Special case mangling for a variable named 't'.

lib/compiler/implementation/ssa/codegen.dart

 // 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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
 
   String generateMethod(WorkItem work, HGraph graph) {
@@ skipping 75 matching lines @@
    * It is generated as either statements (indented and ';'-terminated),
    * expressions (comma separated) or declarations (also comma separated,
    * but expected to be preceeded by a 'var' so it declares its variables);
    */
   static final int STATE_STATEMENT = 0;
   static final int STATE_FIRST_EXPRESSION = 1;
   static final int STATE_FIRST_DECLARATION = 2;
   static final int STATE_EXPRESSION = 3;
   static final int STATE_DECLARATION = 4;
 
+  static final String TEMPORARY_PREFIX = 't';
+
   final Compiler compiler;
   final WorkItem work;
   final StringBuffer buffer;
   final String parameters;
 
   final Map<Element, String> parameterNames;
   final Map<int, String> names;
   final Set<String> usedNames;
   final Map<String, int> prefixes;
   final Set<HInstruction> generateAtUseSite;
@@ skipping 43 matching lines @@
       logicalOperations = new Map<HPhi, String>(),
       breakAction = new Map<Element, ElementAction>(),
       continueAction = new Map<Element, ElementAction>(),
       phiEquivalence = new Equivalence<HPhi>() {
 
     for (final name in parameterNames.getValues()) {
       prefixes[name] = 0;
     }
 
     // Create a namespace for temporaries.
-    prefixes['t'] = 0;
+    prefixes[TEMPORARY_PREFIX] = 0;
 
     equalsNullElement =
         compiler.builder.interceptors.getEqualsNullInterceptor();
   }
 
   abstract visitTypeGuard(HTypeGuard node);
 
   abstract beginGraph(HGraph graph);
   abstract endGraph(HGraph graph);
 
@@ skipping 100 matching lines @@
 
   void visitConditionGraph(SubGraph conditionSubGraph) {
     visitExpressionGraph(conditionSubGraph);
   }
 
   String temporary(HInstruction instruction) {
     int id = instruction.id;
     String name = names[id];
     if (name !== null) return name;
 
-    String prefix = 't';
+    String prefix = TEMPORARY_PREFIX;
     if (instruction.sourceElement !== null) {
       Element element = instruction.sourceElement;
       if (element !== null && !element.name.isEmpty()) {
         prefix = element.name.slowToString();
+        // Special case the variable named [TEMPORARY_PREFIX] to allow keeping its

[floitsch, 2012/04/20 10:36:37]

80 chars.

+        // name.
+        if (prefix == TEMPORARY_PREFIX && !usedNames.contains(prefix)) {
+          return newName(id, prefix);
+        }
         // If we've never seen that prefix before, try to use it
         // directly.
         if (!prefixes.containsKey(prefix)) {
           // Make sure the variable name does not conflict with our mangling.
           while (usedNames.contains(prefix)) {
             prefix = '${prefix}_';
           }
           prefixes[prefix] = 0;
           return newName(id, prefix);
         }
@@ skipping 1633 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endElse(HIf node) {
     if (node.elseBlock.hasGuards()) {
       endBailoutSwitch();
     }
   }
 }