RF: Honour compilation flags defined in the environment

config/buildSettings.mk

@@ -12,14 +12,14 @@ SYSTYPE := $(shell uname -s)
 # Standard commands
 #
 #####################################################################
-SHELL = /bin/sh
-RM = /bin/rm
-CP = /bin/cp
-MV = /bin/mv
-CHMOD = /bin/chmod
-MKDIR = /bin/mkdir
-INSTALL = install -p
-TCLSH = ${FSLDIR}/bin/fsltclsh
+SHELL   ?= /bin/sh
+RM      ?= /bin/rm
+CP      ?= /bin/cp
+MV      ?= /bin/mv
+CHMOD   ?= /bin/chmod
+MKDIR   ?= /bin/mkdir
+INSTALL ?= install -p
+TCLSH   ?= ${FSLDIR}/bin/fsltclsh
 
 #####################################################################
 #
@@ -53,10 +53,10 @@ ARCHLIBS =
 ifeq ($(SYSTYPE), Darwin)
 
 # Commands
-CC     = cc
-CXX    = c++
-CXX11  = clang++
-RANLIB = ranlib
+CC     ?= cc
+CXX    ?= c++
+CXX11  ?= clang++
+RANLIB ?= ranlib
 
 # Compiler flags
 ARCHCXXFLAGS += -arch x86_64 -O3 -ansi -Wall -pedantic
@@ -87,10 +87,10 @@ endif # if Darwin
 ifeq ($(SYSTYPE), Linux)
 
 # Commands
-CC = gcc
-CXX = c++
-CXX11 = c++
-RANLIB = echo
+CC     ?= gcc
+CXX    ?= c++
+CXX11  ?= c++
+RANLIB ?= echo
 
 # Compiler flags
 ARCHCFLAGS   += -m64 -fPIC -O3 -fexpensive-optimizations \

config/common/vars.mk

@@ -7,38 +7,38 @@ PROJNAME =
 
 # Project-specific compiler/linker flags - these
 # can be overridden in the project Makefile
-USRLDFLAGS =
+USRLDFLAGS  =
 USRINCFLAGS =
-USRCFLAGS =
+USRCFLAGS   =
 USRCXXFLAGS =
-LIBS =
+LIBS        =
 
 # Project outputs - these variables control
 # what gets installed from a project. May
 # be customised/overridden in project
 # Makefiles
-HFILES = *.h
-AFILES = *.a
-SOFILES = *.so
-XFILES =
-SCRIPTS =
-TCLFILES = *.tcl
-MANFILES = man/*
+HFILES    = *.h
+AFILES    = *.a
+SOFILES   = *.so
+XFILES    =
+SCRIPTS   =
+TCLFILES  = *.tcl
+MANFILES  = man/*
 TESTXILES =
 
 # Final install destinations for project outputs
-DESTDIR = ${FSLDEVDIR}
-dest_INCDIR = ${DESTDIR}/include
-dest_LIBDIR = ${DESTDIR}/lib
-dest_BINDIR = ${DESTDIR}/bin
-dest_MANDIR = ${DESTDIR}/man
-dest_TCLDIR = ${DESTDIR}/tcl
-dest_DOCDIR = ${DESTDIR}/doc
+DESTDIR        = ${FSLDEVDIR}
+dest_INCDIR    = ${DESTDIR}/include
+dest_LIBDIR    = ${DESTDIR}/lib
+dest_BINDIR    = ${DESTDIR}/bin
+dest_MANDIR    = ${DESTDIR}/man
+dest_TCLDIR    = ${DESTDIR}/tcl
+dest_DOCDIR    = ${DESTDIR}/doc
 dest_REFDOCDIR = ${DESTDIR}/refdoc
 
 # Standard header/library locations for compiling/linking
-INCDIR = ${FSLDIR}/include
-LIBDIR = ${FSLDIR}/lib
+INCDIR    = ${FSLDIR}/include
+LIBDIR    = ${FSLDIR}/lib
 DEVINCDIR = ${FSLDEVDIR}/include
 DEVLIBDIR = ${FSLDEVDIR}/lib
 
@@ -49,6 +49,11 @@ INCFLAGS = ${USRINCFLAGS} -I. -I${DEVINCDIR} -I${INCDIR}
 # Final compiler/linker flags
 #############################
 
+# Honour any flags provided by the environment
+CFLAGS   ?=
+CXXFLAGS ?=
+LDFLAGS  ?=
+
 # All projects must use these flags for
 # compilation/linking, using the form:
 #
@@ -57,9 +62,8 @@ INCFLAGS = ${USRINCFLAGS} -I. -I${DEVINCDIR} -I${INCDIR}
 #
 # LDFLAGS *must* come at the end, to ensure proper linking.
 
-LDFLAGS = ${ARCHLDFLAGS} ${USRLDFLAGS} \
-  -L. -L${DEVLIBDIR} -L${LIBDIR} \
-  ${LIBS} ${ARCHLIBS}
-
-CFLAGS   = ${ARCHCFLAGS}   ${USRCFLAGS}   ${USRINCFLAGS} ${INCFLAGS}
-CXXFLAGS = ${ARCHCXXFLAGS} ${USRCXXFLAGS} ${USRINCFLAGS} ${INCFLAGS}
+LDFLAGS  += ${ARCHLDFLAGS} ${USRLDFLAGS} \
+            -L. -L${DEVLIBDIR} -L${LIBDIR} \
+            ${LIBS} ${ARCHLIBS}
+CFLAGS   += ${ARCHCFLAGS}   ${USRCFLAGS}   ${INCFLAGS}
+CXXFLAGS += ${ARCHCXXFLAGS} ${USRCXXFLAGS} ${INCFLAGS}