# An explanation of how the build is structured:
#
# There are multiple build stages (0-3) needed to verify that the
# compiler is properly self-hosting. Each stage is divided between
# 'host' artifacts and 'target' artifacts, where the stageN host
# compiler builds artifacts for 1 or more stageN target architectures.
# Once the stageN target compiler has been built for the host
# architecture it is promoted (copied) to a stageN+1 host artifact.
#
# The stage3 host compiler is a compiler that successfully builds
# itself and should (in theory) be bitwise identical to the stage2
# host compiler. The process is bootstrapped using a stage0 host
# compiler downloaded from a previous snapshot.
#
# At no time should stageN artifacts be interacting with artifacts
# from other stages. For consistency, we use the 'promotion' logic
# for all artifacts, even those that don't make sense on non-host
# architectures.
#
# The directory layout for a stage is intended to match the layout
# of the installed compiler, and looks like the following:
#
# stageN - this is the system root, corresponding to, e.g. /usr
#   bin - binaries compiled for the host
#   lib - libraries used by the host compiler
#     rustc - rustc's own place to organize libraries
#       $(target) - target-specific artifacts
#         bin - binaries for target architectures
#         lib - libraries for target architectures
#
# A note about host libraries:
#
# The only libraries that get promoted to stageN/lib are those needed
# by rustc. In general, rust programs, even those compiled for the
# host architecture will use libraries from the target
# directories. This gives rust some freedom to experiment with how
# libraries are managed and versioned without polluting the common
# areas of the filesystem.
#
# General rust binaries may stil live in the host bin directory; they
# will just link against the libraries in the target lib directory.
#
# Admittedly this is a little convoluted.

STAGES = 0 1 2 3

######################################################################
# Residual auto-configuration
######################################################################

include config.mk

ifdef IGNORE_MKFILES
  MKFILE_DEPS :=
else
  OUR_MKFILES := Makefile config.mk $(wildcard $(CFG_SRC_DIR)/mk/*.mk)
  3RDPARTY_MKFILES := $(CFG_SRC_DIR)/src/libuv/Makefile \
                      $(wildcard $(CFG_SRC_DIR)/src/libuv/*.mk)
  GEN_MKFILES := $(wildcard $(CFG_SRC_DIR)/mk/libuv/*/*/*) \
                 $(wildcard $(CFG_SRC_DIR)/mk/libuv/mac/src/libuv/*) \
                 $(wildcard $(CFG_SRC_DIR)/mk/libuv/mac/src/libuv/*) \
                 $(wildcard $(CFG_SRC_DIR)/mk/libuv/mac/src/libuv/*)
  MKFILE_DEPS := $(OUR_MKFILES) $(3RDPARTY_MKFILES) $(GEN_MKFILES)
endif

NON_HOST_TRIPLES = $(filter-out $(CFG_HOST_TRIPLE),$(CFG_TARGET_TRIPLES))

ifneq ($(MAKE_RESTARTS),)
CFG_INFO := $(info cfg: make restarts: $(MAKE_RESTARTS))
endif

CFG_INFO := $(info cfg: shell host triple $(CFG_HOST_TRIPLE))
CFG_INFO := $(info cfg: non host triples $(NON_HOST_TRIPLES))

ifdef CFG_DISABLE_OPTIMIZE
  $(info cfg: disabling rustc optimization (CFG_DISABLE_OPTIMIZE))
  CFG_RUSTC_FLAGS :=
else
  CFG_RUSTC_FLAGS := -O
endif

ifdef SAVE_TEMPS
  CFG_RUSTC_FLAGS += --save-temps
endif
ifdef TIME_PASSES
  CFG_RUSTC_FLAGS += --time-passes
endif
ifdef TIME_LLVM_PASSES
  CFG_RUSTC_FLAGS += --time-llvm-passes
endif
ifdef DEBUG
  CFG_RUSTC_FLAGS += -g
endif

# platform-specific auto-configuration
include $(CFG_SRC_DIR)/mk/platform.mk

# Run the stage1/2 compilers under valgrind
ifdef VALGRIND_COMPILE
  CFG_VALGRIND_COMPILE :=$(CFG_VALGRIND)
else
  CFG_VALGRIND_COMPILE :=
endif

CFG_RUNTIME :=$(call CFG_LIB_NAME,rustrt)
CFG_RUSTLLVM :=$(call CFG_LIB_NAME,rustllvm)
CFG_CORELIB :=$(call CFG_LIB_NAME,core)
CFG_STDLIB :=$(call CFG_LIB_NAME,std)
CFG_LIBRUSTC :=$(call CFG_LIB_NAME,rustc)

STDLIB_GLOB :=$(call CFG_LIB_GLOB,std)
CORELIB_GLOB :=$(call CFG_LIB_GLOB,core)
LIBRUSTC_GLOB :=$(call CFG_LIB_GLOB,rustc)

# version-string calculation
CFG_GIT_DIR := $(CFG_SRC_DIR).git
CFG_VERSION = prerelease
ifneq ($(wildcard $(CFG_GIT)),)
ifneq ($(wildcard $(CFG_GIT_DIR)),)
    CFG_VERSION += $(shell git --git-dir=$(CFG_GIT_DIR) log -1 \
                     --pretty=format:'(%h %ci)')
endif
endif

ifdef CFG_DISABLE_VALGRIND
  $(info cfg: disabling valgrind (CFG_DISABLE_VALGRIND))
  CFG_VALGRIND :=
endif
ifdef CFG_BAD_VALGRIND
  $(info cfg: disabling valgrind due to its unreliability on this platform)
  CFG_VALGRIND :=
endif

DOCS :=
ifeq ($(CFG_MAKEINFO),)
  $(info cfg: no makeinfo found, omitting doc/rust.html)
else
  DOCS += doc/rust.html
endif

ifeq ($(CFG_TEXI2PDF),)
  $(info cfg: no texi2pdf found, omitting doc/rust.pdf)
else
  ifeq ($(CFG_TEX),)
    $(info cfg: no tex found, omitting doc/rust.pdf)
  else
    DOCS += doc/rust.pdf
  endif
endif

ifeq ($(CFG_NATURALDOCS),)
  $(info cfg: no naturaldocs found, omitting library doc build)
else
  DOCS += doc/core/index.html doc/std/index.html
endif

ifdef CFG_DISABLE_DOCS
  $(info cfg: disabling doc build (CFG_DISABLE_DOCS))
  DOCS :=
endif

######################################################################
# Target-and-rule "utility variables"
######################################################################

ifdef VERBOSE
  Q :=
  E =
else
  Q := @
  E = echo $(1)
endif

S := $(CFG_SRC_DIR)
X := $(CFG_EXE_SUFFIX)

# Look in doc and src dirs.
VPATH := $(S)doc $(S)src

# "Source" files we generate in builddir along the way.
GENERATED :=

# Delete the built-in rules.
.SUFFIXES:
%:: %,v
%:: RCS/%,v
%:: RCS/%
%:: s.%
%:: SCCS/s.%

######################################################################
# Core library variables
######################################################################

CORELIB_CRATE := $(S)src/libcore/core.rc
CORELIB_INPUTS := $(wildcard $(addprefix $(S)src/libcore/,        \
                                           core.rc *.rs */*.rs))

######################################################################
# Standard library variables
######################################################################

STDLIB_CRATE := $(S)src/libstd/std.rc
STDLIB_INPUTS := $(wildcard $(addprefix $(S)src/libstd/,          \
                                          std.rc *.rs */*.rs))

######################################################################
# rustc crate variables
######################################################################

COMPILER_CRATE := $(S)src/comp/rustc.rc
COMPILER_INPUTS := $(wildcard $(addprefix $(S)src/comp/, \
                                rustc.rc *.rs */*.rs */*/*.rs))

######################################################################
# LLVM macros
######################################################################

# FIXME: x86-ism
LLVM_COMPONENTS=x86 ipo bitreader bitwriter linker asmparser

define DEF_LLVM_VARS
# The configure script defines these variables with the target triples
# separated by Z. This defines new ones with the expected format.
CFG_LLVM_BUILD_DIR_$(1):=$$(CFG_LLVM_BUILD_DIR_$(subst -,_,$(1)))
CFG_LLVM_INST_DIR_$(1):=$$(CFG_LLVM_INST_DIR_$(subst -,_,$(1)))

# Any rules that depend on LLVM should depend on LLVM_CONFIG
LLVM_CONFIG_$(1):=$$(CFG_LLVM_INST_DIR_$(1))/bin/llvm-config
LLVM_MC_$(1):=$$(CFG_LLVM_INST_DIR_$(1))/bin/llvm-mc
LLVM_VERSION_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --version)
LLVM_BINDIR_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --bindir)
LLVM_INCDIR_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --includedir)
LLVM_LIBDIR_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --libdir)
LLVM_LIBS_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --libs $$(LLVM_COMPONENTS))
LLVM_LDFLAGS_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --ldflags)
LLVM_CXXFLAGS_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --cxxflags)
LLVM_HOST_TRIPLE_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --host-target)

LLVM_AS_$(1)=$$(LLVM_BINDIR_$(1))/llvm-as$$(X)
LLC_$(1)=$$(LLVM_BINDIR_$(1))/llc$$(X)

endef

$(foreach target,$(CFG_TARGET_TRIPLES), \
 $(eval $(call DEF_LLVM_VARS,$(target))))

######################################################################
# Exports for sub-utilities
######################################################################

# Note that any variable that re-configure should pick up needs to be
# exported

export CFG_SRC_DIR
export CFG_BUILD_DIR
export CFG_VERSION
export CFG_HOST_TRIPLE
export CFG_LLVM_ROOT
export CFG_ENABLE_MINGW_CROSS
export CFG_PREFIX

######################################################################
# Subprograms
######################################################################

######################################################################
# Per-stage targets and runner
######################################################################

define SREQ
# $(1) is the stage number
# $(2) is the target triple
# $(3) is the host triple

# Destinations of artifacts for the host compiler
HROOT$(1)_H_$(3) = $(3)/stage$(1)
HBIN$(1)_H_$(3) = $$(HROOT$(1)_H_$(3))/bin
HLIB$(1)_H_$(3) = $$(HROOT$(1)_H_$(3))/lib

# Destinations of artifacts for target architectures
TROOT$(1)_T_$(2)_H_$(3) = $$(HLIB$(1)_H_$(3))/rustc/$(2)
TBIN$(1)_T_$(2)_H_$(3) = $$(TROOT$(1)_T_$(2)_H_$(3))/bin
TLIB$(1)_T_$(2)_H_$(3) = $$(TROOT$(1)_T_$(2)_H_$(3))/lib

# The name of the core and standard libraries used by rustc
ifdef CFG_DISABLE_SHAREDSTD
  HCORELIB_DEFAULT$(1)_H_$(3) = \
    $$(HLIB$(1)_H_$(3))/libcore.rlib
  TCORELIB_DEFAULT$(1)_T_$(2)_H_$(3) = \
    $$(TLIB$(1)_T_$(2)_H_$(3))/libcore.rlib
  HSTDLIB_DEFAULT$(1)_H_$(3) = \
    $$(HLIB$(1)_H_$(3))/libstd.rlib
  TSTDLIB_DEFAULT$(1)_T_$(2)_H_$(3) = \
    $$(TLIB$(1)_T_$(2)_H_$(3))/libstd.rlib
else
  HCORELIB_DEFAULT$(1)_H_$(3) = \
    $$(HLIB$(1)_H_$(3))/$(CFG_CORELIB)
  TCORELIB_DEFAULT$(1)_T_$(2)_H_$(3) = \
    $$(TLIB$(1)_T_$(2)_H_$(3))/$(CFG_CORELIB)
  HSTDLIB_DEFAULT$(1)_H_$(3) = \
    $$(HLIB$(1)_H_$(3))/$(CFG_STDLIB)
  TSTDLIB_DEFAULT$(1)_T_$(2)_H_$(3) = \
    $$(TLIB$(1)_T_$(2)_H_$(3))/$(CFG_STDLIB)
endif

# Preqrequisites for using the stageN compiler
HSREQ$(1)_H_$(3) = \
	$$(HBIN$(1)_H_$(3))/rustc$$(X) \
	$$(HLIB$(1)_H_$(3))/$$(CFG_RUNTIME) \
	$$(HLIB$(1)_H_$(3))/$$(CFG_RUSTLLVM) \
	$$(HCORELIB_DEFAULT$(1)_H_$(3)) \
	$$(HSTDLIB_DEFAULT$(1)_H_$(3)) \
	$$(MKFILE_DEPS)

# Prerequisites for using the stageN compiler to build target artifacts
TSREQ$(1)_T_$(2)_H_$(3) = \
	$$(HSREQ$(1)_H_$(3)) \
	$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_RUNTIME) \
	$$(TLIB$(1)_T_$(2)_H_$(3))/intrinsics.bc \
	$$(TLIB$(1)_T_$(2)_H_$(3))/libmorestack.a

# Prerequisites for complete stageN targets
SREQ$(1)_T_$(2)_H_$(3) = \
	$$(TSREQ$(1)_T_$(2)_H_$(3)) \
	$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_CORELIB) \
	$$(TLIB$(1)_T_$(2)_H_$(3))/$$(CFG_STDLIB)

ifeq ($(1),0)
# Don't run the the stage0 compiler under valgrind - that ship has sailed
CFG_VALGRIND_COMPILE$(1) =
else
CFG_VALGRIND_COMPILE$(1) = $$(CFG_VALGRIND_COMPILE)
endif

STAGE$(1)_T_$(2)_H_$(3) := 						\
	$$(Q)$$(call CFG_RUN_TARG,$(1),				\
		$$(CFG_VALGRIND_COMPILE$(1)) 			\
		$$(HBIN$(1)_H_$(3))/rustc$$(X)			\
		$$(CFG_RUSTC_FLAGS) --target=$(2))

PERF_STAGE$(1)_T_$(2)_H_$(3) := 				\
	$$(Q)$$(call CFG_RUN_TARG,$(1),				\
		$$(CFG_PERF_TOOL) 						\
		$$(HBIN$(1)_H_$(3))/rustc$$(X)			\
		$$(CFG_RUSTC_FLAGS) --target=$(2))

endef

$(foreach build,$(CFG_TARGET_TRIPLES), \
 $(eval $(foreach target,$(CFG_TARGET_TRIPLES), \
  $(eval $(foreach stage,$(STAGES), \
   $(eval $(call SREQ,$(stage),$(target),$(build))))))))

######################################################################
# rustc-H-targets
#
# Builds a functional Rustc for the given host.
######################################################################

define DEF_RUSTC_STAGE_TARGET
# $(1) == architecture
# $(2) == stage

rustc-stage$(2)-H-$(1):							\
	$$(foreach target,$$(CFG_TARGET_TRIPLES),	\
		$$(SREQ$(2)_T_$$(target)_H_$(1)))

endef

$(foreach host,$(CFG_TARGET_TRIPLES),							\
 $(eval $(foreach stage,1 2 3,									\
  $(eval $(call DEF_RUSTC_STAGE_TARGET,$(host),$(stage))))))

define DEF_RUSTC_TARGET
# $(1) == architecture

rustc-H-$(1): rustc-stage3-H-$(1)
endef

$(foreach host,$(CFG_TARGET_TRIPLES),			\
 $(eval $(call DEF_RUSTC_TARGET,$(host))))

rustc-H-all: $(foreach host,$(CFG_TARGET_TRIPLES),rustc-H-$(host))

######################################################################
# Entrypoint rule
######################################################################

.DEFAULT_GOAL := all

ifneq ($(CFG_IN_TRANSITION),)

CFG_INFO := $(info cfg:)
CFG_INFO := $(info cfg: *** compiler is in snapshot transition ***)
CFG_INFO := $(info cfg: *** stage2 and later will not be built ***)
CFG_INFO := $(info cfg:)

all: $(SREQ1$(CFG_HOST_TRIPLE)) $(GENERATED) $(DOCS)

else

TSREQS :=											\
	$(foreach target,$(CFG_TARGET_TRIPLES),			\
		$(SREQ3_T_$(target)_H_$(CFG_HOST_TRIPLE)))
FUZZ := $(HBIN3_H_$(CFG_HOST_TRIPLE))/fuzzer$(X)
CARGO := $(HBIN3_H_$(CFG_HOST_TRIPLE))/cargo$(X)

all: rustc-H-$(CFG_HOST_TRIPLE) $(GENERATED) $(DOCS) $(FUZZ) $(CARGO)

endif


######################################################################
# Re-configuration
######################################################################

ifndef CFG_DISABLE_MANAGE_SUBMODULES
# This is a pretty expensive operation but I don't see any way to avoid it
NEED_GIT_RECONFIG=$(shell cd "$(CFG_SRC_DIR)" && "$(CFG_GIT)" submodule status | grep -c '^\(+\|-\)')
else
NEED_GIT_RECONFIG=0
endif

ifeq ($(NEED_GIT_RECONFIG),0)
else
# If the submodules have changed then always execute config.mk
.PHONY: config.mk
endif

config.mk: $(S)configure $(S)Makefile.in $(S)src/snapshots.txt
	@$(call E, cfg: reconfiguring)
	$(Q)$(S)configure $(CFG_CONFIGURE_ARGS)


######################################################################
# Primary-target makefiles
######################################################################

include $(CFG_SRC_DIR)/mk/target.mk
include $(CFG_SRC_DIR)/mk/host.mk
include $(CFG_SRC_DIR)/mk/stage0.mk
include $(CFG_SRC_DIR)/mk/rt.mk
include $(CFG_SRC_DIR)/mk/rustllvm.mk
include $(CFG_SRC_DIR)/mk/autodep.mk
include $(CFG_SRC_DIR)/mk/tools.mk
include $(CFG_SRC_DIR)/mk/docs.mk
include $(CFG_SRC_DIR)/mk/llvm.mk

######################################################################
# Secondary makefiles, conditionalized for speed
######################################################################

ifneq ($(strip $(findstring dist,$(MAKECMDGOALS))   \
               $(findstring check,$(MAKECMDGOALS))  \
               $(findstring test,$(MAKECMDGOALS))   \
               $(findstring tidy,$(MAKECMDGOALS))   \
               $(findstring clean,$(MAKECMDGOALS))),)
  CFG_INFO := $(info cfg: including dist rules)
  include $(CFG_SRC_DIR)/mk/dist.mk
endif

ifneq ($(strip $(findstring snap,$(MAKECMDGOALS))   \
               $(findstring clean,$(MAKECMDGOALS))),)
  CFG_INFO := $(info cfg: including snap rules)
  include $(CFG_SRC_DIR)/mk/snap.mk
endif

ifneq ($(findstring reformat,$(MAKECMDGOALS)),)
  CFG_INFO := $(info cfg: including reformat rules)
  include $(CFG_SRC_DIR)/mk/pp.mk
endif

ifneq ($(strip $(findstring check,$(MAKECMDGOALS)) \
               $(findstring test,$(MAKECMDGOALS))  \
               $(findstring perf,$(MAKECMDGOALS))  \
               $(findstring tidy,$(MAKECMDGOALS))),)
  CFG_INFO := $(info cfg: including test rules)
  include $(CFG_SRC_DIR)/mk/tests.mk
endif

ifneq ($(findstring perf,$(MAKECMDGOALS)),)
  CFG_INFO := $(info cfg: including perf rules)
  include $(CFG_SRC_DIR)/mk/perf.mk
endif

ifneq ($(findstring clean,$(MAKECMDGOALS)),)
  CFG_INFO := $(info cfg: including clean rules)
  include $(CFG_SRC_DIR)/mk/clean.mk
endif

ifneq ($(findstring install,$(MAKECMDGOALS)),)
  CFG_INFO := $(info cfg: including install rules)
  include $(CFG_SRC_DIR)/mk/install.mk
endif

ifneq ($(strip $(findstring TAGS.emacs,$(MAKECMDGOALS)) \
               $(findstring TAGS.vi,$(MAKECMDGOALS))),)
  CFG_INFO := $(info cfg: including ctags rules)
  include $(CFG_SRC_DIR)/mk/ctags.mk
endif