From e5921d70f1555e262e283660df0cfd87698e6c96 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <nnethercote@mozilla.com>
Date: Wed, 16 Mar 2011 15:17:21 -0700
Subject: [PATCH] Bug 639420 - Speed up the scanner ten ways, part 4. 
 r=brendan.

---
 js/src/jsscan.cpp | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/js/src/jsscan.cpp b/js/src/jsscan.cpp
index 65dde60c326..5a88a4cd3e8 100644
--- a/js/src/jsscan.cpp
+++ b/js/src/jsscan.cpp
@@ -296,7 +296,10 @@ TokenStream::getChar()
 
 /*
  * This gets the next char. It does nothing special with EOL sequences, not
- * even updating the line counters.
+ * even updating the line counters.  It can be used safely if (a) the
+ * resulting char is guaranteed to be ungotten (by ungetCharIgnoreEOL()) if
+ * it's an EOL, and (b) the line-related state (lineno, linebase) is not used
+ * before it's ungotten.
  */
 int32
 TokenStream::getCharIgnoreEOL()
@@ -339,7 +342,6 @@ TokenStream::ungetCharIgnoreEOL(int32 c)
 {
     if (c == EOF)
         return;
-    JS_ASSERT(TokenBuf::isRawEOLChar(c));
     JS_ASSERT(!userbuf.atStart());
     userbuf.ungetRawChar();
 }
@@ -1111,30 +1113,30 @@ TokenStream::getTokenInternal()
       decimal:
         bool hasFracOrExp = false;
         while (JS7_ISDEC(c))
-            c = getChar();
+            c = getCharIgnoreEOL();
 
         if (c == '.') {
             hasFracOrExp = true;
             do {
-                c = getChar();
+                c = getCharIgnoreEOL();
             } while (JS7_ISDEC(c));
         }
         if (JS_TOLOWER(c) == 'e') {
             hasFracOrExp = true;
-            c = getChar();
+            c = getCharIgnoreEOL();
             if (c == '+' || c == '-')
-                c = getChar();
+                c = getCharIgnoreEOL();
             if (!JS7_ISDEC(c)) {
-                ungetChar(c);
+                ungetCharIgnoreEOL(c);
                 ReportCompileErrorNumber(cx, this, NULL, JSREPORT_ERROR,
                                          JSMSG_MISSING_EXPONENT);
                 goto error;
             }
             do {
-                c = getChar();
+                c = getCharIgnoreEOL();
             } while (JS7_ISDEC(c));
         }
-        ungetChar(c);
+        ungetCharIgnoreEOL(c);
 
         if (JS_ISIDSTART(c)) {
             ReportCompileErrorNumber(cx, this, NULL, JSREPORT_ERROR, JSMSG_IDSTART_AFTER_NUMBER);
@@ -1166,18 +1168,18 @@ TokenStream::getTokenInternal()
 
     if (c == '0') {
         int radix;
-        c = getChar();
+        c = getCharIgnoreEOL();
         if (JS_TOLOWER(c) == 'x') {
             radix = 16;
-            c = getChar();
+            c = getCharIgnoreEOL();
             if (!JS7_ISHEX(c)) {
-                ungetChar(c);
+                ungetCharIgnoreEOL(c);
                 ReportCompileErrorNumber(cx, this, NULL, JSREPORT_ERROR, JSMSG_MISSING_HEXDIGITS);
                 goto error;
             }
             numStart = userbuf.addressOfNextRawChar() - 1;
             while (JS7_ISHEX(c))
-                c = getChar();
+                c = getCharIgnoreEOL();
         } else if (JS7_ISDEC(c)) {
             radix = 8;
             numStart = userbuf.addressOfNextRawChar() - 1;
@@ -1199,7 +1201,7 @@ TokenStream::getTokenInternal()
                     }
                     goto decimal;   /* use the decimal scanner for the rest of the number */
                 }
-                c = getChar();
+                c = getCharIgnoreEOL();
             }
         } else {
             /* '0' not followed by 'x', 'X' or a digit;  scan as a decimal number. */
@@ -1207,7 +1209,7 @@ TokenStream::getTokenInternal()
             numStart = userbuf.addressOfNextRawChar() - 1;
             goto decimal;
         }
-        ungetChar(c);
+        ungetCharIgnoreEOL(c);
 
         if (JS_ISIDSTART(c)) {
             ReportCompileErrorNumber(cx, this, NULL, JSREPORT_ERROR, JSMSG_IDSTART_AFTER_NUMBER);