diff --git a/config/config.mk b/config/config.mk
index 6360fe2605c..02460d7bd7a 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -256,7 +256,9 @@ endif
 
 endif # WINNT && !GNU_CC
 
-ifndef MOZ_GLUE_PROGRAM_LDFLAGS
+ifdef MOZ_GLUE_PROGRAM_LDFLAGS
+DEFINES += -DMOZ_GLUE_IN_PROGRAM
+else
 MOZ_GLUE_PROGRAM_LDFLAGS=$(MOZ_GLUE_LDFLAGS)
 endif
 
@@ -810,3 +812,21 @@ OBJ_SUFFIX := i_o
 endif
 endif
 endif
+
+# EXPAND_LIBNAME - $(call EXPAND_LIBNAME,foo)
+# expands to $(LIB_PREFIX)foo.$(LIB_SUFFIX) or -lfoo, depending on linker
+# arguments syntax. Should only be used for system libraries
+
+# EXPAND_LIBNAME_PATH - $(call EXPAND_LIBNAME_PATH,foo,dir)
+# expands to dir/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
+
+# EXPAND_MOZLIBNAME - $(call EXPAND_MOZLIBNAME,foo)
+# expands to $(DIST)/lib/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
+
+ifdef GNU_CC
+EXPAND_LIBNAME = $(addprefix -l,$(1))
+else
+EXPAND_LIBNAME = $(foreach lib,$(1),$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
+endif
+EXPAND_LIBNAME_PATH = $(foreach lib,$(1),$(2)/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
+EXPAND_MOZLIBNAME = $(foreach lib,$(1),$(DIST)/lib/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
diff --git a/config/rules.mk b/config/rules.mk
index f06a7ba789b..991052d1fe9 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -92,24 +92,6 @@ ifdef LIBXUL_SDK
 VPATH += $(LIBXUL_SDK)/lib
 endif
 
-# EXPAND_LIBNAME - $(call EXPAND_LIBNAME,foo)
-# expands to $(LIB_PREFIX)foo.$(LIB_SUFFIX) or -lfoo, depending on linker
-# arguments syntax. Should only be used for system libraries
-
-# EXPAND_LIBNAME_PATH - $(call EXPAND_LIBNAME_PATH,foo,dir)
-# expands to dir/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
-
-# EXPAND_MOZLIBNAME - $(call EXPAND_MOZLIBNAME,foo)
-# expands to $(DIST)/lib/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
-
-ifdef GNU_CC
-EXPAND_LIBNAME = $(addprefix -l,$(1))
-else
-EXPAND_LIBNAME = $(foreach lib,$(1),$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-endif
-EXPAND_LIBNAME_PATH = $(foreach lib,$(1),$(2)/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-EXPAND_MOZLIBNAME = $(foreach lib,$(1),$(DIST)/lib/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-
 ifdef EXTRA_DSO_LIBS
 EXTRA_DSO_LIBS	:= $(call EXPAND_MOZLIBNAME,$(EXTRA_DSO_LIBS))
 endif
diff --git a/configure.in b/configure.in
index 51069133670..d983a02ff42 100644
--- a/configure.in
+++ b/configure.in
@@ -9127,12 +9127,12 @@ ac_configure_args="$ac_configure_args --prefix=$dist"
 ac_configure_args="$ac_configure_args --with-sync-build-files=$_topsrcdir"
 if test "$MOZ_MEMORY"; then
    ac_configure_args="$ac_configure_args --enable-jemalloc"
-   if test -n "$MOZ_GLUE_LDFLAGS"; then
-     export MOZ_GLUE_LDFLAGS
-   fi
-   if test -n "$MOZ_GLUE_PROGRAM_LDFLAGS"; then
-     export MOZ_GLUE_PROGRAM_LDFLAGS
-   fi
+fi
+if test -n "$MOZ_GLUE_LDFLAGS"; then
+   export MOZ_GLUE_LDFLAGS
+fi
+if test -n "$MOZ_GLUE_PROGRAM_LDFLAGS"; then
+   export MOZ_GLUE_PROGRAM_LDFLAGS
 fi
 export MOZ_APP_NAME
 AC_OUTPUT_SUBDIRS(js/src)
diff --git a/js/src/Makefile.in b/js/src/Makefile.in
index 28ffcb92db6..1abd09f1621 100644
--- a/js/src/Makefile.in
+++ b/js/src/Makefile.in
@@ -367,8 +367,7 @@ VPATH += 	$(srcdir)/assembler \
 		$(srcdir)/yarr \
 		$(NONE)
 
-CPPSRCS += 	Assertions.cpp \
-		ExecutableAllocator.cpp \
+CPPSRCS += 	ExecutableAllocator.cpp \
 		ARMAssembler.cpp \
 		MacroAssemblerARM.cpp \
 		MacroAssemblerX86Common.cpp \
@@ -490,6 +489,13 @@ endif
 
 include $(topsrcdir)/config/config.mk
 
+ifeq (,$(MOZ_GLUE_PROGRAM_LDFLAGS))
+# When building standalone, we need to include mfbt sources, and to declare
+# "exported" mfbt symbols on its behalf when we use its headers.
+include $(srcdir)/../../mfbt/sources.mk
+DEFINES += -DIMPL_MFBT
+endif
+
 EXTRA_DSO_LDOPTS += $(NSPR_LIBS)
 
 ifndef BUILD_OPT
@@ -669,11 +675,6 @@ distclean::
 
 DEFINES		+= -DEXPORT_JS_API
 
-# mfbt is always packed with us, so if we're building a shared object,
-# we need to declare "exported" mfbt symbols on its behalf when we use
-# its headers.
-DEFINES		+= -DIMPL_MFBT
-
 INCLUDES	+= -I$(srcdir)
 
 ifdef JS_THREADSAFE
diff --git a/js/src/assembler/assembler/MacroAssemblerX86Common.h b/js/src/assembler/assembler/MacroAssemblerX86Common.h
index 373d3cad102..d3e84cc5782 100644
--- a/js/src/assembler/assembler/MacroAssemblerX86Common.h
+++ b/js/src/assembler/assembler/MacroAssemblerX86Common.h
@@ -91,9 +91,11 @@ public:
         DoubleLessThanOrUnordered = X86Assembler::ConditionB,
         DoubleLessThanOrEqualOrUnordered = X86Assembler::ConditionBE
     };
-    COMPILE_ASSERT(
-        !((X86Assembler::ConditionE | X86Assembler::ConditionNE | X86Assembler::ConditionA | X86Assembler::ConditionAE | X86Assembler::ConditionB | X86Assembler::ConditionBE) & DoubleConditionBits),
-        DoubleConditionBits_should_not_interfere_with_X86Assembler_Condition_codes);
+    static void staticAsserts() {
+        COMPILE_ASSERT(
+            !((X86Assembler::ConditionE | X86Assembler::ConditionNE | X86Assembler::ConditionA | X86Assembler::ConditionAE | X86Assembler::ConditionB | X86Assembler::ConditionBE) & DoubleConditionBits),
+            DoubleConditionBits_should_not_interfere_with_X86Assembler_Condition_codes);
+    }
 
     static const RegisterID stackPointerRegister = X86Registers::esp;
 
diff --git a/js/src/assembler/wtf/Assertions.h b/js/src/assembler/wtf/Assertions.h
index 6c9da1e2e8f..537737a5b82 100644
--- a/js/src/assembler/wtf/Assertions.h
+++ b/js/src/assembler/wtf/Assertions.h
@@ -26,6 +26,18 @@
 #ifndef WTF_Assertions_h
 #define WTF_Assertions_h
 
+#include "Platform.h"
+#include "mozilla/Assertions.h"
+
+#define ASSERT(assertion) MOZ_ASSERT(assertion)
+#define ASSERT_UNUSED(variable, assertion) ASSERT(assertion)
+#define ASSERT_NOT_REACHED() MOZ_NOT_REACHED("")
+#define CRASH() MOZ_Crash()
+#define COMPILE_ASSERT(exp, name) MOZ_STATIC_ASSERT(exp, #name)
+
+#endif
+
+#if 0
 /*
    no namespaces because this file has to be includable from C and Objective-C
 
diff --git a/js/src/config/config.mk b/js/src/config/config.mk
index 6360fe2605c..02460d7bd7a 100644
--- a/js/src/config/config.mk
+++ b/js/src/config/config.mk
@@ -256,7 +256,9 @@ endif
 
 endif # WINNT && !GNU_CC
 
-ifndef MOZ_GLUE_PROGRAM_LDFLAGS
+ifdef MOZ_GLUE_PROGRAM_LDFLAGS
+DEFINES += -DMOZ_GLUE_IN_PROGRAM
+else
 MOZ_GLUE_PROGRAM_LDFLAGS=$(MOZ_GLUE_LDFLAGS)
 endif
 
@@ -810,3 +812,21 @@ OBJ_SUFFIX := i_o
 endif
 endif
 endif
+
+# EXPAND_LIBNAME - $(call EXPAND_LIBNAME,foo)
+# expands to $(LIB_PREFIX)foo.$(LIB_SUFFIX) or -lfoo, depending on linker
+# arguments syntax. Should only be used for system libraries
+
+# EXPAND_LIBNAME_PATH - $(call EXPAND_LIBNAME_PATH,foo,dir)
+# expands to dir/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
+
+# EXPAND_MOZLIBNAME - $(call EXPAND_MOZLIBNAME,foo)
+# expands to $(DIST)/lib/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
+
+ifdef GNU_CC
+EXPAND_LIBNAME = $(addprefix -l,$(1))
+else
+EXPAND_LIBNAME = $(foreach lib,$(1),$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
+endif
+EXPAND_LIBNAME_PATH = $(foreach lib,$(1),$(2)/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
+EXPAND_MOZLIBNAME = $(foreach lib,$(1),$(DIST)/lib/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
diff --git a/js/src/config/rules.mk b/js/src/config/rules.mk
index f06a7ba789b..991052d1fe9 100644
--- a/js/src/config/rules.mk
+++ b/js/src/config/rules.mk
@@ -92,24 +92,6 @@ ifdef LIBXUL_SDK
 VPATH += $(LIBXUL_SDK)/lib
 endif
 
-# EXPAND_LIBNAME - $(call EXPAND_LIBNAME,foo)
-# expands to $(LIB_PREFIX)foo.$(LIB_SUFFIX) or -lfoo, depending on linker
-# arguments syntax. Should only be used for system libraries
-
-# EXPAND_LIBNAME_PATH - $(call EXPAND_LIBNAME_PATH,foo,dir)
-# expands to dir/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
-
-# EXPAND_MOZLIBNAME - $(call EXPAND_MOZLIBNAME,foo)
-# expands to $(DIST)/lib/$(LIB_PREFIX)foo.$(LIB_SUFFIX)
-
-ifdef GNU_CC
-EXPAND_LIBNAME = $(addprefix -l,$(1))
-else
-EXPAND_LIBNAME = $(foreach lib,$(1),$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-endif
-EXPAND_LIBNAME_PATH = $(foreach lib,$(1),$(2)/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-EXPAND_MOZLIBNAME = $(foreach lib,$(1),$(DIST)/lib/$(LIB_PREFIX)$(lib).$(LIB_SUFFIX))
-
 ifdef EXTRA_DSO_LIBS
 EXTRA_DSO_LIBS	:= $(call EXPAND_MOZLIBNAME,$(EXTRA_DSO_LIBS))
 endif
diff --git a/js/src/jsapi-tests/Makefile.in b/js/src/jsapi-tests/Makefile.in
index 525e0cea540..b871ff7a9a2 100644
--- a/js/src/jsapi-tests/Makefile.in
+++ b/js/src/jsapi-tests/Makefile.in
@@ -105,6 +105,9 @@ CSRCS = \
 #  $(NULL)
 
 DEFINES         += -DEXPORT_JS_API
+# Building against js_static requires that we declare mfbt sybols "exported"
+# on its behalf.
+DEFINES         += -DIMPL_MFBT
 
 LIBS      = $(DEPTH)/$(LIB_PREFIX)js_static.$(LIB_SUFFIX) $(NSPR_LIBS)
 
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 4a019656b41..be49e1784d1 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -6601,7 +6601,7 @@ JS_AbortIfWrongThread(JSRuntime *rt)
 {
 #ifdef JS_THREADSAFE
     if (!rt->onOwnerThread())
-        JS_Assert("rt->onOwnerThread()", __FILE__, __LINE__);
+        MOZ_Assert("rt->onOwnerThread()", __FILE__, __LINE__);
 #endif
 }
 
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 4663d11d1dd..ee62f0b05bb 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -70,6 +70,8 @@
 
 /************************************************************************/
 
+#define JS_Assert MOZ_Assert
+
 #ifdef __cplusplus
 namespace JS {
 
diff --git a/js/src/jsinfer.cpp b/js/src/jsinfer.cpp
index 707a6bfcb68..6b7c1fb075b 100644
--- a/js/src/jsinfer.cpp
+++ b/js/src/jsinfer.cpp
@@ -349,7 +349,7 @@ types::TypeFailure(JSContext *cx, const char *fmt, ...)
     cx->compartment->types.print(cx, true);
 
     /* Always active, even in release builds */
-    JS_Assert(msgbuf, __FILE__, __LINE__);
+    MOZ_Assert(msgbuf, __FILE__, __LINE__);
     
     *((volatile int *)NULL) = 0;  /* Should never be reached */
 }
diff --git a/js/src/jsutil.cpp b/js/src/jsutil.cpp
index 42578441dfb..5968e70e71c 100644
--- a/js/src/jsutil.cpp
+++ b/js/src/jsutil.cpp
@@ -69,35 +69,6 @@ JS_PUBLIC_DATA(uint32_t) OOM_counter = 0;
  */
 JS_STATIC_ASSERT(sizeof(void *) == sizeof(void (*)()));
 
-static JS_NEVER_INLINE void
-CrashInJS()
-{
-    /*
-     * We write 123 here so that the machine code for this function is
-     * unique. Otherwise the linker, trying to be smart, might use the
-     * same code for CrashInJS and for some other function. That
-     * messes up the signature in minidumps.
-     */
-
-#if defined(WIN32)
-    /*
-     * We used to call DebugBreak() on Windows, but amazingly, it causes
-     * the MSVS 2010 debugger not to be able to recover a call stack.
-     */
-    *((volatile int *) NULL) = 123;
-    exit(3);
-#elif defined(__APPLE__)
-    /*
-     * On Mac OS X, Breakpad ignores signals. Only real Mach exceptions are
-     * trapped.
-     */
-    *((volatile int *) NULL) = 123;  /* To continue from here in GDB: "return" then "continue". */
-    raise(SIGABRT);  /* In case above statement gets nixed by the optimizer. */
-#else
-    raise(SIGABRT);  /* To continue from here in GDB: "signal 0". */
-#endif
-}
-
 /*
  * |JS_Assert| historically took |JSIntn ln| as its last argument.  We've
  * boiled |JSIntn ln| down to simply |int ln| so that mfbt may declare the
@@ -106,14 +77,6 @@ CrashInJS()
  */
 JS_STATIC_ASSERT((tl::IsSameType<JSIntn, int>::result));
 
-JS_PUBLIC_API(void)
-JS_Assert(const char *s, const char *file, int ln)
-{
-    fprintf(stderr, "Assertion failure: %s, at %s:%d\n", s, file, ln);
-    fflush(stderr);
-    CrashInJS();
-}
-
 #ifdef JS_BASIC_STATS
 
