[LLDB][test] Update Makefile.rules to support Windows host+Linux target (#99266)

These changes aim 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 pass.

Chocolatey make is recommended to be used since it is maintained better
than GnuWin32 mentioned here
https://lldb.llvm.org/resources/build.html#windows (latest GnuWin32
release is dated by 2010) and helps to avoid problems with building
tests (for example, GnuWin32 make doesn't support long paths and there
are some other failures with building for Linux with it).

Co-authored-by: Pavel Labath <[email protected]>

Author: dzhidzhoev

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

@@ -112,14 +112,26 @@ $(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 "$(SDKROOT)" ""
+        SYSROOT_FLAGS := --sysroot "$(SDKROOT)"
+        GCC_TOOLCHAIN_FLAGS := --gcc-toolchain="$(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
 
 #----------------------------------------------------------------------
@@ -210,20 +222,15 @@ 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
@@ -234,9 +241,9 @@ 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"
@@ -267,7 +274,9 @@ 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)))
@@ -378,11 +387,26 @@ ifeq (1, $(USE_SYSTEM_STDLIB))
 	endif
 endif
 
+ifeq (,$(filter 1, $(USE_LIBSTDCPP) $(USE_LIBCPP) $(USE_SYSTEM_STDLIB)))
+  # If no explicit C++ library request was made, but we have paths to a custom libcxx, use
+  # them.  Otherwise, use the system library by default.
+  ifneq ($(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,$(LIBCPP_LIBRARY_DIR) -lc++
+  else
+    USE_SYSTEM_STDLIB := 1
+  endif
+endif
+
 ifeq (1,$(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
 
@@ -416,21 +440,15 @@ 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 += $(GCC_TOOLCHAIN_FLAGS)
+            LDFLAGS += $(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
 #----------------------------------------------------------------------