Processor(Isolate* isolate, Variable* result,
AstValueFactory* ast_value_factory)
: result_(result),
+ result_assigned_(false),
is_set_(false),
+ in_try_(false),
factory_(ast_value_factory) {
InitializeAstVisitor(isolate, ast_value_factory->zone());
}
virtual ~Processor() { }
void Process(ZoneList<Statement*>* statements);
+ bool result_assigned() const { return result_assigned_; }
AstNodeFactory* factory() { return &factory_; }
private:
Variable* result_;
+ // We are not tracking result usage via the result_'s use
+ // counts (we leave the accurate computation to the
+ // usage analyzer). Instead we simple remember if
+ // there was ever an assignment to result_.
+ bool result_assigned_;
+
// To avoid storing to .result all the time, we eliminate some of
// the stores by keeping track of whether or not we're sure .result
// will be overwritten anyway. This is a bit more tricky than what I
- // was hoping for.
+ // was hoping for
bool is_set_;
+ bool in_try_;
AstNodeFactory factory_;
Expression* SetResult(Expression* value) {
+ result_assigned_ = true;
VariableProxy* result_proxy = factory()->NewVariableProxy(result_);
return factory()->NewAssignment(
Token::ASSIGN, result_proxy, value, RelocInfo::kNoPosition);
void Processor::VisitExpressionStatement(ExpressionStatement* node) {
// Rewrite : <x>; -> .result = <x>;
- if (!is_set_) {
+ if (!is_set_ && !node->expression()->IsThrow()) {
node->set_expression(SetResult(node->expression()));
- is_set_ = true;
+ if (!in_try_) is_set_ = true;
}
}
void Processor::VisitIfStatement(IfStatement* node) {
- // Rewrite both branches.
- bool set_after = is_set_;
- Visit(node->then_statement());
- bool set_in_then = is_set_;
- is_set_ = set_after;
+ // Rewrite both then and else parts (reversed).
+ bool save = is_set_;
Visit(node->else_statement());
- is_set_ = is_set_ && set_in_then;
+ bool set_after_then = is_set_;
+ is_set_ = save;
+ Visit(node->then_statement());
+ is_set_ = is_set_ && set_after_then;
}
void Processor::VisitIterationStatement(IterationStatement* node) {
// Rewrite the body.
- bool set_after = is_set_;
- is_set_ = false; // We are in a loop, so we can't rely on [set_after].
+ bool set_after_loop = is_set_;
Visit(node->body());
- is_set_ = is_set_ && set_after;
+ is_set_ = is_set_ && set_after_loop;
}
void Processor::VisitTryCatchStatement(TryCatchStatement* node) {
- // Rewrite both try and catch block.
- bool set_after = is_set_;
- Visit(node->try_block());
- bool set_in_try = is_set_;
- is_set_ = set_after;
+ // Rewrite both try and catch blocks (reversed order).
+ bool set_after_catch = is_set_;
Visit(node->catch_block());
- is_set_ = is_set_ && set_in_try;
+ is_set_ = is_set_ && set_after_catch;
+ bool save = in_try_;
+ in_try_ = true;
+ Visit(node->try_block());
+ in_try_ = save;
}
void Processor::VisitTryFinallyStatement(TryFinallyStatement* node) {
- // Rewrite both try and finally block (in reverse order).
+ // Rewrite both try and finally block (reversed order).
Visit(node->finally_block());
+ bool save = in_try_;
+ in_try_ = true;
Visit(node->try_block());
+ in_try_ = save;
}
void Processor::VisitSwitchStatement(SwitchStatement* node) {
- // Rewrite statements in all case clauses (in reverse order).
+ // Rewrite statements in all case clauses in reversed order.
ZoneList<CaseClause*>* clauses = node->cases();
- bool set_after = is_set_;
+ bool set_after_switch = is_set_;
for (int i = clauses->length() - 1; i >= 0; --i) {
CaseClause* clause = clauses->at(i);
Process(clause->statements());
}
- is_set_ = is_set_ && set_after;
+ is_set_ = is_set_ && set_after_switch;
}
void Processor::VisitWithStatement(WithStatement* node) {
+ bool set_after_body = is_set_;
Visit(node->statement());
+ is_set_ = is_set_ && set_after_body;
}
}
-void Processor::VisitReturnStatement(ReturnStatement* node) { is_set_ = true; }
-
-
// Do nothing:
+void Processor::VisitVariableDeclaration(VariableDeclaration* node) {}
+void Processor::VisitFunctionDeclaration(FunctionDeclaration* node) {}
+void Processor::VisitImportDeclaration(ImportDeclaration* node) {}
+void Processor::VisitExportDeclaration(ExportDeclaration* node) {}
void Processor::VisitEmptyStatement(EmptyStatement* node) {}
+void Processor::VisitReturnStatement(ReturnStatement* node) {}
void Processor::VisitDebuggerStatement(DebuggerStatement* node) {}
-// Expressions are never visited.
