mk: Add build system support for cl.exe

We have a number of support C/C++ files in Rust that we link into the standard
library and other various locations, and these all need to be built with cl.exe
instead of gcc.exe when targeting MSVC. This commit adds helper macros for this
functionality to use different sets of programs/flags/invocations on MSVC than
on GNU-like platforms.

Author: alexcrichton

mk/platform.mk

@@ -133,6 +133,21 @@ endef
 $(foreach target,$(CFG_TARGET), \
   $(eval $(call FILTER_FLAGS,$(target))))
 
+# Configure various macros to pass gcc or cl.exe style arguments
+define CC_MACROS
+  CFG_CC_INCLUDE_$(1)=-I $$(1)
+  ifeq ($$(findstring msvc,$(1)),msvc)
+    CFG_CC_OUTPUT_$(1)=-Fo:$$(1)
+    CFG_CREATE_ARCHIVE_$(1)=$$(AR_$(1)) -OUT:$$(1)
+  else
+    CFG_CC_OUTPUT_$(1)=-o $$(1)
+    CFG_CREATE_ARCHIVE_$(1)=$$(AR_$(1)) crus $$(1)
+  endif
+endef
+
+$(foreach target,$(CFG_TARGET), \
+  $(eval $(call CC_MACROS,$(target))))
+
 
 ifeq ($(CFG_CCACHE_CPP2),1)
   CCACHE_CPP2=1
@@ -163,7 +178,7 @@ define CFG_MAKE_TOOLCHAIN
   CFG_COMPILE_C_$(1) = $$(CC_$(1)) \
         $$(CFG_GCCISH_CFLAGS) \
         $$(CFG_GCCISH_CFLAGS_$(1)) \
-        -c -o $$(1) $$(2)
+        -c $$(call CFG_CC_OUTPUT_$(1),$$(1)) $$(2)
   CFG_LINK_C_$(1) = $$(CC_$(1)) \
         $$(CFG_GCCISH_LINK_FLAGS) -o $$(1) \
         $$(CFG_GCCISH_LINK_FLAGS_$(1)) \
@@ -174,7 +189,7 @@ define CFG_MAKE_TOOLCHAIN
         $$(CFG_GCCISH_CXXFLAGS) \
         $$(CFG_GCCISH_CFLAGS_$(1)) \
         $$(CFG_GCCISH_CXXFLAGS_$(1)) \
-        -c -o $$(1) $$(2)
+        -c $$(call CFG_CC_OUTPUT_$(1),$$(1)) $$(2)
   CFG_LINK_CXX_$(1) = $$(CXX_$(1)) \
         $$(CFG_GCCISH_LINK_FLAGS) -o $$(1) \
         $$(CFG_GCCISH_LINK_FLAGS_$(1)) \

mk/rt.mk

@@ -81,8 +81,8 @@ $$(RT_OUTPUT_DIR_$(1))/%.o: $(S)src/rt/%.c $$(MKFILE_DEPS)
 	@mkdir -p $$(@D)
 	@$$(call E, compile: $$@)
 	$$(Q)$$(call CFG_COMPILE_C_$(1), $$@, \
-		-I $$(S)src/rt/hoedown/src \
-		-I $$(S)src/rt \
+		$$(call CFG_CC_INCLUDE_$(1),$$(S)src/rt/hoedown/src) \
+		$$(call CFG_CC_INCLUDE_$(1),$$(S)src/rt) \
                  $$(RUNTIME_CFLAGS_$(1))) $$<
 
 $$(RT_OUTPUT_DIR_$(1))/%.o: $(S)src/rt/%.S $$(MKFILE_DEPS) \
@@ -109,7 +109,7 @@ OBJS_$(2)_$(1) := $$(OBJS_$(2)_$(1):.S=.o)
 NATIVE_$(2)_$(1) := $$(call CFG_STATIC_LIB_NAME_$(1),$(2))
 $$(RT_OUTPUT_DIR_$(1))/$$(NATIVE_$(2)_$(1)): $$(OBJS_$(2)_$(1))
 	@$$(call E, link: $$@)
-	$$(Q)$$(AR_$(1)) rcs $$@ $$^
+	$$(Q)$$(call CFG_CREATE_ARCHIVE_$(1),$$@) $$^
 
 endef