Add experimental pinning of Erlang/OTP version

By defining the ERLANG_OTP or ERLANG_HIPE variable, you
can let Erlang.mk manage which version of Erlang/OTP will
be used for your project. It will build it if necessary,
and will activate it automatically when make is invoked.

build.config

@@ -8,6 +8,7 @@ core/core
 index/*
 core/index
 core/deps
+core/kerl
 
 # Plugins that must run before Erlang code gets compiled.
 plugins/protobuffs

core/kerl.mk

@@ -0,0 +1,78 @@
+# Copyright (c) 2015-2017, Loïc Hoguin <essen@ninenines.eu>
+# This file is part of erlang.mk and subject to the terms of the ISC License.
+
+.PHONY: distclean-kerl
+
+KERL_INSTALL_DIR ?= $(HOME)/erlang
+
+ifeq ($(strip $(KERL)),)
+KERL := $(ERLANG_MK_TMP)/kerl/kerl
+endif
+
+export KERL
+
+KERL_GIT ?= https://github.com/kerl/kerl
+KERL_COMMIT ?= master
+
+KERL_MAKEFLAGS ?=
+
+OTP_GIT ?= https://github.com/erlang/otp
+
+define kerl_otp_target
+ifeq ($(wildcard $(KERL_INSTALL_DIR)/$(1)),)
+$(KERL_INSTALL_DIR)/$(1): $(KERL)
+	MAKEFLAGS="$(KERL_MAKEFLAGS)" $(KERL) build git $(OTP_GIT) $(1) $(1)
+	$(KERL) install $(1) $(KERL_INSTALL_DIR)/$(1)
+endif
+endef
+
+define kerl_hipe_target
+ifeq ($(wildcard $(KERL_INSTALL_DIR)/$1-native),)
+$(KERL_INSTALL_DIR)/$1-native: $(KERL)
+	KERL_CONFIGURE_OPTIONS=--enable-native-libs \
+		MAKEFLAGS="$(KERL_MAKEFLAGS)" $(KERL) build git $(OTP_GIT) $1 $1-native
+	$(KERL) install $1-native $(KERL_INSTALL_DIR)/$1-native
+endif
+endef
+
+$(KERL):
+	$(verbose) mkdir -p $(ERLANG_MK_TMP)
+	$(gen_verbose) git clone --depth 1 $(KERL_GIT) $(ERLANG_MK_TMP)/kerl
+	$(verbose) cd $(ERLANG_MK_TMP)/kerl && git checkout $(KERL_COMMIT)
+	$(verbose) chmod +x $(KERL)
+
+distclean:: distclean-kerl
+
+distclean-kerl:
+	$(gen_verbose) rm -rf $(KERL)
+
+# Allow users to select which version of Erlang/OTP to use for a project.
+
+ERLANG_OTP ?=
+ERLANG_HIPE ?=
+
+# Use kerl to enforce a specific Erlang/OTP version for a project.
+ifneq ($(strip $(ERLANG_OTP)),)
+export ERLANG_OTP
+export PATH := $(KERL_INSTALL_DIR)/$(ERLANG_OTP)/bin:$(PATH)
+$(eval $(call kerl_otp_target,$(ERLANG_OTP)))
+
+# Build Erlang/OTP only if it doesn't already exist.
+ifeq ($(wildcard $(KERL_INSTALL_DIR)/$(ERLANG_OTP)),)
+BUILD_ERLANG_OTP := $(shell $(MAKE) $(KERL_INSTALL_DIR)/$(ERLANG_OTP))
+endif
+
+else
+# Same for a HiPE enabled VM.
+ifneq ($(strip $(ERLANG_HIPE)),)
+export ERLANG_HIPE
+export PATH := $(KERL_INSTALL_DIR)/$(ERLANG_HIPE)-native/bin:$(PATH)
+$(eval $(call kerl_hipe_target,$(ERLANG_HIPE)))
+
+# Build Erlang/OTP only if it doesn't already exist.
+ifeq ($(wildcard $(KERL_INSTALL_DIR)/$(ERLANG_HIPE)),)
+BUILD_ERLANG_OTP := $(shell $(MAKE) $(KERL_INSTALL_DIR)/$(ERLANG_HIPE))
+endif
+
+endif
+endif

plugins/ci.mk

@@ -1,7 +1,7 @@
-# Copyright (c) 2015-2016, Loïc Hoguin <essen@ninenines.eu>
+# Copyright (c) 2015-2017, Loïc Hoguin <essen@ninenines.eu>
 # This file is part of erlang.mk and subject to the terms of the ISC License.
 
