From c2c29cc03e0d8156095dd18e2f7dcb768253c61a Mon Sep 17 00:00:00 2001 From: Eric Sunshine Date: Mon, 13 Aug 2018 04:47:34 -0400 Subject: [PATCH] chainlint: match arbitrary here-docs tags rather than hard-coded names chainlint.sed swallows top-level here-docs to avoid being fooled by content which might look like start-of-subshell. It likewise swallows here-docs in subshells to avoid marking content lines as breaking the &&-chain, and to avoid being fooled by content which might look like end-of-subshell, start-of-nested-subshell, or other specially-recognized constructs. At the time of implementation, it was believed that it was not possible to support arbitrary here-doc tag names since 'sed' provides no way to stash the opening tag name in a variable for later comparison against a line signaling end-of-here-doc. Consequently, tag names are hard-coded, with "EOF" being the only tag recognized at the top-level, and only "EOF", "EOT", and "INPUT_END" being recognized within subshells. Also, special care was taken to avoid being confused by here-docs nested within other here-docs. In practice, this limited number of hard-coded tag names has been "good enough" for the 13000+ existing Git test, despite many of those tests using tags other than the recognized ones, since the bodies of those here-docs do not contain content which would fool the linter. Nevertheless, the situation is not ideal since someone writing new tests, and choosing a name not in the "blessed" set could potentially trigger a false-positive. To address this shortcoming, upgrade chainlint.sed to handle arbitrary here-doc tag names, both at the top-level and within subshells. Signed-off-by: Eric Sunshine Signed-off-by: Junio C Hamano --- t/chainlint.sed | 57 +++++++++++++++++++++--------------- t/chainlint/here-doc.expect | 2 ++ t/chainlint/here-doc.test | 7 +++++ t/chainlint/nested-here-doc.expect | 2 ++ t/chainlint/nested-here-doc.test | 10 +++++++ t/chainlint/subshell-here-doc.expect | 4 +++ t/chainlint/subshell-here-doc.test | 8 +++++ 7 files changed, 67 insertions(+), 23 deletions(-) diff --git a/t/chainlint.sed b/t/chainlint.sed index 5f0882cb38..2af1a687f8 100644 --- a/t/chainlint.sed +++ b/t/chainlint.sed @@ -61,6 +61,22 @@ # "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 <out" is seen, the here-doc tag is moved to the front +# of the line enclosed in angle brackets as a sentinel, giving "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 "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 "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 @@ -78,14 +94,17 @@ # here-doc -- swallow it to avoid false hits within its body (but keep the # command to which it was attached) -/<<[ ]*[-\\]*EOF[ ]*/ { - s/[ ]*<<[ ]*[-\\]*EOF// - h +/<<[ ]*[-\\]*[A-Za-z0-9_]/ { + s/^\(.*\)<<[ ]*[-\\]*\([A-Za-z0-9_][A-Za-z0-9_]*\)/<\2>\1<]*\)>.*\n[ ]*\1[ ]*$/!{ + s/\n.*$// + bhereslurp + } + s/^<[^>]*>// + s/\n.*$// } # one-liner "(...) &&" @@ -139,9 +158,7 @@ s/.*\n// /"[^'"]*'[^'"]*"/!bsqstring } # here-doc -- swallow it -/<<[ ]*[-\\]*EOF/bheredoc -/<<[ ]*[-\\]*EOT/bheredoc -/<<[ ]*[-\\]*INPUT_END/bheredoc +/<<[ ]*[-\\]*[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 @@ -249,23 +266,17 @@ s/\n// bcheckchain # found here-doc -- swallow it to avoid false hits within its body (but keep -# the command to which it was attached); take care to handle here-docs nested -# within here-docs by only recognizing closing tag matching outer here-doc -# opening tag +# the command to which it was attached) :heredoc -/EOF/{ s/[ ]*<<[ ]*[-\\]*EOF//; s/^/EOF/; } -/EOT/{ s/[ ]*<<[ ]*[-\\]*EOT//; s/^/EOT/; } -/INPUT_END/{ s/[ ]*<<[ ]*[-\\]*INPUT_END//; s/^/INPUT_END/; } +s/^\(.*\)<<[ ]*[-\\]*\([A-Za-z0-9_][A-Za-z0-9_]*\)/<\2>\1<]*\)>.*\n[ ]*\1[ ]*$/!{ + s/\n.*$// + bhereslurpsub +} +s/^<[^>]*>// s/\n.*$// bcheckchain diff --git a/t/chainlint/here-doc.expect b/t/chainlint/here-doc.expect index 2328fe7753..33bc3cc0b4 100644 --- a/t/chainlint/here-doc.expect +++ b/t/chainlint/here-doc.expect @@ -1,3 +1,5 @@ boodle wobba gorgo snoot wafta snurb && +cat >foo && + horticulture diff --git a/t/chainlint/here-doc.test b/t/chainlint/here-doc.test index bd36f6e1d3..8986eefe74 100644 --- a/t/chainlint/here-doc.test +++ b/t/chainlint/here-doc.test @@ -7,6 +7,13 @@ quoth the raven, nevermore... EOF +# LINT: swallow here-doc with arbitrary tag +cat <<-Arbitrary_Tag_42 >foo && +snoz +boz +woz +Arbitrary_Tag_42 + # LINT: swallow here-doc (EOF is last line of test) horticulture <<\EOF gomez diff --git a/t/chainlint/nested-here-doc.expect b/t/chainlint/nested-here-doc.expect index 559301e005..0c9ef1cfc6 100644 --- a/t/chainlint/nested-here-doc.expect +++ b/t/chainlint/nested-here-doc.expect @@ -1,3 +1,5 @@ +cat >foop && + ( cat && ?!AMP?! cat diff --git a/t/chainlint/nested-here-doc.test b/t/chainlint/nested-here-doc.test index 027e0bb3ff..f35404bf0f 100644 --- a/t/chainlint/nested-here-doc.test +++ b/t/chainlint/nested-here-doc.test @@ -1,3 +1,13 @@ +# LINT: inner "EOF" not misintrepreted as closing ARBITRARY here-doc +cat <foop && +naddle +fub <bip echo >bop +>) && +( + cat >bup && + meep >) diff --git a/t/chainlint/subshell-here-doc.test b/t/chainlint/subshell-here-doc.test index 9c3564c247..05139af0b5 100644 --- a/t/chainlint/subshell-here-doc.test +++ b/t/chainlint/subshell-here-doc.test @@ -20,4 +20,12 @@ wednesday pugsly EOF +) && +( +# LINT: swallow here-doc with arbitrary tag + cat <<-\ARBITRARY >bup && + glink + FIZZ + ARBITRARY + meep ) -- 2.11.4.GIT