Iterate over PcDescriptors only via iterators, not via an index. (preparation for more compression …

runtime/vm/stack_frame.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/stack_frame.h"
 
 #include "vm/assembler.h"
 #include "vm/deopt_instructions.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 206 matching lines @@
   ExceptionHandlers& handlers = reused_exception_handlers_handle.Handle();
   handlers = code.exception_handlers();
   if (handlers.Length() == 0) {
     return false;
   }
 
   // Find pc descriptor for the current pc.
   REUSABLE_PC_DESCRIPTORS_HANDLESCOPE(isolate);
   PcDescriptors& descriptors = reused_pc_descriptors_handle.Handle();
   descriptors = code.pc_descriptors();
-  const intptr_t len = descriptors.Length();
-  for (intptr_t i = 0; i < len; i++) {
-    if ((static_cast<uword>(descriptors.PC(i)) == pc()) &&
-        (descriptors.TryIndex(i) != -1)) {
-      const intptr_t try_index = descriptors.TryIndex(i);
+  PcDescriptors::Iterator iter(descriptors);
+  while (iter.HasNext()) {
+    const RawPcDescriptors::PcDescriptorRec& rec = iter.Next();
+    if ((rec.pc == pc()) && (rec.try_index != -1)) {
+      const intptr_t try_index = rec.try_index;
       RawExceptionHandlers::HandlerInfo handler_info;
       handlers.GetHandlerInfo(try_index, &handler_info);
       *handler_pc = handler_info.handler_pc;
       *needs_stacktrace = handler_info.needs_stacktrace;
       *has_catch_all = handler_info.has_catch_all;
       return true;
     }
   }
   return false;
 }
 
 
 intptr_t StackFrame::GetTokenPos() const {
   const Code& code = Code::Handle(LookupDartCode());
   if (code.IsNull()) {
     return -1;  // Stub frames do not have token_pos.
   }
   const PcDescriptors& descriptors =
       PcDescriptors::Handle(code.pc_descriptors());
   ASSERT(!descriptors.IsNull());
-  for (int i = 0; i < descriptors.Length(); i++) {
-    if (static_cast<uword>(descriptors.PC(i)) == pc()) {
-      return descriptors.TokenPos(i);
+  PcDescriptors::Iterator iter(descriptors);
+  while (iter.HasNext()) {
+    const RawPcDescriptors::PcDescriptorRec& rec = iter.Next();
+    if (rec.pc == pc()) {
+      return rec.token_pos;
     }
   }
   return -1;
 }
 
 
 
 bool StackFrame::IsValid() const {
   if (IsEntryFrame() || IsExitFrame() || IsStubFrame()) {
     return true;
@@ skipping 217 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return (index - num_materializations_);
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart