diff options
Diffstat (limited to 't/chainlint.sed')
| -rw-r--r-- | t/chainlint.sed | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/t/chainlint.sed b/t/chainlint.sed new file mode 100644 index 0000000000..8544df38df --- /dev/null +++ b/t/chainlint.sed @@ -0,0 +1,370 @@ +#------------------------------------------------------------------------------ +# 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/[ ]*<<// + :hereslurp + N + /^<\([^>]*\)>.*\n[ ]*\1[ ]*$/!{ + s/\n.*$// + bhereslurp + } + 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 "...\" +/\\$/bincomplete +# 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/bcheckchain +# 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[ ]*$/bdone +/^[ ]*fi[ ]*[<>|]/bdone +/^[ ]*fi[ ]*)/bdone +# nested one-liner "(...) &&" +/^[ ]*(.*)[ ]*&&[ ]*$/bcheckchain +# nested one-liner "(...)" +/^[ ]*(.*)[ ]*$/bcheckchain +# nested one-liner "(...) >x" (or "2>x" or "<x" or "|x") +/^[ ]*(.*)[ ]*[0-9]*[<>|]/bcheckchain +# nested multi-line "(...\n...)" +/^[ ]*(/bnest +# multi-line "{...\n...}" +/^[ ]*{/bblock +# closing ")" on own line -- exit subshell +/^[ ]*)/bclosesolo +# "$((...))" -- arithmetic expansion; not closing ")" +/\$(([^)][^)]*))[^)]*$/bcheckchain +# "$(...)" -- command substitution; not closing ")" +/\$([^)][^)]*)[^)]*$/bcheckchain +# multi-line "$(...\n...)" -- command substitution; treat as nested subshell +/\$([^)]*$/bnest +# "=(...)" -- Bash array assignment; not closing ")" +/=(/bcheckchain +# closing "...) &&" +/)[ ]*&&[ ]*$/bclose +# closing "...)" +/)[ ]*$/bclose +# closing "...) >x" (or "2>x" or "<x" or "|x") +/)[ ]*[<>|]/bclose +:checkchain +# mark suspect if line uses ";" internally rather than "&&" (but not ";" in a +# string and not ";;" in one-liner "case...esac") +/;/{ + /;;/!{ + /"[^"]*;[^"]*"/!s/^/?!SEMI?!/ + } +} +# line ends with pipe "...|" -- valid; not missing "&&" +/|[ ]*$/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 +:incomplete +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/[ ]*<<// +:hereslurpsub +N +/^<\([^>]*\)>.*\n[ ]*\1[ ]*$/!{ + s/\n.*$// + bhereslurpsub +} +s/^<[^>]*>// +s/\n.*$// +bfolded + +# found "case ... in" -- pass through untouched +:case +x +n +/^[ ]*esac/bslurp +bcase + +# found "else" or "elif" -- drop "suspect" from final line before "else" since +# that line legitimately lacks "&&" +:else +x +s/?!AMP?!// +x +bcontinue + +# found "done" closing for-loop or while-loop, or "fi" closing if-then -- drop +# "suspect" from final contained line since that line legitimately lacks "&&" +:done +x +s/?!AMP?!// +x +# is 'done' or 'fi' cuddled with ")" to close subshell? +/done.*)/bclose +/fi.*)/bclose +bcheckchain + +# found nested multi-line "(...\n...)" -- pass through untouched +:nest +x +:nestslurp +n +# closing ")" on own line -- stop nested slurp +/^[ ]*)/bnestclose +# comment -- not closing ")" if in comment +/^[ ]*#/bnestcontinue +# "$((...))" -- arithmetic expansion; not closing ")" +/\$(([^)][^)]*))[^)]*$/bnestcontinue +# "$(...)" -- command substitution; not closing ")" +/\$([^)][^)]*)[^)]*$/bnestcontinue +# closing "...)" -- stop nested slurp +/)/bnestclose +:nestcontinue +x +bnestslurp +:nestclose +s/^/>>/ +# is it "))" which closes nested and parent subshells? +/)[ ]*)/bslurp +bcheckchain + +# found multi-line "{...\n...}" block -- pass through untouched +:block +x +n +# closing "}" -- stop block slurp +/}/bcheckchain +bblock + +# found closing ")" on own line -- drop "suspect" from final line of subshell +# since that line legitimately lacks "&&" and exit subshell loop +:closesolo +x +s/?!AMP?!// +p +x +s/^/>/ +b + +# found closing "...)" -- exit subshell loop +:close +x +p +x +s/^/>/ +b |