 #include <math.h>
diff --git a/js/src/jsutil.h b/js/src/jsutil.h
index a602dc01885..c20fbf14333 100644
--- a/js/src/jsutil.h
+++ b/js/src/jsutil.h
@@ -331,9 +331,9 @@ inline __attribute__ ((unused)) void MUST_FLOW_THROUGH(const char *label) {}
 #ifdef JS_CRASH_DIAGNOSTICS
 # define JS_POISON(p, val, size) memset((p), (val), (size))
 # define JS_OPT_ASSERT(expr)                                                  \
-    ((expr) ? (void)0 : JS_Assert(#expr, __FILE__, __LINE__))
+    ((expr) ? (void)0 : MOZ_Assert(#expr, __FILE__, __LINE__))
 # define JS_OPT_ASSERT_IF(cond, expr)                                         \
-    ((!(cond) || (expr)) ? (void)0 : JS_Assert(#expr, __FILE__, __LINE__))
+    ((!(cond) || (expr)) ? (void)0 : MOZ_Assert(#expr, __FILE__, __LINE__))
 #else
 # define JS_POISON(p, val, size) ((void) 0)
 # define JS_OPT_ASSERT(expr) ((void) 0)
diff --git a/js/src/shell/Makefile.in b/js/src/shell/Makefile.in
index 4df10ed2ff9..cf27c4dc2af 100644
--- a/js/src/shell/Makefile.in
+++ b/js/src/shell/Makefile.in
@@ -53,6 +53,9 @@ CPPSRCS		= \
   $(NULL)
 
 DEFINES         += -DEXPORT_JS_API
+# Building against js_static requires that we declare mfbt sybols "exported"
+# on its behalf.
+DEFINES         += -DIMPL_MFBT
 
 LIBS      = $(NSPR_LIBS) $(EDITLINE_LIBS) $(DEPTH)/$(LIB_PREFIX)js_static.$(LIB_SUFFIX)
 ifdef MOZ_NATIVE_FFI
diff --git a/js/src/vm/Stack.cpp b/js/src/vm/Stack.cpp
index 82d1b8eb730..b410abf9d31 100644
--- a/js/src/vm/Stack.cpp
+++ b/js/src/vm/Stack.cpp
@@ -1052,7 +1052,7 @@ CrashIfInvalidSlot(StackFrame *fp, Value *vp)
     if (vp < fp->slots() || vp >= fp->slots() + fp->script()->nslots) {
         JS_ASSERT(false && "About to dereference invalid slot");
         *(int *)0xbad = 0;  // show up nicely in crash-stats
-        JS_Assert("About to dereference invalid slot", __FILE__, __LINE__);
+        MOZ_Assert("About to dereference invalid slot", __FILE__, __LINE__);
     }
 }
 
