1 // Copyright 2013 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_ALLOCATION_SITE_SCOPES_H_ 29 #define V8_ALLOCATION_SITE_SCOPES_H_ 30 31 #include "ast.h" 32 #include "handles.h" 33 #include "objects.h" 34 #include "zone.h" 35 36 namespace v8 { 37 namespace internal { 38 39 40 // AllocationSiteContext is the base class for walking and copying a nested 41 // boilerplate with AllocationSite and AllocationMemento support. 42 class AllocationSiteContext { 43 public: AllocationSiteContext(Isolate * isolate)44 explicit AllocationSiteContext(Isolate* isolate) { 45 isolate_ = isolate; 46 }; 47 top()48 Handle<AllocationSite> top() { return top_; } current()49 Handle<AllocationSite> current() { return current_; } 50 ShouldCreateMemento(Handle<JSObject> object)51 bool ShouldCreateMemento(Handle<JSObject> object) { return false; } 52 isolate()53 Isolate* isolate() { return isolate_; } 54 55 protected: update_current_site(AllocationSite * site)56 void update_current_site(AllocationSite* site) { 57 *(current_.location()) = site; 58 } 59 InitializeTraversal(Handle<AllocationSite> site)60 void InitializeTraversal(Handle<AllocationSite> site) { 61 top_ = site; 62 current_ = Handle<AllocationSite>(*top_, isolate()); 63 } 64 65 private: 66 Isolate* isolate_; 67 Handle<AllocationSite> top_; 68 Handle<AllocationSite> current_; 69 }; 70 71 72 // AllocationSiteCreationContext aids in the creation of AllocationSites to 73 // accompany object literals. 74 class AllocationSiteCreationContext : public AllocationSiteContext { 75 public: AllocationSiteCreationContext(Isolate * isolate)76 explicit AllocationSiteCreationContext(Isolate* isolate) 77 : AllocationSiteContext(isolate) { } 78 79 Handle<AllocationSite> EnterNewScope(); 80 void ExitScope(Handle<AllocationSite> site, Handle<JSObject> object); 81 }; 82 83 84 // AllocationSiteUsageContext aids in the creation of AllocationMementos placed 85 // behind some/all components of a copied object literal. 86 class AllocationSiteUsageContext : public AllocationSiteContext { 87 public: AllocationSiteUsageContext(Isolate * isolate,Handle<AllocationSite> site,bool activated)88 AllocationSiteUsageContext(Isolate* isolate, Handle<AllocationSite> site, 89 bool activated) 90 : AllocationSiteContext(isolate), 91 top_site_(site), 92 activated_(activated) { } 93 EnterNewScope()94 inline Handle<AllocationSite> EnterNewScope() { 95 if (top().is_null()) { 96 InitializeTraversal(top_site_); 97 } else { 98 // Advance current site 99 Object* nested_site = current()->nested_site(); 100 // Something is wrong if we advance to the end of the list here. 101 ASSERT(nested_site->IsAllocationSite()); 102 update_current_site(AllocationSite::cast(nested_site)); 103 } 104 return Handle<AllocationSite>(*current(), isolate()); 105 } 106 ExitScope(Handle<AllocationSite> scope_site,Handle<JSObject> object)107 inline void ExitScope(Handle<AllocationSite> scope_site, 108 Handle<JSObject> object) { 109 // This assert ensures that we are pointing at the right sub-object in a 110 // recursive walk of a nested literal. 111 ASSERT(object.is_null() || *object == scope_site->transition_info()); 112 } 113 114 bool ShouldCreateMemento(Handle<JSObject> object); 115 116 private: 117 Handle<AllocationSite> top_site_; 118 bool activated_; 119 }; 120 121 122 } } // namespace v8::internal 123 124 #endif // V8_ALLOCATION_SITE_SCOPES_H_ 125