Split off build environment configuration to a dedicated file

Resolution option 2-1 for https://github.com/matthew-brett/multibuild/issues/116

README.rst

@@ -50,6 +50,7 @@ functions and variables in earlier scripts:
 * multibuild/common_utils.sh
 * multibuild/osx_utils.sh
 * env_vars.sh
+* multibuild/configure_build.sh
 * multibuild/library_builders.sh
 * config.sh
 
@@ -80,6 +81,7 @@ following bash scripts:
 * multibuild/common_utils.sh
 * multibuild/manylinux_utils.sh
 * env_vars.sh
+* multibuild/configure_build.sh
 * multibuild/library_builders.sh
 * config.sh
 
@@ -321,10 +323,11 @@ To use these scripts
   Optionally you can specify a different location for ``config.sh`` file with
   the ``$CONFIG_PATH`` environment variable.
 
-* Optionally, create an ``env_vars.sh`` file to set defaults for any build
-  environment variables used in ``library_builders.sh``. In Linux, they cannot
-  be just set in the global environment because the build runs in Docker, so
-  only the variables explicitly passed to ``docker run`` are propagated.
+* Optionally, create an ``env_vars.sh`` file to override the defaults for any
+  environment variables used by ``configure_build.sh``/``library_builders.sh``.
+  In Linux, they cannot be just set in the initial environment because the
+  build runs in Docker, so only the variables explicitly passed to
+  ``docker run`` are propagated.
 
   Likewise, you can specify a different location for the file by setting the
   the ``$ENV_VARS_PATH`` environment variable.

configure_build.sh

@@ -0,0 +1,23 @@
+# Find, load common utilities
+# Defines IS_OSX, fetch_unpack
+MULTIBUILD_DIR=$(dirname "${BASH_SOURCE[0]}")
+source $MULTIBUILD_DIR/common_utils.sh
+
+PLAT="${PLAT:x86_64}"
+BUILD_PREFIX="${BUILD_PREFIX:-/usr/local}"
+
+# Default compilation flags for OSX
+# IS_OSX is defined in common_utils.sh
+if [ -n "$IS_OSX" ]; then
+    # Dual arch build by default
+    ARCH_FLAGS=${ARCH_FLAGS:-"-arch i386 -arch x86_64"}
+    # Only set CFLAGS, FFLAGS if they are not already defined.  Build functions
+    # can override the arch flags by setting CFLAGS, FFLAGS
+    export CFLAGS="${CFLAGS:-$ARCH_FLAGS}"
+    export CXXFLAGS="${CXXFLAGS:-$ARCH_FLAGS}"
+    export FFLAGS="${FFLAGS:-$ARCH_FLAGS}"
+fi
+
+# Promote BUILD_PREFIX on search path to any newly built libs
+export CPPFLAGS="-L$BUILD_PREFIX/include $CPPFLAGS"
+export LIBRARY_PATH="$BUILD_PREFIX/lib:$LIBRARY_PATH"

docker_build_wrap.sh

@@ -24,6 +24,7 @@ MULTIBUILD_DIR=$(dirname "${BASH_SOURCE[0]}")
 # These routines also source common_utils.sh
 source $MULTIBUILD_DIR/manylinux_utils.sh
 if [ -r "$ENV_VARS_PATH" ]; then source "$ENV_VARS_PATH"; fi
+source $MULTIBUILD_DIR/configure_build.sh
 source $MULTIBUILD_DIR/library_builders.sh
 
 if [ "$USE_CCACHE" == "1" ]; then

library_builders.sh

@@ -1,11 +1,10 @@
-# Find, load common utilities
-# Defines IS_OSX, fetch_unpack
+#Functions and environment variables to build various
+#native libraries commonly used as dependencies
+
 MULTIBUILD_DIR=$(dirname "${BASH_SOURCE[0]}")
-source $MULTIBUILD_DIR/common_utils.sh
 source $MULTIBUILD_DIR/_gfortran_utils.sh
 
 # For OpenBLAS
-PLAT="${PLAT:x86_64}"
 GF_LIB_URL="https://3f23b170c54c2533c070-1c8a9b3114517dc5fe17b7c3f8c63a43.ssl.cf2.rackcdn.com"
 
 # Recipes for building some libraries
@@ -45,20 +44,8 @@ OPENSSL_HASH=ce07195b659e75f4e1db43552860070061f156a98bb37b672b101ba6e3ddf30c
 OPENSSL_DOWNLOAD_URL=https://www.openssl.org/source
 
 
-BUILD_PREFIX="${BUILD_PREFIX:-/usr/local}"
 ARCHIVE_SDIR=${ARCHIVE_DIR:-archives}
 
-# Set default library compilation flags for OSX
-# IS_OSX defined in common_utils.sh
-if [ -n "$IS_OSX" ]; then
-    # Dual arch build by default
-    ARCH_FLAGS=${ARCH_FLAGS:-"-arch i386 -arch x86_64"}
-    # Only set CFLAGS, FFLAGS if they are not already defined.  Build functions
-    # can override the arch flags by setting CFLAGS, FFLAGS
-    export CFLAGS="${CFLAGS:-$ARCH_FLAGS}"
-    export CXXFLAGS="${CXXFLAGS:-$ARCH_FLAGS}"
-    export FFLAGS="${FFLAGS:-$ARCH_FLAGS}"
-fi
 
 function build_simple {
     # Example: build_simple libpng $LIBPNG_VERSION \

tests/test_library_builders.sh

@@ -2,6 +2,7 @@
 # Smoke test
 export BUILD_PREFIX="${PWD}/builds"
 rm_mkdir $BUILD_PREFIX
+source configure_build.sh
 source library_builders.sh
 
 # set -e -x

travis_osx_steps.sh

@@ -11,6 +11,7 @@ ENV_VARS_PATH=${ENV_VARS_PATH:-env_vars.sh}
 # These load common_utils.sh
 source $MULTIBUILD_DIR/osx_utils.sh
 if [ -r "$ENV_VARS_PATH" ]; then source "$ENV_VARS_PATH"; fi
+source $MULTIBUILD_DIR/configure_build.sh
 source $MULTIBUILD_DIR/library_builders.sh
 
 # NB - config.sh sourced at end of this function.

travis_steps.sh

@@ -10,7 +10,3 @@ if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
 else
     source $MULTIBUILD_DIR/travis_linux_steps.sh
 fi
-
-# Promote BUILD_PREFIX on search path to any newly built libs
-export CPPFLAGS="-L$BUILD_PREFIX/include $CPPFLAGS"
-export LIBRARY_PATH="$BUILD_PREFIX/lib:$LIBRARY_PATH"