Handle tr end async trace events

Kernel commit

https://lore.kernel.org/lkml/[email protected]/

set `PERF_IP_FLAG_ASYNC` on trace end events. As per

https://github.com/torvalds/linux/blob/7ee022567bf9e2e0b3cd92461a2f4986ecc99673/tools/perf/builtin-script.c#L1546

This means that where `perf` would have previously outputted
`tr end  jmp`, it now outputs `tr end  async`.

Adjust our regex to allow `async`, and treat it as a branch.

Signed-off-by: Tudor Brindus <[email protected]>

Author: Xyene

src/perf_decode.ml

@@ -22,7 +22,7 @@ let perf_callstack_entry_re = Re.Perl.re "^\t *([0-9a-f]+) (.*)$" |> Re.compile
 
 let perf_branches_event_re =
   Re.Perl.re
-    {|^ *(call|return|tr strt|syscall|sysret|hw int|iret|tr end|tr strt tr end|tr end  (?:call|return|syscall|sysret|iret)|jmp|jcc) +([0-9a-f]+) (.*) => +([0-9a-f]+) (.*)$|}
+    {|^ *(call|return|tr strt|syscall|sysret|hw int|iret|tr end|tr strt tr end|tr end  (?:async|call|return|syscall|sysret|iret)|jmp|jcc) +([0-9a-f]+) (.*) => +([0-9a-f]+) (.*)$|}
   |> Re.compile
 ;;
 
@@ -262,6 +262,16 @@ let parse_perf_branches_event ?perf_maps (thread : Event.Thread.t) time line : E
       | "hw int" -> Some Hardware_interrupt
       | "iret" -> Some Iret
       | "sysret" -> Some Sysret
+      | "async" ->
+        (match trace_state_change with
+         | Some End -> Some Jump
+         | _ ->
+           raise_s
+             [%message
+               "BUG: async flag set on something other than a trace end event. Please \
+                report this to https://github.com/janestreet/magic-trace/issues/"
+                 (trace_state_change : Trace_state_change.t option)
+                 (line : string)])
       | "" -> None
       | _ ->
         printf "Warning: skipping unrecognized perf output: %s\n%!" line;
@@ -688,6 +698,18 @@ let%test_module _ =
           ((thread ((pid (25375)) (tid (25375)))) (time 52d4h33m11.343298468s)
            (data (Trace (kind Call) (src 0x7f6fce0b71f4) (dst 0x7ffd193838e0)))))) |}]
     ;;
+
+    let%expect_test "tr end  async" =
+      check
+        {| 25375/25375 4509191.343298468:                            1   branches:uH:   tr end  async                     7f6fce0b71f4 [unknown] (foo.so) =>     0 [unknown] ([unknown])|};
+      [%expect
+        {|
+        ((Ok
+          ((thread ((pid (25375)) (tid (25375)))) (time 52d4h33m11.343298468s)
+           (data
+            (Trace (trace_state_change End) (kind Jump) (src 0x7f6fce0b71f4)
+             (dst 0x0)))))) |}]
+    ;;
   end)
 ;;