diff --git a/mfbt/Assertions.cpp b/mfbt/Assertions.cpp
new file mode 100644
index 00000000000..5259eb7217d
--- /dev/null
+++ b/mfbt/Assertions.cpp
@@ -0,0 +1,91 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sw=4 et tw=99 ft=cpp:
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at:
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Code.
+ *
+ * The Initial Developer of the Original Code is
+ *   The Mozilla Foundation
+ * Portions created by the Initial Developer are Copyright (C) 2012
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Mike Hommey <mh@glandium.org>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Types.h"
+
+#include <cstdio>
+#include <cstdlib>
+#ifndef WIN32
+#include <signal.h>
+#endif
+
+/* Implementations of runtime and static assertion macros for C and C++. */
+
+extern "C" {
+
+MOZ_EXPORT_API(void)
+MOZ_Crash()
+{
+  /*
+   * We write 123 here so that the machine code for this function is
+   * unique. Otherwise the linker, trying to be smart, might use the
+   * same code for MOZ_Crash and for some other function. That
+   * messes up the signature in minidumps.
+   */
+
+#if defined(WIN32)
+  /*
+   * We used to call DebugBreak() on Windows, but amazingly, it causes
+   * the MSVS 2010 debugger not to be able to recover a call stack.
+   */
+  *((volatile int *) NULL) = 123;
+  exit(3);
+#elif defined(__APPLE__)
+  /*
+   * On Mac OS X, Breakpad ignores signals. Only real Mach exceptions are
+   * trapped.
+   */
+  *((volatile int *) NULL) = 123;  /* To continue from here in GDB: "return" then "continue". */
+  raise(SIGABRT);  /* In case above statement gets nixed by the optimizer. */
+#else
+  raise(SIGABRT);  /* To continue from here in GDB: "signal 0". */
+#endif
+}
+
+MOZ_EXPORT_API(void)
+MOZ_Assert(const char* s, const char* file, int ln)
+{
+  fprintf(stderr, "Assertion failure: %s, at %s:%d\n", s, file, ln);
+  fflush(stderr);
+  MOZ_Crash();
+}
+
+}
diff --git a/mfbt/Assertions.h b/mfbt/Assertions.h
index 43cd4e9d34a..097914fc821 100644
--- a/mfbt/Assertions.h
+++ b/mfbt/Assertions.h
@@ -126,26 +126,15 @@
 
 #define MOZ_STATIC_ASSERT_IF(cond, expr, reason)  MOZ_STATIC_ASSERT(!(cond) || (expr), reason)
 
-/*
- * XXX: we're cheating here in order to avoid creating object files
- * for mfbt /just/ to provide a function like FatalError() to be used
- * by MOZ_ASSERT().  (It'll happen eventually, but for just ASSERT()
- * it isn't worth the pain.)  JS_Assert(), although unfortunately
- * named, is part of SpiderMonkey's stable, external API, so this
- * isn't quite as bad as it seems.
- *
- * Once mfbt needs object files, this unholy union with JS_Assert()
- * will be broken.
- *
- * JS_Assert is present even in release builds, for the benefit of applications
- * that build DEBUG and link against a non-DEBUG SpiderMonkey library.
- */
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 extern MFBT_API(void)
-JS_Assert(const char* s, const char* file, int ln);
+MOZ_Crash(void);
+
+extern MFBT_API(void)
+MOZ_Assert(const char* s, const char* file, int ln);
 
 #ifdef __cplusplus
 } /* extern "C" */
@@ -186,10 +175,10 @@ JS_Assert(const char* s, const char* file, int ln);
 #ifdef DEBUG
    /* First the single-argument form. */
 #  define MOZ_ASSERT_HELPER1(expr) \
-     ((expr) ? ((void)0) : JS_Assert(#expr, __FILE__, __LINE__))
+     ((expr) ? ((void)0) : MOZ_Assert(#expr, __FILE__, __LINE__))
    /* Now the two-argument form. */
 #  define MOZ_ASSERT_HELPER2(expr, explain) \
-     ((expr) ? ((void)0) : JS_Assert(#expr " (" explain ")", __FILE__, __LINE__))
+     ((expr) ? ((void)0) : MOZ_Assert(#expr " (" explain ")", __FILE__, __LINE__))
    /* And now, helper macrology up the wazoo. */
    /* Count the number of arguments passed to MOZ_ASSERT. */
 #  define MOZ_COUNT_ASSERT_ARGS(...) \
@@ -239,7 +228,7 @@ JS_Assert(const char* s, const char* file, int ln);
  *   }
  */
 #ifdef DEBUG
-#  define MOZ_NOT_REACHED(reason)    JS_Assert(reason, __FILE__, __LINE__)
+#  define MOZ_NOT_REACHED(reason)    MOZ_Assert(reason, __FILE__, __LINE__)
 #else
 #  define MOZ_NOT_REACHED(reason)    ((void)0)
 #endif
diff --git a/mfbt/GuardObjects.h b/mfbt/GuardObjects.h
index 7a134d65591..2e50405b062 100644
--- a/mfbt/GuardObjects.h
+++ b/mfbt/GuardObjects.h
@@ -100,7 +100,7 @@ namespace detail {
  * For more details, and examples of using these macros, see
  * https://developer.mozilla.org/en/Using_RAII_classes_in_Mozilla
  */
-class MFBT_API(GuardObjectNotifier)
+class MOZ_EXPORT_API(GuardObjectNotifier)
 {
   private:
     bool* statementDone;
@@ -117,7 +117,7 @@ class MFBT_API(GuardObjectNotifier)
     }
 };
 
-class MFBT_API(GuardObjectNotificationReceiver)
+class MOZ_EXPORT_API(GuardObjectNotificationReceiver)
 {
   private:
     bool statementDone;
diff --git a/mfbt/Makefile.in b/mfbt/Makefile.in
index 9a0b26cf79a..4755f42632d 100644
--- a/mfbt/Makefile.in
+++ b/mfbt/Makefile.in
@@ -42,6 +42,11 @@ VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+MODULE = mozglue
+LIBRARY_NAME = mfbt
+FORCE_STATIC_LIB = 1
+STL_FLAGS =
+
 DIRS =
 
 # exported_headers.mk defines the headers exported by mfbt.  It is included by
@@ -49,4 +54,11 @@ DIRS =
 # work to install mfbt's exported headers itself.
 include $(srcdir)/exported_headers.mk
 
+# sources.mk defines the source files built for mfbt. It is included by mfbt
+# itself and by the JS engine, which, when built standalone, must do the work
+# to build mfbt sources itself.
+include $(srcdir)/sources.mk
+
+DEFINES += -DIMPL_MFBT
+
 include $(topsrcdir)/config/rules.mk
diff --git a/mfbt/Types.h b/mfbt/Types.h
index 17de4d9841e..7a122890662 100644
--- a/mfbt/Types.h
+++ b/mfbt/Types.h
@@ -129,8 +129,17 @@
 #  define MFBT_API(type)        MOZ_EXPORT_API(type)
 #  define MFBT_DATA(type)       MOZ_EXPORT_DATA(type)
 #else
-#  define MFBT_API(type)        MOZ_IMPORT_API(type)
-#  define MFBT_DATA(type)       MOZ_IMPORT_DATA(type)
+  /*
+   * When mozglue is linked in the program, we need the MFBT API symbols
+   * to be weak.
+   */
+#  if defined(MOZ_GLUE_IN_PROGRAM)
+#    define MFBT_API(type)        __attribute__((weak)) MOZ_IMPORT_API(type)
+#    define MFBT_DATA(type)       __attribute__((weak)) MOZ_IMPORT_DATA(type)
+#  else
+#    define MFBT_API(type)        MOZ_IMPORT_API(type)
+#    define MFBT_DATA(type)       MOZ_IMPORT_DATA(type)
+#  endif
 #endif
 
 /*
diff --git a/mfbt/sources.mk b/mfbt/sources.mk
new file mode 100644
index 00000000000..747a8b3861d
--- /dev/null
+++ b/mfbt/sources.mk
@@ -0,0 +1,3 @@
+CPPSRCS += \
+  Assertions.cpp \
+  $(NULL)
diff --git a/mozglue/build/Makefile.in b/mozglue/build/Makefile.in
index 07702ff470b..986a6c5e452 100644
--- a/mozglue/build/Makefile.in
+++ b/mozglue/build/Makefile.in
@@ -93,6 +93,8 @@ ifdef MOZ_LINKER
 SHARED_LIBRARY_LIBS += $(call EXPAND_LIBNAME_PATH,linker,../linker)
 endif
 
+SHARED_LIBRARY_LIBS += $(call EXPAND_LIBNAME_PATH,mfbt,$(DEPTH)/mfbt)
+
 ifeq (Android, $(OS_TARGET))
 WRAP_LDFLAGS =
 endif