Merge branch 'lang/memory-gaps' into lang/foundations

examples/lang/arena_pool.ludic

@@ -0,0 +1,40 @@
+# arena_pool.ludic - a pool that keeps its records across frames through a generic push (the shape of
+# ludic.ui's nd_take and ui_kept). Built with --arena, a record the pool keeps must not come from the
+# frame's scratch: run with R3D_ARENA_CHECK=1 (each reset filled with 0xDD) it prints what it prints
+# with the arena off (R3D_ARENA=0) - `7 3498`.
+program ArenaPool {
+  property Cell { v: int = 0, tag: string = "" }
+  property Pool { cells: []Cell = new []Cell, used: int = 0 }
+  function kept<T>(xs: []T, v: T) -> void { push(xs, v) }
+  function take(p: Pool, f: int) -> Cell {
+    if p.used < len(p.cells) {
+      let c = p.cells[p.used]
+      p.used += 1
+      return c
+    }
+    let c = new Cell { v: f }
+    kept(p.cells, c)
+    p.used += 1
+    return c
+  }
+  function step(p: Pool, f: int) -> int {
+    p.used = 0
+    var s = 0
+    for k in 0 .. (f % 8) {
+      let c = take(p, f)
+      c.v = f + k
+      s += c.v
+    }
+    return s
+  }
+  entry {
+    let p = new Pool
+    for f in 0 .. 500 {
+      step(p, f)
+      Mem.frame()
+    }
+    var sum = 0
+    for i in 0 .. len(p.cells) { sum += p.cells[i].v }
+    print(`{len(p.cells)} {sum}`)
+  }
+}

selfhost/backend/emit_escape.ludic

@@ -224,6 +224,16 @@ function es_val(e: Node) -> int {
       var i = 0
       while i < len(e.a.kids) { es_store(es_ref(e.a.kids[i].a), s);  i += 1 }
     }
+    # a field's default is made with the record and held by it (`facts: Queue<F> = queue_new(...)`)
+    let lay = find_comp(e.s)
+    if lay != null and lay.kids != null {
+      var j = 0
+      while j < len(lay.kids) {
+        let fd = lay.kids[j]
+        if fd.a != null and not es_overridden(e, fd.s) { es_store(es_ref(fd.a), s) }
+        j += 1
+      }
+    }
     return s
   }
   if k == E_LIST {
@@ -242,6 +252,39 @@ function es_val(e: Node) -> int {
   return g_es_heap
 }
 
+function es_overridden(e: Node, field: pointer) -> bool {
+  if e.a == null or e.a.kids == null { return false }
+  var i = 0
+  while i < len(e.a.kids) { if (e.a.kids[i].s == field) { return true };  i += 1 }
+  return false
+}
+
+# the function records a call to `nm` reaches: nm itself, or every instance of a generic nm
+function es_fns_for(nm: pointer) -> []int {
+  let out = new []int
+  let f = es_fn(nm)
+  if f >= 0 {
+    push(out, f)
+    return out
+  }
+  let pre = `{nm}$`
+  var i = 0
+  while i < len(g_es_fnode) {
+    let d = g_es_fnode[i]
+    if d.s != null and str_starts(d.s, pre) { push(out, i) }
+    i += 1
+  }
+  return out
+}
+
+function es_keeps_nothing(nm: pointer) -> bool {
+  if (nm == "quit") or (nm == "exit") or (nm == "panic") or (nm == "assert") or (nm == "expect") or (nm == "expect_eq") or (nm == "expect_near") { return true }
+  if (nm == "min") or (nm == "max") or (nm == "abs") or (nm == "clamp") or (nm == "sqrt") or (nm == "floor") or (nm == "ceil") or (nm == "round") { return true }
+  if (nm == "int") or (nm == "float") or (nm == "long") or (nm == "double") or (nm == "fixed") or (nm == "as_int") or (nm == "as_fixed") { return true }
+  if (nm == "float_bits") or (nm == "float_from_bits") or (nm == "sin") or (nm == "cos") or (nm == "atan2") or (nm == "file_write") or (nm == "file_close") { return true }
+  return false
+}
+
 function es_args_escape(e: Node) -> void {
   var i = 0
   while i < len(e.kids) { es_escape(es_val(e.kids[i]));  i += 1 }
@@ -293,28 +336,49 @@ function es_call(e: Node) -> int {
       return -1
     }
     if (nm == "len") { es_args_walk(e);  return -1 }
-    let f = es_fn(nm)
-    if f >= 0 {
+    if (nm == "view") and len(e.kids) >= 1 {        # a view shares its list's storage
+      let base = es_val(e.kids[0])
+      var vi = 1
+      while vi < len(e.kids) { es_val(e.kids[vi]);  vi += 1 }
+      return base
+    }
+    # a generic's call names the generic; its instances (ui_kept$UiNode) are what is analysed, and
+    # the call reaches every one of them
+    let fs = es_fns_for(nm)
+    if len(fs) > 0 {
+      let r = es_new(0)
+      var fi = 0
+      while fi < len(fs) {
+        let f = fs[fi]
         push(g_es_calls_f, g_es_cur)
         push(g_es_calls_t, f)
-      let d = g_es_fnode[f]
+        es_flow(g_es_fret[f], r)
+        fi += 1
+      }
       var i = 0
       while i < len(e.kids) {
         let v = es_ref(e.kids[i])
+        var fj = 0
+        while fj < len(fs) {
+          let d = g_es_fnode[fs[fj]]
           if i < len(d.kids) and d.kids[i].kind == N_PARAM {
-          if not es_prim(d.kids[i].ty) { es_flow(v, g_es_fparam[f] + i) }
+            if not es_prim(d.kids[i].ty) { es_flow(v, g_es_fparam[fs[fj]] + i) }
           } else { es_escape(v) }
+          fj += 1
+        }
         i += 1
       }
-      let r = es_new(0)
-      es_flow(g_es_fret[f], r)
       return r
     }
-    # an intrinsic or a runtime builtin of the emitter's own: it keeps nothing it is handed, and
-    # what it hands back is its own
+    # an intrinsic known to keep nothing it is handed; anything else unknown keeps it all - the
+    # arena is only as safe as this default
+    if es_keeps_nothing(nm) {
       es_args_walk(e)
       return g_es_heap
     }
+    es_args_escape(e)
+    return g_es_heap
+  }
   if es_is_mem_frame(e) {
     if g_es_cur >= 0 { g_es_fspans[g_es_cur] = true }
     return -1
@@ -541,6 +605,18 @@ function escape_analyse() -> void {
     f += 1
   }
   g_es_cur = -1
+  # a global's initializer - a state's instance, a module's table - is made to be kept
+  var gi = 0
+  while gi < len(prog) {
+    let gd = prog[gi]
+    if gd.kind == N_VAR and gd.a != null {
+      g_es_ln = new []pointer
+      g_es_lc = new []int
+      g_es_lt = new []pointer
+      es_escape(es_ref(gd.a))
+    }
+    gi += 1
+  }
   # an @On body keeps nothing it makes unless it stores it; it has no function record of its own
   var li = 0
   while li < len(g_onlisten) {
@@ -557,7 +633,9 @@ function escape_analyse() -> void {
     let c = g_es_site_cls[s]
     let fi = g_es_site_fn[s]
     let spans = fi < 0 or g_es_fspans[fi]
-    if c >= 0 and (g_es_flag[c] & ES_ESC) == 0 and not spans {
+    # LOCAL only when it can neither be kept (ESC) nor share storage with what is (HEAP): a push's
+    # growth into a parameter's list is the list's own buffer, and the list may be a state's
+    if c >= 0 and (g_es_flag[c] & (ES_ESC | ES_HEAP)) == 0 and not spans {
       n.uns = ES_SCRATCH
       g_es_local_n += 1
     } else {

selfhost/backend/emit_frame.ludic

@@ -151,6 +151,7 @@ function deps_frame(f: pointer) -> void {
     let d = prog[i]
     if d.kind == N_SYS and d.s != null and fr_phase_frame(d.ty) { fr_mark_root(d.s) }
     if d.kind == N_FN and d.s != null and str_starts(d.s, "ludic_reduce__") { fr_mark_root(d.s) }
+    if d.kind == N_FN and d.s != null and d.cm >= 0 { fr_mark_root(d.s) }   # a component's own: it runs while its page is open
     fr_find_roots(d)
     i += 1
   }

tools/ludic-cli/test.ludic

@@ -817,6 +817,17 @@ function alloc_fence_auto_case() -> void {
   else { bad2(lbl, `rc={string(rc)} head=[{head}] count=[{through}]`) }
 }
 
+# 25.3: a pool that keeps records across frames through a generic push must not take them from the
+# frame's scratch - poisoned on every reset it prints what the heap does
+function arena_pool_case() -> void {
+  let lbl = "arena_pool.ludic (--arena: a generic push into a kept pool keeps its records and its buffer on the heap; 0xDD poison changes nothing)"
+  let b = `{tmp_dir()}/e_arena_pool`
+  if not shq(`bin/ludicc --arena examples/lang/arena_pool.ludic -o {b} 2>/dev/null`) { bad2(lbl, "did not build"); return }
+  let poisoned = capture_line(`R3D_ARENA_CHECK=1 R3D_ALLOC_FENCE=off {b} < /dev/null`)
+  let heap = capture_line(`R3D_ARENA=0 R3D_ALLOC_FENCE=off {b} < /dev/null`)
+  if (poisoned == "7 3498") and (heap == "7 3498") { ok(lbl) } else { bad2(lbl, `poisoned [{poisoned}] heap [{heap}]`) }
+}
+
 # issue #45: `bin/ludic-dev test --coverage`. Compile each test-spec with `--coverage`,
 # run it with LUDIC_COVERAGE pointed at a per-file dump, then aggregate the dumps
 # into a clean per-file line-coverage report. The instrumentation is flag-gated,
@@ -1115,6 +1126,7 @@ function cmd_dev_test() -> int {
   feat_case("lang/alloc_fence", "", "frames 300 kept 0 bad 0", "alloc_fence.ludic (25.1: a frame that makes only what it frees or reuses keeps nothing, and the fence passes it)")
   alloc_fence_leak_case()
   alloc_fence_auto_case()
+  arena_pool_case()
   feat_case("lang/nested_templates", "", "outer [inner 3 {x}] \"`}\" end", "nested_templates.ludic (a template literal inside another's hole)")
   feat_case("lang/aliases", "", "10 5 3", "aliases.ludic (L6: a namespace method declared as an alias of a function, labelled or by its parameters)")
   reject_case("rejected/alias_arity", "this call to Trail.length leaves out to, which has no default", "an alias's arguments are checked against its target")