make/hotspot/lib/JvmMapfile.gmk

#
# Copyright (c) 2013, 2020, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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$(eval $(call IncludeCustomExtension, hotspot/lib/JvmMapfile.gmk))

################################################################################
# Combine a list of static symbols

ifeq ($(call And, $(call isTargetOs, windows) $(call isTargetCpu, x86_64)), false)
  # On Windows x86_64, we should not have any symbols at all, since that
  # results in duplicate warnings from the linker (JDK-8043491).
  SYMBOLS_SRC += $(TOPDIR)/make/data/hotspot-symbols/symbols-shared
endif

ifeq ($(call isTargetOsType, unix), true)
  SYMBOLS_SRC += $(TOPDIR)/make/data/hotspot-symbols/symbols-unix
endif

ifneq ($(wildcard $(TOPDIR)/make/data/hotspot-symbols/symbols-$(OPENJDK_TARGET_OS)), )
  SYMBOLS_SRC += $(TOPDIR)/make/data/hotspot-symbols/symbols-$(OPENJDK_TARGET_OS)
endif

ifneq ($(findstring debug, $(DEBUG_LEVEL)), )
  ifneq ($(wildcard $(TOPDIR)/make/data/hotspot-symbols/symbols-$(OPENJDK_TARGET_OS)-debug), )
    SYMBOLS_SRC += $(TOPDIR)/make/data/hotspot-symbols/symbols-$(OPENJDK_TARGET_OS)-debug
  endif
endif

################################################################################
# Create a dynamic list of symbols from the built object files. This is highly
# platform dependent.

ifeq ($(call isTargetOs, linux), true)
  DUMP_SYMBOLS_CMD := $(NM) $(NMFLAGS) --extern-only --defined-only *$(OBJ_SUFFIX)
  ifneq ($(FILTER_SYMBOLS_PATTERN), )
    FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)|
  endif
  FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)^_ZTV|^gHotSpotVM|^UseSharedSpaces$$
  FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)|^_ZN9Arguments17SharedArchivePathE$$
  FILTER_SYMBOLS_AWK_SCRIPT := \
      '{ \
        if ($$3 ~ /$(FILTER_SYMBOLS_PATTERN)/) print $$3; \
      }'

else ifeq ($(call isTargetOs, macosx), true)
  # nm on macosx prints out "warning: nm: no name list" to stderr for
  # files without symbols. Hide this, even at the expense of hiding real errors.
  DUMP_SYMBOLS_CMD := $(NM) $(NMFLAGS) -Uj *$(OBJ_SUFFIX) 2> /dev/null
  ifneq ($(FILTER_SYMBOLS_PATTERN), )
    FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)|
  endif
  FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)^_ZTV|^gHotSpotVM
  FILTER_SYMBOLS_AWK_SCRIPT := \
      '{ \
        if ($$3 ~ /$(FILTER_SYMBOLS_PATTERN)/) print $$3; \
      }'

# NOTE: The script is from the old build. It is broken and finds no symbols.
# The script below might be what was intended, but it fails to link with tons
# of 'cannot export hidden symbol vtable for X'.
#  '{ if ($$1 ~ /^__ZTV/ || $$1 ~ /^_gHotSpotVM/) print substr($$1, 2) }'
else ifeq ($(call isTargetOs, aix), true)
  # NOTE: The old build had the solution below. This should to be fixed in
  # configure instead.

  # On AIX we have to prevent that we pick up the 'nm' version from the GNU binutils
  # which may be installed under /opt/freeware/bin. So better use an absolute path here!
  # NM=/usr/bin/nm

  DUMP_SYMBOLS_CMD := $(NM) $(NMFLAGS) -B -C *$(OBJ_SUFFIX)
  FILTER_SYMBOLS_AWK_SCRIPT := \
      '{ \
        if (($$2="d" || $$2="D") && ($$3 ~ /^__vft/ || $$3 ~ /^gHotSpotVM/)) print $$3; \
        if ($$3 ~ /^UseSharedSpaces$$/) print $$3; \
        if ($$3 ~ /^SharedArchivePath__9Arguments$$/) print $$3; \
       }'

else ifeq ($(call isTargetOs, windows), true)
  DUMP_SYMBOLS_CMD := $(DUMPBIN) -symbols *$(OBJ_SUFFIX)

  # The following lines create a list of vftable symbols to be filtered out of
  # the mapfile. Removing this line causes the linker to complain about too many
  # (> 64K) symbols, so the _guess_ is that this line is here to keep down the
  # number of exported symbols below that limit.
  #
  # Some usages of C++ lambdas require the vftable symbol of classes that use
  # the lambda type as a template parameter. The usage of those classes won't
  # link if their vftable symbols are removed. That's why there's an exception
  # for vftable symbols containing the string 'lambda'.
  #
  # A very simple example of a lambda usage that fails if the lambda vftable
  # symbols are missing in the mapfile:
  #
  # #include <functional>
  # std::function<void()> f = [](){}

  FILTER_SYMBOLS_AWK_SCRIPT := \
      '{ \
        if ($$7 ~ /??_7.*@@6B@/ && $$7 !~ /type_info/ && $$7 !~ /lambda/) print $$7; \
      }'

else
  $(error Unknown target OS $(OPENJDK_TARGET_OS) in JvmMapfile.gmk)
endif

# A more correct solution would be to send BUILD_LIBJVM_ALL_OBJS instead of
# cd && *.o, but this will result in very long command lines, which is
# problematic on some platforms.
$(JVM_OUTPUTDIR)/symbols-objects: $(BUILD_LIBJVM_ALL_OBJS)
	$(call LogInfo, Generating symbol list from object files)
	$(CD) $(JVM_OUTPUTDIR)/objs && \
	  $(DUMP_SYMBOLS_CMD) | $(AWK) $(FILTER_SYMBOLS_AWK_SCRIPT) | $(SORT) -u > $@

SYMBOLS_SRC += $(JVM_OUTPUTDIR)/symbols-objects

################################################################################
# Now concatenate all symbol lists into a single file and remove comments.

$(JVM_OUTPUTDIR)/symbols: $(SYMBOLS_SRC)
	$(SED) -e '/^#/d' $^ > $@

################################################################################
# Finally convert the symbol list into a platform-specific mapfile

ifeq ($(call isTargetOs, macosx), true)
  # On macosx, we need to add a leading underscore
  define create-mapfile-work
	  $(AWK) '{ if ($$0 ~ ".") { print "  _" $$0 } }'  < $^ > $@.tmp
  endef
else ifeq ($(call isTargetOs, windows), true)
  # On windows, add an 'EXPORTS' header
  define create-mapfile-work
	  $(ECHO) "EXPORTS" > $@.tmp
	  $(AWK) '{ if ($$0 ~ ".") { print "  " $$0 } }'  < $^ >> $@.tmp
  endef
else
  # Assume standard linker script
  define create-mapfile-work
	  $(PRINTF) "SUNWprivate_1.1 { \n  global: \n" > $@.tmp
	  $(AWK) '{ if ($$0 ~ ".") { print "    " $$0 ";" } }' < $^ >> $@.tmp
	  $(PRINTF) "  local: \n    *; \n }; \n" >> $@.tmp
  endef
endif

define create-mapfile
	$(call LogInfo, Creating mapfile)
	$(call MakeDir, $(@D))
	$(call create-mapfile-work)
	$(RM) $@
	$(MV) $@.tmp $@
endef

$(JVM_MAPFILE): $(JVM_OUTPUTDIR)/symbols
	$(call create-mapfile)