Set previous instruction pointers when building the graph.

runtime/vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
@@ skipping 40 matching lines @@
 }
 
 
 void EffectGraphVisitor::Append(const EffectGraphVisitor& other_fragment) {
   ASSERT(is_open());
   if (other_fragment.is_empty()) return;
   if (is_empty()) {
     entry_ = other_fragment.entry();
     exit_ = other_fragment.exit();
   } else {
-    exit()->set_next(other_fragment.entry());
+    exit()->LinkTo(other_fragment.entry());
     exit_ = other_fragment.exit();
   }
   temp_index_ = other_fragment.temp_index();
 }
 
 
 Value* EffectGraphVisitor::Bind(Definition* definition) {
   ASSERT(is_open());
   DeallocateTempIndex(definition->InputCount());
   definition->set_use_kind(Definition::kValue);
   definition->set_temp_index(AllocateTempIndex());
   if (is_empty()) {
     entry_ = definition;
   } else {
-    exit()->set_next(definition);
+    exit()->LinkTo(definition);
   }
   exit_ = definition;
   return new Value(definition);
 }
 
 
 void EffectGraphVisitor::Do(Definition* definition) {
   ASSERT(is_open());
   DeallocateTempIndex(definition->InputCount());
   definition->set_use_kind(Definition::kEffect);
   if (is_empty()) {
     entry_ = definition;
   } else {
-    exit()->set_next(definition);
+    exit()->LinkTo(definition);
   }
   exit_ = definition;
 }
 
 
 void EffectGraphVisitor::AddInstruction(Instruction* instruction) {
   ASSERT(is_open());
   ASSERT(instruction->IsPushArgument() || !instruction->IsDefinition());
   ASSERT(!instruction->IsBlockEntry());
   DeallocateTempIndex(instruction->InputCount());
   if (is_empty()) {
     entry_ = exit_ = instruction;
   } else {
-    exit()->set_next(instruction);
+    exit()->LinkTo(instruction);
     exit_ = instruction;
   }
 }
 
 
 void EffectGraphVisitor::Goto(JoinEntryInstr* join) {
   ASSERT(is_open());
   if (is_empty()) {
     entry_ = new GotoInstr(join);
   } else {
     exit()->Goto(join);
   }
   exit_ = NULL;
 }
 
 
 // Appends a graph fragment to a block entry instruction.  Returns the entry
 // instruction if the fragment was empty or else the exit of the fragment if
 // it was non-empty (so NULL if the fragment is closed).
 //
 // Note that the fragment is no longer a valid fragment after calling this
 // function -- the fragment is closed at its entry because the entry has a
 // predecessor in the graph.
 static Instruction* AppendFragment(BlockEntryInstr* entry,
                                    const EffectGraphVisitor& fragment) {
   if (fragment.is_empty()) return entry;
-  entry->set_next(fragment.entry());
+  entry->LinkTo(fragment.entry());
   return fragment.exit();
 }
 
 
 void EffectGraphVisitor::Join(const TestGraphVisitor& test_fragment,
                               const EffectGraphVisitor& true_fragment,
                               const EffectGraphVisitor& false_fragment) {
   // We have: a test graph fragment with zero, one, or two available exits;
   // and a pair of effect graph fragments with zero or one available exits.
   // We want to append the branch and (if necessary) a join node to this
@@ skipping 43 matching lines @@
   BlockEntryInstr* body_entry = test_fragment.CreateTrueSuccessor();
   Instruction* body_exit = AppendFragment(body_entry, body_fragment);
 
   // 2. Connect the test to this graph, including the body if reachable and
   // using a fresh join node if the body is reachable and has an open exit.
   if (body_exit == NULL) {
     Append(test_fragment);
   } else {
     JoinEntryInstr* join =
         new JoinEntryInstr(owner()->AllocateBlockId(), owner()->try_index());
-    join->set_next(test_fragment.entry());
+    join->LinkTo(test_fragment.entry());
     Goto(join);
     body_exit->Goto(join);
   }
 
   // 3. Set the exit to the graph to be the false successor of the test, a
   // fresh target node
 
   exit_ = test_fragment.CreateFalseSuccessor();
 }
 
@@ skipping 1036 matching lines @@
       new JoinEntryInstr(owner()->AllocateBlockId(), owner()->try_index());
   Goto(body_entry_join);
   Instruction* body_exit = AppendFragment(body_entry_join, for_body);
 
   JoinEntryInstr* join = node->label()->join_for_continue();
   if ((body_exit != NULL) || (join != NULL)) {
     if (join == NULL) {
       join =
           new JoinEntryInstr(owner()->AllocateBlockId(), owner()->try_index());
     }
-    join->set_next(for_test.entry());
+    join->LinkTo(for_test.entry());
     if (body_exit != NULL) {
       body_exit->Goto(join);
     }
   }
 
 
   for_test.IfTrueGoto(body_entry_join);
   if (node->label()->join_for_break() == NULL) {
     exit_ = for_test.CreateFalseSuccessor();
   } else {
@@ skipping 1380 matching lines @@
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart