diff -r 000000000000 -r 6474c204b198 js/src/jit/IonLinker.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/IonLinker.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,108 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#ifndef jit_IonLinker_h
+#define jit_IonLinker_h
+
+#include "jscntxt.h"
+#include "jscompartment.h"
+#include "jsgc.h"
+
+#include "assembler/jit/ExecutableAllocator.h"
+#include "jit/IonCode.h"
+#include "jit/IonMacroAssembler.h"
+#include "jit/JitCompartment.h"
+
+namespace js {
+namespace jit {
+
+class Linker
+{
+    MacroAssembler &masm;
+
+    JitCode *fail(JSContext *cx) {
+        js_ReportOutOfMemory(cx);
+        return nullptr;
+    }
+
+    template <AllowGC allowGC>
+    JitCode *newCode(JSContext *cx, JSC::ExecutableAllocator *execAlloc, JSC::CodeKind kind) {
+        JS_ASSERT(kind == JSC::ION_CODE ||
+                  kind == JSC::BASELINE_CODE ||
+                  kind == JSC::OTHER_CODE);
+        JS_ASSERT(masm.numAsmJSAbsoluteLinks() == 0);
+
+        gc::AutoSuppressGC suppressGC(cx);
+        if (masm.oom())
+            return fail(cx);
+
+        JSC::ExecutablePool *pool;
+        size_t bytesNeeded = masm.bytesNeeded() + sizeof(JitCode *) + CodeAlignment;
+        if (bytesNeeded >= MAX_BUFFER_SIZE)
+            return fail(cx);
+
+        // ExecutableAllocator requires bytesNeeded to be word-size aligned.
+        bytesNeeded = AlignBytes(bytesNeeded, sizeof(void *));
+
+        uint8_t *result = (uint8_t *)execAlloc->alloc(bytesNeeded, &pool, kind);
+        if (!result)
+            return fail(cx);
+
+        // The JitCode pointer will be stored right before the code buffer.
+        uint8_t *codeStart = result + sizeof(JitCode *);
+
+        // Bump the code up to a nice alignment.
+        codeStart = (uint8_t *)AlignBytes((uintptr_t)codeStart, CodeAlignment);
+        uint32_t headerSize = codeStart - result;
+        JitCode *code = JitCode::New<allowGC>(cx, codeStart, bytesNeeded - headerSize,
+                                              headerSize, pool, kind);
+        if (!code)
+            return nullptr;
+        if (masm.oom())
+            return fail(cx);
+        code->copyFrom(masm);
+        masm.link(code);
+#ifdef JSGC_GENERATIONAL
+        if (masm.embedsNurseryPointers())
+            cx->runtime()->gcStoreBuffer.putWholeCell(code);
+#endif
+        return code;
+    }
+
+  public:
+    Linker(MacroAssembler &masm)
+      : masm(masm)
+    {
+        masm.finish();
+    }
+
+    template <AllowGC allowGC>
+    JitCode *newCode(JSContext *cx, JSC::CodeKind kind) {
+        return newCode<allowGC>(cx, cx->runtime()->jitRuntime()->execAlloc(), kind);
+    }
+
+    JitCode *newCodeForIonScript(JSContext *cx) {
+#ifdef JS_CODEGEN_ARM
+        // ARM does not yet use implicit interrupt checks, see bug 864220.
+        return newCode<CanGC>(cx, JSC::ION_CODE);
+#else
+        // The caller must lock the runtime against interrupt requests, as the
+        // thread requesting an interrupt may use the executable allocator below.
+        JS_ASSERT(cx->runtime()->currentThreadOwnsInterruptLock());
+
+        JSC::ExecutableAllocator *alloc = cx->runtime()->jitRuntime()->getIonAlloc(cx);
+        if (!alloc)
+            return nullptr;
+
+        return newCode<CanGC>(cx, alloc, JSC::ION_CODE);
+#endif
+    }
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_IonLinker_h */