auto merge of #6714 : thomaslee/rust/rustrt-stage, r=brson

As discussed with @brson on IRC:

This lets us use #ifdefs to determine which stage of the build we happen
to be in, which is useful in the event we need to make changes to rustrt
that are incompatible with the code generated by a stage0 rustc.

Example of the _RUST_STAGEN flag in action here: https://gist.github.com/thomaslee/5641890

I'm not sure what tests for this change should look like, so please advise if I need to do some work around that.

3 files changed, 64 insertions, 54 deletions

diff --git a/configure b/configure
index 0b8189416bb..4fb0ed01bdf 100755
--- a/configure
+++ b/configure
@@ -665,12 +665,16 @@ make_dir rt
 for t in $CFG_TARGET_TRIPLES
 do
   make_dir rt/$t
-  for i in                                          \
-    isaac linenoise sync test \
-    arch/i386 arch/x86_64 arch/arm arch/mips  \
-    libuv libuv/src/ares libuv/src/eio libuv/src/ev
+  for s in 0 1 2 3
   do
-    make_dir rt/$t/$i
+    make_dir rt/$t/stage$s
+    for i in                                          \
+      isaac linenoise sync test \
+      arch/i386 arch/x86_64 arch/arm arch/mips  \
+      libuv libuv/src/ares libuv/src/eio libuv/src/ev
+    do
+      make_dir rt/$t/stage$s/$i
+    done
   done
 done
 
diff --git a/mk/rt.mk b/mk/rt.mk
index 2087945afb5..d8d74d0d0e3 100644
--- a/mk/rt.mk
+++ b/mk/rt.mk
@@ -41,14 +41,19 @@ ifneq ($(strip $(findstring snap,$(MAKECMDGOALS))),)
 	SNAP_DEFINES=-DRUST_SNAPSHOT
 endif
 
-
 define DEF_RUNTIME_TARGETS
 
 ######################################################################
 # Runtime (C++) library variables
 ######################################################################
 
-RUNTIME_CXXS_$(1) := \
+# $(1) is the target triple
+# $(2) is the stage number
+
+RUNTIME_CFLAGS_$(1)_$(2) = -D_RUST_STAGE$(2)
+RUNTIME_CXXFLAGS_$(1)_$(2) = -D_RUST_STAGE$(2)
+
+RUNTIME_CXXS_$(1)_$(2) := \
               rt/sync/timer.cpp \
               rt/sync/lock_and_signal.cpp \
               rt/sync/rust_thread.cpp \
@@ -83,70 +88,70 @@ RUNTIME_CXXS_$(1) := \
               rt/rust_android_dummy.cpp \
               rt/rust_test_helpers.cpp
 
-RUNTIME_CS_$(1) := rt/linenoise/linenoise.c rt/linenoise/utf8.c
+RUNTIME_CS_$(1)_$(2) := rt/linenoise/linenoise.c rt/linenoise/utf8.c
 
-RUNTIME_S_$(1) := rt/arch/$$(HOST_$(1))/_context.S \
-                  rt/arch/$$(HOST_$(1))/ccall.S \
-                  rt/arch/$$(HOST_$(1))/record_sp.S
+RUNTIME_S_$(1)_$(2) := rt/arch/$$(HOST_$(1))/_context.S \
+			rt/arch/$$(HOST_$(1))/ccall.S \
+			rt/arch/$$(HOST_$(1))/record_sp.S
 
 ifeq ($$(CFG_WINDOWSY_$(1)), 1)
-  LIBUV_OSTYPE_$(1) := win
-  LIBUV_LIB_$(1) := rt/$(1)/libuv/libuv.a
+  LIBUV_OSTYPE_$(1)_$(2) := win
+  LIBUV_LIB_$(1)_$(2) := rt/$(1)/stage$(2)/libuv/libuv.a
 else ifeq ($(OSTYPE_$(1)), apple-darwin)
-  LIBUV_OSTYPE_$(1) := mac
-  LIBUV_LIB_$(1) := rt/$(1)/libuv/libuv.a
+  LIBUV_OSTYPE_$(1)_$(2) := mac
+  LIBUV_LIB_$(1)_$(2) := rt/$(1)/stage$(2)/libuv/libuv.a
 else ifeq ($(OSTYPE_$(1)), unknown-freebsd)
-  LIBUV_OSTYPE_$(1) := unix/freebsd
-  LIBUV_LIB_$(1) := rt/$(1)/libuv/libuv.a
+  LIBUV_OSTYPE_$(1)_$(2) := unix/freebsd
+  LIBUV_LIB_$(1)_$(2) := rt/$(1)/stage$(2)/libuv/libuv.a
 else ifeq ($(OSTYPE_$(1)), linux-androideabi)
-  LIBUV_OSTYPE_$(1) := unix/android
-  LIBUV_LIB_$(1) := rt/$(1)/libuv/libuv.a
+  LIBUV_OSTYPE_$(1)_$(2) := unix/android
+  LIBUV_LIB_$(1)_$(2) := rt/$(1)/stage$(2)/libuv/libuv.a
 else
-  LIBUV_OSTYPE_$(1) := unix/linux
-  LIBUV_LIB_$(1) := rt/$(1)/libuv/libuv.a
+  LIBUV_OSTYPE_$(1)_$(2) := unix/linux
+  LIBUV_LIB_$(1)_$(2) := rt/$(1)/stage$(2)/libuv/libuv.a
 endif
 
-RUNTIME_DEF_$(1) := rt/rustrt$(CFG_DEF_SUFFIX_$(1))
-RUNTIME_INCS_$(1) := -I $$(S)src/rt -I $$(S)src/rt/isaac -I $$(S)src/rt/uthash \
+RUNTIME_DEF_$(1)_$(2) := rt/rustrt$(CFG_DEF_SUFFIX_$(1))
+RUNTIME_INCS_$(1)_$(2) := -I $$(S)src/rt -I $$(S)src/rt/isaac -I $$(S)src/rt/uthash \
                      -I $$(S)src/rt/arch/$$(HOST_$(1)) \
                      -I $$(S)src/rt/linenoise \
                      -I $$(S)src/libuv/include
-RUNTIME_OBJS_$(1) := $$(RUNTIME_CXXS_$(1):rt/%.cpp=rt/$(1)/%.o) \
-                     $$(RUNTIME_CS_$(1):rt/%.c=rt/$(1)/%.o) \
-                     $$(RUNTIME_S_$(1):rt/%.S=rt/$(1)/%.o)
-ALL_OBJ_FILES += $$(RUNTIME_OBJS_$(1))
+RUNTIME_OBJS_$(1)_$(2) := $$(RUNTIME_CXXS_$(1)_$(2):rt/%.cpp=rt/$(1)/stage$(2)/%.o) \
+                     $$(RUNTIME_CS_$(1)_$(2):rt/%.c=rt/$(1)/stage$(2)/%.o) \
+                     $$(RUNTIME_S_$(1)_$(2):rt/%.S=rt/$(1)/stage$(2)/%.o)
+ALL_OBJ_FILES += $$(RUNTIME_OBJS_$(1)_$(2))
 
-MORESTACK_OBJ_$(1) := rt/$(1)/arch/$$(HOST_$(1))/morestack.o
-ALL_OBJ_FILES += $$(MORESTACK_OBJS_$(1))
+MORESTACK_OBJ_$(1)_$(2) := rt/$(1)/stage$(2)/arch/$$(HOST_$(1))/morestack.o
+ALL_OBJ_FILES += $$(MORESTACK_OBJS_$(1)_$(2))
 
-RUNTIME_LIBS_$(1) := $$(LIBUV_LIB_$(1))
+RUNTIME_LIBS_$(1)_$(2) := $$(LIBUV_LIB_$(1)_$(2))
 
-rt/$(1)/%.o: rt/%.cpp $$(MKFILE_DEPS)
+rt/$(1)/stage$(2)/%.o: rt/%.cpp $$(MKFILE_DEPS)
 	@$$(call E, compile: $$@)
-	$$(Q)$$(call CFG_COMPILE_CXX_$(1), $$@, $$(RUNTIME_INCS_$(1)) \
-                 $$(SNAP_DEFINES)) $$<
+	$$(Q)$$(call CFG_COMPILE_CXX_$(1), $$@, $$(RUNTIME_INCS_$(1)_$(2)) \
+                 $$(SNAP_DEFINES) $$(RUNTIME_CXXFLAGS_$(1)_$(2))) $$<
 
-rt/$(1)/%.o: rt/%.c $$(MKFILE_DEPS)
+rt/$(1)/stage$(2)/%.o: rt/%.c $$(MKFILE_DEPS)
 	@$$(call E, compile: $$@)
-	$$(Q)$$(call CFG_COMPILE_C_$(1), $$@, $$(RUNTIME_INCS_$(1)) \
-                 $$(SNAP_DEFINES)) $$<
+	$$(Q)$$(call CFG_COMPILE_C_$(1), $$@, $$(RUNTIME_INCS_$(1)_$(2)) \
+                 $$(SNAP_DEFINES) $$(RUNTIME_CFLAGS_$(1)_$(2))) $$<
 
-rt/$(1)/%.o: rt/%.S  $$(MKFILE_DEPS) \
+rt/$(1)/stage$(2)/%.o: rt/%.S  $$(MKFILE_DEPS) \
                      $$(LLVM_CONFIG_$$(CFG_BUILD_TRIPLE))
 	@$$(call E, compile: $$@)
 	$$(Q)$$(call CFG_ASSEMBLE_$(1),$$@,$$<)
 
-rt/$(1)/arch/$$(HOST_$(1))/libmorestack.a: $$(MORESTACK_OBJ_$(1))
+rt/$(1)/stage$(2)/arch/$$(HOST_$(1))/libmorestack.a: $$(MORESTACK_OBJ_$(1)_$(2))
 	@$$(call E, link: $$@)
 	$$(Q)$(AR_$(1)) rcs $$@ $$<
 
-rt/$(1)/$(CFG_RUNTIME_$(1)): $$(RUNTIME_OBJS_$(1)) $$(MKFILE_DEPS) \
-                        $$(RUNTIME_DEF_$(1)) \
-                        $$(RUNTIME_LIBS_$(1))
+rt/$(1)/stage$(2)/$(CFG_RUNTIME_$(1)): $$(RUNTIME_OBJS_$(1)_$(2)) $$(MKFILE_DEPS) \
+                        $$(RUNTIME_DEF_$(1)_$(2)) \
+                        $$(RUNTIME_LIBS_$(1)_$(2))
 	@$$(call E, link: $$@)
-	$$(Q)$$(call CFG_LINK_CXX_$(1),$$@, $$(RUNTIME_OBJS_$(1)) \
-	  $$(CFG_GCCISH_POST_LIB_FLAGS_$(1)) $$(RUNTIME_LIBS_$(1)) \
-	  $$(CFG_LIBUV_LINK_FLAGS_$(1)),$$(RUNTIME_DEF_$(1)),$$(CFG_RUNTIME_$(1)))
+	$$(Q)$$(call CFG_LINK_CXX_$(1),$$@, $$(RUNTIME_OBJS_$(1)_$(2)) \
+	  $$(CFG_GCCISH_POST_LIB_FLAGS_$(1)) $$(RUNTIME_LIBS_$(1)_$(2)) \
+	  $$(CFG_LIBUV_LINK_FLAGS_$(1)),$$(RUNTIME_DEF_$(1)_$(2)),$$(CFG_RUNTIME_$(1)))
 
 # FIXME: For some reason libuv's makefiles can't figure out the
 # correct definition of CC on the mingw I'm using, so we are
@@ -165,13 +170,13 @@ endif
 
 # XXX: Shouldn't need platform-specific conditions here
 ifdef CFG_WINDOWSY_$(1)
-$$(LIBUV_LIB_$(1)): $$(LIBUV_DEPS)
+$$(LIBUV_LIB_$(1)_$(2)): $$(LIBUV_DEPS)
 	$$(Q)$$(MAKE) -C $$(S)src/libuv/ \
-		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/libuv" \
+		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/stage$(2)/libuv" \
 		OS=mingw \
 		V=$$(VERBOSE)
 else ifeq ($(OSTYPE_$(1)), linux-androideabi)
-$$(LIBUV_LIB_$(1)): $$(LIBUV_DEPS)
+$$(LIBUV_LIB_$(1)_$(2)): $$(LIBUV_DEPS)
 	$$(Q)$$(MAKE) -C $$(S)src/libuv/ \
 		CFLAGS="$$(CFG_GCCISH_CFLAGS) $$(LIBUV_FLAGS_$$(HOST_$(1))) $$(SNAP_DEFINES)" \
 		LDFLAGS="$$(CFG_GCCISH_LINK_FLAGS) $$(LIBUV_FLAGS_$$(HOST_$(1)))" \
@@ -179,18 +184,18 @@ $$(LIBUV_LIB_$(1)): $$(LIBUV_DEPS)
 		CXX="$$(CXX_$(1))" \
 		AR="$$(AR_$(1))" \
 		BUILDTYPE=Release \
-		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/libuv" \
+		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/stage$(2)/libuv" \
 		host=android OS=linux \
 		V=$$(VERBOSE)
 else
-$$(LIBUV_LIB_$(1)): $$(LIBUV_DEPS)
+$$(LIBUV_LIB_$(1)_$(2)): $$(LIBUV_DEPS)
 	$$(Q)$$(MAKE) -C $$(S)src/libuv/ \
 		CFLAGS="$$(CFG_GCCISH_CFLAGS) $$(LIBUV_FLAGS_$$(HOST_$(1))) $$(SNAP_DEFINES)" \
 		LDFLAGS="$$(CFG_GCCISH_LINK_FLAGS) $$(LIBUV_FLAGS_$$(HOST_$(1)))" \
 		CC="$$(CC_$(1))" \
 		CXX="$$(CXX_$(1))" \
 		AR="$$(AR_$(1))" \
-		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/libuv" \
+		builddir_name="$$(CFG_BUILD_DIR)/rt/$(1)/stage$(2)/libuv" \
 		V=$$(VERBOSE)
 endif
 
@@ -229,5 +234,6 @@ endif
 endef
 
 # Instantiate template for all stages
-$(foreach target,$(CFG_TARGET_TRIPLES), \
- $(eval $(call DEF_RUNTIME_TARGETS,$(target))))
+$(foreach stage,$(STAGES), \
+	$(foreach target,$(CFG_TARGET_TRIPLES), \
+	 $(eval $(call DEF_RUNTIME_TARGETS,$(target),$(stage)))))
diff --git a/mk/target.mk b/mk/target.mk
index 9b4153d7ed5..2aeed841e35 100644
--- a/mk/target.mk
+++ b/mk/target.mk
@@ -18,13 +18,13 @@
 define TARGET_STAGE_N
 
 $$(TLIB$(1)_T_$(2)_H_$(3))/libmorestack.a: \
-		rt/$(2)/arch/$$(HOST_$(2))/libmorestack.a \
+		rt/$(2)/stage$(1)/arch/$$(HOST_$(2))/libmorestack.a \
 		| $$(TLIB$(1)_T_$(2)_H_$(3))/
 	@$$(call E, cp: $$@)
 	$$(Q)cp $$< $$@
 
 $$(TLIB$(1)_T_$(2)_H_$(3))/$(CFG_RUNTIME_$(2)): \
-		rt/$(2)/$(CFG_RUNTIME_$(2)) \
+		rt/$(2)/stage$(1)/$(CFG_RUNTIME_$(2)) \
 		| $$(TLIB$(1)_T_$(2)_H_$(3))/
 	@$$(call E, cp: $$@)
 	$$(Q)cp $$< $$@