Remove the magic that sets CXX in the toplevel Makefile

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
 #       with the distribution.
 #     * Neither the name of Google Inc. nor the names of its
 #       contributors may be used to endorse or promote products derived
 #       from this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 # Variable default definitions. Override them by exporting them in your shell.
-CXX ?= g++
-LINK ?= g++
 OUTDIR ?= out
 TESTJOBS ?=
 GYPFLAGS ?=
 TESTFLAGS ?=
 ANDROID_NDK_ROOT ?=
 ANDROID_NDK_HOST_ARCH ?=
 ANDROID_TOOLCHAIN ?=
 ANDROID_V8 ?= /data/local/tmp/v8
 NACL_SDK_ROOT ?=
 
@@ skipping 95 matching lines @@
 endif
 # i18nsupport=off
 ifeq ($(i18nsupport), off)
   GYPFLAGS += -Dv8_enable_i18n_support=0
   TESTFLAGS += --noi18n
 endif
 # deprecation_warnings=on
 ifeq ($(deprecationwarnings), on)
   GYPFLAGS += -Dv8_deprecation_warnings=1
 endif
-# asan=/path/to/clang++
-ifneq ($(strip $(asan)),)
-  GYPFLAGS += -Dasan=1
-  export CC=$(dir $(asan))clang
-  export CXX=$(asan)
-  export CXX_host=$(asan)
-  export LINK=$(asan)
-  export ASAN_SYMBOLIZER_PATH=$(dir $(asan))llvm-symbolizer
+# asan=on
+ifeq ($(asan), on)
+  GYPFLAGS += -Dasan=1 -Dclang=1
   TESTFLAGS += --asan
   ifeq ($(lsan), on)
     GYPFLAGS += -Dlsan=1
   endif
 endif
 
 # arm specific flags.
 # arm_version=<number | "default">
 ifneq ($(strip $(arm_version)),)
   GYPFLAGS += -Darm_version=$(arm_version)
@@ skipping 119 matching lines @@
 
 # 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.$$@
         @$(MAKE) -C "$(OUTDIR)" -f Makefile.$@ \
-                 CXX="$(CXX)" LINK="$(LINK)" \
                  BUILDTYPE=$(shell echo $(subst .,,$(suffix $@)) | \
                              python -c "print \
                              raw_input().replace('opt', '').capitalize()") \
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
 native: $(OUTDIR)/Makefile.native
         @$(MAKE) -C "$(OUTDIR)" -f Makefile.native \
-                 CXX="$(CXX)" LINK="$(LINK)" BUILDTYPE=Release \
+                 BUILDTYPE=Release \
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
 $(ANDROID_ARCHES): $(addprefix $$@.,$(MODES))
 
 $(ANDROID_BUILDS): $(GYPFILES) $(ENVFILE) build/android.gypi \
                    must-set-ANDROID_NDK_ROOT_OR_TOOLCHAIN Makefile.android
         @$(MAKE) -f Makefile.android $@ \
                 ARCH="$(basename $@)" \
                 MODE="$(subst .,,$(suffix $@))" \
                 OUTDIR="$(OUTDIR)" \
@@ skipping 148 matching lines @@
 
 # Replaces the old with the new environment file if they're different, which
 # will trigger GYP to regenerate Makefiles.
 $(ENVFILE): $(ENVFILE).new
         @if test -r $(ENVFILE) && cmp $(ENVFILE).new $(ENVFILE) > /dev/null; \
             then rm $(ENVFILE).new; \
             else mv $(ENVFILE).new $(ENVFILE); fi
 
 # Stores current GYPFLAGS in a file.
 $(ENVFILE).new:
-        @mkdir -p $(OUTDIR); echo "GYPFLAGS=$(GYPFLAGS)" > $(ENVFILE).new; \
-            echo "CXX=$(CXX)" >> $(ENVFILE).new
+        $(eval CXX_TARGET_ARCH:=$(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)))
+        @mkdir -p $(OUTDIR); echo "GYPFLAGS=$(GYPFLAGS) -Dtarget_arch=$(CXX_TARGET_ARCH)" > $(ENVFILE).new;
 
 # Heap constants for grokdump.
 DUMP_FILE = tools/v8heapconst.py
 grokdump: ia32.release
         @cat $(DUMP_FILE).tmpl > $(DUMP_FILE)
         @$(OUTDIR)/ia32.release/d8 --dump-heap-constants >> $(DUMP_FILE)
 
 # Support for the GNU GLOBAL Source Code Tag System.
 gtags.files: $(GYPFILES) $(ENVFILE)
         @find include src test -name '*.h' -o -name '*.cc' -o -name '*.c' > $@
@@ skipping 22 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''}]"