[thirdparty/git.git] / t / chainlint.sed

#------------------------------------------------------------------------------
# Detect broken &&-chains in tests.
#
# At present, only &&-chains in subshells are examined by this linter;
# top-level &&-chains are instead checked directly by the test framework. Like
# the top-level &&-chain linter, the subshell linter (intentionally) does not
# check &&-chains within {...} blocks.
#
# Checking for &&-chain breakage is done line-by-line by pure textual
# inspection.
#
# Incomplete lines (those ending with "\") are stitched together with following
# lines to simplify processing, particularly of "one-liner" statements.
# Top-level here-docs are swallowed to avoid false positives within the
# here-doc body, although the statement to which the here-doc is attached is
# retained.
#
# Heuristics are used to detect end-of-subshell when the closing ")" is cuddled
# with the final subshell statement on the same line:
#
#    (cd foo &&
#        bar)
#
# in order to avoid misinterpreting the ")" in constructs such as "x=$(...)"
# and "case $x in *)" as ending the subshell.
#
# Lines missing a final "&&" are flagged with "?!AMP?!", and lines which chain
# commands with ";" internally rather than "&&" are flagged "?!SEMI?!". A line
# may be flagged for both violations.
#
# Detection of a missing &&-link in a multi-line subshell is complicated by the
# fact that the last statement before the closing ")" must not end with "&&".
# Since processing is line-by-line, it is not known whether a missing "&&" is
# legitimate or not until the _next_ line is seen. To accommodate this, within
# multi-line subshells, each line is stored in sed's "hold" area until after
# the next line is seen and processed. If the next line is a stand-alone ")",
# then a missing "&&" on the previous line is legitimate; otherwise a missing
# "&&" is a break in the &&-chain.
#
#    (
#         cd foo &&
#         bar
#    )
#
# In practical terms, when "bar" is encountered, it is flagged with "?!AMP?!",
# but when the stand-alone ")" line is seen which closes the subshell, the
# "?!AMP?!" violation is removed from the "bar" line (retrieved from the "hold"
# area) since the final statement of a subshell must not end with "&&". The
# final line of a subshell may still break the &&-chain by using ";" internally
# to chain commands together rather than "&&", so "?!SEMI?!" is never removed
# from a line (even though "?!AMP?!" might be).
#
# Care is taken to recognize the last _statement_ of a multi-line subshell, not
# necessarily the last textual _line_ within the subshell, since &&-chaining
# applies to statements, not to lines. Consequently, blank lines, comment
# lines, and here-docs are swallowed (but not the command to which the here-doc
# is attached), leaving the last statement in the "hold" area, not the last
# line, thus simplifying &&-link checking.
#
# The final statement before "done" in for- and while-loops, and before "elif",
# "else", and "fi" in if-then-else likewise must not end with "&&", thus
# receives similar treatment.
#
# Swallowing here-docs with arbitrary tags requires a bit of finesse. When a
# line such as "cat <<EOF >out" is seen, the here-doc tag is moved to the front
# of the line enclosed in angle brackets as a sentinel, giving "<EOF>cat >out".
# As each subsequent line is read, it is appended to the target line and a
# (whitespace-loose) back-reference match /^<(.*)>\n\1$/ is attempted to see if
# the content inside "<...>" matches the entirety of the newly-read line. For
# instance, if the next line read is "some data", when concatenated with the
# target line, it becomes "<EOF>cat >out\nsome data", and a match is attempted
# to see if "EOF" matches "some data". Since it doesn't, the next line is
# attempted. When a line consisting of only "EOF" (and possible whitespace) is
# encountered, it is appended to the target line giving "<EOF>cat >out\nEOF",
# in which case the "EOF" inside "<...>" does match the text following the
# newline, thus the closing here-doc tag has been found. The closing tag line
# and the "<...>" prefix on the target line are then discarded, leaving just
# the target line "cat >out".
#
# To facilitate regression testing (and manual debugging), a ">" annotation is
# applied to the line containing ")" which closes a subshell, ">>" to a line
# closing a nested subshell, and ">>>" to a line closing both at once. This
# makes it easy to detect whether the heuristics correctly identify
# end-of-subshell.
#------------------------------------------------------------------------------

# incomplete line -- slurp up next line
:squash
/\\$/ {
	N
	s/\\\n//
	bsquash
}

# here-doc -- swallow it to avoid false hits within its body (but keep the
# command to which it was attached)
/<<[ 	]*[-\\'"]*[A-Za-z0-9_]/ {
	s/^\(.*\)<<[ 	]*[-\\'"]*\([A-Za-z0-9_][A-Za-z0-9_]*\)['"]*/<\2>\1<</
	s/[ 	]*<<//
	:hered
	N
	/^<\([^>]*\)>.*\n[ 	]*\1[ 	]*$/!{
		s/\n.*$//
		bhered
	}
	s/^<[^>]*>//
	s/\n.*$//
}

# one-liner "(...) &&"
/^[ 	]*!*[ 	]*(..*)[ 	]*&&[ 	]*$/boneline

# same as above but without trailing "&&"
/^[ 	]*!*[ 	]*(..*)[ 	]*$/boneline

# one-liner "(...) >x" (or "2>x" or "<x" or "|x" or "&"
/^[ 	]*!*[ 	]*(..*)[ 	]*[0-9]*[<>|&]/boneline

# multi-line "(...\n...)"
/^[ 	]*(/bsubshell

# innocuous line -- print it and advance to next line
b

# found one-liner "(...)" -- mark suspect if it uses ";" internally rather than
# "&&" (but not ";" in a string)
:oneline
/;/{
	/"[^"]*;[^"]*"/!s/^/?!SEMI?!/
}
b

:subshell
# bare "(" line? -- stash for later printing
/^[ 	]*([	]*$/ {
	h
	bnextline
}
# "(..." line -- split off and stash "(", then process "..." as its own line
x
s/.*/(/
x
s/(//
bslurp

