Sergey,

thanks for the patch! Please see my comments below.

Now information about the abort of the trace is saved in the
`abort_reason` field of the corresponding structure. The
`jit.parse.finish()` returns now the second table containing aborted
traces. Each table key is a trace number containing an array of
potentially traces with this number, which was aborted.

Needed for tarantool/tarantool#9924
---
 .../unit-jit-parse-abort.test.lua             | 38 +++++++++++++++++++
 test/tarantool-tests/utils/jit/parse.lua      | 22 ++++++++---
 2 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100644 test/tarantool-tests/unit-jit-parse-abort.test.lua

diff --git a/test/tarantool-tests/unit-jit-parse-abort.test.lua b/test/tarantool-tests/unit-jit-parse-abort.test.lua
new file mode 100644
index 00000000..91af5a56
--- /dev/null
+++ b/test/tarantool-tests/unit-jit-parse-abort.test.lua
@@ -0,0 +1,38 @@
+local tap = require('tap')
+local test = tap.test('unit-jit-parse'):skipcond({

Usually a name passed to `tap.test` matches to test file name,

but here it is not matched.

+  ['Test requires JIT enabled'] = not jit.status(),
+  ['Disabled on *BSD due to #4819'] = jit.os == 'BSD',
+})
+
+local jparse = require('utils').jit.parse
+
+-- XXX: Avoid other traces compilation due to hotcount collisions
+-- for predictable results.
+jit.off()
+jit.flush()
+
+test:plan(1)
+
+jit.on()
+-- We only need the abort reason in the test.
+jparse.start('t')

I would add a comment with explanation what does 't' flag mean.

Feel free to ignore.

+
+-- XXX: A trace always has at least 3 IR constants: for `nil`,
+-- `false`, and `true`. Always fails to record with the set
+-- `maxirconst` limit.
+jit.opt.start('hotloop=1', 'maxirconst=1')
+
+for _ = 1, 3 do end
+
+local _, aborted_traces = jparse.finish()
+
+jit.off()
+
+assert(aborted_traces and aborted_traces[1], 'aborted trace is persisted')
+
+-- We tried to compile only one trace.
+local reason = aborted_traces[1][1].abort_reason
+
+test:like(reason, 'trace too long', 'abort reason is correct')
+
+test:done(true)
diff --git a/test/tarantool-tests/utils/jit/parse.lua b/test/tarantool-tests/utils/jit/parse.lua
index bcef5b35..0ce7f7c8 100644
--- a/test/tarantool-tests/utils/jit/parse.lua
+++ b/test/tarantool-tests/utils/jit/parse.lua
@@ -22,6 +22,7 @@ local function trace_new(n)
     parent = nil,
     parent_exitno = nil,
     is_stitched = false,
+    abort_reason = nil,
     start_loc = nil,
     bc = {},
     ir = {},
@@ -87,9 +88,17 @@ local header_handlers = {
     ctx.parsing_trace = nil
     ctx.parsing = nil
   end,
-  abort = function(ctx, trace_num)
+  abort = function(ctx, trace_num, line)
     local traces = ctx.traces
     assert(ctx.parsing_trace == trace_num)
+
+    local aborted_traces = ctx.aborted_traces
+    if not aborted_traces[trace_num] then
+      aborted_traces[trace_num] = {}
+    end
+    traces[trace_num].abort_reason = line:match('-- (.+)$')
+    table.insert(aborted_traces[trace_num], traces[trace_num])
+
     ctx.parsing_trace = nil
     ctx.parsing = nil
     traces[trace_num] = nil
@@ -137,11 +146,14 @@ end
 local JDUMP_FILE
 
 local function parse_jit_dump()
-  local ctx = {traces = {}}
+  local ctx = {
+    aborted_traces = {},
+    traces = {},
+  }
   for line in io.lines(JDUMP_FILE) do
     parse_line(ctx, line)
   end
-  return ctx.traces
+  return ctx.traces, ctx.aborted_traces
 end
 
 -- Start `jit.dump()` utility with the given flags, saving the
@@ -167,10 +179,10 @@ M.finish = function()
   -- Enable traces compilation for `jit.dump` back.
   jit.on(jdump.on, true)
   jit.on(jdump.off, true)
-  local traces = parse_jit_dump()
+  local traces, aborted_traces = parse_jit_dump()
   os.remove(JDUMP_FILE)
   JDUMP_FILE = nil
-  return traces
+  return traces, aborted_traces
 end
 
 -- Turn off compilation for the module to avoid side effects.