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>

8 files changed, 104 insertions, 12 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:
diff --git a/compilerplugins/clang/pluginhandler.cxx b/compilerplugins/clang/pluginhandler.cxx
index c61477594395..5712f02dcc3a 100644
--- a/compilerplugins/clang/pluginhandler.cxx
+++ b/compilerplugins/clang/pluginhandler.cxx
@@ -96,9 +96,11 @@ void PluginHandler::handleOption( const std::string& option )
             ; // ok
         else
         {
+#if !defined _WIN32 //TODO, S_ISDIR
             struct stat st;
             if( stat(( SRCDIR "/" + scope ).c_str(), &st ) != 0 || !S_ISDIR( st.st_mode ))
                 report( DiagnosticsEngine::Fatal, "unknown scope %0 (no such module directory)" ) << scope;
+#endif
         }
     }
     else if( option.substr( 0, 14 ) == "warnings-only=" )
diff --git a/compilerplugins/clang/unusedfieldsremove.cxx b/compilerplugins/clang/unusedfieldsremove.cxx
index ab2359e430a4..eebc2bcfb51e 100644
--- a/compilerplugins/clang/unusedfieldsremove.cxx
+++ b/compilerplugins/clang/unusedfieldsremove.cxx
@@ -7,6 +7,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+#if !defined _WIN32 //TODO, #include <sys/mman.h>
+
 #include <cassert>
 #include <string>
 #include <iostream>
@@ -128,4 +130,6 @@ loplugin::Plugin::Registration< UnusedFieldsRemove > X("unusedfieldsremove", fal
 
 }
 
+#endif
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/compilerplugins/clang/unusedmethodsremove.cxx b/compilerplugins/clang/unusedmethodsremove.cxx
index 09187edfc7c0..5452b51f42a2 100644
--- a/compilerplugins/clang/unusedmethodsremove.cxx
+++ b/compilerplugins/clang/unusedmethodsremove.cxx
@@ -7,6 +7,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+#if !defined _WIN32 //TODO, #include <sys/mman.h>
+
 #include <cassert>
 #include <string>
 #include <iostream>
@@ -145,4 +147,6 @@ loplugin::Plugin::Registration< UnusedMethodsRemove > X("unusedmethodsremove", f
 
 }
 
+#endif
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/config_host.mk.in b/config_host.mk.in
index 1903d31c898c..eae6050bc262 100644
--- a/config_host.mk.in
+++ b/config_host.mk.in
@@ -60,6 +60,7 @@ export CDR_CFLAGS=$(gb_SPACE)@CDR_CFLAGS@
 export CDR_LIBS=$(gb_SPACE)@CDR_LIBS@
 @x_CFLAGS@ export CFLAGS=@CFLAGS@
 export CLANGDIR=@CLANGDIR@
+export CLANGLIBDIR=@CLANGLIBDIR@
 export CLUCENE_CFLAGS=$(gb_SPACE)@CLUCENE_CFLAGS@
 export CLUCENE_LIBS=$(gb_SPACE)@CLUCENE_LIBS@
 export LIBCMIS_CFLAGS=$(gb_SPACE)@LIBCMIS_CFLAGS@
@@ -72,6 +73,7 @@ export COMMONS_LOGGING_VERSION=@COMMONS_LOGGING_VERSION@
 export COMPATH=@COMPATH@
 export COMPILER_PLUGINS=@COMPILER_PLUGINS@
 export COMPILER_PLUGINS_CXX=@COMPILER_PLUGINS_CXX@
+export COMPILER_PLUGINS_CXX_LINKFLAGS=@COMPILER_PLUGINS_CXX_LINKFLAGS@
 export COM_IS_CLANG=@COM_IS_CLANG@
 export CPPUNIT_CFLAGS=$(gb_SPACE)@CPPUNIT_CFLAGS@
 export CPPUNIT_LIBS=$(gb_SPACE)@CPPUNIT_LIBS@
diff --git a/configure.ac b/configure.ac
index c0414f8452af..0b184164e43a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6450,7 +6450,9 @@ else
 fi
 AC_SUBST(COMPILER_PLUGINS)
 AC_SUBST(COMPILER_PLUGINS_CXX)
+AC_SUBST(COMPILER_PLUGINS_CXX_LINKFLAGS)
 AC_SUBST(CLANGDIR)
+AC_SUBST(CLANGLIBDIR)
 
 # Plugin to help linker.
 # Add something like LD_PLUGIN=/usr/lib64/LLVMgold.so to your autogen.input.
diff --git a/solenv/gbuild/platform/com_MSC_class.mk b/solenv/gbuild/platform/com_MSC_class.mk
index 79107f926760..660ba83d73ef 100644
--- a/solenv/gbuild/platform/com_MSC_class.mk
+++ b/solenv/gbuild/platform/com_MSC_class.mk
@@ -49,16 +49,18 @@ $(call gb_Helper_abbreviate_dirs,\
 		$(if $(EXTERNAL_CODE), \
 			$(if $(filter -clr,$(2)),,$(if $(COM_IS_CLANG),-Wno-undef)), \
 			$(gb_DEFS_INTERNAL)) \
-		$(if $(WARNINGS_NOT_ERRORS),,$(gb_CFLAGS_WERROR)) \
+		$(if $(WARNINGS_NOT_ERRORS),$(if $(ENABLE_WERROR),$(if $(PLUGIN_WARNINGS_AS_ERRORS),$(gb_COMPILER_PLUGINS_WARNINGS_AS_ERRORS))),$(gb_CFLAGS_WERROR)) \
+		$(if $(filter -clr,$(2)),,$(if $(5),$(gb_COMPILER_PLUGINS))) \
+		$(if $(COMPILER_TEST),-fsyntax-only -ferror-limit=0 -Xclang -verify) \
 		-Fd$(PDBFILE) \
 		$(PCHFLAGS) \
-		$(gb_COMPILERDEPFLAGS) \
+		$(if $(COMPILER_TEST),,$(gb_COMPILERDEPFLAGS)) \
 		-I$(dir $(3)) \
 		$(INCLUDE) \
 		$(if $(filter YES,$(CXXOBJECT_X64)), -U_X86_ -D_AMD64_,) \
 		-c $(3) \
 		-Fo$(1)) $(if $(filter $(true),$(gb_SYMBOL)),/link /DEBUG:FASTLINK) \
-		$(call gb_create_deps,$(4),$(1),$(3))
+		$(if $(COMPILER_TEST),,$(call gb_create_deps,$(4),$(1),$(3)))
 endef
 
 # PrecompiledHeader class
diff --git a/solenv/gbuild/platform/com_MSC_defs.mk b/solenv/gbuild/platform/com_MSC_defs.mk
index 9aa1435a5a94..dd3e31952ed8 100644
--- a/solenv/gbuild/platform/com_MSC_defs.mk
+++ b/solenv/gbuild/platform/com_MSC_defs.mk
@@ -224,7 +224,7 @@ gb_PCHWARNINGS = \
 gb_STDLIBS := \
 	advapi32.lib \
 
-gb_CFLAGS_WERROR := $(if $(ENABLE_WERROR),-WX)
+gb_CFLAGS_WERROR = $(if $(ENABLE_WERROR),-WX)
 
 # there does not seem to be a way to force C++03 with MSVC
 gb_CXX03FLAGS :=
@@ -301,6 +301,28 @@ gb_CXXFLAGS += \
 
 endif
 
+ifeq ($(COM_IS_CLANG),TRUE)
+gb_COMPILER_TEST_FLAGS := -Xclang -plugin-arg-loplugin -Xclang --unit-test-mode
+ifeq ($(COMPILER_PLUGIN_TOOL),)
+gb_COMPILER_PLUGINS := -Xclang -load -Xclang $(BUILDDIR)/compilerplugins/obj/plugin.dll -Xclang -add-plugin -Xclang loplugin
+ifneq ($(COMPILER_PLUGIN_WARNINGS_ONLY),)
+gb_COMPILER_PLUGINS += -Xclang -plugin-arg-loplugin -Xclang \
+    --warnings-only='$(COMPILER_PLUGIN_WARNINGS_ONLY)'
+endif
+else
+gb_COMPILER_PLUGINS := -Xclang -load -Xclang $(BUILDDIR)/compilerplugins/obj/plugin.dll -Xclang -plugin -Xclang loplugin $(foreach plugin,$(COMPILER_PLUGIN_TOOL), -Xclang -plugin-arg-loplugin -Xclang $(plugin))
+ifneq ($(UPDATE_FILES),)
+gb_COMPILER_PLUGINS += -Xclang -plugin-arg-loplugin -Xclang --scope=$(UPDATE_FILES)
+endif
+endif
+gb_COMPILER_PLUGINS_WARNINGS_AS_ERRORS := \
+    -Xclang -plugin-arg-loplugin -Xclang --warnings-as-errors
+else
+gb_COMPILER_TEST_FLAGS :=
+gb_COMPILER_PLUGINS :=
+gb_COMPILER_PLUGINS_WARNINGS_AS_ERRORS :=
+endif
+
 # Helper class
 
 ifeq ($(GNUMAKE_WIN_NATIVE),TRUE)