#  Phusion Passenger - https://www.phusionpassenger.com/
#  Copyright (c) 2010-2013 Phusion
#
#  "Phusion Passenger" is a trademark of Hongli Lai & Ninh Bui.
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in
#  all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#  THE SOFTWARE.

require 'phusion_passenger/platform_info'
require 'phusion_passenger/platform_info/compiler'
require 'phusion_passenger/platform_info/operating_system'

module PhusionPassenger

module PlatformInfo
	# Linker flags that should be used for linking every C/C++ program,
	# for portability reasons. These flags should be specified as last
	# when invoking the linker.
	def self.portability_ldflags
		if os_name =~ /solaris/
			result = '-lxnet -lsocket -lnsl -lpthread'
		else
			result = '-lpthread'
		end
		result << ' -lrt' if has_rt_library?
		result << ' -lmath' if has_math_library?
		return result
	end
	memoize :portability_ldflags

	# Extra compiler flags that should always be passed to the C compiler,
	# last in the command string.
	def self.default_extra_cflags
		return default_extra_c_or_cxxflags(:cc)
	end
	memoize :default_extra_cflags, true

	# Extra compiler flags that should always be passed to the C++ compiler,
	# last in the command string.
	def self.default_extra_cxxflags
		return default_extra_c_or_cxxflags(:cxx)
	end
	memoize :default_extra_cxxflags, true

private
	def self.check_unordered_map(flags, class_name, header_name, macro_name)
		ok = try_compile("Checking for unordered_map", :cxx, %Q{
			#include <#{header_name}>
			int
			main() {
				#{class_name}<int, int> m;
				return 0;
			}
		})
		flags << "-D#{macro_name}" if ok
		return ok
	end
	private_class_method :check_unordered_map
	
	def self.check_hash_map(flags)
		hash_namespace = nil
		ok = false
		['__gnu_cxx', '', 'std', 'stdext'].each do |namespace|
			['hash_map', 'ext/hash_map'].each do |hash_map_header|
				ok = try_compile("Checking for #{hash_map_header}", :cxx, %Q{
					#include <#{hash_map_header}>
					int
					main() {
						#{namespace}::hash_map<int, int> m;
						return 0;
					}
				})
				if ok
					hash_namespace = namespace
					flags << "-DHASH_NAMESPACE=\"#{namespace}\""
					flags << "-DHASH_MAP_HEADER=\"<#{hash_map_header}>\""
					flags << "-DHASH_MAP_CLASS=\"hash_map\""
					break
				end
			end
			break if ok
		end
		['ext/hash_fun.h', 'functional', 'tr1/functional',
		 'ext/stl_hash_fun.h', 'hash_fun.h', 'stl_hash_fun.h',
		 'stl/_hash_fun.h'].each do |hash_function_header|
			ok = try_compile("Checking for #{hash_function_header}", :cxx, %Q{
				#include <#{hash_function_header}>
				int
				main() {
					#{hash_namespace}::hash<int>()(5);
					return 0;
				}
			})
			if ok
				flags << "-DHASH_FUN_H=\"<#{hash_function_header}>\""
				break
			end
		end
	end
	private_class_method :check_hash_map

	def self.default_extra_c_or_cxxflags(cc_or_cxx)
		flags = ["-D_REENTRANT", "-I/usr/local/include"]

		if !send("#{cc_or_cxx}_is_sun_studio?")
			flags << "-Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-long-long"
			if send("#{cc_or_cxx}_supports_wno_missing_field_initializers_flag?")
				flags << "-Wno-missing-field-initializers"
			end
			if requires_no_tls_direct_seg_refs? && send("#{cc_or_cxx}_supports_no_tls_direct_seg_refs_option?")
				flags << "-mno-tls-direct-seg-refs"
			end
			# Work around Clang warnings in ev++.h.
			if send("#{cc_or_cxx}_is_clang?")
				flags << "-Wno-ambiguous-member-template"
			end
		end

		if !send("#{cc_or_cxx}_is_sun_studio?")
			flags << "-fcommon"
			if send("#{cc_or_cxx}_supports_feliminate_unused_debug?")
				flags << "-feliminate-unused-debug-symbols -feliminate-unused-debug-types"
			end
			if send("#{cc_or_cxx}_supports_visibility_flag?")
				flags << "-fvisibility=hidden -DVISIBILITY_ATTRIBUTE_SUPPORTED"
				if send("#{cc_or_cxx}_visibility_flag_generates_warnings?") &&
				   send("#{cc_or_cxx}_supports_wno_attributes_flag?")
					flags << "-Wno-attributes"
				end
			end
		end

		flags << debugging_cflags
		flags << '-DHAS_ALLOCA_H' if has_alloca_h?
		flags << '-DHAVE_ACCEPT4' if has_accept4?
		flags << '-DHAS_SFENCE' if supports_sfence_instruction?
		flags << '-DHAS_LFENCE' if supports_lfence_instruction?
		flags << "-DPASSENGER_DEBUG -DBOOST_DISABLE_ASSERTS"

		if cc_or_cxx == :cxx
			# There are too many implementations of of the hash map!
			# Figure out the right one.
			check_unordered_map(flags, "std::unordered_map", "unordered_map", "HAS_UNORDERED_MAP") ||
				check_unordered_map(flags, "std::tr1::unordered_map", "unordered_map", "HAS_TR1_UNORDERED_MAP") ||
				check_hash_map(flags)
		end

		if os_name =~ /solaris/
			if send("#{cc_or_cxx}_is_sun_studio?")
				flags << '-mt'
			else
				flags << '-pthreads'
			end
			if os_name =~ /solaris2\.11/
				# skip the _XOPEN_SOURCE and _XPG4_2 definitions in later versions of Solaris / OpenIndiana
				flags << '-D__EXTENSIONS__ -D__SOLARIS__ -D_FILE_OFFSET_BITS=64'
			else
				flags << '-D_XOPEN_SOURCE=500 -D_XPG4_2 -D__EXTENSIONS__ -D__SOLARIS__ -D_FILE_OFFSET_BITS=64'
				flags << '-D__SOLARIS9__ -DBOOST__STDC_CONSTANT_MACROS_DEFINED' if os_name =~ /solaris2\.9/
			end
			flags << '-DBOOST_HAS_STDINT_H' unless os_name =~ /solaris2\.9/
			if send("#{cc_or_cxx}_is_sun_studio?")
				flags << '-xtarget=ultra' if RUBY_PLATFORM =~ /sparc/
			else
				flags << '-mcpu=ultrasparc' if RUBY_PLATFORM =~ /sparc/
			end
		elsif os_name =~ /openbsd/
			flags << '-DBOOST_HAS_STDINT_H -D_GLIBCPP__PTHREADS'
		elsif os_name =~ /aix/
			flags << '-pthread'
			flags << '-DOXT_DISABLE_BACKTRACES'
		elsif RUBY_PLATFORM =~ /(sparc-linux|arm-linux|^arm.*-linux|sh4-linux)/
			# http://code.google.com/p/phusion-passenger/issues/detail?id=200
			# http://groups.google.com/group/phusion-passenger/t/6b904a962ee28e5c
			# http://groups.google.com/group/phusion-passenger/browse_thread/thread/aad4bd9d8d200561
			flags << '-DBOOST_SP_USE_PTHREADS'
		end

		return flags.compact.map{ |str| str.strip }.join(" ").strip
	end
	private_class_method :default_extra_c_or_cxxflags
end

end # module PhusionPassenger