Partially reland Auto-generate v8 version based on tags.

Makefile

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 250 matching lines @@
 NACL_BUILDS = $(foreach mode,$(MODES), \
                    $(addsuffix .$(mode),$(NACL_ARCHES)))
 # Generates corresponding test targets, e.g. "ia32.release.check".
 CHECKS = $(addsuffix .check,$(BUILDS))
 QUICKCHECKS = $(addsuffix .quickcheck,$(BUILDS))
 ANDROID_CHECKS = $(addsuffix .check,$(ANDROID_BUILDS))
 NACL_CHECKS = $(addsuffix .check,$(NACL_BUILDS))
 # File where previously used GYPFLAGS are stored.
 ENVFILE = $(OUTDIR)/environment
 
-.PHONY: all check clean builddeps dependencies $(ENVFILE).new native \
+.PHONY: all check clean builddeps dependencies $(ENVFILE).new native version \
         qc quickcheck $(QUICKCHECKS) turbocheck \
         $(addsuffix .quickcheck,$(MODES)) $(addsuffix .quickcheck,$(ARCHES)) \
         $(ARCHES) $(MODES) $(BUILDS) $(CHECKS) $(addsuffix .clean,$(ARCHES)) \
         $(addsuffix .check,$(MODES)) $(addsuffix .check,$(ARCHES)) \
         $(ANDROID_ARCHES) $(ANDROID_BUILDS) $(ANDROID_CHECKS) \
         must-set-ANDROID_NDK_ROOT_OR_TOOLCHAIN \
         $(NACL_ARCHES) $(NACL_BUILDS) $(NACL_CHECKS) \
         must-set-NACL_SDK_ROOT
 
 # Target definitions. "all" is the default.
 all: $(DEFAULT_MODES)
 
+# Target for generating the v8 version file from git tags.
+version:
+        build/generate_version.py
+
 # Special target for the buildbots to use. Depends on $(OUTDIR)/Makefile
 # having been created before.
-buildbot:
+buildbot: version
         $(MAKE) -C "$(OUTDIR)" BUILDTYPE=$(BUILDTYPE) \
                 builddir="$(abspath $(OUTDIR))/$(BUILDTYPE)"
 
 # Compile targets. MODES and ARCHES are convenience targets.
 .SECONDEXPANSION:
 $(MODES): $(addsuffix .$$@,$(DEFAULT_ARCHES))
 
 $(ARCHES): $(addprefix $$@.,$(DEFAULT_MODES))
 
 # Defines how to build a particular target (e.g. ia32.release).
-$(BUILDS): $(OUTDIR)/Makefile.$$@
+$(BUILDS): $(OUTDIR)/Makefile.$$@ version
         @$(MAKE) -C "$(OUTDIR)" -f Makefile.$@ \
                  BUILDTYPE=$(shell echo $(subst .,,$(suffix $@)) | \
                              python -c "print \
                              raw_input().replace('opt', '').capitalize()") \
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
-native: $(OUTDIR)/Makefile.native
+native: $(OUTDIR)/Makefile.native version
         @$(MAKE) -C "$(OUTDIR)" -f Makefile.native \
                  BUILDTYPE=Release \
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
 $(ANDROID_ARCHES): $(addprefix $$@.,$(MODES))
 
 $(ANDROID_BUILDS): $(GYPFILES) $(ENVFILE) build/android.gypi \
-                   must-set-ANDROID_NDK_ROOT_OR_TOOLCHAIN Makefile.android
+                   must-set-ANDROID_NDK_ROOT_OR_TOOLCHAIN Makefile.android \
+                   version
         @$(MAKE) -f Makefile.android $@ \
                 ARCH="$(basename $@)" \
                 MODE="$(subst .,,$(suffix $@))" \
                 OUTDIR="$(OUTDIR)" \
                 GYPFLAGS="$(GYPFLAGS)"
 
 $(NACL_ARCHES): $(addprefix $$@.,$(MODES))
 
 $(NACL_BUILDS): $(GYPFILES) $(ENVFILE) \
-                   Makefile.nacl must-set-NACL_SDK_ROOT
+                   Makefile.nacl must-set-NACL_SDK_ROOT version
         @$(MAKE) -f Makefile.nacl $@ \
                 ARCH="$(basename $@)" \
                 MODE="$(subst .,,$(suffix $@))" \
                 OUTDIR="$(OUTDIR)" \
                 GYPFLAGS="$(GYPFLAGS)"
 
 # Test targets.
 check: all
         @tools/run-tests.py $(TESTJOBS) --outdir=$(OUTDIR) \
             --arch=$(shell echo $(DEFAULT_ARCHES) | sed -e 's/ /,/g') \
@@ skipping 79 matching lines @@
         rm -rf $(OUTDIR)/$(basename $@).release
         rm -rf $(OUTDIR)/$(basename $@).debug
         rm -rf $(OUTDIR)/$(basename $@).optdebug
         find $(OUTDIR) -regex '.*\(host\|target\)\.$(basename $@).*\.mk' -delete
 
 native.clean:
         rm -f $(OUTDIR)/Makefile.native
         rm -rf $(OUTDIR)/native
         find $(OUTDIR) -regex '.*\(host\|target\)\.native\.mk' -delete
 
-clean: $(addsuffix .clean, $(ARCHES) $(ANDROID_ARCHES) $(NACL_ARCHES)) native.clean gtags.clean
+version.clean:
+        rm -f src/version_gen.cc
+
+clean: $(addsuffix .clean, $(ARCHES) $(ANDROID_ARCHES) $(NACL_ARCHES)) native.clean gtags.clean version.clean
 
 # GYP file generation targets.
 OUT_MAKEFILES = $(addprefix $(OUTDIR)/Makefile.,$(BUILDS))
 $(OUT_MAKEFILES): $(GYPFILES) $(ENVFILE)
         $(eval CXX_TARGET_ARCH:=$(shell $(CXX) -v 2>&1 | grep ^Target: | \
                 cut -f 2 -d " " | cut -f 1 -d "-" ))
         $(eval CXX_TARGET_ARCH:=$(subst aarch64,arm64,$(CXX_TARGET_ARCH)))
         $(eval CXX_TARGET_ARCH:=$(subst x86_64,x64,$(CXX_TARGET_ARCH)))
         $(eval V8_TARGET_ARCH:=$(subst .,,$(suffix $(basename $@))))
         PYTHONPATH="$(shell pwd)/tools/generate_shim_headers:$(shell pwd)/build:$(PYTHONPATH):$(shell pwd)/build/gyp/pylib:$(PYTHONPATH)" \
@@ skipping 80 matching lines @@
               third_party/icu --revision 277999 ; \
         fi
         svn checkout --force https://googletest.googlecode.com/svn/trunk \
             testing/gtest --revision 692
         svn checkout --force https://googlemock.googlecode.com/svn/trunk \
             testing/gmock --revision 485
 
 dependencies: builddeps
         # The spec is a copy of the hooks in v8's DEPS file.
         gclient sync -r fb782d4369d5ae04f17a2fceef7de5a63e50f07b --spec="solutions = [{u'managed': False, u'name': u'buildtools', u'url': u'https://chromium.googlesource.com/chromium/buildtools.git', u'custom_deps': {}, u'custom_hooks': [{u'name': u'clang_format_win',u'pattern': u'.',u'action': [u'download_from_google_storage',u'--no_resume',u'--platform=win32',u'--no_auth',u'--bucket',u'chromium-clang-format',u'-s',u'buildtools/win/clang-format.exe.sha1']},{u'name': u'clang_format_mac',u'pattern': u'.',u'action': [u'download_from_google_storage',u'--no_resume',u'--platform=darwin',u'--no_auth',u'--bucket',u'chromium-clang-format',u'-s',u'buildtools/mac/clang-format.sha1']},{u'name': u'clang_format_linux',u'pattern': u'.',u'action': [u'download_from_google_storage',u'--no_resume',u'--platform=linux*',u'--no_auth',u'--bucket',u'chromium-clang-format',u'-s',u'buildtools/linux64/clang-format.sha1']}],u'deps_file': u'.DEPS.git', u'safesync_url': u''}]"