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Diffstat (limited to 'solenv/gbuild/PrecompiledHeaders.mk')
| -rw-r--r-- | solenv/gbuild/PrecompiledHeaders.mk | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/solenv/gbuild/PrecompiledHeaders.mk b/solenv/gbuild/PrecompiledHeaders.mk new file mode 100644 index 000000000..b6d3ecdfe --- /dev/null +++ b/solenv/gbuild/PrecompiledHeaders.mk @@ -0,0 +1,184 @@ +# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*- +# +# This file is part of the LibreOffice project. +# +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. +# +# This file incorporates work covered by the following license notice: +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed +# with this work for additional information regarding copyright +# ownership. The ASF licenses this file to you under the Apache +# License, Version 2.0 (the "License"); you may not use this file +# except in compliance with the License. You may obtain a copy of +# the License at http://www.apache.org/licenses/LICENSE-2.0 . +# + + +# PrecompiledHeader class + +# Use different PCH file depending on whether we use debugging symbols. +gb_PrecompiledHeader__get_debugdir = $(if $(call gb_target_symbols_enabled,$(1)),debug,nodebug) + +# $(call gb_PrecompiledHeader_generate_timestamp_rule,linktargetmakefilename) +define gb_PrecompiledHeader_generate_timestamp_rule +$(call gb_LinkTarget_get_pch_timestamp,$(1)) : + mkdir -p $$(dir $$@) && touch $$@ + +endef + +ifneq ($(gb_ENABLE_PCH),) + +# IMPORTANT: Since these defines get expanded, every $ needs to be doubled to $$, except +# for $(1)'s and things that are constant. +# The defines are needed to get the right version of gb_PrecompiledHeader__get_debugdir. + +# all cxxflags to use for compilation +gb_PrecompiledHeader_cxxflags_includes := $$(PCH_DEFS) $$(PCH_CXXFLAGS) $$(gb_PrecompiledHeader_EXCEPTIONFLAGS) +# flags to save to the .flags file to check if they are the same as last time +# (note: the leading space in sed is important, to remove the option and its separating space) +gb_PrecompiledHeader_flags_for_flags_file := $$(sort $(gb_PrecompiledHeader_cxxflags_includes)) \ + $(if $(gb_PrecompiledHeader_ignore_flags_for_flags_file),| sed 's/ $(gb_PrecompiledHeader_ignore_flags_for_flags_file)//') + +# $(call gb_PrecompiledHeader_generate_rules,pchtarget,linktarget,linktargetmakefilename,pchcxxfile,compiler) +define gb_PrecompiledHeader_generate_rules + +$(call gb_PrecompiledHeader_get_dep_target,$(1),$(3)) : + $$(call gb_Helper_abbreviate_dirs,\ + mkdir -p $$(dir $$@) && \ + echo "$$(call gb_PrecompiledHeader_get_target,$(1),$(3)) : $$(gb_Helper_PHONY)" > $$@) + +# keep the flags the PCH was built with in a separate file, update the file if and only if the flags +# change, and make the PCH depend on it => the PCH will be rebuilt on any flags change +.PHONY: force +$(call gb_PrecompiledHeader_get_flags_file,$(1),$(3)) : force + $$(call gb_Helper_abbreviate_dirs,\ + mkdir -p $$(dir $$@) && \ + echo $(gb_PrecompiledHeader_flags_for_flags_file) | cmp -s - $$@ \ + || echo $(gb_PrecompiledHeader_flags_for_flags_file) > $$@) + +# despite this being only one .d file, need to run concat-deps on it to +# re-write external headers from UnpackedTarball +$(call gb_PrecompiledHeader_get_target,$(1),$(3)) : + test "$$(PCH_LINKTARGETMAKEFILENAME)" = "$(3)" \ + || ( echo "Error, PCH $(1) built by $$(PCH_LINKTARGETMAKEFILENAME) instead of $(3)" >&2; exit 1) + rm -f $$@ + $$(call gb_PrecompiledHeader__command,$$@,$(1),$$<,$(gb_PrecompiledHeader_cxxflags_includes),$$(INCLUDE),$(3),$(5)) + $$(call gb_PrecompiledHeader__sum_command,$$@,$(1),$$<,$(gb_PrecompiledHeader_cxxflags_includes),$$(INCLUDE),$(3),$(5)) +ifeq ($(gb_FULLDEPS),$(true)) + $$(call gb_Helper_abbreviate_dirs,\ + RESPONSEFILE=$$(call gb_var2file,$$(shell $$(gb_MKTEMP)),200,$$(call gb_PrecompiledHeader_get_dep_target_tmp,$(1),$(3))) && \ + $$(call gb_Executable_get_command,concat-deps) $$$${RESPONSEFILE} \ + > $$(call gb_PrecompiledHeader_get_dep_target,$(1),$(3)) && \ + rm -f $$$${RESPONSEFILE} $$(call gb_PrecompiledHeader_get_dep_target_tmp,$(1),$(3))) +endif + +$(call gb_PrecompiledHeader_get_for_reuse_target,$(1),$(3)) : $(call gb_LinkTarget_get_target,$(2)) + $$(call gb_PrecompiledHeader__create_reuse_files,$(2),$(1),$(3)) + mkdir -p $$(dir $$@) && touch $$@ + +.PHONY : $(call gb_PrecompiledHeader_get_clean_target,$(1)) +$(call gb_PrecompiledHeader_get_clean_target,$(1)) : + $$(call gb_Output_announce,$(1),$(false),PCH,1) + -$$(call gb_Helper_abbreviate_dirs,\ + rm -f $$(call gb_PrecompiledHeader_get_target,$(1),$(3)) \ + $$(call gb_PrecompiledHeader_get_target,$(1),$(3)).obj \ + $$(call