branch: elpa/flamegraph
commit d2a06fe3f900d1ee8231b4d535115ebbcc5ee757
Author: Dmitry Gutov <[email protected]>
Commit: Dmitry Gutov <[email protected]>
Collapse self-recursion in the Calls tree
A function called once in source but recursing in the profile showed as a
chain (e.g. file-truename nested six deep under find-file-noselect): after
matching a call, the walker searched its enclosing form including the head
symbol, so each recursive child re-matched the same occurrence.
Search a matched call's arguments from past the head symbol, so a
recursive callee no longer re-anchors on its own name.
---
flamegraph.el | 11 +++++++----
test/flamegraph-tests.el | 23 +++++++++++++++++++++++
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/flamegraph.el b/flamegraph.el
index 78024ac578..94508c8d47 100644
--- a/flamegraph.el
+++ b/flamegraph.el
@@ -746,10 +746,13 @@ tree may show cold callees the snippet omits."
(push (list mb me weight) regions))
(when-let* ((sub
(flamegraph--enclosing-form-region
mb)))
- ;; Clamp to REGION so a stray enclosing form
- ;; can never widen the search.
- (walk k (cons (max (car sub) (car region))
- (min (cdr sub) (cdr region)))
+ ;; Search K's own calls in this call's
+ ;; arguments: from past the matched head to the
+ ;; form end, clamped to REGION so a stray
+ ;; enclosing form cannot widen it. Starting at
+ ;; the head's end keeps a recursive callee from
+ ;; re-matching its own name.
+ (walk k (cons me (min (cdr sub) (cdr region)))
nil)))))
(when (or found concealed-ok)
(when shown (puthash k t shown))
diff --git a/test/flamegraph-tests.el b/test/flamegraph-tests.el
index 74bab16492..4410fee4e7 100644
--- a/test/flamegraph-tests.el
+++ b/test/flamegraph-tests.el
@@ -131,6 +131,29 @@ stray `bar' is outside the foo-form's region."
(should (equal (flamegraph-test--region-texts regions)
'("foo" "bar" "baz"))))))
+(ert-deftest flamegraph-test-walker-self-recursion-not-renested ()
+ "A function called once in source but recursing deeply in the profile
+is shown once, not as a chain: searching a matched call's arguments must
+not re-match the call's own head symbol."
+ (flamegraph-test--with-elisp-source
+ "(defun outer ()
+ (rec x))"
+ (let* ((rec3 (profiler-make-calltree :entry 'rec :count 1))
+ (rec2 (profiler-make-calltree :entry 'rec :count 2
+ :children (list rec3)))
+ (rec1 (profiler-make-calltree :entry 'rec :count 3
+ :children (list rec2)))
+ (outer (profiler-make-calltree :entry 'outer :count 3
+ :children (list rec1)))
+ (shown (make-hash-table :test 'eq))
+ (regions (flamegraph--collect-nested-call-sites
+ outer (point-min) (point-max) shown)))
+ ;; Only the one written `(rec x)' is a call site.
+ (should (equal (flamegraph-test--region-texts regions) '("rec")))
+ (should (gethash rec1 shown))
+ (should-not (gethash rec2 shown))
+ (should-not (gethash rec3 shown)))))
+
(ert-deftest flamegraph-test-walker-macro-expansion-transparent ()
"Skip-through frames absent from source must not stop the descent.
The profiler records post-expansion frames (here `while'/`let' from
