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author | Eric Sunshine <sunshine@sunshineco.com> | 2018-08-13 08:47:34 (GMT) |
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committer | Junio C Hamano <gitster@pobox.com> | 2018-08-13 19:22:11 (GMT) |
commit | c2c29cc03e0d8156095dd18e2f7dcb768253c61a (patch) | |
tree | 2855d21e402814ae594e7c93cd01b49f5596bc46 /t/chainlint.sed | |
parent | ace64e56c10a61b184e1fcfc0dae34b4e78036de (diff) | |
download | git-c2c29cc03e0d8156095dd18e2f7dcb768253c61a.zip git-c2c29cc03e0d8156095dd18e2f7dcb768253c61a.tar.gz git-c2c29cc03e0d8156095dd18e2f7dcb768253c61a.tar.bz2 |
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 <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/chainlint.sed')
-rw-r--r-- | t/chainlint.sed | 57 |
1 files changed, 34 insertions, 23 deletions
diff --git a/t/chainlint.sed b/t/chainlint.sed index 5f0882c..2af1a68 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 <<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 @@ -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<</ + s/[ ]*<<// :hereslurp N - s/.*\n// - /^[ ]*EOF[ ]*$/!bhereslurp - x + /^<\([^>]*\)>.*\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<</ +s/[ ]*<<// :hereslurpsub N -/^EOF.*\n[ ]*EOF[ ]*$/bhereclose -/^EOT.*\n[ ]*EOT[ ]*$/bhereclose -/^INPUT_END.*\n[ ]*INPUT_END[ ]*$/bhereclose -bhereslurpsub -:hereclose -s/^EOF// -s/^EOT// -s/^INPUT_END// +/^<\([^>]*\)>.*\n[ ]*\1[ ]*$/!{ + s/\n.*$// + bhereslurpsub +} +s/^<[^>]*>// s/\n.*$// bcheckchain |