:nextline
N
s/.*\n//

:slurp
# incomplete line "...\"
/\\$/bicmplte
# multi-line quoted string "...\n..."?
/"/bdqstring
# multi-line quoted string '...\n...'? (but not contraction in string "it's")
/'/{
	/"[^'"]*'[^'"]*"/!bsqstring
}
:folded
# here-doc -- swallow it
/<<[ 	]*[-\\'"]*[A-Za-z0-9_]/bheredoc
# comment or empty line -- discard since final non-comment, non-empty line
# before closing ")", "done", "elsif", "else", or "fi" will need to be
# re-visited to drop "suspect" marking since final line of those constructs
# legitimately lacks "&&", so "suspect" mark must be removed
/^[ 	]*#/bnextline
/^[ 	]*$/bnextline
# in-line comment -- strip it (but not "#" in a string, Bash ${#...} array
# length, or Perforce "//depot/path#42" revision in filespec)
/[ 	]#/{
	/"[^"]*#[^"]*"/!s/[ 	]#.*$//
}
# one-liner "case ... esac"
/^[ 	]*case[ 	]*..*esac/bchkchn
# multi-line "case ... esac"
/^[ 	]*case[ 	]..*[ 	]in/bcase
# multi-line "for ... done" or "while ... done"
/^[ 	]*for[ 	]..*[ 	]in/bcontinue
/^[ 	]*while[ 	]/bcontinue
/^[ 	]*do[ 	]/bcontinue
/^[ 	]*do[ 	]*$/bcontinue
/;[ 	]*do/bcontinue
/^[ 	]*done[ 	]*&&[ 	]*$/bdone
/^[ 	]*done[ 	]*$/bdone
/^[ 	]*done[ 	]*[<>|]/bdone
/^[ 	]*done[ 	]*)/bdone
/||[ 	]*exit[ 	]/bcontinue
/||[ 	]*exit[ 	]*$/bcontinue
# multi-line "if...elsif...else...fi"
/^[ 	]*if[ 	]/bcontinue
/^[ 	]*then[ 	]/bcontinue
/^[ 	]*then[ 	]*$/bcontinue
/;[ 	]*then/bcontinue
/^[ 	]*elif[ 	]/belse
/^[ 	]*elif[ 	]*$/belse
/^[ 	]*else[ 	]/belse
/^[ 	]*else[ 	]*$/belse
/^[ 	]*fi[ 	]*&&[ 	]*$/bdone
/^[ 	]*fi[ 	]*$/bdone
/^[ 	]*fi[ 	]*[<>|]/bdone
/^[ 	]*fi[ 	]*)/bdone
# nested one-liner "(...) &&"
/^[ 	]*(.*)[ 	]*&&[ 	]*$/bchkchn
# nested one-liner "(...)"
/^[ 	]*(.*)[ 	]*$/bchkchn
# nested one-liner "(...) >x" (or "2>x" or "<x" or "|x")
/^[ 	]*(.*)[ 	]*[0-9]*[<>|]/bchkchn
# nested multi-line "(...\n...)"
/^[ 	]*(/bnest
# multi-line "{...\n...}"
/^[ 	]*{/bblock
# closing ")" on own line -- exit subshell
/^[ 	]*)/bclssolo
# "$((...))" -- arithmetic expansion; not closing ")"
/\$(([^)][^)]*))[^)]*$/bchkchn
# "$(...)" -- command substitution; not closing ")"
/\$([^)][^)]*)[^)]*$/bchkchn
# multi-line "$(...\n...)" -- command substitution; treat as nested subshell
/\$([^)]*$/bnest
# "=(...)" -- Bash array assignment; not closing ")"
/=(/bchkchn
# closing "...) &&"
/)[ 	]*&&[ 	]*$/bclose
# closing "...)"
/)[ 	]*$/bclose
# closing "...) >x" (or "2>x" or "<x" or "|x")
/)[ 	]*[<>|]/bclose
:chkchn
# mark suspect if line uses ";" internally rather than "&&" (but not ";" in a
# string and not ";;" in one-liner "case...esac")
/;/{
	/;;/!{
		/"[^"]*;[^"]*"/!s/^/?!SEMI?!/
	}
}
# line ends with pipe "...|" -- valid; not missing "&&"
/|[ 	]*$/bcontinue
# missing end-of-line "&&" -- mark suspect
/&&[ 	]*$/!s/^/?!AMP?!/
:continue
# retrieve and print previous line
x
n
bslurp

# found incomplete line "...\" -- slurp up next line
:icmplte
N
s/\\\n//
bslurp

# check for multi-line double-quoted string "...\n..." -- fold to one line
:dqstring
# remove all quote pairs
s/"\([^"]*\)"/@!\1@!/g
# done if no dangling quote
/"/!bdqdone
# otherwise, slurp next line and try again
N
s/\n//
bdqstring
:dqdone
s/@!/"/g
bfolded

# check for multi-line single-quoted string '...\n...' -- fold to one line
:sqstring
# remove all quote pairs
s/'\([^']*\)'/@!\1@!/g
# done if no dangling quote
/'/!bsqdone
# otherwise, slurp next line and try again
N
s/\n//
bsqstring
:sqdone
s/@!/'/g
bfolded

# found here-doc -- swallow it to avoid false hits within its body (but keep
# the command to which it was attached)
:heredoc
s/^\(.*\)<<[ 	]*[-\\'"]*\([A-Za-z0-9_][A-Za-z0-9_]*\)['"]*/<\2>\1<</
s/[ 	]*<<//
:heredsub
N
/^<\([^>]*\)>.*\n[ 	]*\1[ 	]*$/!{
	s/\n.*$//
	bheredsub
}
s/^<[^>]*>//
s/\n.*$//
bfolded

