From c669a16e2dd2731db9f924b9bc202ef345c5808d Mon Sep 17 00:00:00 2001
From: Wes Kocher <wkocher@mozilla.com>
Date: Mon, 21 Apr 2014 16:11:20 -0700
Subject: [PATCH] Backed out changeset 0c0a5a6b57d9 (bug 616491) for jsreftest
 failures

---
 js/src/yarr/YarrPattern.cpp | 36 +++++++++++++-----------------------
 1 file changed, 13 insertions(+), 23 deletions(-)

diff --git a/js/src/yarr/YarrPattern.cpp b/js/src/yarr/YarrPattern.cpp
index b04be18fe79..60dca3f02ab 100644
--- a/js/src/yarr/YarrPattern.cpp
+++ b/js/src/yarr/YarrPattern.cpp
@@ -304,22 +304,6 @@ public:
         m_pattern.m_disjunctions.append(m_pattern.m_body);
     }
 
-    void setStackBase(uint8_t *stackBase) {
-        m_stackBase = stackBase;
-    }
-
-    bool isOverRecursed() {
-        /*
-         * Bug 616491: attempt detection of over-recursion.
-         * "256KB should be enough stack for anyone."
-         */
-        uint8_t stackDummy_;
-        JS_ASSERT(m_stackBase != nullptr);
-        if (m_stackBase - &stackDummy_ > (1 << 18))
-            return true;
-        return false;
-    }
-
     void assertionBOL()
     {
         if (!m_alternative->m_terms.size() & !m_invertParentheticalAssertion) {
@@ -590,7 +574,12 @@ public:
     ErrorCode setupAlternativeOffsets(PatternAlternative* alternative, unsigned currentCallFrameSize, unsigned initialInputPosition,
                                       unsigned *callFrameSizeOut)
     {
-        if (isOverRecursed())
+        /*
+         * Attempt detection of over-recursion:
+         * "1MB should be enough stack for anyone."
+         */
+        uint8_t stackDummy_;
+        if (m_stackBase - &stackDummy_ > 1024*1024)
             return PatternTooLarge;
 
         alternative->m_hasFixedSize = true;
@@ -685,9 +674,6 @@ public:
 
     ErrorCode setupDisjunctionOffsets(PatternDisjunction* disjunction, unsigned initialCallFrameSize, unsigned initialInputPosition, unsigned *maximumCallFrameSizeOut)
     {
-        if (isOverRecursed())
-            return PatternTooLarge;
-
         if ((disjunction != m_pattern.m_body) && (disjunction->m_alternatives.size() > 1))
             initialCallFrameSize += YarrStackSpaceForBackTrackInfoAlternative;
 
@@ -864,6 +850,10 @@ public:
         }
     }
 
+    void setStackBase(uint8_t *stackBase) {
+        m_stackBase = stackBase;
+    }
+
 private:
     YarrPattern& m_pattern;
     uint8_t * m_stackBase;
@@ -877,9 +867,6 @@ ErrorCode YarrPattern::compile(const String& patternString)
 {
     YarrPatternConstructor constructor(*this);
 
-    uint8_t stackDummy_;
-    constructor.setStackBase(&stackDummy_);
-
     if (ErrorCode error = parse(constructor, patternString))
         return error;
 
@@ -900,6 +887,9 @@ ErrorCode YarrPattern::compile(const String& patternString)
         ASSERT(numSubpatterns == m_numSubpatterns);
     }
 
+    uint8_t stackDummy_;
+    constructor.setStackBase(&stackDummy_);
+
     constructor.checkForTerminalParentheses();
     constructor.optimizeDotStarWrappedExpressions();
     constructor.optimizeBOL();