1 files changed, 141 insertions, 0 deletions
diff --git a/js/src/builtin/RegExpLocalReplaceOpt.h.js b/js/src/builtin/RegExpLocalReplaceOpt.h.js
new file mode 100644
index 0000000000..1fb30cb032
--- /dev/null
+++ b/js/src/builtin/RegExpLocalReplaceOpt.h.js
@@ -0,0 +1,141 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Function template for the following functions:
+//   * RegExpLocalReplaceOpt
+//   * RegExpLocalReplaceOptFunc
+//   * RegExpLocalReplaceOptSubst
+// Define the following macro and include this file to declare function:
+//   * FUNC_NAME     -- function name (required)
+//       e.g.
+//         #define FUNC_NAME RegExpLocalReplaceOpt
+// Define the following macro (without value) to switch the code:
+//   * SUBSTITUTION     -- replaceValue is a string with "$"
+//   * FUNCTIONAL       -- replaceValue is a function
+//   * SHORT_STRING     -- replaceValue is a string without "$" and lengthS < 0x7fff
+//   * neither of above -- replaceValue is a string without "$"
+
+// ES 2017 draft 6390c2f1b34b309895d31d8c0512eac8660a0210 21.2.5.8
+// steps 11.a-16.
+// Optimized path for @@replace with the following conditions:
+//   * global flag is false
+function FUNC_NAME(rx, S, lengthS, replaceValue
+#ifdef SUBSTITUTION
+                   , firstDollarIndex
+#endif
+                  )
+{
+    // 21.2.5.2.2 RegExpBuiltinExec, step 4.
+    var lastIndex = ToLength(rx.lastIndex);
+
+    // 21.2.5.2.2 RegExpBuiltinExec, step 5.
+    // Side-effects in step 4 can recompile the RegExp, so we need to read the
+    // flags again and handle the case when global was enabled even though this
+    // function is optimized for non-global RegExps.
+    var flags = UnsafeGetInt32FromReservedSlot(rx, REGEXP_FLAGS_SLOT);
+
+    // 21.2.5.2.2 RegExpBuiltinExec, steps 6-7.
+    var globalOrSticky = !!(flags & (REGEXP_GLOBAL_FLAG | REGEXP_STICKY_FLAG));
+
+    if (globalOrSticky) {
+        // 21.2.5.2.2 RegExpBuiltinExec, step 12.a.
+        if (lastIndex > lengthS) {
+            if (globalOrSticky)
+                rx.lastIndex = 0;
+
+            // Steps 12-16.
+            return S;
+        }
+    } else {
+        // 21.2.5.2.2 RegExpBuiltinExec, step 8.
+        lastIndex = 0;
+    }
+
+#if !defined(SHORT_STRING)
+    // Step 11.a.
+    var result = RegExpMatcher(rx, S, lastIndex);
+
+    // Step 11.b.
+    if (result === null) {
+        // 21.2.5.2.2 RegExpBuiltinExec, steps 12.a.i, 12.c.i.
+        if (globalOrSticky)
+            rx.lastIndex = 0;
+
+        // Steps 12-16.
+        return S;
+    }
+#else
+    // Step 11.a.
+    var result = RegExpSearcher(rx, S, lastIndex);
+
+    // Step 11.b.
+    if (result === -1) {
+        // 21.2.5.2.2 RegExpBuiltinExec, steps 12.a.i, 12.c.i.
+        if (globalOrSticky)
+            rx.lastIndex = 0;
+
+        // Steps 12-16.
+        return S;
+    }
+#endif
+
+    // Steps 11.c, 12-13.
+
+#if !defined(SHORT_STRING)
+    // Steps 14.a-b.
+    assert(result.length >= 1, "RegExpMatcher doesn't return an empty array");
+
+    // Step 14.c.
+    var matched = result[0];
+
+    // Step 14.d.
+    var matchLength = matched.length;
+
+    // Step 14.e-f.
+    var position = result.index;
+
+    // Step 14.m.iii (reordered)
+    // To set rx.lastIndex before RegExpGetFunctionalReplacement.
+    var nextSourcePosition = position + matchLength;
+#else
+    // Steps 14.a-d (skipped).
+
+    // Step 14.e-f.
+    var position = result & 0x7fff;
+
+    // Step 14.l.iii (reordered)
+    var nextSourcePosition = (result >> 15) & 0x7fff;
+#endif
+
+    // 21.2.5.2.2 RegExpBuiltinExec, step 15.
+    if (globalOrSticky)
+       rx.lastIndex = nextSourcePosition;
+
+    var replacement;
+    // Steps g-l.
+#if defined(FUNCTIONAL)
+    replacement = RegExpGetFunctionalReplacement(result, S, position, replaceValue);
+#elif defined(SUBSTITUTION)
+    // Step l.i
+    var namedCaptures = result.groups;
+    if (namedCaptures !== undefined) {
+        namedCaptures = ToObject(namedCaptures);
+    }
+    // Step l.ii
+    replacement = RegExpGetSubstitution(result, S, position, replaceValue, firstDollarIndex,
+                                        namedCaptures);
+#else
+    replacement = replaceValue;
+#endif
+
+    // Step 14.m.ii.
+    var accumulatedResult = Substring(S, 0, position) + replacement;
+
+    // Step 15.
+    if (nextSourcePosition >= lengthS)
+        return accumulatedResult;
+
+    // Step 16.
+    return accumulatedResult + Substring(S, nextSourcePosition, lengthS - nextSourcePosition);
+}