disabled multi file optimization when setting OPTIMIZATION=OFF and improved comments on compiler switches

code/makefile

@@ -46,7 +46,11 @@ OPENMP ?= ON
 OPTIMIZATION ?= DEFENSIVE
 
 ifeq "$(F90)" "ifort"
+ifeq "$(OPTIMIZATION)" "OFF"
+ARCHIVE_COMMAND :=ar
+else
 ARCHIVE_COMMAND :=xiar
+endif
 else
 ARCHIVE_COMMAND :=ar
 endif
@@ -192,10 +196,10 @@ COMPILE_OPTIONS_gfortran :=-xf95-cpp-input\
                            -Wunderflow\
                            -Wswitch\
                            -Wstrict-overflow\
-                           -Wextra\
                            -Wattributes\
                            -Wunsafe-loop-optimizations\
-                           -Wunused
+                           -Wunused\
+                           -Wextra
 
 #-xf95-cpp-input:              preprocessor
 #-ffree-line-length-132:       restrict line length to the standard 132 characters
@@ -211,15 +215,15 @@ COMPILE_OPTIONS_gfortran :=-xf95-cpp-input\
 #-Waliasing:                   warn about possible aliasing of dummy arguments. Specifically, it warns if the same actual argument is associated with a dummy argument with "INTENT(IN)" and a dummy argument with "INTENT(OUT)" in a call with an explicit interface. 
 #-Wconversion:                 warn about implicit conversions between different type
 #-Wsurprising:                 warn when "suspicious" code constructs are encountered. While technically legal these usually indicate that an error has been made. 
-#-Wunused-value:
-#-Wunused-parameter:       find usused variables with "parameter" attribute
 #-Wunderflow:                  produce a warning when numerical constant expressions are encountered, which yield an UNDERFLOW during compilation
-#-Wswitch:                 warn whenever a "switch" statement has an index of enumerated type and lacks a "case" for one or more of the named codes of that
-#                          enumeration.  (The presence of a "default" label prevents this warning.)  "case" labels outside the enumeration range also provoke
-#                            warnings when this option is used (even if there is a "default" label)
-#-Wstrict-overflow
-#-Wattributes                Warn about inappropriate attribute usage                              
-# -Wunsafe-loop-optimizations Warn if the loop cannot be optimized due to nontrivial assumptions.
+#-Wswitch:                     warn whenever a "switch" statement has an index of enumerated type and lacks a "case" for one or more of the named codes of that enumeration.  (The presence of a "default" label prevents this warning.) "case" labels outside the enumeration range also provokewarnings when this option is used (even if there is a "default" label)
+#-Wstrict-overflow:
+#-Wattributes:                 warn about inappropriate attribute usage                              
+#-Wunsafe-loop-optimizations:  warn if the loop cannot be optimized due to nontrivial assumptions.
+#-Wunused:   
+#        -value:
+#        -parameter:           find usused variables with "parameter" attribute
+#-Wextra:
 ###################################################################################################
 #OPTIONS FOR GFORTRAN 4.6
 #-Wsuggest-attribute=const: