# 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, rustc 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.

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

include config.mk
MKFILES := Makefile config.mk $(wildcard $(CFG_SRC_DIR)/mk/*.mk)
MKFILES += $(CFG_SRC_DIR)/src/rt/libuv/Makefile
MKFILES += $(wildcard $(CFG_SRC_DIR)/src/rt/libuv/*.mk)

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: llvm host triple $(CFG_LLVM_TRIPLE))
CFG_INFO := $(info cfg: llvm target triples $(CFG_LLVM_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 NO_TYPESTATE
  CFG_RUSTC_FLAGS += --no-typestate
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_STDLIB :=$(call CFG_LIB_NAME,std)
CFG_LIBRUSTC :=$(call CFG_LIB_NAME,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

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.%

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

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

######################################################################
# 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
######################################################################

LLVM_AS := $(CFG_LLVM_BINDIR)/llvm-as$(X)

LLC := $(CFG_LLVM_BINDIR)/llc$(X)

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

define SREQ

# Destinations of artifacts for the host compiler
HOST_ROOT$(1) = stage$(1)
HOST_BIN$(1) = $$(HOST_ROOT$(1))/bin
HOST_LIB$(1) = $$(HOST_ROOT$(1))/lib

# Destinations of artifacts for target architectures
TARGET_ROOT$(1)$(2) = $$(HOST_LIB$(1))/rustc/$(2)
TARGET_BIN$(1)$(2) = $$(TARGET_ROOT$(1)$(2))/bin
TARGET_LIB$(1)$(2) = $$(TARGET_ROOT$(1)$(2))/lib

# The target locations of artifacts for the host architecture (used for
# promoting target binaries to host binaries)
TARGET_HOST_ROOT$(1) = $$(TARGET_ROOT$(1)$$(CFG_HOST_TRIPLE))
TARGET_HOST_BIN$(1) = $$(TARGET_BIN$(1)$$(CFG_HOST_TRIPLE))
TARGET_HOST_LIB$(1) = $$(TARGET_LIB$(1)$$(CFG_HOST_TRIPLE))

# The name of the standard library used by rustc
ifdef CFG_DISABLE_SHAREDSTD
  HOST_STDLIB_DEFAULT$(1) = $$(HOST_LIB$(1))/libstd.rlib
  TARGET_STDLIB_DEFAULT$(1)$(2) = $$(TARGET_LIB$(1)$(2))/libstd.rlib
else
  HOST_STDLIB_DEFAULT$(1) = $$(HOST_LIB$(1))/$(CFG_STDLIB)
  TARGET_STDLIB_DEFAULT$(1)$(2) = $$(TARGET_LIB$(1)$(2))/$(CFG_STDLIB)
endif

# Preqrequisites for using the stageN compiler
HOST_SREQ$(1) = \
	$$(HOST_BIN$(1))/rustc$$(X) \
	$$(HOST_LIB$(1))/$$(CFG_RUNTIME) \
	$$(HOST_LIB$(1))/$$(CFG_RUSTLLVM) \
	$$(HOST_STDLIB_DEFAULT$(1)) \
	$$(MKFILES)

# Prerequisites for using the stageN compiler to build target artifacts
TARGET_SREQ$(1)$(2) = \
	$$(HOST_SREQ$(1)) \
	$$(TARGET_LIB$(1)$(2))/$$(CFG_RUNTIME) \
	$$(TARGET_LIB$(1)$(2))/intrinsics.bc \
	$$(TARGET_LIB$(1)$(2))/main.o

# Prerequisites for complete stageN targets
SREQ$(1)$(2) = \
	$$(TARGET_SREQ$(1)$(2)) \
	$$(TARGET_LIB$(1)$(2))/$$(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) := $$(Q)$$(call CFG_RUN_TARG,$(1), \
                $$(CFG_VALGRIND_COMPILE) $$(HOST_BIN$(1))/rustc$$(X) \
                $$(CFG_RUSTC_FLAGS) --target=$(2))

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

endef

$(foreach target,$(CFG_TARGET_TRIPLES), \
 $(eval $(call SREQ,0,$(target))) \
 $(eval $(call SREQ,1,$(target))) \
 $(eval $(call SREQ,2,$(target))) \
 $(eval $(call SREQ,3,$(target))))

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

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

FUZZ := $(HOST_BIN3)/fuzzer$(X)

all: $(SREQ3$(CFG_HOST_TRIPLE)) $(GENERATED) $(DOCS) $(FUZZ)

endif


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

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/intrinsics.mk
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


######################################################################
# 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