# found "case ... in" -- pass through untouched
:case
x
n
/^[ 	]*esac/bslurp
bcase

# found "else" or "elif" -- drop "suspect" from final line before "else" since
# that line legitimately lacks "&&"
:else
x
s/?!AMP?!//
x
bcontinue

# found "done" closing for-loop or while-loop, or "fi" closing if-then -- drop
# "suspect" from final contained line since that line legitimately lacks "&&"
:done
x
s/?!AMP?!//
x
# is 'done' or 'fi' cuddled with ")" to close subshell?
/done.*)/bclose
/fi.*)/bclose
bchkchn

# found nested multi-line "(...\n...)" -- pass through untouched
:nest
x
:nstslurp
n
# closing ")" on own line -- stop nested slurp
/^[ 	]*)/bnstclose
# comment -- not closing ")" if in comment
/^[ 	]*#/bnstcnt
# "$((...))" -- arithmetic expansion; not closing ")"
/\$(([^)][^)]*))[^)]*$/bnstcnt
# "$(...)" -- command substitution; not closing ")"
/\$([^)][^)]*)[^)]*$/bnstcnt
# closing "...)" -- stop nested slurp
/)/bnstclose
:nstcnt
x
bnstslurp
:nstclose
s/^/>>/
# is it "))" which closes nested and parent subshells?
/)[ 	]*)/bslurp
bchkchn

# found multi-line "{...\n...}" block -- pass through untouched
:block
x
n
# closing "}" -- stop block slurp
/}/bchkchn
bblock

# found closing ")" on own line -- drop "suspect" from final line of subshell
# since that line legitimately lacks "&&" and exit subshell loop
:clssolo
x
s/?!AMP?!//
p
x
s/^/>/
b

# found closing "...)" -- exit subshell loop
:close
x
p
x
s/^/>/
b
Commit	Line	Data
878f9883 ES	1	#------------------------------------------------------------------------------
	2	# Detect broken &&-chains in tests.
	3	#
	4	# At present, only &&-chains in subshells are examined by this linter;
	5	# top-level &&-chains are instead checked directly by the test framework. Like
	6	# the top-level &&-chain linter, the subshell linter (intentionally) does not
	7	# check &&-chains within {...} blocks.
	8	#
	9	# Checking for &&-chain breakage is done line-by-line by pure textual
	10	# inspection.
	11	#
	12	# Incomplete lines (those ending with "\") are stitched together with following
	13	# lines to simplify processing, particularly of "one-liner" statements.
	14	# Top-level here-docs are swallowed to avoid false positives within the
	15	# here-doc body, although the statement to which the here-doc is attached is
	16	# retained.
	17	#
	18	# Heuristics are used to detect end-of-subshell when the closing ")" is cuddled
	19	# with the final subshell statement on the same line:
	20	#
	21	# (cd foo &&
	22	# bar)
	23	#
	24	# in order to avoid misinterpreting the ")" in constructs such as "x=$(...)"
	25	# and "case $x in *)" as ending the subshell.
	26	#
	27	# Lines missing a final "&&" are flagged with "?!AMP?!", and lines which chain
	28	# commands with ";" internally rather than "&&" are flagged "?!SEMI?!". A line
	29	# may be flagged for both violations.
	30	#
	31	# Detection of a missing &&-link in a multi-line subshell is complicated by the
	32	# fact that the last statement before the closing ")" must not end with "&&".
	33	# Since processing is line-by-line, it is not known whether a missing "&&" is
	34	# legitimate or not until the _next_ line is seen. To accommodate this, within
	35	# multi-line subshells, each line is stored in sed's "hold" area until after
	36	# the next line is seen and processed. If the next line is a stand-alone ")",
	37	# then a missing "&&" on the previous line is legitimate; otherwise a missing
	38	# "&&" is a break in the &&-chain.
	39	#
	40	# (
	41	# cd foo &&
	42	# bar
	43	# )
	44	#
	45	# In practical terms, when "bar" is encountered, it is flagged with "?!AMP?!",
	46	# but when the stand-alone ")" line is seen which closes the subshell, the
	47	# "?!AMP?!" violation is removed from the "bar" line (retrieved from the "hold"
	48	# area) since the final statement of a subshell must not end with "&&". The
	49	# final line of a subshell may still break the &&-chain by using ";" internally
	50	# to chain commands together rather than "&&", so "?!SEMI?!" is never removed
	51	# from a line (even though "?!AMP?!" might be).
	52	#
	53	# Care is taken to recognize the last _statement_ of a multi-line subshell, not
	54	# necessarily the last textual _line_ within the subshell, since &&-chaining
	55	# applies to statements, not to lines. Consequently, blank lines, comment
	56	# lines, and here-docs are swallowed (but not the command to which the here-doc
	57	# is attached), leaving the last statement in the "hold" area, not the last
	58	# line, thus simplifying &&-link checking.
	59	#
	60	# The final statement before "done" in for- and while-loops, and before "elif",
	61	# "else", and "fi" in if-then-else likewise must not end with "&&", thus
	62	# receives similar treatment.
	63	#
c2c29cc0 ES	64	# Swallowing here-docs with arbitrary tags requires a bit of finesse. When a
	65	# line such as "cat <<EOF >out" is seen, the here-doc tag is moved to the front
	66	# of the line enclosed in angle brackets as a sentinel, giving "<EOF>cat >out".
	67	# As each subsequent line is read, it is appended to the target line and a
	68	# (whitespace-loose) back-reference match /^<(.*)>\n\1$/ is attempted to see if
	69	# the content inside "<...>" matches the entirety of the newly-read line. For
	70	# instance, if the next line read is "some data", when concatenated with the
	71	# target line, it becomes "<EOF>cat >out\nsome data", and a match is attempted
	72	# to see if "EOF" matches "some data". Since it doesn't, the next line is
	73	# attempted. When a line consisting of only "EOF" (and possible whitespace) is
	74	# encountered, it is appended to the target line giving "<EOF>cat >out\nEOF",
	75	# in which case the "EOF" inside "<...>" does match the text following the
	76	# newline, thus the closing here-doc tag has been found. The closing tag line
	77	# and the "<...>" prefix on the target line are then discarded, leaving just
	78	# the target line "cat >out".
	79	#
878f9883 ES	80	# To facilitate regression testing (and manual debugging), a ">" annotation is
	81	# applied to the line containing ")" which closes a subshell, ">>" to a line
	82	# closing a nested subshell, and ">>>" to a line closing both at once. This
	83	# makes it easy to detect whether the heuristics correctly identify
	84	# end-of-subshell.
	85	#------------------------------------------------------------------------------
	86
	87	# incomplete line -- slurp up next line
	88	:squash
	89	/\\$/ {
ace64e56 ES	90	N
	91	s/\\\n//
	92	bsquash
878f9883 ES	93	}
	94
	95	# here-doc -- swallow it to avoid false hits within its body (but keep the
	96	# command to which it was attached)
3042b6bb ES	97	/<<[ ][-\\'"][A-Za-z0-9_]/ {
3042b6bb ES	98	s/^\(.\)<<[ ][-\\'"]\([A-Za-z0-9_][A-Za-z0-9_]\)['"]*/<\2>\1<</
c2c29cc0	99	s/[ ]*<<//
a3c4c884	100	:hered
878f9883	101	N
c2c29cc0 ES	102	/^<\([^>]\)>.\n[ ]\1[ ]$/!{
c2c29cc0 ES	103	s/\n.*$//
a3c4c884	104	bhered
c2c29cc0 ES	105	}
	106	s/^<[^>]*>//
	107	s/\n.*$//
878f9883 ES	108	}
	109
	110	# one-liner "(...) &&"
	111	/^[ ]![ ](..)[ ]&&[ ]$/boneline
	112
	113	# same as above but without trailing "&&"
	114	/^[ ]![ ](..)[ ]*$/boneline
	115
	116	# one-liner "(...) >x" (or "2>x" or "<x" or "\|x" or "&"
	117	/^[ ]![ ](..)[ ][0-9][<>\|&]/boneline
	118
	119	# multi-line "(...\n...)"
	120	/^[ ]*(/bsubshell
	121
	122	# innocuous line -- print it and advance to next line
	123	b
	124
	125	# found one-liner "(...)" -- mark suspect if it uses ";" internally rather than
	126	# "&&" (but not ";" in a string)
	127	:oneline
	128	/;/{
	129	/"[^"];[^"]"/!s/^/?!SEMI?!/
	130	}
	131	b
	132
	133	:subshell
2d9ded8a	134	# bare "(" line? -- stash for later printing
878f9883	135	/^[ ]([ ]$/ {
878f9883 ES	136	h
	137	bnextline
	138	}
	139	# "(..." line -- split off and stash "(", then process "..." as its own line
	140	x
	141	s/.*/(/
	142	x
	143	s/(//
	144	bslurp
	145
	146	:nextline
	147	N
	148	s/.*\n//
	149
	150	:slurp
	151	# incomplete line "...\"
a3c4c884	152	/\\$/bicmplte
22e3e024 ES	153	# multi-line quoted string "...\n..."?
	154	/"/bdqstring
	155	# multi-line quoted string '...\n...'? (but not contraction in string "it's")
