# +-======-+ 
#  Copyright (c) 2003-2018 United States Government as represented by 
#  the Admistrator of the National Aeronautics and Space Administration.  
#  All Rights Reserved.
#  
#  THIS OPEN  SOURCE  AGREEMENT  ("AGREEMENT") DEFINES  THE  RIGHTS  OF USE,
#  REPRODUCTION,  DISTRIBUTION,  MODIFICATION AND REDISTRIBUTION OF CERTAIN 
#  COMPUTER SOFTWARE ORIGINALLY RELEASED BY THE UNITED STATES GOVERNMENT AS 
#  REPRESENTED BY THE GOVERNMENT AGENCY LISTED BELOW ("GOVERNMENT AGENCY").  
#  THE UNITED STATES GOVERNMENT, AS REPRESENTED BY GOVERNMENT AGENCY, IS AN 
#  INTENDED  THIRD-PARTY  BENEFICIARY  OF  ALL  SUBSEQUENT DISTRIBUTIONS OR 
#  REDISTRIBUTIONS  OF THE  SUBJECT  SOFTWARE.  ANYONE WHO USES, REPRODUCES, 
#  DISTRIBUTES, MODIFIES  OR REDISTRIBUTES THE SUBJECT SOFTWARE, AS DEFINED 
#  HEREIN, OR ANY PART THEREOF,  IS,  BY THAT ACTION, ACCEPTING IN FULL THE 
#  RESPONSIBILITIES AND OBLIGATIONS CONTAINED IN THIS AGREEMENT.
#  
#  Government Agency: National Aeronautics and Space Administration
#  Government Agency Original Software Designation: GSC-15354-1
#  Government Agency Original Software Title:  GEOS-5 GCM Modeling Software
#  User Registration Requested.  Please Visit http://opensource.gsfc.nasa.gov
#  Government Agency Point of Contact for Original Software:  
#  			Dale Hithon, SRA Assistant, (301) 286-2691
#  
# +-======-+ 
  # -----------
  # GNU Fortran
  # -----------

  ifeq ($(ESMA_FC), gfortran)
     MKL_COMPILER = gnu_f

     EXTENDED_SOURCE := -ffixed-line-length-132
     FREE_SOURCE = 
     FIXED_SOURCE = -ffixed-form
     FREAL4   := 
     FREAL8   := -fdefault-real-8 -fdefault-double-8
     FINT8    := -fdefault-integer-8
     # This is needed for m_fpe.F90
     NO_RANGE_CHECK   := -fno-range-check 
     FPIC   := -fPIC
     # For some reason this does not work at the moment.
     #BIG_ENDIAN := -fconvert=swap
     FPE = -ffpe-trap=zero,overflow -fbacktrace
     ALIGNCOM = -falign-commons
     BYTERECLEN = -frecord-marker=4

     OMPFLAG = -fopenmp
     PP = -cpp

     ifeq ("$(BOPT)","g")
        FOPT = -O0 -g -fcheck=all,no-array-temps -finit-real=snan
     else
     ifeq ("$(BOPT)","Og")
        FOPT = -Og -g
     else
     ifeq ("$(BOPT)","fast")
        -include $(ESMACFG)/vectorize.mk
     else
        #FOPT = $(FOPT3)
        #FOPT = $(FOPT3) -march=native -funroll-loops
        #FOPT = $(FOPT3) -march=native -funroll-loops -ffast-math
        FOPT = $(FOPT3) -march=westmere -mtune=generic -funroll-loops -g
     endif
     endif
     endif

     # Suggested by ESMF
     # This is broken in GCC 8.1. For now just do not use
     #FOPT += -fcoarray=single

     CFLAGS   += -Wno-missing-include-dirs
     fFLAGS   += $(D)__GFORTRAN__ $(NO_RANGE_CHECK) -Wno-missing-include-dirs
     FFLAGS   += $(D)__GFORTRAN__ $(NO_RANGE_CHECK) -Wno-missing-include-dirs
     f90FLAGS += $(D)__GFORTRAN__ -ffree-line-length-none $(NO_RANGE_CHECK) -Wno-missing-include-dirs
     F90FLAGS += $(D)__GFORTRAN__ -ffree-line-length-none $(NO_RANGE_CHECK) -Wno-missing-include-dirs

     # Define LIB_SYS
     # --------------

     LIB_SYS := -ldl -lc -lpthread
     ifeq ($(ARCH),Linux)
        LIB_SYS += -lrt
     endif

     USING_CLANG := $(word 1,$(shell $(CC) --version))
     ifeq ("$(USING_CLANG)","Apple")
        LIB_SYS += -lc++
     else
        GCC_DIR := $(shell dirname `gcc --print-libgcc-file-name`)
        GXX_DIR := $(shell dirname `gcc -print-file-name=libstdc++.a`)

        LIB_SYS += -L$(GCC_DIR) -L$(GXX_DIR) -lstdc++ -lgcc_eh
     endif

  endif # gfortran