Backport to 3.10 of r11696: Limit work done analyzing regexps with very large fanout.

src/jsregexp.h

Index: src/jsregexp.h
===================================================================
--- src/jsregexp.h	(revision 11709)
+++ src/jsregexp.h	(working copy)
@@ -574,9 +574,12 @@
   // Collects information on the possible code units (mod 128) that can match if
   // we look forward.  This is used for a Boyer-Moore-like string searching
   // implementation.  TODO(erikcorry):  This should share more code with
-  // EatsAtLeast, GetQuickCheckDetails.
+  // EatsAtLeast, GetQuickCheckDetails.  The budget argument is used to limit
+  // the number of nodes we are willing to look at in order to create this data.
+  static const int kFillInBMBudget = 200;
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start) {
     UNREACHABLE();
@@ -679,9 +682,11 @@
   virtual RegExpNode* FilterASCII(int depth);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start) {
-    on_success_->FillInBMInfo(offset, recursion_depth + 1, bm, not_at_start);
+    on_success_->FillInBMInfo(
+        offset, recursion_depth + 1, budget - 1, bm, not_at_start);
     if (offset == 0) set_bm_info(not_at_start, bm);
   }
 
@@ -736,6 +741,7 @@
   }
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
   Type type() { return type_; }
@@ -807,6 +813,7 @@
       RegExpCompiler* compiler);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
   void CalculateOffsets();
@@ -869,6 +876,7 @@
                                     bool not_at_start);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
   AssertionNodeType type() { return type_; }
@@ -909,6 +917,7 @@
   }
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
 
@@ -936,6 +945,7 @@
   }
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start) {
     // Returning 0 from EatsAtLeast should ensure we never get here.
@@ -1028,6 +1038,7 @@
                                     bool not_at_start);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
 
@@ -1080,10 +1091,11 @@
                                     bool not_at_start);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start) {
     alternatives_->at(1).node()->FillInBMInfo(
-        offset, recursion_depth + 1, bm, not_at_start);
+        offset, recursion_depth + 1, budget - 1, bm, not_at_start);
     if (offset == 0) set_bm_info(not_at_start, bm);
   }
   // For a negative lookahead we don't emit the quick check for the
@@ -1115,6 +1127,7 @@
                                     bool not_at_start);
   virtual void FillInBMInfo(int offset,
                             int recursion_depth,
+                            int budget,
                             BoyerMooreLookahead* bm,
                             bool not_at_start);
   RegExpNode* loop_node() { return loop_node_; }