-.PHONY: ci ci-prepare ci-setup distclean-kerl
+.PHONY: ci ci-prepare ci-setup
 
 CI_OTP ?=
 CI_HIPE ?=
@@ -19,24 +19,9 @@ ifeq ($(strip $(CI_OTP) $(CI_HIPE) $(CI_ERLLVM)),)
 ci::
 else
 
-ifeq ($(strip $(KERL)),)
-KERL := $(ERLANG_MK_TMP)/kerl/kerl
-endif
-
-export KERL
-
-KERL_GIT ?= https://github.com/kerl/kerl
-KERL_COMMIT ?= master
-
-KERL_MAKEFLAGS ?=
-
-OTP_GIT ?= https://github.com/erlang/otp
-
-CI_INSTALL_DIR ?= $(HOME)/erlang
-
 ci:: $(addprefix ci-,$(CI_OTP) $(addsuffix -native,$(CI_HIPE)) $(addsuffix -erllvm,$(CI_ERLLVM)))
 
-ci-prepare: $(addprefix $(CI_INSTALL_DIR)/,$(CI_OTP) $(addsuffix -native,$(CI_HIPE)))
+ci-prepare: $(addprefix $(KERL_INSTALL_DIR)/,$(CI_OTP) $(addsuffix -native,$(CI_HIPE)))
 
 ci-setup::
 
@@ -46,10 +31,10 @@ ci_verbose_0 = @echo " CI    " $(1);
 ci_verbose = $(ci_verbose_$(V))
 
 define ci_target
-ci-$1: $(CI_INSTALL_DIR)/$2
+ci-$1: $(KERL_INSTALL_DIR)/$2
 	$(verbose) $(MAKE) --no-print-directory clean
 	$(ci_verbose) \
-		PATH="$(CI_INSTALL_DIR)/$2/bin:$(PATH)" \
+		PATH="$(KERL_INSTALL_DIR)/$2/bin:$(PATH)" \
 		CI_OTP_RELEASE="$1" \
 		CT_OPTS="-label $1" \
 		CI_VM="$3" \
@@ -61,32 +46,8 @@ $(foreach otp,$(CI_OTP),$(eval $(call ci_target,$(otp),$(otp),otp)))
 $(foreach otp,$(CI_HIPE),$(eval $(call ci_target,$(otp)-native,$(otp)-native,native)))
 $(foreach otp,$(CI_ERLLVM),$(eval $(call ci_target,$(otp)-erllvm,$(otp)-native,erllvm)))
 
-define ci_otp_target
-ifeq ($(wildcard $(CI_INSTALL_DIR)/$(1)),)
-$(CI_INSTALL_DIR)/$(1): $(KERL)
-	MAKEFLAGS="$(KERL_MAKEFLAGS)" $(KERL) build git $(OTP_GIT) $(1) $(1)
-	$(KERL) install $(1) $(CI_INSTALL_DIR)/$(1)
-endif
-endef
-
-$(foreach otp,$(CI_OTP),$(eval $(call ci_otp_target,$(otp))))
-
-define ci_hipe_target
-ifeq ($(wildcard $(CI_INSTALL_DIR)/$1-native),)
-$(CI_INSTALL_DIR)/$1-native: $(KERL)
-	KERL_CONFIGURE_OPTIONS=--enable-native-libs \
-		MAKEFLAGS="$(KERL_MAKEFLAGS)" $(KERL) build git $(OTP_GIT) $1 $1-native
-	$(KERL) install $1-native $(CI_INSTALL_DIR)/$1-native
-endif
-endef
-
-$(foreach otp,$(sort $(CI_HIPE) $(CI_ERLLLVM)),$(eval $(call ci_hipe_target,$(otp))))
-
-$(KERL):
-	$(verbose) mkdir -p $(ERLANG_MK_TMP)
-	$(gen_verbose) git clone --depth 1 $(KERL_GIT) $(ERLANG_MK_TMP)/kerl
-	$(verbose) cd $(ERLANG_MK_TMP)/kerl && git checkout $(KERL_COMMIT)
-	$(verbose) chmod +x $(KERL)
+$(foreach otp,$(CI_OTP),$(eval $(call kerl_otp_target,$(otp))))
+$(foreach otp,$(sort $(CI_HIPE) $(CI_ERLLLVM)),$(eval $(call kerl_hipe_target,$(otp))))
 
 help::
 	$(verbose) printf "%s\n" "" \
@@ -96,8 +57,4 @@ help::
 		"The CI_OTP variable must be defined with the Erlang versions" \
 		"that must be tested. For example: CI_OTP = OTP-17.3.4 OTP-17.5.3"
 
-distclean:: distclean-kerl
-
-distclean-kerl:
-	$(gen_verbose) rm -rf $(KERL)
 endif