One more iteration of PcDescriptor iterator improvement: do not copy record but access individual …

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 38356)
+++ runtime/vm/object.cc	(working copy)
@@ -10359,14 +10359,13 @@
   intptr_t len = 1;  // Trailing '\0'.
   Iterator iter(*this, RawPcDescriptors::kAnyKind);
   while (iter.HasNext()) {

[hausner, 2014/07/17 23:22:56]

See other comment. This loop would become:

while (iter.HasNext()) {
  iter.MoveNext();
  uword pc = iter.pc();
  len += OS::SNPrint(NULL, 0, kFormat, addr_width,
              pc,
              KindAsStr(iter.kind()),
              iter.deopt_id(),
              iter.token_pos(),
              iter.try_index());
}

[srdjan, 2014/07/18 18:16:45]

Good suggestion, changed to:

while (iter.MoveNext()) {
  ...iter.Pc(), iter.Kind()...
}

-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
+    uword pc = iter.NextPc();
     len += OS::SNPrint(NULL, 0, kFormat, addr_width,
-                       rec.pc(),
-                       KindAsStr(rec.kind()),
-                       rec.deopt_id(),
-                       rec.token_pos(),
-                       rec.try_index());
+                       pc,
+                       KindAsStr(iter.current_kind()),
+                       iter.current_deopt_id(),
+                       iter.current_token_pos(),
+                       iter.current_try_index());
   }
   // Allocate the buffer.
   char* buffer = Isolate::Current()->current_zone()->Alloc<char>(len);
@@ -10374,14 +10373,13 @@
   intptr_t index = 0;
   Iterator iter2(*this, RawPcDescriptors::kAnyKind);
   while (iter2.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter2.NextRec(&rec);
+    uword pc = iter2.NextPc();
     index += OS::SNPrint((buffer + index), (len - index), kFormat, addr_width,
-                         rec.pc(),
-                         KindAsStr(rec.kind()),
-                         rec.deopt_id(),
-                         rec.token_pos(),
-                         rec.try_index());
+                         pc,
+                         KindAsStr(iter.current_kind()),
+                         iter.current_deopt_id(),
+                         iter.current_token_pos(),
+                         iter.current_try_index());
   }
   return buffer;
 }
@@ -10396,14 +10394,13 @@
   JSONArray members(jsobj, "members");
   Iterator iter(*this, RawPcDescriptors::kAnyKind);
   while (iter.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
+    uword pc = iter.NextPc();
     JSONObject descriptor(&members);
-    descriptor.AddPropertyF("pc", "%" Px "", rec.pc());
-    descriptor.AddProperty("kind", KindAsStr(rec.kind()));
-    descriptor.AddProperty("deoptId",  static_cast<intptr_t>(rec.deopt_id()));
-    descriptor.AddProperty("tokenPos",  static_cast<intptr_t>(rec.token_pos()));
-    descriptor.AddProperty("tryIndex",  static_cast<intptr_t>(rec.try_index()));
+    descriptor.AddPropertyF("pc", "%" Px "", pc);
+    descriptor.AddProperty("kind", KindAsStr(iter.current_kind()));
+    descriptor.AddProperty("deoptId", iter.current_deopt_id());
+    descriptor.AddProperty("tokenPos", iter.current_token_pos());
+    descriptor.AddProperty("tryIndex", iter.current_try_index());
   }
 }
 
@@ -10435,11 +10432,10 @@
   }
   Iterator iter(*this, RawPcDescriptors::kDeopt | RawPcDescriptors::kIcCall);
   while (iter.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
+    const intptr_t deopt_id = iter.NextDeoptId();
     // 'deopt_id' is set for kDeopt and kIcCall and must be unique for one kind.
 
-    if (Isolate::IsDeoptAfter(rec.deopt_id())) {
+    if (Isolate::IsDeoptAfter(deopt_id)) {
       // TODO(vegorov): some instructions contain multiple calls and have
       // multiple "after" targets recorded. Right now it is benign but might
       // lead to issues in the future. Fix that and enable verification.
@@ -10448,10 +10444,9 @@
 
     Iterator nested(iter);
     while (nested.HasNext()) {
-      RawPcDescriptors::PcDescriptorRec nested_rec;
-      nested.NextRec(&nested_rec);
-      if (rec.kind() == nested_rec.kind()) {
-        ASSERT(nested_rec.deopt_id() != rec.deopt_id());
+      intptr_t nested_deopt_id = nested.NextDeoptId();
+      if (iter.current_kind() == nested.current_kind()) {
+        ASSERT(nested_deopt_id != iter.current_deopt_id());
       }
     }
   }
@@ -11961,10 +11956,9 @@
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
   PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
   while (iter.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
-    if (rec.pc() == pc) {
-      return rec.token_pos();
+    const uword current_pc = iter.NextPc();
+    if (current_pc == pc) {
+      return iter.current_token_pos();
     }
   }
   return -1;
@@ -11976,10 +11970,9 @@
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
   PcDescriptors::Iterator iter(descriptors, kind);
   while (iter.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
-    if (rec.deopt_id() == deopt_id) {
-      uword pc = rec.pc();
+    const intptr_t current_deopt_id = iter.NextDeoptId();
+    if (current_deopt_id == deopt_id) {
+      uword pc = iter.current_pc();
       ASSERT(ContainsInstructionAt(pc));
       return pc;
     }
@@ -11992,10 +11985,9 @@
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
   PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kOsrEntry);
   while (iter.HasNext()) {
-    RawPcDescriptors::PcDescriptorRec rec;
-    iter.NextRec(&rec);
-    if (rec.pc() == pc) {
-      return rec.deopt_id();
+    const uword current_pc = iter.NextPc();
+    if (current_pc == pc) {
+      return iter.current_deopt_id();
     }
   }
   return Isolate::kNoDeoptId;