BF,RF: Fix linux CFLAGS default assignment.

Always add -fPIC on all platforms.

For NVCC, use same variable naming conventions as used in conda-forge build
env.

Use -ccbin rather than --compiler-bindir (they are equivalent), as the
conda-forge nvcc wrapper only checks for the former.

Fix path to supportedGencodes.sh script.

config/buildSettings.mk

@@ -39,10 +39,10 @@ TCLSH   ?= ${FSLDIR}/bin/fsltclsh
 # environment.
 
 # Compiler flags for C projects
-ARCHCFLAGS = -std=c99
+ARCHCFLAGS = -std=c99 -fPIC
 
 # Compiler flags for C++ projects.
-ARCHCXXFLAGS = -std=c++11
+ARCHCXXFLAGS = -std=c++11 -fPIC
 
 # Preprocesor flags for C/C++ projects.
 ARCHCPPFLAGS =
@@ -54,9 +54,11 @@ ARCHLDFLAGS =
 ARCHLIBS =
 
 # Compiler flags for CUDA projects.
+# This is set in the nvcc block below.
 ARCHNVCCFLAGS =
 
 # Linker flags for CUDA projects.
+# This is set in the nvcc block below.
 ARCHNVCCLDFLAGS =
 
 # Allow flags to be provided by the environment.
@@ -77,8 +79,8 @@ ifeq ($(SYSTYPE), Darwin)
   # LDFLAGS may be overridden by the environment.
   CC       ?= clang
   CXX      ?= clang++
-  CFLAGS   ?= -arch x86_64 -Wall -pedantic -fPIC
-  CXXFLAGS ?= -arch x86_64 -Wall -pedantic -fPIC
+  CFLAGS   ?= -arch x86_64 -Wall -pedantic
+  CXXFLAGS ?= -arch x86_64 -Wall -pedantic
   LDFLAGS  ?= -Wl,-search_paths_first
   ARCHLIBS += -llapack -lblas -lz -lm
 endif
@@ -95,8 +97,9 @@ ifeq ($(SYSTYPE), Linux)
   CC       ?= gcc
   CXX      ?= g++
   CFLAGS   ?= -fexpensive-optimizations \
-                  -Wall -pedantic -Wno-long-long -fPIC
+              -Wall -pedantic -Wno-long-long
   CXXFLAGS ?= -fexpensive-optimizations \
+              -Wall -pedantic -Wno-long-long
   LDFLAGS  ?= -Wl,-rpath,'$$ORIGIN/../lib'
   ARCHLIBS += -lopenblas -lz -lm
 endif # if Linux
@@ -110,10 +113,15 @@ endif # if Linux
 # CUDA/nvcc compiler options
 ifneq ($(shell which nvcc), )
 
+  # We specifically use variable names "CUDA_VER"
+  # and "CUDA_HOME" because they will be set in
+  # the conda-forge CUDA build environment (and
+  # will take precedence over these definitions
+  # here when they are set).
   NVCC         ?= nvcc
-  CUDAVER      ?= $(shell nvcc --version | grep -Po "release \K[0-9\.]+")
-  GENCODEFLAGS ?= $(shell ${FSLCONFDIR}/common/supportedGencodes.sh ${CUDAVER})
-  CUDADIR      ?= ${FSLDIR}
+  CUDA_HOME    ?= ${FSLDIR}
+  CUDA_VER     ?= $(shell nvcc --version | grep -Po "release \K[0-9\.]+")
+  GENCODEFLAGS ?= $(shell ${FSLCONFDIR}/supportedGencodes.sh ${CUDA_VER})
 
   # nvcc-specific tweaks:
   #  - Define ARMA_ALLOW_FAKE_GCC, otherwise byte-alignment issues
@@ -122,16 +130,18 @@ ifneq ($(shell which nvcc), )
   #  - Do not use -pedantic, otherwise *every single line* of
   #    transpiled cuda code will trigger "warning: style of line
   #    directive is a GCC extension".
-  #  - Specify the compiler to use with --compiler-bindir, as nvcc
-  #    might otherwise naively call "gcc"
-  ARCHNVCCFLAGS   = -I${CUDADIR}/include  \
-                    -maxrregcount=64      \
-                    ${GENCODEFLAGS}       \
-                    -DARMA_ALLOW_FAKE_GCC \
-                    --compiler-bindir     \
-                    $(shell which $(CC))  \
-                    --compiler-options    \
+  #  - Specify the compiler to use with -ccbin, as nvcc
+  #    might otherwise naively call "gcc" (we specifically use
+  #    "-ccbin" rather than "--compiler-bindir" here, because the
+  #    conda-forge nvcc wrapper checks for -ccbin, and adds its own
+  #    if not present).
+  ARCHNVCCFLAGS   = -I${CUDA_HOME}/include \
+                    -maxrregcount=64       \
+                    ${GENCODEFLAGS}        \
+                    -DARMA_ALLOW_FAKE_GCC  \
+                    -ccbin $(CXX)          \
+                    --compiler-options     \
                     "$(filter-out -pedantic, ${ARCHCXXFLAGS})"
-  ARCHNVCCLDFLAGS = -L${CUDADIR}/lib \
-                    -L${CUDADIR}/lib/stubs
+  ARCHNVCCLDFLAGS = -L${CUDA_HOME}/lib \
+                    -L${CUDA_HOME}/lib/stubs
 endif