+// Expressions are never visited yet.
#define DEF_VISIT(type) \
void Processor::Visit##type(type* expr) { UNREACHABLE(); }
EXPRESSION_NODE_LIST(DEF_VISIT)
#undef DEF_VISIT
-// Declarations are never visited.
-#define DEF_VISIT(type) \
- void Processor::Visit##type(type* expr) { UNREACHABLE(); }
-DECLARATION_NODE_LIST(DEF_VISIT)
-#undef DEF_VISIT
-
-
// Assumes code has been parsed. Mutates the AST, so the AST should not
// continue to be used in the case of failure.
bool Rewriter::Rewrite(ParseInfo* info) {
processor.Process(body);
if (processor.HasStackOverflow()) return false;
- DCHECK(function->end_position() != RelocInfo::kNoPosition);
- // Set the position of the assignment statement one character past the
- // source code, such that it definitely is not in the source code range
- // of an immediate inner scope. For example in
- // eval('with ({x:1}) x = 1');
- // the end position of the function generated for executing the eval code
- // coincides with the end of the with scope which is the position of '1'.
- int pos = function->end_position();
- VariableProxy* result_proxy =
- processor.factory()->NewVariableProxy(result, pos);
- Statement* result_statement =
- processor.factory()->NewReturnStatement(result_proxy, pos);
- body->Add(result_statement, info->zone());
+ if (processor.result_assigned()) {
+ DCHECK(function->end_position() != RelocInfo::kNoPosition);
+ // Set the position of the assignment statement one character past the
+ // source code, such that it definitely is not in the source code range
+ // of an immediate inner scope. For example in
+ // eval('with ({x:1}) x = 1');
+ // the end position of the function generated for executing the eval code
+ // coincides with the end of the with scope which is the position of '1'.
+ int pos = function->end_position();
+ VariableProxy* result_proxy =
+ processor.factory()->NewVariableProxy(result, pos);
+ Statement* result_statement =
+ processor.factory()->NewReturnStatement(result_proxy, pos);
+ body->Add(result_statement, info->zone());
+ }
}
return true;
shouldBe('eval("1;")', "1");
shouldBe('eval("1; try { foo = [2,3,throwFunc(), 4]; } catch (e){}")', "1");
-shouldBe('eval("1; try { 2; throw \\"\\"; } catch (e){}")', "1");
-shouldBe('eval("1; try { 2; throwFunc(); } catch (e){}")', "1");
+shouldBe('eval("1; try { 2; throw \\"\\"; } catch (e){}")', "2");
+shouldBe('eval("1; try { 2; throwFunc(); } catch (e){}")', "2");
shouldBe('eval("1; try { 2; throwFunc(); } catch (e){3;} finally {}")', "3");
shouldBe('eval("1; try { 2; throwFunc(); } catch (e){3;} finally {4;}")', "4");
shouldBe('eval("function blah() { 1; }\\n blah();")', "undefined");
shouldBe('eval("var x = 1;")', "undefined");
shouldBe('eval("if (true) { 1; } else { 2; }")', "1");
shouldBe('eval("if (false) { 1; } else { 2; }")', "2");
-shouldBe('eval("try{1; if (true) { 2; throw \\"\\"; } else { 2; }} catch(e){}")', "undefined");
+shouldBe('eval("try{1; if (true) { 2; throw \\"\\"; } else { 2; }} catch(e){}")', "2");
shouldBe('eval("1; var i = 0; do { ++i; 2; } while(i!=1);")', "2");
-//shouldBe('eval("try{1; var i = 0; do { ++i; 2; throw \\"\\"; } while(i!=1);} catch(e){}")', "undefined");
-shouldBe('eval("1; try{2; throwOnReturn();} catch(e){}")', "1");
+shouldBe('eval("try{1; var i = 0; do { ++i; 2; throw \\"\\"; } while(i!=1);} catch(e){}")', "2");
+shouldBe('eval("1; try{2; throwOnReturn();} catch(e){}")', "2");
shouldBe('eval("1; twoFunc();")', "undefined");
shouldBe('eval("1; with ( { a: 0 } ) { 2; }")', "2");
projects / platform / upstream / v8.git / commitdiff