[elpa] externals/relint d0fa8a8 10/16: Fix false positives in regexp provenance checks

[Mattias Engdegård]

branch: externals/relint
commit d0fa8a8d13263c09962d5c8e9f5da644a1f78843
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Mattias Engdegård <mattiase@acm.org>

    Fix false positives in regexp provenance checks
    
    Detect more common functions which harmlessly absorb regexps without
    returning them.
---
 relint.el       | 30 +++++++++++++++++++++++++++---
 test/6.elisp    |  6 +++++-
 test/6.expected | 33 +++++++++++++++++----------------
 3 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/relint.el b/relint.el
index 7a45323..81859ac 100644
--- a/relint.el
+++ b/relint.el
@@ -1284,12 +1284,36 @@ EXPANDED is a list of expanded functions, to prevent 
recursion."
    ((atom expr) nil)
    ((memq (car expr) relint--regexp-returning-functions)
     (list (car expr)))
-   ((memq (car expr) '(looking-at re-search-forward re-search-backward
-                       string-match string-match-p looking-back looking-at-p))
+   ((memq (car expr)
+          ;; These forms never produce regexps at all, but are listed here
+          ;; to prevent false positives since their bodies often do.
+          '(while
+            looking-at re-search-forward re-search-backward
+            string-match string-match-p looking-back looking-at-p
+            replace-regexp
+            query-replace-regexp
+            posix-looking-at posix-search-backward
+            posix-search-forward
+            posix-string-match
+            search-forward-regexp search-backward-regexp
+            kill-matching-buffers
+            keep-lines flush-lines how-many
+            delete-matching-lines delete-non-matching-lines
+            count-matches
+            s-matches? s-matches-p s-matched-positions-all
+            s-count-matches s-count-matches-all))
     nil)
    ((null (cdr (last expr)))
     (let* ((head (car expr))
-           (args (if (memq head '(if when unless while))
+           (args
+            (if (memq head
+                      ;; These forms may generate regexps but the provenance
+                      ;; of their first argument is irrelevant.
+                      ;; This list, too, could be expanded vastly.
+                      '(if when unless
+                        replace-regexp-in-string
+                        s-match-strings-all s-match s-slice-at
+                        s-split s-split-up-to))
                      (cddr expr)
                    (cdr expr)))
            (alias (assq head relint--alias-defs)))
diff --git a/test/6.elisp b/test/6.elisp
index cbbdf4b..2180df6 100644
--- a/test/6.elisp
+++ b/test/6.elisp
@@ -17,7 +17,11 @@
    (format "[%s]" (regexp-quote x))
    (format "[%s]" (myrefun y))
    (format "[%s]" (rx ?a "b" nonl))
-   (format "[%s]" (rx-to-string z))))
+   (format "[%s]" (rx-to-string z))
+   (format "[%s]" (f (string-match (regexp-quote x) a))) ; ok
+   (format "[%s]" (f (replace-regexp-in-string (regexp-quote x) a b))) ; ok
+   (format "[%s]" (f (replace-regexp-in-string a b (regexp-quote x)))) ; bad
+   ))
 
 ;; Test skip-chars
 (defun test-skip-chars (x y z)
diff --git a/test/6.expected b/test/6.expected
index 0e8728e..e8851d5 100644
--- a/test/6.expected
+++ b/test/6.expected
@@ -8,27 +8,28 @@
 6.elisp:18:19: Value from `regexp-opt' cannot be spliced into `[...]'
 6.elisp:19:19: Value from `rx' cannot be spliced into `[...]'
 6.elisp:20:19: Value from `rx-to-string' cannot be spliced into `[...]'
-6.elisp:24:24: In call to skip-chars-forward: Suspect skip set framed in 
`[...]' (pos 0)
+6.elisp:23:19: Value from `regexp-quote' cannot be spliced into `[...]'
+6.elisp:28:24: In call to skip-chars-forward: Suspect skip set framed in 
`[...]' (pos 0)
   "[a-z]"
    ^
-6.elisp:25:26: In call to skip-chars-backward: Duplicated character `a' (pos 1)
+6.elisp:29:26: In call to skip-chars-backward: Duplicated character `a' (pos 1)
   "aa"
    .^
-6.elisp:26:23: `some-re' cannot be used for arguments to `skip-chars-forward'
-6.elisp:27:24: `regexp-quote' cannot be used for arguments to 
`skip-chars-backward'
-6.elisp:28:23: `regexp-opt' cannot be used for arguments to 
`skip-chars-forward'
-6.elisp:29:24: `rx' cannot be used for arguments to `skip-chars-backward'
-6.elisp:30:23: `rx-to-string' cannot be used for arguments to 
`skip-chars-forward'
-6.elisp:34:27: In call to skip-syntax-forward: Invalid char `s' in syntax 
string (pos 1)
+6.elisp:30:23: `some-re' cannot be used for arguments to `skip-chars-forward'
+6.elisp:31:24: `regexp-quote' cannot be used for arguments to 
`skip-chars-backward'
+6.elisp:32:23: `regexp-opt' cannot be used for arguments to 
`skip-chars-forward'
+6.elisp:33:24: `rx' cannot be used for arguments to `skip-chars-backward'
+6.elisp:34:23: `rx-to-string' cannot be used for arguments to 
`skip-chars-forward'
+6.elisp:38:27: In call to skip-syntax-forward: Invalid char `s' in syntax 
string (pos 1)
   "\\s-"
    ..^
-6.elisp:35:27: In call to skip-syntax-backward: Duplicated syntax code ` ' 
(pos 1)
+6.elisp:39:27: In call to skip-syntax-backward: Duplicated syntax code ` ' 
(pos 1)
   "- "
    .^
-6.elisp:36:24: `some-re' cannot be used for arguments to `skip-syntax-forward'
-6.elisp:37:25: `regexp-quote' cannot be used for arguments to 
`skip-syntax-backward'
-6.elisp:38:24: `regexp-opt' cannot be used for arguments to 
`skip-syntax-forward'
-6.elisp:39:25: `rx' cannot be used for arguments to `skip-syntax-backward'
-6.elisp:40:24: `rx-to-string' cannot be used for arguments to 
`skip-syntax-forward'
-6.elisp:64:23: `make-a-nice-regexp' cannot be used for arguments to 
`skip-chars-forward'
-6.elisp:65:24: `make-something' cannot be used for arguments to 
`skip-chars-backward'
+6.elisp:40:24: `some-re' cannot be used for arguments to `skip-syntax-forward'
+6.elisp:41:25: `regexp-quote' cannot be used for arguments to 
`skip-syntax-backward'
+6.elisp:42:24: `regexp-opt' cannot be used for arguments to 
`skip-syntax-forward'
+6.elisp:43:25: `rx' cannot be used for arguments to `skip-syntax-backward'
+6.elisp:44:24: `rx-to-string' cannot be used for arguments to 
`skip-syntax-forward'
+6.elisp:68:23: `make-a-nice-regexp' cannot be used for arguments to 
`skip-chars-forward'
+6.elisp:69:24: `make-something' cannot be used for arguments to 
`skip-chars-backward'