From 8fff9a5d9b8c89f2e8d1a0a294a8e0ea64edb86b Mon Sep 17 00:00:00 2001
From: Michael Schwarz <michael.schwarz93@gmail.com>
Date: Fri, 24 Jan 2025 17:43:27 +0100
Subject: [PATCH] Onces

---
 src/analyses/pthreadOnce.ml          | 90 ++++++++++++++++++++++++++++
 src/framework/constraints.ml         |  9 ++-
 tests/regression/83-once/01-sanity.c |  2 +-
 3 files changed, 99 insertions(+), 2 deletions(-)
 create mode 100644 src/analyses/pthreadOnce.ml

diff --git a/src/analyses/pthreadOnce.ml b/src/analyses/pthreadOnce.ml
new file mode 100644
index 0000000000..30c7756089
--- /dev/null
+++ b/src/analyses/pthreadOnce.ml
@@ -0,0 +1,90 @@
+(** Must active and have passed pthreadOnce calls ([pthreadOnce]). *)
+
+open GoblintCil
+open Analyses
+module LF = LibraryFunctions
+
+module Spec =
+struct
+  module Onces = struct
+    include SetDomain.ToppedSet (CilType.Varinfo) (struct let topname = "All onces" end)
+    let name () = "mayOnces"
+  end
+
+  module ActiveOnces = struct
+    include Lattice.Reverse (Onces)
+    let name () = "active"
+  end
+
+  module SeenOnces = struct
+    include Lattice.Reverse (Onces)
+    let name () = "seen"
+  end
+
+  include Analyses.DefaultSpec
+
+  let name () = "pthreadOnce"
+  module D = Lattice.Prod (ActiveOnces) (SeenOnces)
+  include Analyses.ValueContexts(D)
+
+  (* transfer functions *)
+  let assign man (lval:lval) (rval:exp) : D.t =
+    man.local
+
+  let branch man (exp:exp) (tv:bool) : D.t =
+    man.local
+
+  let body man (f:fundec) : D.t =
+    man.local
+
+  let return man (exp:exp option) (f:fundec) : D.t =
+    man.local
+
+  let enter man (lval: lval option) (f:fundec) (args:exp list) : (D.t * D.t) list =
+    [man.local, man.local]
+
+  let combine_env man lval fexp f args fc au f_ask =
+    au
+
+  let combine_assign man (lval:lval option) fexp (f:fundec) (args:exp list) fc (au:D.t) (f_ask: Queries.ask) : D.t =
+    man.local
+
+  let special man (lval: lval option) (f:varinfo) (arglist:exp list) : D.t =
+    man.local
+
+  let startstate v = (Onces.empty (), Onces.empty ())
+
+  let possible_vinfos (a: Queries.ask) barrier =
+    Queries.AD.to_var_may (a.f (Queries.MayPointTo barrier))
+
+  let event man (e: Events.t) oman : D.t =
+    match e with
+    | Events.EnterOnce { once_control; tf } ->
+      (let (active, seen) = man.local in
+       let ask = Analyses.ask_of_man man in
+       match possible_vinfos ask once_control with
+       | [v] ->
+         (Onces.add v active, seen)
+       | _ ->
+         man.local)
+    | Events.LeaveOnce { once_control } ->
+      (let (active, seen) = man.local in
+       let ask = Analyses.ask_of_man man in
+       let active' = Onces.diff active (Onces.of_list (possible_vinfos ask once_control)) in
+       let seen' = match possible_vinfos ask once_control with
+         | [v] -> Onces.add v seen
+         | _ -> seen
+       in
+       (active', seen'))
+    | _ -> man.local
+
+  let threadenter man ~multiple lval f args =
+    let (_, seen) = man.local in
+    [Onces.empty (), seen]
+
+  let threadspawn man ~multiple lval f args fman = man.local
+  let exitstate  v = D.top ()
+end
+
+let _ =
+  MCP.register_analysis (module Spec : MCPSpec)
diff --git a/src/framework/constraints.ml b/src/framework/constraints.ml
index d2c1c8215b..97dffe5d6c 100644
--- a/src/framework/constraints.ml
+++ b/src/framework/constraints.ml
@@ -271,7 +271,14 @@ struct
         S.event proc_man (Events.LeaveOnce { once_control }) proc_man
       in
       let not_enter =
-        S.event man (Events.EnterOnce { once_control;  tf = false }) man
+        let d' = S.event man (Events.EnterOnce { once_control;  tf = false }) man in
+        let rec d'_man =
+          { man with
+            ask = (fun (type a) (q: a Queries.t) -> S.query d'_man q);
+            local = d';
+          }
+        in
+        S.event d'_man (Events.LeaveOnce { once_control }) d'_man
       in
       D.join enter not_enter
     in
diff --git a/tests/regression/83-once/01-sanity.c b/tests/regression/83-once/01-sanity.c
index 954f70dd4b..3d7875e0c5 100644
--- a/tests/regression/83-once/01-sanity.c
+++ b/tests/regression/83-once/01-sanity.c
@@ -1,4 +1,4 @@
-// PARAM: --set pre.cppflags[+] "-DGOBLINT_NO_PTHREAD_ONCE"
+// PARAM: --set pre.cppflags[+] "-DGOBLINT_NO_PTHREAD_ONCE" --set ana.activated[+] pthreadOnce
 #include <pthread.h>
 #include <stdio.h>