Support loplugin in clang-cl

This works at least with a recent Clang trunk (towards Clang 6.0).

In order for the plugin.dll to find the LLVM/Clang symbols, it needs to be
loaded into clang.exe not clang-cl.exe, so set CC/CXX to 'clang.exe
--driver-mode=cl ...'.

Buidling the plugin requires some linker flags that must go at the very end of
the COMPILER_PLUGINS_CXX command line, after a /link switch, so introduce
another COMPILER_PLUGINS_CXX_LINKFLAGS variable for that.  Also, clang.lib is
not installed as part of LLVM's 'cmake --build ... --target install' step, so
is not available under CLANGDIR and needs to be taken from the build tree
instead, so introduce another CLANGLIBDIR variable for that.  autogen.input
settings that work for me on Windows 8.1 with Microsoft Visual Studio 14.0 are:

> CLANGDIR=C:/llvm/inst
> CLANGLIBDIR=C:/llvm/build/lib
> COMPILER_PLUGINS_CXX=C:/PROGRA~2/MICROS~3.0/VC/bin/amd64/cl.exe /IC:\PROGRA~2\MICROS~3.0\VC\INCLUDE /IC:\PROGRA~2\MICROS~3.0\VC\ATLMFC\INCLUDE /IC:\PROGRA~2\WI3CF2~1\10\include\100102~1.0\ucrt /IC:\PROGRA~2\WI3CF2~1\NETFXSDK\46D346~1.1\include\um /IC:\PROGRA~2\WI3CF2~1\8.1\include\shared /IC:\PROGRA~2\WI3CF2~1\8.1\include\um /IC:\PROGRA~2\WI3CF2~1\8.1\include\winrt
> COMPILER_PLUGINS_CXX_LINKFLAGS=/LIBPATH:C:/PROGRA~2/MICROS~3.0/VC/LIB/amd64 /LIBPATH:C:/PROGRA~2/MICROS~3.0/VC/ATLMFC/LIB/amd64 /LIBPATH:C:/PROGRA~2/WI3CF2~1/10/lib/100102~1.0/ucrt/x64 /LIBPATH:C:/PROGRA~2/WI3CF2~1/NETFXSDK/46D346~1.1/lib/um/x64 /LIBPATH:C:/PROGRA~2/WI3CF2~1/8.1/lib/winv6.3/um/x64

(The last two are "C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/
amd64/cl.exe" and translations of %INCLUDE% and %LIB% as set in the "VS2015 x64
Native Tools Command Prompt" shell.
AC_CHECK_HEADER(clang/AST/RecursiveASTVisitor.h, ...) in configure.ac wouldn't
like CXX to start with INCLUDE=... LIB=... environment variable settings, so it
wouldn't work to instead pass %INCLUDE% and %LIB% to cl.exe that way.  See
<https://wiki.documentfoundation.org/Development/clang-cl> for general
information about building with clang-cl on Windows.)

There's still some room for improvement marked "TODO".  (And some of the unused*
plugins, which are not run by default anyway, use Unix-style functionality, so
have been disabled for now.)

Change-Id: I6c28bdeb801af39ce2bae03111f455e2338d66c9
Reviewed-on: https://gerrit.libreoffice.org/42931
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 62 insertions, 8 deletions

diff --git a/compilerplugins/Makefile-clang.mk b/compilerplugins/Makefile-clang.mk
index 4839fdef2feb..89a798ebd34a 100644
--- a/compilerplugins/Makefile-clang.mk
+++ b/compilerplugins/Makefile-clang.mk
@@ -10,6 +10,14 @@
 
 CLANG_COMMA :=,
 
+ifeq ($(OS),WNT)
+CLANG_DL_EXT = .dll
+CLANG_EXE_EXT = .exe
+else
+CLANG_DL_EXT = .so
+CLANG_EXE_EXT =
+endif
+
 ifeq ($(COMPILER_PLUGINS_CXX),)
 CLANGCXX=$(filter-out -m32 -m64 -fsanitize%,$(CXX))
 else
@@ -18,15 +26,32 @@ endif
 
 # Compile flags ('make CLANGCXXFLAGS=-g' if you need to debug the plugin); you
 # may occasionally want to override these:
+ifeq ($(OS),WNT)
+# See LLVM's cmake/modules/AddLLVM.cmake and LLVM build's
+# tools/llvm-config/BuildVariables.inc:
+# * Ignore "warning C4141: 'inline': used more than once" as emitted upon
+#   "LLVM_ATTRIBUTE_ALWAYS_INLINE inline" in various LLVM include files.
+# * Ignore "warning C4577: 'noexcept' used with no exception handling mode
+#   specified; termination on exception is not guaranteed. Specify /EHsc".
+CLANGCXXFLAGS=/nologo /D_HAS_EXCEPTIONS=0 /wd4141 /wd4577 /O2 /Oi /EHs-c- /GR-
+else
 CLANGCXXFLAGS=-O2 -Wall -Wextra -Wundef -g
+endif
 
