[LLDB][test] Update Makefile.rules to support Windows host+Linux target

These changes are aimed to support cross compilation build on Windows
host for Linux target for API tests execution. They're not final:
changes will follow for refactoring and adjustments to make all tests
passing.

Chocolatey make is recommended to use, since it is maintained
better than GnuWin32 recommended here https://lldb.llvm.org/resources/build.html#codesigning
(it was updated last time in 2010) and helps to avoid problems
with building tests (for example, GnuWin32 doesn't support long paths
and there are some other failures with building for Linux with it).

This commit contains following changes:
1. Better SHELL detection for make to use on Windows host.
2. Paths are turned into POSIX-style since some tests and Unix utilities
   use them for manipulating files. It helps to avoid compiler/linker
   errors because of broken paths.
3. Compiler and linker flags are cleaned up to enable cross-compilation.

Author: dzhidzhoev

lldb/packages/Python/lldbsuite/test/make/Makefile.rules

@@ -47,7 +47,8 @@ LLDB_BASE_DIR := $(THIS_FILE_DIR)/../../../../../
 .DEFAULT_GOAL := all
 
 #----------------------------------------------------------------------
-# If OS is not defined, use 'uname -s' to determine the OS name.
+# If OS or/and HOST_OS are not defined, use 'uname -s' to determine 
+# the OS name.
 #
 # GNUWin32 uname gives "windows32" or "server version windows32" while
 # some versions of MSYS uname return "MSYS_NT*", but most environments
@@ -56,15 +57,12 @@ LLDB_BASE_DIR := $(THIS_FILE_DIR)/../../../../../
 # inherited all the way down to the process spawned for make.
 #----------------------------------------------------------------------
 ifeq "$(HOST_OS)" ""
-  HOST_OS := $(shell uname -s)
-endif
-
-ifneq (,$(findstring windows32,$(HOST_OS)))
-	HOST_OS := Windows_NT
-endif
-
-ifneq (,$(findstring MSYS_NT,$(HOST_OS)))
-	HOST_OS := Windows_NT
+    HOST_OS := $(shell uname -s)
+    ifneq (,$(or \
+            $(findstring windows32,$(HOST_OS)),\
+            $(findstring MSYS_NT,$(HOST_OS))))
+        HOST_OS := Windows_NT
+    endif
 endif
 
 ifeq "$(OS)" ""
@@ -80,9 +78,21 @@ endif
 # Also reset BUILDDIR value because "pwd" returns cygwin or msys path
 # which needs to be converted to windows path.
 #----------------------------------------------------------------------
-ifeq "$(OS)" "Windows_NT"
-	SHELL = $(WINDIR)\system32\cmd.exe
+path_wrapper = $(1)
+ifeq "$(HOST_OS)" "Windows_NT"
+	# Windows 10 and later has the lower-case 'windir' env variable.
+       SHELL := $(or $(windir),$(WINDIR),C:\WINDOWS)\system32\cmd.exe
 	BUILDDIR := $(shell echo %cd%)
+
+  ifneq (,$(filter $(OS), Linux Android))
+      path_wrapper =  $(subst \,/,$(1))
+      # Normalize base paths at the same time.
+      override SRCDIR := $(call path_wrapper,$(SRCDIR))
+      override BUILDDIR := $(call path_wrapper,$(BUILDDIR))
+      override MAKEFILE_RULES := $(call path_wrapper,$(MAKEFILE_RULES))
+      override THIS_FILE_DIR := $(call path_wrapper,$(THIS_FILE_DIR))
+      override LLDB_BASE_DIR := $(call path_wrapper,$(LLDB_BASE_DIR))
+  endif
 endif
 
 #----------------------------------------------------------------------
@@ -135,14 +145,26 @@ $(error "C compiler is not specified. Please run tests through lldb-dotest or li
 endif
 
 #----------------------------------------------------------------------
-# Handle SDKROOT on Darwin
+# Handle SDKROOT for the cross platform builds.
 #----------------------------------------------------------------------
 
 ifeq "$(OS)" "Darwin"
     ifeq "$(SDKROOT)" ""
 	# We haven't otherwise set the SDKROOT, so set it now to macosx
 	SDKROOT := $(shell xcrun --sdk macosx --show-sdk-path)
     endif
+    SYSROOT_FLAGS := -isysroot "$(SDKROOT)"
+    GCC_TOOLCHAIN_FLAGS :=
+else
+    ifneq "$(SDKROOT)" ""
+        SYSROOT_FLAGS := --sysroot "$(call path_wrapper,$(SDKROOT))"
+        GCC_TOOLCHAIN_FLAGS := --gcc-toolchain="$(call path_wrapper,$(SDKROOT)/usr)"
+    else
+        # Do not set up these options if SDKROOT was not specified.
+        # This is a regular build in that case (or Android).
+        SYSROOT_FLAGS :=
+        GCC_TOOLCHAIN_FLAGS :=
+    endif
 endif
 
 #----------------------------------------------------------------------
@@ -239,20 +261,15 @@ endif
 DEBUG_INFO_FLAG ?= -g
 
 CFLAGS ?= $(DEBUG_INFO_FLAG) -O0
-
-ifeq "$(OS)" "Darwin"
-	ifneq "$(SDKROOT)" ""
-		CFLAGS += -isysroot "$(SDKROOT)"
-	endif
-endif
+CFLAGS += $(SYSROOT_FLAGS)
 
 ifeq "$(OS)" "Darwin"
 	CFLAGS += $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES)
 else
 	CFLAGS += $(ARCHFLAG)$(ARCH)
 endif
-CFLAGS += -I$(LLDB_BASE_DIR)include -I$(LLDB_OBJ_ROOT)/include
 
+CFLAGS += -I$(LLDB_BASE_DIR)/include -I$(LLDB_OBJ_ROOT)/include
 CFLAGS += -I$(SRCDIR) -I$(THIS_FILE_DIR)
 
 ifndef NO_TEST_COMMON_H
@@ -263,9 +280,9 @@ CFLAGS += $(NO_LIMIT_DEBUG_INFO_FLAGS) $(ARCH_CFLAGS)
 
 # Use this one if you want to build one part of the result without debug information:
 ifeq "$(OS)" "Darwin"
-	CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES) $(ARCH_CFLAGS) $(CFLAGS_EXTRAS) -isysroot "$(SDKROOT)"
+	CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES) $(ARCH_CFLAGS) $(CFLAGS_EXTRAS) $(SYSROOT_FLAGS)
 else
-	CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG)$(ARCH) $(FRAMEWORK_INCLUDES) $(ARCH_CFLAGS) $(CFLAGS_EXTRAS)
+	CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG)$(ARCH) $(FRAMEWORK_INCLUDES) $(ARCH_CFLAGS) $(CFLAGS_EXTRAS) $(SYSROOT_FLAGS)
 endif
 
 ifeq "$(MAKE_DWO)" "YES"
@@ -275,7 +292,7 @@ endif
 ifeq "$(USE_PRIVATE_MODULE_CACHE)" "YES"
 THE_CLANG_MODULE_CACHE_DIR := $(BUILDDIR)/private-module-cache
 else
-THE_CLANG_MODULE_CACHE_DIR := $(CLANG_MODULE_CACHE_DIR)
+THE_CLANG_MODULE_CACHE_DIR := $(call path_wrapper,$(CLANG_MODULE_CACHE_DIR))
 endif
 
 MODULE_BASE_FLAGS := -fmodules -gmodules -fmodules-cache-path=$(THE_CLANG_MODULE_CACHE_DIR)
@@ -296,11 +313,13 @@ endif
 CFLAGS += $(CFLAGS_EXTRAS)
 CXXFLAGS += -std=c++11 $(CFLAGS) $(ARCH_CXXFLAGS)
 LD = $(CC)
-LDFLAGS ?= $(CFLAGS)
+# Copy common options to the linker flags (dwarf, arch. & etc).
+#Note: we get some 'garbage' options for linker here (such as -I, --isystem & etc).
+LDFLAGS += $(CFLAGS)
 LDFLAGS += $(LD_EXTRAS) $(ARCH_LDFLAGS)
 ifeq (,$(filter $(OS), Windows_NT Android Darwin))
 	ifneq (,$(filter YES,$(ENABLE_THREADS)))
-		LDFLAGS += -pthread
+		LDFLAGS += -lpthread
 	endif
 endif
 OBJECTS =
@@ -418,11 +437,28 @@ ifeq (1, $(USE_SYSTEM_STDLIB))
 	endif
 endif
 
+# No C++ library has been specifieed. Use libstdc++ by default.
+ifeq (,$(filter 1, $(USE_LIBSTDCPP) $(USE_LIBCPP) $(USE_SYSTEM_STDLIB)))
+  # If no explicit request was made, but we have paths to a custom libcxx, use
+  # them.
+  ifneq ($(and $(LIBCPP_INCLUDE_DIR), $(LIBCPP_LIBRARY_DIR)),)
+    CXXFLAGS += -nostdlib++ -nostdinc++ -cxx-isystem $(LIBCPP_INCLUDE_DIR)
+    ifneq "$(LIBCPP_INCLUDE_TARGET_DIR)" ""
+      CXXFLAGS += -cxx-isystem $(LIBCPP_INCLUDE_TARGET_DIR)
+    endif
+    LDFLAGS += -L$(LIBCPP_LIBRARY_DIR) -Wl,-rpath,$(LIBCPP_LIBRARY_DIR) -lc++ -lc++abi
+  # Otherwise no C++ library has been specified. Use stdc++ by default.
+  else
+    USE_LIBSTDCPP := 1
+  endif
+endif
+
 ifeq (1,$(USE_LIBSTDCPP))
 	# Clang requires an extra flag: -stdlib=libstdc++
 	ifneq (,$(findstring clang,$(CC)))
-		CXXFLAGS += -stdlib=libstdc++
-		LDFLAGS += -stdlib=libstdc++
+    # Force clang looking for the gcc's headers at specific rootfs folder.
+		CXXFLAGS += -stdlib=libstdc++ $(GCC_TOOLCHAIN_FLAGS)
+		LDFLAGS += -stdlib=libstdc++ $(GCC_TOOLCHAIN_FLAGS)
 	endif
 endif
 
@@ -432,18 +468,18 @@ ifeq (1,$(USE_LIBCPP))
 		ifneq "$(LIBCPP_INCLUDE_TARGET_DIR)" ""
 				CXXFLAGS += -cxx-isystem $(LIBCPP_INCLUDE_TARGET_DIR)
 		endif
-		LDFLAGS += -L$(LIBCPP_LIBRARY_DIR) -Wl,-rpath,$(LIBCPP_LIBRARY_DIR) -lc++
+		LDFLAGS += -L$(LIBCPP_LIBRARY_DIR) -Wl,-rpath,$(LIBCPP_LIBRARY_DIR) -lc++ -lc++abi
 	else
 		ifeq "$(OS)" "Android"
 				# Nothing to do, this is already handled in
 				# Android.rules.
 		else
 				CXXFLAGS += -stdlib=libc++
-				LDFLAGS += -stdlib=libc++
+				LDFLAGS += -stdlib=libc++ -lc++abi
 		endif
 		ifneq (,$(filter $(OS), FreeBSD Linux NetBSD))
 				ifneq (,$(LLVM_LIBS_DIR))
-				LDFLAGS += -Wl,-rpath,$(LLVM_LIBS_DIR)
+            LDFLAGS += -Wl,-rpath,$(LLVM_LIBS_DIR)
 				endif
 		endif
 	endif
@@ -456,21 +492,15 @@ ifeq (1, $(USE_SYSTEM_STDLIB))
         endif
         CXXFLAGS += -nostdlib++ -nostdinc++ -cxx-isystem $(SDKROOT)/usr/include/c++/v1
         LDFLAGS += -L$(SDKROOT)/usr/lib -Wl,-rpath,$(SDKROOT)/usr/lib -lc++
+    else
+        ifneq (,$(findstring clang,$(CC)))
+            # Force clang looking for the gcc's headers at specific rootfs folder.
+            CXXFLAGS += -stdlib=libstdc++ $(GCC_TOOLCHAIN_FLAGS)
+            LDFLAGS += -stdlib=libstdc++ $(GCC_TOOLCHAIN_FLAGS)
+        endif
     endif
 endif
 
-# If no explicit request was made, but we have paths to a custom libcxx, use
-# them.
-ifeq ($(or $(USE_LIBSTDCPP), $(USE_LIBCPP), $(USE_SYSTEM_STDLIB)),)
-	ifneq ($(and $(LIBCPP_INCLUDE_DIR), $(LIBCPP_LIBRARY_DIR)),)
-		CXXFLAGS += -nostdlib++ -nostdinc++ -cxx-isystem $(LIBCPP_INCLUDE_DIR)
-		ifneq "$(LIBCPP_INCLUDE_TARGET_DIR)" ""
-				CXXFLAGS += -cxx-isystem $(LIBCPP_INCLUDE_TARGET_DIR)
-		endif
-		LDFLAGS += -L$(LIBCPP_LIBRARY_DIR) -Wl,-rpath,$(LIBCPP_LIBRARY_DIR) -lc++
-	endif
-endif
-
 #----------------------------------------------------------------------
 # Additional system libraries
 #----------------------------------------------------------------------
@@ -659,20 +689,20 @@ endif
 
 ifneq "$(PCH_OUTPUT)" ""
 $(PCH_OUTPUT) : $(PCH_CXX_SOURCE)
-	$(CXX) $(CXXFLAGS) -x c++-header -o $@ $<
+	$(CXX) $(CXXFLAGS) -x c++-header -o $@ $(call path_wrapper,$<)
 endif
 
 %.o: %.c %.d
-	$(CC) $(CFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<
+	$(CC) $(CFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $(call path_wrapper,$<)
 
 %.o: %.cpp %.d $(PCH_OUTPUT)
-	$(CXX) $(PCHFLAGS) $(CXXFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<
+	$(CXX) $(PCHFLAGS) $(CXXFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $(call path_wrapper,$<)
 
 %.o: %.m %.d
-	$(CC) $(CFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<
+	$(CC) $(CFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $(call path_wrapper,$<)
 
 %.o: %.mm %.d
-	$(CXX) $(CXXFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<
+	$(CXX) $(CXXFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $(call path_wrapper,$<)
 
 #----------------------------------------------------------------------
 # Automatic variables based on items already entered. Below we create

lldb/test/API/commands/settings/use_source_cache/Makefile

@@ -5,4 +5,4 @@ include Makefile.rules
 
 # Copy file into the build folder to enable the test to modify it.
 main-copy.cpp: main.cpp
-	cp -f $< $@
+	cp -f $(call path_wrapper,$<) $@

lldb/test/API/functionalities/breakpoint/comp_dir_symlink/Makefile

@@ -6,4 +6,4 @@ include Makefile.rules
 
 # Force relative filenames by copying it into the build directory.
 relative.cpp: main.cpp
-	cp -f $< $@
+	cp -f $(call path_wrapper,$<) $@

lldb/test/API/functionalities/inline-sourcefile/Makefile

@@ -8,4 +8,4 @@ OBJECTS += inline.o
 $(EXE): main.c inline.o
 
 %.o: %.ll
-	$(CC) $< -c -o $@
+	$(CC) $(call path_wrapper,$<) -c -o $@

lldb/test/API/functionalities/multiple-slides/Makefile

@@ -8,5 +8,5 @@ include Makefile.rules
 # sliding the binary, the address of `first` and
 # `second` are not slid for some reason on Darwin.
 main.o: main.c
-	$(CC) $(CFLAGS_NO_DEBUG) -c $< -o $@
+	$(CC) $(CFLAGS_NO_DEBUG) -c $(call path_wrapper,$<) -o $@
 

lldb/test/API/functionalities/postmortem/netbsd-core/GNUmakefile

@@ -8,8 +8,8 @@ clean:
 	rm -f $(CORES) $(EXECS)
 
 %.core: %
-	sysctl -w proc.$$$$.corename=$@; ulimit -s 16; ! ./$<
+	sysctl -w proc.$$$$.corename=$@; ulimit -s 16; ! ./$(call path_wrapper,$<)
 %.$(ARCH): %.c
-	$(CC) -o $@ -g $<
+	$(CC) -o $@ -g $(call path_wrapper,$<)
 
 .PHONY: all clean

lldb/test/API/functionalities/step-avoids-no-debug/Makefile

@@ -3,4 +3,4 @@ C_SOURCES := with-debug.c without-debug.c
 include Makefile.rules
 
 without-debug.o: without-debug.c
-	$(CC) $(CFLAGS_NO_DEBUG) -c $<
+	$(CC) $(CFLAGS_NO_DEBUG) -c $(call path_wrapper,$<)

lldb/test/API/functionalities/valobj_errors/Makefile

@@ -4,6 +4,6 @@ LD_EXTRAS = hidden.o
 a.out: hidden.o
 
 hidden.o: hidden.c
-	$(CC) -g0 -c -o $@ $<
+	$(CC) -g0 -c -o $@ $(call path_wrapper,$<)
 
 include Makefile.rules

lldb/test/API/lang/cpp/operator-overload/Makefile

@@ -3,4 +3,4 @@ CXX_SOURCES = a.cpp b.cpp
 include Makefile.rules
 
 a.o: a.cpp
-	$(CC) $(CFLAGS_NO_DEBUG) -c $< -o $@
+	$(CC) $(CFLAGS_NO_DEBUG) -c $(call path_wrapper,$<) -o $@

lldb/test/API/lang/objcxx/class-name-clash/Makefile

@@ -3,4 +3,4 @@ include Makefile.rules
 
 # myobject.o needs to be built without debug info
 myobject.o: myobject.mm
-	$(CXX) $(CFLAGS_NO_DEBUG) -c -o $@ $<
+	$(CXX) $(CFLAGS_NO_DEBUG) -c -o $@ $(call path_wrapper,$<)

lldb/test/API/linux/add-symbols/Makefile

@@ -4,6 +4,6 @@ LD_EXTRAS := -Wl,--build-id=none
 all: stripped.out
 
 stripped.out : a.out
-	$(OBJCOPY) --remove-section=.note.gnu.build-id --remove-section=.gnu_debuglink --strip-debug $< $@
+	$(OBJCOPY) --remove-section=.note.gnu.build-id --remove-section=.gnu_debuglink --strip-debug $(call path_wrapper,$<) $@
 
 include Makefile.rules

lldb/test/API/linux/sepdebugsymlink/Makefile

@@ -5,7 +5,7 @@ all: dirsymlink
 dirreal: a.out
 	$(RM) -r $@
 	mkdir $@
-	$(OBJCOPY) --only-keep-debug $< $@/stripped.debug
+	$(OBJCOPY) --only-keep-debug $(call path_wrapper,$<) $@/stripped.debug
 	$(OBJCOPY) --strip-all --add-gnu-debuglink=$@/stripped.debug $< $@/stripped.out
 
 dirsymlink: dirreal

lldb/test/API/macosx/function-starts/Makefile

@@ -5,4 +5,4 @@ MAKE_DSYM := NO
 include Makefile.rules
 
 main.o: main.cpp
-	$(CC) $(CFLAGS_NO_DEBUG) -c $< -o $@
+	$(CC) $(CFLAGS_NO_DEBUG) -c $(call path_wrapper,$<) -o $@

lldb/test/API/macosx/posix_spawn/Makefile

@@ -6,13 +6,13 @@ include Makefile.rules
 all: fat.out
 
 x86_64.out: x86_64.c
-	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o x86_64.out $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o x86_64.out $(call path_wrapper,$<)
 
 x86_64h.out: x86_64h.c
-	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o x86_64h.out $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o x86_64h.out $(call path_wrapper,$<)
 
 arm64.out: arm64.c
-	$(CC) -isysroot $(SDKROOT) -target arm64-apple-macosx10.9 -o arm64.out $<
+	$(CC) -isysroot $(SDKROOT) -target arm64-apple-macosx10.9 -o arm64.out $(call path_wrapper,$<)
 
 fat.out: x86_64.out x86_64h.out arm64.out
 	$(LIPO) -o fat.out -create $^

lldb/test/API/macosx/universal/Makefile

@@ -8,13 +8,13 @@ testit: testit.x86_64h testit.x86_64
 	lipo -create -o testit $^
 
 testit.x86_64h: testit.x86_64h.o
-	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o testit.x86_64h $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o testit.x86_64h $(call path_wrapper,$<)
 
 testit.x86_64: testit.x86_64.o
-	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o testit.x86_64 $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o testit.x86_64 $(call path_wrapper,$<)
 
 testit.x86_64h.o: main.c
-	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64h-apple-macosx10.9 -c -o testit.x86_64h.o $<
+	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64h-apple-macosx10.9 -c -o testit.x86_64h.o $(call path_wrapper,$<)
 
 testit.x86_64.o: main.c
-	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64-apple-macosx10.9 -c -o testit.x86_64.o $<
+	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64-apple-macosx10.9 -c -o testit.x86_64.o $(call path_wrapper,$<)

lldb/test/API/macosx/universal64/Makefile

@@ -12,13 +12,13 @@ fat.out: fat.x86_64h.out fat.x86_64.out
 	lipo -fat64 -create -o $@ $^
 
 fat.x86_64.out: fat.x86_64.o
-	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o $@ $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64-apple-macosx10.9 -o $@ $(call path_wrapper,$<)
 
 fat.x86_64h.out: fat.x86_64h.o
-	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o $@ $<
+	$(CC) -isysroot $(SDKROOT) -target x86_64h-apple-macosx10.9 -o $@ $(call path_wrapper,$<)
 
 fat.x86_64.o: main.c
-	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64-apple-macosx10.9 -c -o $@ $<
+	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64-apple-macosx10.9 -c -o $@ $(call path_wrapper,$<)
 
 fat.x86_64h.o: main.c
-	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64h-apple-macosx10.9 -c -o $@ $<
+	$(CC) -isysroot $(SDKROOT) -g -O0 -target x86_64h-apple-macosx10.9 -c -o $@ $(call path_wrapper,$<)

lldb/test/API/source-manager/Makefile

@@ -4,4 +4,4 @@ include Makefile.rules
 
 # Copy file into the build folder to enable the test to modify it.
 main-copy.c: main.c
-	cp -f $< $@
+	cp -f $(call path_wrapper,$<) $@