WASM: add initial support for Emscripten cross build

- configure with:
- --host=wasm64-local-emscripten
- had to make a few externals optional, so adding:
- --disable-nss
- --disable-cmis
- --disable-curl

Change-Id: I48d1c73d2675ad2e2beaf2c341578199efbd24ee
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111130
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>

4 files changed, 81 insertions, 3 deletions

diff --git a/solenv/bin/run-configure b/solenv/bin/run-configure
new file mode 100755
index 000000000000..9758ff1d86c6
--- /dev/null
+++ b/solenv/bin/run-configure
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+# We could run emconfigure here, but LO's gbuild should have set up everything
+# correctly. If something breaks because of this, we likely have mre problems.
+if test "$OS" = "EMSCRIPTEN"; then
+    export EMMAKEN_JUST_CONFIGURE=1
+fi
+
+exec "$@"
diff --git a/solenv/gbuild/gbuild.mk b/solenv/gbuild/gbuild.mk
index fa5c767271b7..1afa9e0451af 100644
--- a/solenv/gbuild/gbuild.mk
+++ b/solenv/gbuild/gbuild.mk
@@ -191,6 +191,7 @@ include $(SRCDIR)/RepositoryExternal.mk
 $(eval $(call gb_Helper_collect_knownlibs))
 
 gb_Library_DLLPOSTFIX := lo
+gb_RUN_CONFIGURE :=
 
 # Include platform/cpu/compiler specific config/definitions
 
@@ -278,6 +279,7 @@ gb_TEST_ENV_VARS += SAL_DISABLE_SYNCHRONOUS_PRINTER_DETECTION=1
 ifeq (,$(SAL_USE_VCLPLUGIN))
 gb_TEST_ENV_VARS += SAL_USE_VCLPLUGIN=svp
 endif
+gb_TEST_ENV_VARS += UNO_HOME=file://$$I/program
 
 # This is used to detect whether LibreOffice is being built (as opposed to building
 # 3rd-party code). Used for tag deprecation for API we want to
diff --git a/solenv/gbuild/platform/EMSCRIPTEN_INTEL_GCC.mk b/solenv/gbuild/platform/EMSCRIPTEN_INTEL_GCC.mk
new file mode 100644
index 000000000000..3131bbec0959
--- /dev/null
+++ b/solenv/gbuild/platform/EMSCRIPTEN_INTEL_GCC.mk
@@ -0,0 +1,64 @@
+# -*- 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/.
+#
+
+gb_UnoApiHeadersTarget_select_variant = $(if $(filter udkapi,$(1)),comprehensive,$(2))
+
+include $(GBUILDDIR)/platform/unxgcc.mk
+
+gb_RUN_CONFIGURE := $(SRCDIR)/solenv/bin/run-configure
+# avoid -s SAFE_HEAP=1 - c.f. gh#8584 this breaks source maps
+gb_EMSCRIPTEN_CPPFLAGS := -pthread -s TOTAL_MEMORY=1GB -s USE_PTHREADS=1 -s PTHREAD_POOL_SIZE=4
+gb_EMSCRIPTEN_LDFLAGS := $(gb_EMSCRIPTEN_CPPFLAGS) --bind -s ERROR_ON_UNDEFINED_SYMBOLS=1 -s FETCH=1 -s ASSERTIONS=2 -s EXIT_RUNTIME=1 -s EXTRA_EXPORTED_RUNTIME_METHODS=["UTF16ToString","stringToUTF16"]
+gb_EMSCRIPTEN_QTDEFS := -DQT_NO_LINKED_LIST -DQT_NO_JAVA_STYLE_ITERATORS -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB
+
+gb_Executable_EXT := .html
+gb_EMSCRIPTEN_EXCEPT := -s DISABLE_EXCEPTION_CATCHING=0
+
+gb_LinkTarget_CFLAGS += $(gb_EMSCRIPTEN_CPPFLAGS) $(gb_EMSCRIPTEN_QTDEFS)
+gb_LinkTarget_CXXFLAGS += $(gb_EMSCRIPTEN_CPPFLAGS) $(gb_EMSCRIPTEN_QTDEFS) $(gb_EMSCRIPTEN_EXCEPT)
+gb_LinkTarget_LDFLAGS += $(gb_EMSCRIPTEN_LDFLAGS) $(gb_EMSCRIPTEN_CPPFLAGS) $(gb_EMSCRIPTEN_EXCEPT)
+
+# Linker and compiler optimize + debug flags are handled in LinkTarget.mk
+gb_LINKEROPTFLAGS :=
+gb_LINKERSTRIPDEBUGFLAGS :=
+# This maps to g4, AKA sorce maps. The LO default would otherwise be g2!
+gb_DEBUGINFO_FLAGS = -g
+# We need at least code elimination, otherwise linking OOMs even with 64GB.
+# So we "fake" -Og support to mean -O1 for Emscripten and always enable it for debug in configure.
+gb_COMPILERDEBUGOPTFLAGS := -O1
+gb_COMPILERNOOPTFLAGS := -O1 -fstrict-aliasing -fstrict-overflow
+
+# cleanup addition JS and wasm files for binaries
+define gb_Executable_Executable_platform
+$(call gb_LinkTarget_add_auxtargets,$(2),\
+        $(patsubst %.lib,%.wasm,$(3)) \
+        $(patsubst %.lib,%.js,$(3)) \
+        $(patsubst %.lib,%.worker.js,$(3)) \
+)
+
+endef
+
+define gb_CppunitTest_CppunitTest_platform
+$(call gb_LinkTarget_add_auxtargets,$(2),\
+        $(patsubst %.lib,%.wasm,$(3)) \
+        $(patsubst %.lib,%.js,$(3)) \
+        $(patsubst %.lib,%.worker.js,$(3)) \
+)
+
+endef
+
+gb_SUPPRESS_TESTS := $(true)
+
+define gb_Library_get_rpath
+endef
+
+define gb_Executable_get_rpath
+endef
+
+# vim: set noet sw=4 ts=4
diff --git a/solenv/gbuild/platform/com_GCC_defs.mk b/solenv/gbuild/platform/com_GCC_defs.mk
index e07bd2824ff5..fe99e98ea4c4 100644
--- a/solenv/gbuild/platform/com_GCC_defs.mk
+++ b/solenv/gbuild/platform/com_GCC_defs.mk
@@ -49,6 +49,7 @@ gb_COMPILERDEFS := \
 	-DBOOST_ERROR_CODE_HEADER_ONLY \
 	-DBOOST_SYSTEM_NO_DEPRECATED \
 	-DCPPU_ENV=$(gb_CPPU_ENV) \
+	$(if $(filter EMSCRIPTEN,$(OS)),-U_FORTIFY_SOURCE) \
 
