SubDir HAIKU_TOP src tools gensyscalls ;


# What want to do here is analyze the <syscalls.h> header and generate headers
# and sources containing information about the syscalls (like what parameters
# of what sizes and types they take, etc.) which will be used in other places
# (e.g. the kernel code or the strace tool).
#
# The strategy to achieve this is:
# * Preprocess the <syscalls.h> header, so that it is easier to parse.
# * Feed the preprocessed header to the gensyscallinfos tool. It will generate
#	a source file, gensyscalls_infos.cpp, which implements a function that
#	builds a table with all the syscall info information we need. The source
#	file needs specific infos about sizes of types, which aren't easily
#	available. That's why gensyscallinfos also generates a source file which
#	via the CreateAsmStructOffsetsHeader rule is turned into a header with
#	macro definitions for those type size. The header is included by
#	gensyscalls_infos.cpp.
# * gensyscalls.cpp and the generated gensyscalls_infos.cpp are compiled into
#	the gensyscalls tool.
# * gensyscalls has options to generate the various output files:
#	- <syscalls!$(architecture>syscalls.S.inc: Used to define the syscall
#     functions in libroot.
#	- <syscalls!$(architecture>syscall_dispatcher.h: Big "switch" statement for
#     the syscall dispatcher in the kernel.
#	- <syscalls!$(architecture>syscall_numbers.h: Macro definitions assigning
#     indices to the syscalls.
#	- <syscalls!$(architecture>syscall_table.h: An array with syscall
#     information in the kernel. Used for dispatching syscalls e.g. for x86.
#	- <syscalls!$(architecture>strace_syscalls.h: Syscall information needed by
#     strace.


rule PreprocessSyscalls preprocessedHeader : header : architecture
{
	# PreprocessSyscalls <preprocessedHeader> : <header> : <architecture> ;

	Depends $(preprocessedHeader) : $(header) $(PLATFORM) ;

	local headers = [ on $(preprocessedHeader)
		return $(SEARCH_SOURCE) $(SUBDIRHDRS) $(HDRS) ] ;
	local sysHeaders =
		$(TARGET_PRIVATE_SYSTEM_HEADERS_$(architecture))
		[ ArchHeaders $(TARGET_ARCH_$(architecture)) ]
		[ on $(preprocessedHeader) return $(SUBDIRSYSHDRS) $(SYSHDRS) ]
		[ FStandardHeaders $(architecture) ]
		$(TARGET_HDRS_$(architecture)) ;

	HDRS on $(preprocessedHeader) = $(headers) ;
	SYSHDRS on $(preprocessedHeader) = $(sysHeaders) ;

	HDRRULE on $(header) = HdrRule ;
	HDRSCAN on $(header) = $(HDRPATTERN) ;
	HDRSEARCH on $(header) = $(headers) $(sysHeaders) $(STDHDRS) ;
	HDRGRIST on $(header) = $(HDRGRIST) ;

	DEFINES on $(preprocessedHeader) += $(TARGET_DEFINES_$(architecture))
		$(TARGET_DEFINES) GEN_SYSCALL_INFOS_PROCESSING ;

	CC on $(preprocessedHeader) = $(TARGET_C++_$(architecture)) ;
	CCFLAGS on $(preprocessedHeader) += $(TARGET_CCFLAGS_$(architecture))
		$(SUBDIRCCFLAGS) $(OPTIM) ;
	CCHDRS on $(preprocessedHeader) =
		[ FIncludes $(headers)
			: $(TARGET_LOCAL_INCLUDES_OPTION_$(architecture)) ]
		$(TARGET_INCLUDES_SEPARATOR_$(architecture))
		[ FSysIncludes $(sysHeaders)
			: $(TARGET_SYSTEM_INCLUDES_OPTION_$(architecture)) ] ;
	CCDEFS on $(preprocessedHeader)
		= [ on $(preprocessedHeader) FDefines $(DEFINES) ] ;
}


actions PreprocessSyscalls
{
	$(CC) -xc++ -E "$(2)" $(CCFLAGS) $(CCDEFS) $(CCHDRS) -o "$(1)" ;
}


rule GenSyscallInfos targets : sources : gensyscallinfos
{
	Depends $(targets) : $(gensyscallinfos) $(sources) ;
	GenSyscallInfos1 $(targets) : $(gensyscallinfos) $(sources) ;
}


actions GenSyscallInfos1
{
	$(2[1]) $(2[2]) $(1)
}


rule GenSyscallsFile file : gensyscalls : option
{
	GENSYSCALLS_FILE_OPTION on $(file) = $(option) ;
	Depends $(file) : $(gensyscalls) ;
	GenSyscallsFile1 $(file) : $(gensyscalls) ;
}


actions GenSyscallsFile1
{
	$(2[1]) $(GENSYSCALLS_FILE_OPTION) $(1)
}


local syscallsHeader = [ FGristFiles syscalls.h ] ;
SEARCH on $(syscallsHeader) = [ FDirName $(HAIKU_TOP) headers private system ] ;

local architectureObject ;
for architectureObject in [ MultiArchSubDirSetup ] {
	on $(architectureObject) {
		local architecture = $(TARGET_PACKAGING_ARCH) ;

		# Generate the preprocessed syscalls.h header. It will be parsed by
		# gensyscallinfos (it contains marker #pragmas).
		local syscallsHeaderPPParsable
			= [ FGristFiles syscalls.h.pp.parsable ] ;
		MakeLocateArch $(syscallsHeaderPPParsable) ;
		PreprocessSyscalls $(syscallsHeaderPPParsable) : $(syscallsHeader)
			: $(architecture) ;

		# build gensyscallinfos

		local gensyscallinfos = gensyscallinfos_$(architecture) ;
		SourceHdrs gensyscallinfos.cpp
			: [ FDirName $(SUBDIR) arch $(TARGET_ARCH_$(architecture)) ] ;
		MakeLocate [ FGristFiles gensyscallinfos$(SUFOBJ) ]
			: [ FDirName $(HOST_DEBUG_$(DEBUG)_LOCATE_TARGET) $(architecture) ] ;
		BuildPlatformMain $(gensyscallinfos)
			: gensyscallinfos.cpp
			: $(HOST_LIBSTDC++) $(HOST_LIBSUPC++)
			;

		# generate the syscall infos source file and the source for the header
		# it includes

		local syscallInfos = [ FGristFiles gensyscalls_infos.cpp ] ;
		local syscallTypesSizesSource
			= [ FGristFiles syscall_types_sizes.h.cpp ] ;
		local syscallTypesSizes = [ FGristFiles syscall_types_sizes.h ] ;
		MakeLocateArch $(syscallInfos) $(syscallTypesSizesSource)
			$(syscallTypesSizes) ;

		GenSyscallInfos $(syscallInfos) $(syscallTypesSizesSource)
			: $(syscallsHeaderPPParsable) : $(gensyscallinfos) ;

		TARGET_HDRS_$(architecture) on $(syscallTypesSizes)
			= [ on $(syscallTypesSizes) return $(TARGET_HDRS_$(architecture)) ]
				[ FDirName $(SUBDIR) arch $(TARGET_ARCH_$(architecture)) ]
				$(TARGET_PRIVATE_SYSTEM_HEADERS_$(architecture)) ;
		CreateAsmStructOffsetsHeader $(syscallTypesSizes)
			: $(syscallTypesSizesSource) : $(TARGET_PACKAGING_ARCH) ;

		#Includes $(syscallInfos) : $(syscallTypesSizes) ;
			# explicitly tell jam about the inclusion of the generated header
		Depends $(syscallInfos:S=$(SUFOBJ)) : $(syscallTypesSizes) ;
			# NOTE: Jam messes up the "Includes" declaration, so we have to declare
			# the dependency more directly.

		# build gensyscalls

		local gensyscalls = gensyscalls_$(architecture) ;
		MakeLocate [ FGristFiles gensyscalls$(SUFOBJ) gensyscalls_infos$(SUFOBJ) ]
			: [ FDirName $(HOST_DEBUG_$(DEBUG)_LOCATE_TARGET) $(architecture) ] ;
		BuildPlatformMain $(gensyscalls)
			: gensyscalls.cpp $(syscallInfos) ;
		LinkAgainst $(gensyscalls) : $(HOST_LIBSTDC++) $(HOST_LIBSUPC++) ;

		# generate the output files

		# place them where they are needed
		local dir = $(TARGET_COMMON_DEBUG_OBJECT_DIR_$(architecture)) ;
		MakeLocate <syscalls!$(architecture)>syscalls.S.inc
			: [ FDirName $(dir) system libroot os ] ;
		MakeLocate <syscalls!$(architecture)>syscall_dispatcher.h
			: [ FDirName $(dir) system kernel ] ;
		MakeLocate <syscalls!$(architecture)>syscall_numbers.h
			: [ FDirName $(dir) system kernel ] ;
		MakeLocate <syscalls!$(architecture)>syscall_table.h
			: [ FDirName $(dir) system kernel ] ;
		MakeLocate <syscalls!$(architecture)>strace_syscalls.h
			: [ FDirName $(dir) bin debug strace ] ;

		GenSyscallsFile <syscalls!$(architecture)>syscalls.S.inc
			: $(gensyscalls) : -c ;
		GenSyscallsFile <syscalls!$(architecture)>syscall_dispatcher.h
			: $(gensyscalls) : -d ;
		GenSyscallsFile <syscalls!$(architecture)>syscall_numbers.h
			: $(gensyscalls) : -n ;
		GenSyscallsFile <syscalls!$(architecture)>syscall_table.h
			: $(gensyscalls) : -t ;
		GenSyscallsFile <syscalls!$(architecture)>strace_syscalls.h
			: $(gensyscalls) : -s ;
	}
}