.cpp \
-               snapmerge.cpppp \
+               snapmerge.cpp \
                util.cpp \
                writedsk.cpp
 
@@ -268,9 +270,9 @@ IFOS_FILES := absorb.cpp \
               splitsrc.cpp \
               steplength.cpp \
               stfi.cpp \
-              stfi.cppalc.cpp \
+              stfi_calc.cpp \
               stfi_apply.cpp \
-              stfi_merge.cpppp \
+              stfi_merge.cpp \
               su_gather.cpp \
               su_struct.cpp \
               surface_ssg_elastic.cpp \
@@ -296,8 +298,8 @@ IFOS_FILES := absorb.cpp \
               zero_wavefield.cpp\
               zero_wavefield_acoustic.cpp
 
-MERGE_OBJ := $(addprefix $(MERGE_O)/, $(patsubst %.c, %.o, $(MERGE_FILES)))
-IFOS_OBJ := $(addprefix $(IFOS_O)/, $(patsubst %.c, %.o, $(IFOS_FILES)))
+MERGE_OBJ := $(addprefix $(MERGE_O)/, $(patsubst %.cpp, %.o, $(MERGE_FILES)))
+IFOS_OBJ := $(addprefix $(IFOS_O)/, $(patsubst %.cpp, %.o, $(IFOS_FILES)))
 SEIFE_OBJ := $(addprefix $(SEIFE_O)/, $(patsubst %.c, %.o, $(SEIFE_FILES)))
 KISS_OBJ := $(addprefix $(KISS_O)/, $(patsubst %.c, %.o, $(KISS_FILES)))
 
@@ -340,6 +342,7 @@ help:
 	@echo "   $(strip $(INSTDIR))"
 	@echo -e "Compiler / linker and flags:"
 	@echo "   CC: $(CC)"
+	@echo "   CXX: $(CXX)"
 	@echo "   CPPFLAGS: $(CPPFLAGS) [$(EXTRA_CPPFLAGS)]"
 	@echo "   CFLAGS: $(CFLAGS)"
 	@echo "   LD: $(LD)"
@@ -411,8 +414,8 @@ $(MERGE_EXE): $(MERGE_OBJ)
 	$(call cmd,link)
 
 $(MERGE_O)/%.o: CPPFLAGS += -I$(SRCTREE)/../libkissfft/
-$(MERGE_O)/%.o: $(SRCTREE)/%.c
-	$(call cmd,compile_cc)
+$(MERGE_O)/%.o: $(SRCTREE)/%.cpp
+	$(call cmd,compile_cxx)
 
 $(SEIFE_O)/%.o: CPPFLAGS += -I$(SRCTREE)/../libcseife/
 $(SEIFE_O)/%.o: $(SRCTREE)/../libcseife/%.c
@@ -429,14 +432,17 @@ $(IFOS_EXE): $(IFOS_OBJ)
 	$(call cmd,link)
 
 $(IFOS_O)/%.o: CPPFLAGS += -I$(SRCTREE)/../libcseife/ -I$(SRCTREE)/../libkissfft/ $(EXTRA_CPPFLAGS)
-$(IFOS_O)/%.o: $(SRCTREE)/%.c
-	$(call cmd,compile_cc)
-$(IFOS_O)/%.o: $(MODTREE)/%.c
-	$(call cmd,compile_cc)
+$(IFOS_O)/%.o: $(SRCTREE)/%.cpp
+	$(call cmd,compile_cxx)
+$(IFOS_O)/%.o: $(MODTREE)/%.cpp
+	$(call cmd,compile_cxx)
 
 quiet_cmd_compile_cc = \e[32m[CC]\e[0m    $@
       cmd_compile_cc = $(CC) -o$@ $(CDEPEND) $(CFLAGS.$@) $(CPPFLAGS) -I$(SRCTREE) $(CFLAGS) -c $<
 
+quiet_cmd_compile_cxx = \e[32m[CC]\e[0m    $@
+      cmd_compile_cxx = $(CXX) -o$@ $(CDEPEND) $(CXXFLAGS.$@) $(CPPFLAGS) -I$(SRCTREE) $(CXXFLAGS) -c $<
+
 quiet_cmd_link = \e[94m[LD]\e[0m    $@
       cmd_link = $(LD) $(CFLAGS) -o$@ $^ $(LDFLAGS.$@) $(LDFLAGS)