	156	/'/{
878f9883 ES	157	/"[^'"]'[^'"]"/!bsqstring
878f9883 ES	158	}
d9387114	159	:folded
878f9883	160	# here-doc -- swallow it
3042b6bb	161	/<<[ ][-\\'"][A-Za-z0-9_]/bheredoc
878f9883 ES	162	# comment or empty line -- discard since final non-comment, non-empty line
	163	# before closing ")", "done", "elsif", "else", or "fi" will need to be
	164	# re-visited to drop "suspect" marking since final line of those constructs
	165	# legitimately lacks "&&", so "suspect" mark must be removed
	166	/^[ ]*#/bnextline
	167	/^[ ]*$/bnextline
	168	# in-line comment -- strip it (but not "#" in a string, Bash ${#...} array
	169	# length, or Perforce "//depot/path#42" revision in filespec)
	170	/[ ]#/{
	171	/"[^"]#[^"]"/!s/[ ]#.*$//
	172	}
	173	# one-liner "case ... esac"
a3c4c884	174	/^[ ]case[ ]..*esac/bchkchn
878f9883 ES	175	# multi-line "case ... esac"
	176	/^[ ]case[ ]..[ ]in/bcase
	177	# multi-line "for ... done" or "while ... done"
	178	/^[ ]for[ ]..[ ]in/bcontinue
	179	/^[ ]*while[ ]/bcontinue
	180	/^[ ]*do[ ]/bcontinue
	181	/^[ ]do[ ]$/bcontinue
	182	/;[ ]*do/bcontinue
	183	/^[ ]done[ ]&&[ ]*$/bdone
	184	/^[ ]done[ ]$/bdone
	185	/^[ ]done[ ][<>\|]/bdone
	186	/^[ ]done[ ])/bdone
	187	/\|\|[ ]*exit[ ]/bcontinue
	188	/\|\|[ ]exit[ ]$/bcontinue
	189	# multi-line "if...elsif...else...fi"
	190	/^[ ]*if[ ]/bcontinue
	191	/^[ ]*then[ ]/bcontinue
	192	/^[ ]then[ ]$/bcontinue
	193	/;[ ]*then/bcontinue
	194	/^[ ]*elif[ ]/belse
	195	/^[ ]elif[ ]$/belse
	196	/^[ ]*else[ ]/belse
	197	/^[ ]else[ ]$/belse
	198	/^[ ]fi[ ]&&[ ]*$/bdone
	199	/^[ ]fi[ ]$/bdone
	200	/^[ ]fi[ ][<>\|]/bdone
	201	/^[ ]fi[ ])/bdone
	202	# nested one-liner "(...) &&"
a3c4c884	203	/^[ ](.)[ ]&&[ ]$/bchkchn
878f9883	204	# nested one-liner "(...)"
a3c4c884	205	/^[ ](.)[ ]*$/bchkchn
878f9883	206	# nested one-liner "(...) >x" (or "2>x" or "<x" or "\|x")
a3c4c884	207	/^[ ](.)[ ][0-9][<>\|]/bchkchn
878f9883 ES	208	# nested multi-line "(...\n...)"
	209	/^[ ]*(/bnest
	210	# multi-line "{...\n...}"
	211	/^[ ]*{/bblock
	212	# closing ")" on own line -- exit subshell
a3c4c884	213	/^[ ]*)/bclssolo
878f9883	214	# "$((...))" -- arithmetic expansion; not closing ")"
a3c4c884	215	/\$(([^)][^)]))[^)]$/bchkchn
878f9883	216	# "$(...)" -- command substitution; not closing ")"
a3c4c884	217	/\$([^)][^)])[^)]$/bchkchn
878f9883	218	# multi-line "$(...\n...)" -- command substitution; treat as nested subshell
06fc5c9f	219	/\$([^)]*$/bnest
878f9883	220	# "=(...)" -- Bash array assignment; not closing ")"
a3c4c884	221	/=(/bchkchn
878f9883 ES	222	# closing "...) &&"
	223	/)[ ]&&[ ]$/bclose
	224	# closing "...)"
	225	/)[ ]*$/bclose
	226	# closing "...) >x" (or "2>x" or "<x" or "\|x")
	227	/)[ ]*[<>\|]/bclose
a3c4c884	228	:chkchn
878f9883 ES	229	# mark suspect if line uses ";" internally rather than "&&" (but not ";" in a
	230	# string and not ";;" in one-liner "case...esac")
	231	/;/{
	232	/;;/!{
	233	/"[^"];[^"]"/!s/^/?!SEMI?!/
	234	}
	235	}
	236	# line ends with pipe "...\|" -- valid; not missing "&&"
	237	/\|[ ]*$/bcontinue
	238	# missing end-of-line "&&" -- mark suspect
	239	/&&[ ]*$/!s/^/?!AMP?!/
	240	:continue
	241	# retrieve and print previous line
	242	x
	243	n
	244	bslurp
	245
	246	# found incomplete line "...\" -- slurp up next line
a3c4c884	247	:icmplte
878f9883 ES	248	N
	249	s/\\\n//
	250	bslurp
	251
22e3e024	252	# check for multi-line double-quoted string "...\n..." -- fold to one line
878f9883	253	:dqstring
22e3e024 ES	254	# remove all quote pairs
	255	s/"\([^"]*\)"/@!\1@!/g
	256	# done if no dangling quote
	257	/"/!bdqdone
	258	# otherwise, slurp next line and try again
878f9883 ES	259	N
878f9883 ES	260	s/\n//
22e3e024 ES	261	bdqstring
	262	:dqdone
	263	s/@!/"/g
d9387114	264	bfolded
878f9883	265
22e3e024	266	# check for multi-line single-quoted string '...\n...' -- fold to one line
878f9883	267	:sqstring
22e3e024 ES	268	# remove all quote pairs
	269	s/'\([^']*\)'/@!\1@!/g
	270	# done if no dangling quote
	271	/'/!bsqdone
	272	# otherwise, slurp next line and try again
878f9883 ES	273	N
878f9883 ES	274	s/\n//
22e3e024 ES	275	bsqstring
	276	:sqdone
	277	s/@!/'/g
d9387114	278	bfolded
878f9883 ES	279
878f9883 ES	280	# found here-doc -- swallow it to avoid false hits within its body (but keep
c2c29cc0	281	# the command to which it was attached)
878f9883	282	:heredoc
3042b6bb	283	s/^\(.\)<<[ ][-\\'"]\([A-Za-z0-9_][A-Za-z0-9_]\)['"]*/<\2>\1<</
c2c29cc0	284	s/[ ]*<<//
a3c4c884	285	:heredsub
878f9883	286	N
c2c29cc0 ES	287	/^<\([^>]\)>.\n[ ]\1[ ]$/!{
c2c29cc0 ES	288	s/\n.*$//
a3c4c884	289	bheredsub
c2c29cc0 ES	290	}
c2c29cc0 ES	291	s/^<[^>]*>//
878f9883	292	s/\n.*$//
d9387114	293	bfolded
878f9883 ES	294
	295	# found "case ... in" -- pass through untouched
	296	:case
	297	x
	298	n
	299	/^[ ]*esac/bslurp
	300	bcase
	301
	302	# found "else" or "elif" -- drop "suspect" from final line before "else" since
	303	# that line legitimately lacks "&&"
	304	:else
	305	x
	306	s/?!AMP?!//
	307	x
	308	bcontinue
	309
	310	# found "done" closing for-loop or while-loop, or "fi" closing if-then -- drop
	311	# "suspect" from final contained line since that line legitimately lacks "&&"
	312	:done
	313	x
	314	s/?!AMP?!//
	315	x
	316	# is 'done' or 'fi' cuddled with ")" to close subshell?
	317	/done.*)/bclose
	318	/fi.*)/bclose
a3c4c884	319	bchkchn
878f9883 ES	320
	321	# found nested multi-line "(...\n...)" -- pass through untouched
	322	:nest
	323	x
a3c4c884	324	:nstslurp
878f9883 ES	325	n
878f9883 ES	326	# closing ")" on own line -- stop nested slurp
a3c4c884	327	/^[ ]*)/bnstclose
878f9883	328	# comment -- not closing ")" if in comment
a3c4c884	329	/^[ ]*#/bnstcnt
878f9883	330	# "$((...))" -- arithmetic expansion; not closing ")"
a3c4c884	331	/\$(([^)][^)]))[^)]$/bnstcnt
878f9883	332	# "$(...)" -- command substitution; not closing ")"
a3c4c884	333	/\$([^)][^)])[^)]$/bnstcnt
878f9883	334	# closing "...)" -- stop nested slurp
a3c4c884 ÆAB	335	/)/bnstclose
a3c4c884 ÆAB	336	:nstcnt
878f9883	337	x
a3c4c884 ÆAB	338	bnstslurp
a3c4c884 ÆAB	339	:nstclose
878f9883 ES	340	s/^/>>/
	341	# is it "))" which closes nested and parent subshells?
	342	/)[ ]*)/bslurp
a3c4c884	343	bchkchn
878f9883 ES	344
	345	# found multi-line "{...\n...}" block -- pass through untouched
	346	:block
	347	x
	348	n
	349	# closing "}" -- stop block slurp
a3c4c884	350	/}/bchkchn
878f9883 ES	351	bblock
	352
	353	# found closing ")" on own line -- drop "suspect" from final line of subshell
	354	# since that line legitimately lacks "&&" and exit subshell loop
a3c4c884	355	:clssolo
878f9883 ES	356	x
	357	s/?!AMP?!//
	358	p
	359	x
	360	s/^/>/
	361	b
	362
	363	# found closing "...)" -- exit subshell loop
	364	:close
	365	x
	366	p
	367	x
	368	s/^/>/
	369	b