 gb_CFLAGS_COMMON := \
 	-Wall \
@@ -63,7 +64,7 @@ gb_CFLAGS_COMMON := \
 	-fmessage-length=0 \
 	-fno-common \
 	-pipe \
-	-fstack-protector-strong \
+	$(if $(filter EMSCRIPTEN,$(OS)),-fno-stack-protector,-fstack-protector-strong) \
 	$(if $(gb_COLOR),-fdiagnostics-color=always) \
 
 gb_CXXFLAGS_COMMON := \
@@ -80,7 +81,7 @@ gb_CXXFLAGS_COMMON := \
 	-fmessage-length=0 \
 	-fno-common \
 	-pipe \
-	-fstack-protector-strong \
+	$(if $(filter EMSCRIPTEN,$(OS)),-fno-stack-protector,-fstack-protector-strong) \
 	$(if $(gb_COLOR),-fdiagnostics-color=always) \
 
 ifeq ($(HAVE_WDEPRECATED_COPY_DTOR),TRUE)
@@ -109,8 +110,10 @@ endif
 ifeq ($(DISABLE_DYNLOADING),TRUE)
 gb_CFLAGS_COMMON += -ffunction-sections -fdata-sections
 gb_CXXFLAGS_COMMON += -ffunction-sections -fdata-sections
+ifneq ($(OS),EMSCRIPTEN)
 gb_LinkTarget_LDFLAGS += -Wl,--gc-sections
 endif
+endif
 
 ifeq ($(COM_IS_CLANG),TRUE)
 gb_CXXFLAGS_COMMON += \
@@ -143,7 +146,7 @@ endif
 gb_VISIBILITY_FLAGS_CXX := -fvisibility-inlines-hidden
 gb_CXXFLAGS_COMMON += $(gb_VISIBILITY_FLAGS_CXX)
 
-gb_LinkTarget_LDFLAGS += -fstack-protector-strong
+gb_LinkTarget_LDFLAGS += $(if $(filter EMSCRIPTEN,$(OS)),-fno-stack-protector,-fstack-protector-strong)
 
 ifneq ($(gb_ENABLE_PCH),)
 ifeq ($(COM_IS_CLANG),TRUE)