gb_PrecompiledHeader_get_target,$(1),$(3)).pdb \ + $$(call gb_PrecompiledHeader_get_target,$(1),$(3)).sum \ + $$(call gb_PrecompiledHeader_get_flags_file,$(1),$(3)) \ + $$(call gb_PrecompiledHeader_get_for_reuse_target,$(1),$(3)) \ + $$(call gb_PrecompiledHeader_get_dep_target,$(1),$(3))) + +endef + +# $(call gb_PrecompiledHeader_check_flags,linktargetmakefilename,pchcxxfile,pchfile,flags) +# When creating a PCH, the PCH's CXXFLAGS are saved to a matching .flags file. When reusing the PCH +# from another linktarget, use the file to check that the linktarget uses the same CXXFLAGS as the PCH. +# This complements the check in gb_CxxObject__set_pchflags. +define gb_PrecompiledHeader_check_flags +$$(call gb_Helper_abbreviate_dirs,\ + $$(if $$(strip $$(call gb_PrecompiledHeader_check_flags_internal,$$(shell cat $(4)),$(5),$(2))),false,true) || ( \ + echo Error reusing $(2) by $(1). >&2 && \ + echo -n " precompiled header flags : ">&2 && \ + cat $(4) >&2 && \ + echo " object flags : "$$(sort $(5)) >&2 && \ + echo " reason : $$(call gb_PrecompiledHeader_check_flags_internal,$$(shell cat $(4)),$(5),$(2))" >&2 && \ + echo Incorrect precompiled header setup or internal gbuild error. >&2 ; \ + exit 1) \ +) + +endef + +# When trying to reuse one PCH between multiple linktargets, there is a problem that we have +# various defines that cause mismatch in the check above, but these defines actually should not affect the PCH. +# Specifically, there are 3 kinds: +# - -DXXX_DLLIMPLEMENTATION - they are used only in our headers, should not affect system headers. +# - -DSYSTEM_XXX - they are used only by our code (if at all), should not affect system headers +# - various LO configuration defines - they again should only be used by our code and not system headers +# Technically, different compilers handle additional defines like this: +# - GCC +# * It is explicitly allowed to have different macros, as long as they do not affect the PCH. +# * With -Winvalid-pch GCC will even warn if there is a change in a macro affecting the PCH. +# * https://gcc.gnu.org/onlinedocs/gcc/Precompiled-Headers.html +# - Clang +# * I could not find an official statement on what happens if definitions are different. +# * In practice a conflict does not seem to be detected, but the PCH and all the code in it +# acts according to the settings it was built with. Using a PCH and adding more defines +# seems to be functionally equivalent to creating the definitions only after the PCH inclusion. +# * As a side-effect, macros defined on the command line not present in the PCH suddenly +# trigger the -Wunused-macros warning. See bottom of pch/inc/clangfix.hxx . +# - MSVC +# * MSVC explicitly states that the definitions must be the same, but they are not checked, +# and "unpredictable results can occur" if files depend on them. +# * In practice the situation seems to be the same as with Clang, the PCH and the code from it +# act according to the settings it was built with. +# * https://docs.microsoft.com/en-us/cpp/build/creating-precompiled-header-files +# So while this is officially tricky, in practice it seems to work to allow PCH reuse if the linktarget +# has more defines than the PCH was built with, as long as the defines do not affect the PCH. +gb_PrecompiledHeader_ignore_flags_system := \ +-DFASTSAX_DLLIMPLEMENTATION \ +-DSAX_DLLIMPLEMENTATION \ +-DSCQAHELPER_DLLIMPLEMENTATION \ +-DVCLPLUG_WIN_IMPLEMENTATION \ +-DVCLPLUG_GEN_IMPLEMENTATION \ +-DSYSTEM_EXPAT \ +-DSYSTEM_LIBXML \ +-DSYSTEM_ZLIB \ +-DSYSTEM_NSS \ +-DHAVE_VALGRIND_HEADERS \ +-DUSE_RANDR \ +-DUSE_XINERAMA_XORG \ +-DDISABLE_CVE_TESTS \ +-DCPPUNIT_PLUGIN_EXPORT='extern "C" SAL_DLLPUBLIC_EXPORT' \ +-DOOO_DLLIMPLEMENTATION_TEST \ +-DSK_USER_CONFIG_HEADER=% \ +-DSKIA_DLL \ +-DGLM_FORCE_CTOR_INIT \ +-DVCL_INTERNALS \ +-DZLIB_CONST \ +$(gb_CXXFLAGS_include)$(SRCDIR)/pch/inc/clangfix.hxx \ +$(gb_CXXFLAGS_no_pch_warnings) \ +$(gb_PrecompiledHeader_ignore_flags_for_flags_file) \ + +# Probably also update pch/inc/clangfix.hxx if you extend the list. + +# $(call gb_PrecompiledHeader_check_flags_internal,pchfileflags,flags,pchcxxfile) +# Check if two sets of flags are compatible, allowing reuse of the PCH. Flags are compatible if +# - they are the same +# - the PCH is precompiled_system and the linktarget has additional defines listed above +define gb_PrecompiledHeader_check_flags_internal +$(if $(filter-out $(2),$(1)),$(filter-out $(2),$(1)), \ + $(if $(filter-out $(1),$(2)),\ + $(if $(filter-out precompiled_system,$(notdir $(3))),$(filter-out $(1),$(2)), \ + $(foreach flag,$(filter-out $(1),$(2)),$(filter-out $(gb_PrecompiledHeader_ignore_flags_system),$(flag))) \ + ) \ + ,) \ +) +endef + +endif + +# vim: set noet sw=4: |