Added support for expression statements to the CFG builder and

fast-mode compiler.

This will generate a compiler temporary for complex expressions and
then immediately throw it away, so a better approach (to be
implemented later) is to pass to the expression builder whether an
expression is in an effect or value context.

Review URL: http://codereview.chromium.org/162006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2630 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/cfg.cc

@@ -424,7 +424,19 @@ void StatementBuilder::VisitBlock(Block* stmt) {
 
 
 void StatementBuilder::VisitExpressionStatement(ExpressionStatement* stmt) {
-  BAILOUT("ExpressionStatement");
+  ExpressionBuilder builder;
+  builder.Build(stmt->expression());
+  if (builder.cfg() == NULL) {
+    BAILOUT("unsupported expression in expression statement");
+  }
+  // Here's a temporary hack: we bang on the last instruction of the
+  // expression (if any) to set its location to Effect.
+  if (!builder.cfg()->is_empty()) {
+    InstructionBlock* block = InstructionBlock::cast(builder.cfg()->exit());
+    Instruction* instr = block->instructions()->last();
+    instr->set_location(CfgGlobals::current()->effect_location());
+  }
+  cfg_->Concatenate(builder.cfg());
 }
 
 

src/cfg.h

@@ -201,11 +201,13 @@ class Location : public Value {
 // computation is not needed (though its side effects are).
 class Effect : public Location {
  public:
-  // We should not try to emit code to read or write to Effect.
+  // We should not try to emit code to read Effect.
   void Get(MacroAssembler* masm, Register reg) { UNREACHABLE(); }
-  void Set(MacroAssembler* masm, Register reg) { UNREACHABLE(); }
   void Push(MacroAssembler* masm) { UNREACHABLE(); }
 
+  // Setting Effect is ignored.
+  void Set(MacroAssembler* masm, Register reg) {}
+
 #ifdef DEBUG
   void Print();
 #endif
@@ -311,6 +313,7 @@ class Instruction : public ZoneObject {
 
   // Accessors.
   Location* location() { return loc_; }
+  void set_location(Location* loc) { loc_ = loc; }
 
   // Support for fast-compilation mode: