add ccache and enable by default

.gitignore

@@ -5,6 +5,7 @@
 /pkg
 /wip/
 /tmp-*
+/.ccache
 
 # generated by build-pkg
 /*-*.list

Makefile

@@ -69,6 +69,11 @@ STRIP_TOOLCHAIN := $(true)
 STRIP_LIB       := $(false)
 STRIP_EXE       := $(true)
 
+# disable by setting MXE_USE_CCACHE
+MXE_USE_CCACHE      := mxe
+MXE_CCACHE_DIR      := $(PWD)/.ccache
+MXE_CCACHE_BASE_DIR := $(PWD)
+
 # define some whitespace variables
 define newline
 
@@ -431,7 +436,13 @@ $(PREFIX)/installed/print-git-oneline-$(GIT_HEAD): | $(PREFIX)/installed/.gitkee
 # cross libraries depend on virtual toolchain package, variable used
 # in `cleanup-deps-style` rule below
 CROSS_COMPILER := cc
-MXE_REQS_PKGS   =
+
+# set reqs and bootstrap variables to recursive so pkgs can add themselves
+# CROSS_COMPILER depends (order-only) on MXE_REQS_PKGS
+# all depend (order-only) on BOOTSTRAP_PKGS
+# BOOTSTRAP_PKGS may be prefixed with $(BUILD)~
+MXE_REQS_PKGS  =
+BOOTSTRAP_PKGS =
 
 # warning about switching from `gcc` to `cc`
 $(if $(and $(filter gcc,$(LOCAL_PKG_LIST)$(MAKECMDGOALS)),\
@@ -521,6 +532,7 @@ $(foreach PKG,$(PKGS), \
         $(eval $(PKG)_OO_DEPS += $(BUILD)~autotools)) \
     $(if $(filter $(PKG),$(CMAKE_PKGS)),$(eval $(PKG)_OO_DEPS += cmake-conf)) \
     $(if $(filter $(PKG),$(MXE_CONF_PKGS)),,$(eval $(PKG)_OO_DEPS += mxe-conf)) \
+    $(if $(filter %$(PKG),$(MXE_CONF_PKGS) $(BOOTSTRAP_PKGS)),,$(eval $(PKG)_OO_DEPS += $(BOOTSTRAP_PKGS))) \
     $(eval $(PKG)_TARGETS := $(sort $($(PKG)_TARGETS))) \
     $(if $($(PKG)_TARGETS),,$(eval $(PKG)_TARGETS := $(CROSS_TARGETS))) \
     $(foreach TARGET,$(filter $($(PKG)_TARGETS),$(CROSS_TARGETS) $(BUILD)), \
@@ -918,6 +930,9 @@ BUILD_PKG_TMP_FILES := *-*.list mxe-*.tar.xz mxe-*.deb* wheezy jessie
 clean:
 	rm -rf $(call TMP_DIR,*) $(PREFIX) \
 	       $(addprefix $(TOP_DIR)/, $(BUILD_PKG_TMP_FILES))
+	@echo
+	@echo 'review ccache size with:'
+	@echo '$(MXE_CCACHE_DIR)/bin/ccache -s'
 
 .PHONY: clean-pkg
 clean-pkg:

README.md

@@ -18,6 +18,7 @@ various target platforms, which:
   * is able to update the version numbers of all packages automatically
   * directly uses source packages, thus ensuring the whole build mechanism is transparent
   * allows inter-package and intra-package parallel builds whenever possible
+  * bundles [ccache](https://ccache.samba.org) to speed up repeated builds
   * integrates well with autotools, cmake, qmake, and hand-written makefiles.
   * has been in continuous development since 2007 and is used by several projects
 

docs/index.html

@@ -83,6 +83,10 @@
         <a href="#usage">parallel builds</a>
         whenever possible
     </li>
+    <li>
+        bundles <a href="https://ccache.samba.org">ccache</a> to speed
+        up repeated builds
+    </li>
     <li>
         integrates well with <a href="#tutorial-5a">autotools</a>,
         <a href="#tutorial-5b">cmake</a>, <a href="#tutorial-5c">qmake</a>,
@@ -1216,6 +1220,13 @@ local-pkg-list: $(LOCAL_PKG_LIST)</pre>
         (short option "-j 4 -k")
         </dd>
 
+    <dt>make foo bar MXE_USE_CCACHE=</dt>
+
+        <dd>
+        disables use of <a href="https://ccache.samba.org">ccache</a>
+        to eliminate potential error sources when debugging
+        </dd>
+
     <dt>make EXCLUDE_PKGS='foo bar'</dt>
 
         <dd>

src/ccache.mk

@@ -0,0 +1,94 @@
+# This file is part of MXE. See LICENSE.md for licensing information.
+
+PKG             := ccache
+$(PKG)_WEBSITE  := https://ccache.samba.org
+$(PKG)_DESCR    := ccache – a fast compiler cache
+$(PKG)_IGNORE   :=
+$(PKG)_VERSION  := 3.6
+$(PKG)_CHECKSUM := a6b129576328fcefad00cb72035bc87bc98b6a76aec0f4b59bed76d67a399b1f
+$(PKG)_SUBDIR   := ccache-$($(PKG)_VERSION)
+$(PKG)_FILE     := ccache-$($(PKG)_VERSION).tar.xz
+$(PKG)_URL      := https://www.samba.org/ftp/ccache/ccache-$($(PKG)_VERSION).tar.xz
+$(PKG)_DEPS     := $(BUILD)~$(PKG)
+$(PKG)_TARGETS  := $(BUILD) $(MXE_TARGETS)
+
+$(PKG)_DEPS_$(BUILD) :=
+
+define $(PKG)_UPDATE
+    $(call GET_LATEST_VERSION, https://www.samba.org/ftp/ccache)
+endef
+
+BOOTSTRAP_PKGS += ccache
+
+$(PKG)_SYS_CONF := $(MXE_CCACHE_DIR)/etc/$(PKG).conf
+$(PKG)_USR_CONF := $(MXE_CCACHE_DIR)/$(PKG).conf
+
+ifeq (mxe,$(MXE_USE_CCACHE))
+define $(PKG)_BUILD_$(BUILD)
+    # remove any previous symlinks
+    rm -fv '$(PREFIX)/$(BUILD)/bin/$(BUILD_CC)' '$(PREFIX)/$(BUILD)/bin/$(BUILD_CXX)'
+
+    # minimal reqs build with bundled zlib
+    cd '$(BUILD_DIR)' && $(SOURCE_DIR)/configure \
+        $(MXE_CONFIGURE_OPTS) \
+        --with-bundled-zlib \
+        --disable-man \
+        --prefix='$(MXE_CCACHE_DIR)' \
+        --sysconfdir='$(dir $($(PKG)_SYS_CONF))'
+    $(MAKE) -C '$(BUILD_DIR)' -j '$(JOBS)' $(MXE_DISABLE_DOCS)
+    $(MAKE) -C '$(BUILD_DIR)' -j 1 install $(MXE_DISABLE_DOCS)
+
+    # setup symlinks
+    ln -sf '$(MXE_CCACHE_DIR)/bin/ccache' '$(PREFIX)/$(BUILD)/bin/$(BUILD_CC)'
+    ln -sf '$(MXE_CCACHE_DIR)/bin/ccache' '$(PREFIX)/$(BUILD)/bin/$(BUILD_CXX)'
+
+    # https://ccache.samba.org/manual/latest.html#_configuration_settings
+    # always set/replace mxe `system` config
+    mkdir -p '$(dir $($(PKG)_SYS_CONF))'
+    (echo '# ccache system config'; \
+     echo '# this file is controlled by mxe, user config is in:'; \
+     echo '# $($(PKG)_USR_CONF)'; \
+     echo; \
+     echo 'base_dir = $(MXE_CCACHE_BASE_DIR)'; \
+     echo 'cache_dir = $(MXE_CCACHE_DIR)'; \
+     echo 'compiler_check = %compiler% -v'; \
+     ) > '$($(PKG)_SYS_CONF)'
+
+    # leave user config alone if set
+    [ -f '$($(PKG)_USR_CONF)' ] || \
+    (mkdir -p '$(dir $($(PKG)_USR_CONF))' && \
+    (echo '# ccache user config'; \
+     echo '# https://ccache.samba.org/manual/latest.html#_configuration_settings'; \
+     echo '# system config: $($(PKG)_SYS_CONF)'; \
+     echo; \
+     echo 'max_size = 20.0G'; \
+     ) > '$($(PKG)_USR_CONF)')
+endef
+
+define $(PKG)_BUILD
+    # setup symlinks
+    ln -sf '$(MXE_CCACHE_DIR)/bin/ccache' '$(PREFIX)/$(BUILD)/bin/$(TARGET)-gcc'
+    ln -sf '$(MXE_CCACHE_DIR)/bin/ccache' '$(PREFIX)/$(BUILD)/bin/$(TARGET)-g++'
+
+    # setup cmake toolchain to allow runtime override
+    # CMAKE_CXX_COMPILER_LAUNCHER shows original cc and isn't clear in logs etc.
+    mkdir -p '$(CMAKE_TOOLCHAIN_DIR)'
+    (echo 'option(MXE_USE_CCACHE "Enable ccache by default" ON)'; \
+     echo 'if(MXE_USE_CCACHE)'; \
+     echo '  set(CMAKE_C_COMPILER $(PREFIX)/$(BUILD)/bin/$(TARGET)-gcc)'; \
+     echo '  set(CMAKE_CXX_COMPILER $(PREFIX)/$(BUILD)/bin/$(TARGET)-g++)'; \
+     echo 'endif()'; \
+     ) > '$(CMAKE_TOOLCHAIN_DIR)/$(PKG).cmake'
+endef
+else
+define $(PKG)_BUILD_$(BUILD)
+    # remove symlinks
+    rm -fv '$(PREFIX)/$(BUILD)/bin/$(BUILD_CC)' '$(PREFIX)/$(BUILD)/bin/$(BUILD_CXX)'
+endef
+
+define $(PKG)_BUILD
+    # remove symlinks and cmake toolchain
+    rm -fv '$(PREFIX)/$(BUILD)/bin/$(TARGET)-'*
+    rm -fv '$(CMAKE_TOOLCHAIN_DIR)/$(PKG).cmake'
+endef
+endif