# Check for important gcc warning

gcc_warn_check() {
	local f

	# Evaluate misc gcc warnings
	if [[ -n ${PORTAGE_LOG_FILE} && -r ${PORTAGE_LOG_FILE} ]] ; then
		# In debug mode, this variable definition and corresponding grep calls
		# will produce false positives if they're shown in the trace.
		local reset_debug=0
		if [[ ${-/x/} != $- ]] ; then
			set +x
			reset_debug=1
		fi
		local m msgs=(
			# only will and does, no might :)
			'warning: .*will.*\[-Wstrict-aliasing\]'
			'warning: .*does.*\[-Wstrict-aliasing\]'
			# implicit declaration of function ‘...’
			'warning: .*\[-Wimplicit-function-declaration\]'
			# with -Wall, goes in pair with -Wimplicit-function-declaration
			# but without -Wall, we need to assert for it alone
			'warning: .*incompatible implicit declaration of built-in function'
			# 'is used uninitialized in this function' and some more
			'warning: .*\[-Wuninitialized\]'
			# comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning
			'warning: .*mathematical meaning*\[-Wparentheses\]'
			# null argument where non-null required
			'warning: .*\[-Wnonnull\]'
			# array subscript is above/below/outside array bounds
			'warning: .*\[-Warray-bounds\]'
			# attempt to free a non-heap object
			'warning: .*\[-Wfree-nonheap-object\]'
			# those three do not have matching -W flags, it seems
			'warning: .*will always overflow destination buffer'
			'warning: .*assuming pointer wraparound does not occur'
			'warning: .*escape sequence out of range'
			# left-hand operand of comma expression has no effect
			'warning: .*left.*comma.*\[-Wunused-value\]'
			# converting to non-pointer type ... from NULL and likes
			'warning: .*\[-Wconversion-null\]'
			# NULL used in arithmetic
			'warning: .*NULL.*\[-Wpointer-arith\]'
			# pointer to a function used in arithmetic and likes
			'warning: .*function.*\[-Wpointer-arith\]'
			# the address of ... will never be NULL and likes
			# (uses of function refs & string constants in conditionals)
			'warning: .*\[-Waddress\]'
			# outdated?
			'warning: .*too few arguments for format'
			# format ... expects a matching ... argument
			# (iow, too few arguments for format in new wording :))
			'warning: .*matching.*\[-Wformat=\]'
			# function returns address of local variable
			'warning: .*\[-Wreturn-local-addr\]'
			# argument to sizeof ... is the same expression as the source
			'warning: .*\[-Wsizeof-pointer-memaccess\]'
			# iteration invokes undefined behavior
			'warning: .*\[-Waggressive-loop-optimizations\]'

			# this may be valid code :/
			#': warning: multi-character character constant'
			# need to check these two ...
			#': warning: assuming signed overflow does not occur when'
			#': warning: comparison with string literal results in unspecified behav'
			# yacc/lex likes to trigger this one
			#': warning: extra tokens at end of .* directive'
			# only gcc itself triggers this ?
			#': warning: .*noreturn.* function does return'
			# these throw false positives when 0 is used instead of NULL
			#': warning: missing sentinel in function call'
			#': warning: not enough variable arguments to fit a sentinel'
		)

		# join all messages into one grep-expression
		local joined_msgs
		printf -v joined_msgs '%s|' "${msgs[@]}"
		joined_msgs=${joined_msgs%|}

		local abort="no"
		local grep_cmd=grep
		[[ $PORTAGE_LOG_FILE = *.gz ]] && grep_cmd=zgrep

		# force C locale to work around slow unicode locales #160234
		f=$(LC_CTYPE=C LC_COLLATE=C "${grep_cmd}" -E "${joined_msgs}" "${PORTAGE_LOG_FILE}" | uniq)
		if [[ -n ${f} ]] ; then
			abort="yes"
			# for now, don't make this fatal (see bug #337031)
			#if [[ ${f} == *'will always overflow destination buffer'* ]]; then
			#	always_overflow=yes
			#fi
			if [[ $always_overflow = yes ]] ; then
				eerror
				eerror "QA Notice: Package triggers severe warnings which indicate that it"
				eerror "           may exhibit random runtime failures."
				eerror
				eerror "${f}"
				eerror
				eerror " Please file a bug about this at http://bugs.gentoo.org/"
				eerror " with the maintaining herd of the package."
				eerror
			else
				__vecho -ne '\n'
				eqawarn "QA Notice: Package triggers severe warnings which indicate that it"
				eqawarn "           may exhibit random runtime failures."
				eqawarn "${f}"
				__vecho -ne '\n'
			fi
		fi

		local cat_cmd=cat
		[[ $PORTAGE_LOG_FILE = *.gz ]] && cat_cmd=zcat
		[[ $reset_debug = 1 ]] && set -x
		# Use safe cwd, avoiding unsafe import for bug #469338.
		f=$(cd "${PORTAGE_PYM_PATH}" ; $cat_cmd "${PORTAGE_LOG_FILE}" | \
			"${PORTAGE_PYTHON:-/usr/bin/python}" "$PORTAGE_BIN_PATH"/check-implicit-pointer-usage.py || die "check-implicit-pointer-usage.py failed")
		if [[ -n ${f} ]] ; then

			# In the future this will be a forced "die". In preparation,
			# increase the log level from "qa" to "eerror" so that people
			# are aware this is a problem that must be fixed asap.

			# just warn on 32bit hosts but bail on 64bit hosts
			case ${CHOST} in
				alpha*|hppa64*|ia64*|powerpc64*|mips64*|sparc64*|sparcv9*|x86_64*) gentoo_bug=yes ;;
			esac

			abort=yes

			if [[ $gentoo_bug = yes ]] ; then
				eerror
				eerror "QA Notice: Package triggers severe warnings which indicate that it"
				eerror "           will almost certainly crash on 64bit architectures."
				eerror
				eerror "${f}"
				eerror
				eerror " Please file a bug about this at http://bugs.gentoo.org/"
				eerror " with the maintaining herd of the package."
				eerror
			else
				__vecho -ne '\n'
				eqawarn "QA Notice: Package triggers severe warnings which indicate that it"
				eqawarn "           will almost certainly crash on 64bit architectures."
				eqawarn "${f}"
				__vecho -ne '\n'
			fi

		fi
		if [[ ${abort} == "yes" ]] ; then
			if [[ $gentoo_bug = yes || $always_overflow = yes ]] ; then
				die "install aborted due to severe warnings shown above"
			else
				echo "Please do not file a Gentoo bug and instead" \
				"report the above QA issues directly to the upstream" \
				"developers of this software." | fmt -w 70 | \
				while read -r line ; do eqawarn "${line}" ; done
				eqawarn "Homepage: ${HOMEPAGE}"
				has stricter ${FEATURES} && \
					die "install aborted due to severe warnings shown above"
			fi
		fi
	fi
}

gcc_warn_check
: # guarantee successful exit

# vim:ft=sh