 # The uninteresting rest.
 
 # Clang headers require these.
-CLANGDEFS=-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -fno-rtti
+CLANGDEFS=-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
+ifneq ($(OS),WNT)
+CLANGDEFS += -fno-rtti
+endif
 # All include locations needed (using -isystem silences various warnings when
 # including those files):
+ifeq ($(OS),WNT)
+CLANGINCLUDES=-I$(CLANGDIR)/include
+else
 CLANGINCLUDES=$(if $(filter /usr,$(CLANGDIR)),,-isystem $(CLANGDIR)/include)
+endif
 
 # Clang/LLVM libraries are intentionally not linked in, they are usually built as static libraries, which means the resulting
 # plugin would be big (even though the clang binary already includes it all) and it'd be necessary to explicitly specify
@@ -40,8 +65,13 @@ CLANGOUTDIR=$(BUILDDIR)/compilerplugins/obj
 QUIET=$(if $(verbose),,@)
 
 ifneq ($(ENABLE_WERROR),)
+ifeq ($(OS),WNT)
+CLANGWERROR :=
+#TODO: /WX
+else
 CLANGWERROR := -Werror
 endif
+endif
 
 compilerplugins: compilerplugins-build
 
@@ -61,14 +91,14 @@ CLANGSRCCHANGED= \
 ifeq ($(CLANGSRCCHANGED),1)
 .PHONY: CLANGFORCE
 CLANGFORCE:
-$(CLANGOUTDIR)/plugin.so: CLANGFORCE
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): CLANGFORCE
 endif
 # Make the .so also explicitly depend on the sources list, to force update in case CLANGSRCCHANGED was e.g. during 'make clean'.
-$(CLANGOUTDIR)/plugin.so: $(CLANGOUTDIR)/sources.txt
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): $(CLANGOUTDIR)/sources.txt
 $(CLANGOUTDIR)/sources.txt:
 	touch $@
 
-compilerplugins-build: $(CLANGOUTDIR) $(CLANGOUTDIR)/plugin.so
+compilerplugins-build: $(CLANGOUTDIR) $(CLANGOUTDIR)/plugin$(CLANG_DL_EXT)
 
 compilerplugins-clean:
 	rm -rf $(CLANGOUTDIR)
@@ -78,6 +108,23 @@ $(CLANGOUTDIR):
 
 CLANGOBJS=
 
+ifeq ($(OS),WNT)
+
+define clangbuildsrc
+$(3): $(2) $(SRCDIR)/compilerplugins/Makefile-clang.mk $(CLANGOUTDIR)/clang-timestamp
+	@echo [build CXX] $(subst $(SRCDIR)/,,$(2))
+	$(QUIET)$(CLANGCXX) $(CLANGCXXFLAGS) $(CLANGWERROR) $(CLANGDEFS) \
+        $(CLANGINCLUDES) /I$(BUILDDIR)/config_host $(2) $(CXXFLAGS_CXX11) /MD \
+        /c /Fo: $(3)
+
+-include $(CLANGOUTDIR)/$(1).d #TODO
+
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): $(3)
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): CLANGOBJS += $(3)
+endef
+
+else
+
 define clangbuildsrc
 $(3): $(2) $(SRCDIR)/compilerplugins/Makefile-clang.mk $(CLANGOUTDIR)/clang-timestamp
 	@echo [build CXX] $(subst $(SRCDIR)/,,$(2))
@@ -85,20 +132,27 @@ $(3): $(2) $(SRCDIR)/compilerplugins/Makefile-clang.mk $(CLANGOUTDIR)/clang-time
 
 -include $(CLANGOUTDIR)/$(1).d
 
-$(CLANGOUTDIR)/plugin.so: $(3)
-$(CLANGOUTDIR)/plugin.so: CLANGOBJS += $(3)
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): $(3)
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): CLANGOBJS += $(3)
 endef
 
+endif
+
 $(foreach src, $(CLANGSRC), $(eval $(call clangbuildsrc,$(src),$(CLANGINDIR)/$(src),$(CLANGOUTDIR)/$(src:.cxx=.o))))
 
-$(CLANGOUTDIR)/plugin.so: $(CLANGOBJS)
+$(CLANGOUTDIR)/plugin$(CLANG_DL_EXT): $(CLANGOBJS)
 	@echo [build LNK] $(subst $(BUILDDIR)/,,$@)
+ifeq ($(OS),WNT)
+	$(QUIET)$(CLANGCXX) /LD $(CLANGOBJS) /Fe: $@ $(CLANGLIBDIR)/clang.lib \
+        mincore.lib version.lib /link $(COMPILER_PLUGINS_CXX_LINKFLAGS)
+else
 	$(QUIET)$(CLANGCXX) -shared $(CLANGOBJS) -o $@ \
 		$(if $(filter MACOSX,$(OS)),-Wl$(CLANG_COMMA)-flat_namespace \
 			-Wl$(CLANG_COMMA)-undefined -Wl$(CLANG_COMMA)suppress)
+endif
 
 # Clang most probably doesn't maintain binary compatibility, so rebuild when clang changes.
-$(CLANGOUTDIR)/clang-timestamp: $(CLANGDIR)/bin/clang
+$(CLANGOUTDIR)/clang-timestamp: $(CLANGDIR)/bin/clang$(CLANG_EXE_EXT)
 	$(QUIET)touch $@
 
 # vim: set noet sw=4 ts=4: