--- a/build/autoconf/compiler-opts.m4
+++ b/build/autoconf/compiler-opts.m4
@@ -235,16 +235,23 @@ if test "$GNU_CC" -a -n "$MOZ_FORCE_GOLD
             if $CC -B $_objdir/build/unix/gold -Wl,--version 2>&1 | grep -q "GNU gold"; then
                 LDFLAGS="$LDFLAGS -B $_objdir/build/unix/gold"
             else
                 rm -rf $_objdir/build/unix/gold
             fi
         fi
     fi
 fi
+if test "$GNU_CC"; then
+    if $CC $LDFLAGS -Wl,--version 2>&1 | grep -q "GNU ld"; then
+        LD_IS_BFD=1
+    fi
+fi
+
+AC_SUBST([LD_IS_BFD])
 
 if test "$GNU_CC"; then
     if test -z "$DEVELOPER_OPTIONS"; then
         CFLAGS="$CFLAGS -ffunction-sections -fdata-sections"
         CXXFLAGS="$CXXFLAGS -ffunction-sections -fdata-sections"
     fi
     CFLAGS="$CFLAGS -fno-math-errno"
     CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-math-errno"

--- a/config/config.mk
+++ b/config/config.mk
@@ -817,16 +817,17 @@ endif
 
 ifeq (,$(filter $(OS_TARGET),WINNT Darwin))
 CHECK_TEXTREL = @$(TOOLCHAIN_PREFIX)readelf -d $(1) | grep TEXTREL > /dev/null && echo 'TEST-UNEXPECTED-FAIL | check_textrel | We do not want text relocations in libraries and programs' || true
 endif
 
 define CHECK_BINARY
 $(call CHECK_STDCXX,$(1))
 $(call CHECK_TEXTREL,$(1))
+$(call LOCAL_CHECKS,$(1))
 endef
 
 # autoconf.mk sets OBJ_SUFFIX to an error to avoid use before including
 # this file
 OBJ_SUFFIX := $(_OBJ_SUFFIX)
 
 # PGO builds with GCC build objects with instrumentation in a first pass,
 # then objects optimized, without instrumentation, in a second pass. If

new file mode 100644
--- /dev/null
+++ b/toolkit/library/StaticXULComponents.ld
@@ -0,0 +1,5 @@
+SECTIONS {
+  .data.rel.ro : {
+    *(.kPStaticModules)
+  }
+}

new file mode 100644
--- /dev/null
+++ b/toolkit/library/StaticXULComponentsEnd/StaticXULComponentsEnd.cpp
@@ -0,0 +1,14 @@
+#include "mozilla/Module.h"
+#include "mozilla/NullPtr.h"
+
+/* Ensure end_kPStaticModules is at the end of the .kPStaticModules section
+ * on Windows. Somehow, placing the object last is not enough with PGO/LTCG. */
+#ifdef _MSC_VER
+/* Sections on Windows are in two parts, separated with $. When linking,
+ * sections with the same first part are all grouped, and ordered
+ * alphabetically with the second part as sort key. */
+#  pragma section(".kPStaticModules$Z", read)
+#  undef NSMODULE_SECTION
+#  define NSMODULE_SECTION __declspec(allocate(".kPStaticModules$Z"), dllexport)
+#endif
+NSMODULE_DEFN(end_kPStaticModules) = nullptr;

new file mode 100644
--- /dev/null
+++ b/toolkit/library/StaticXULComponentsEnd/moz.build
@@ -0,0 +1,11 @@
+# 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/.
+
+SOURCES += [
+    'StaticXULComponentsEnd.cpp',
+]
+
+LIBRARY_NAME = 'StaticXULComponentsEnd'
+
+DEFINES['MOZILLA_INTERNAL_API'] = True

new file mode 100644
--- /dev/null
+++ b/toolkit/library/StaticXULComponentsStart.cpp
@@ -0,0 +1,4 @@
+#include "mozilla/Module.h"
+#include "mozilla/NullPtr.h"
+
+NSMODULE_DEFN(start_kPStaticModules) = nullptr;

--- a/toolkit/library/libxul.mk
+++ b/toolkit/library/libxul.mk
@@ -241,8 +241,33 @@ LIBXUL_AUTOLOAD = $(topsrcdir)/toolkit/l
 LIBXUL_AUTOLOAD_FLAGS := -Dtopsrcdir=$(abspath $(topsrcdir))
 endif
 
 OS_LIBS += $(LIBICONV)
 
 ifeq ($(MOZ_WIDGET_TOOLKIT),windows)
 OS_LIBS += $(call EXPAND_LIBNAME,usp10 oleaut32)
 endif
+
+EXTRA_DSO_LDOPTS += $(call EXPAND_LIBNAME_PATH,StaticXULComponentsEnd,$(DEPTH)/toolkit/library/StaticXULComponentsEnd)
+
+# BFD ld doesn't create multiple PT_LOADs as usual when an unknown section
+# exists. Using an implicit linker script to make it fold that section in
+# .data.rel.ro makes it create multiple PT_LOADs. That implicit linker
+# script however makes gold misbehave, first because it doesn't like that
+# the linker script is given after crtbegin.o, and even past that, replaces
+# the default section rules with those from the script instead of
+# supplementing them. Which leads to a lib with a huge load of sections.
+ifdef LD_IS_BFD
+EXTRA_DSO_LDOPTS += $(topsrcdir)/toolkit/library/StaticXULComponents.ld
+endif
+
+ifeq (WINNT,$(OS_TARGET))
+get_first_and_last = dumpbin -exports $1 | grep _NSModule@@ | sort -k 3 | sed -n 's/^.*?\([^@]*\)@@.*$$/\1/;1p;$$p'
+else
+get_first_and_last = $(TOOLCHAIN_PREFIX)nm -g $1 | grep _NSModule$$ | sort | sed -n 's/^.* _*\([^ ]*\)$$/\1/;1p;$$p'
+endif
+
+LOCAL_CHECKS = test "$$($(get_first_and_last) | xargs echo)" != "start_kPStaticModules_NSModule end_kPStaticModules_NSModule" && echo "NSModules are not ordered appropriately" && exit 1 || exit 0
+
+ifeq (Linux,$(OS_ARCH))
+LOCAL_CHECKS += ; test "$$($(TOOLCHAIN_PREFIX)readelf -l $1 | awk '$1 == "LOAD" { t += 1 } END { print t }')" -le 1 && echo "Only one PT_LOAD segment" && exit 1 || exit 0
+endif

--- a/toolkit/library/moz.build
+++ b/toolkit/library/moz.build
@@ -2,59 +2,34 @@
 # vim: set filetype=python:
 # 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/.
 
 LIBRARY_NAME = 'xul'
 
 SOURCES += [
-    'nsStaticXULComponents.cpp',
+    'StaticXULComponentsStart.cpp',
 ]
 
+# This, combined with the fact the file is first, makes the start pointer
+# it contains first in Windows PGO builds.
+SOURCES['StaticXULComponentsStart.cpp'].no_pgo = True
+
 if CONFIG['OS_ARCH'] == 'WINNT':
     SOURCES += [
         'nsDllMain.cpp',
     ]
 
-# component libraries
-additional_defines = (
-    'MOZ_AUTH_EXTENSION',
-    'MOZ_GIO_COMPONENT',
-    'MOZ_JSDEBUGGER',
-    'MOZ_PERMISSIONS',
-    'MOZ_PREF_EXTENSIONS',
-    'MOZ_SPELLCHECK',
-    'MOZ_UNIVERSALCHARDET',
-    'MOZ_ZIPWRITER',
-)
-
-for var in additional_defines:
-    if CONFIG[var]:
-        DEFINES[var] = True
-
-if CONFIG['MOZ_DEBUG'] and CONFIG['ENABLE_TESTS']:
-    DEFINES['ENABLE_LAYOUTDEBUG'] = True
-
-if CONFIG['MOZ_WIDGET_TOOLKIT'] not in ('android', 'gonk', 'qt',
-                                        'cocoa', 'windows') and \
-   CONFIG['MOZ_XUL']:
-    DEFINES['MOZ_FILEVIEW'] = True
-
-# Platform-specific icon channel stuff - supported mostly-everywhere
-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('windows', 'mac', 'cocoa',
-                                    'gtk2', 'gtk3', 'qt', 'android'):
-    DEFINES['ICON_DECODER'] = True
-
 LOCAL_INCLUDES += [
     '/config',
     # need widget/windows for resource.h (included from widget.rc)
     '/widget/windows',
 ]
 
 if CONFIG['OS_ARCH'] == 'WINNT' and not CONFIG['GNU_CC']:
     LOCAL_INCLUDES += [
         '/xpcom/base',
     ]
 
 FAIL_ON_WARNINGS = True
 
-DIRS += ['build', 'gtest']
+DIRS += ['StaticXULComponentsEnd', 'build', 'gtest']

deleted file mode 100644
--- a/toolkit/library/nsStaticXULComponents.cpp
+++ /dev/null
@@ -1,276 +0,0 @@
-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/* 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/. */
-
-#include "mozilla/Module.h"
-#include "nsXPCOM.h"
-#include "nsMemory.h"
-
-#ifdef MOZ_AUTH_EXTENSION
-#define AUTH_MODULE    MODULE(nsAuthModule)
-#else
-#define AUTH_MODULE
-#endif
-
-#ifdef MOZ_PERMISSIONS
-#define PERMISSIONS_MODULES                  \
-    MODULE(nsCookieModule)                   \
-    MODULE(nsPermissionsModule)
-#else
-#define PERMISSIONS_MODULES
-#endif
-
-#ifdef MOZ_UNIVERSALCHARDET
-#define UNIVERSALCHARDET_MODULE MODULE(nsUniversalCharDetModule)
-#else
-#define UNIVERSALCHARDET_MODULE
-#endif
-
-#ifdef XP_WIN
-#  define WIDGET_MODULES MODULE(nsWidgetModule)
-#elif defined(XP_MACOSX)
-#  define WIDGET_MODULES MODULE(nsWidgetMacModule)
-#elif defined(MOZ_WIDGET_GTK)
-#  define WIDGET_MODULES MODULE(nsWidgetGtk2Module)
-#elif defined(MOZ_WIDGET_QT)
-#  define WIDGET_MODULES MODULE(nsWidgetQtModule)
-#elif defined(MOZ_WIDGET_ANDROID)
-#  define WIDGET_MODULES MODULE(nsWidgetAndroidModule)
-#elif defined(MOZ_WIDGET_GONK)
-#  define WIDGET_MODULES MODULE(nsWidgetGonkModule)
-#else
-#  error Unknown widget module.
-#endif
-
-#ifndef MOZ_B2G
-#define CONTENT_PROCESS_WIDGET_MODULES MODULE(nsContentProcessWidgetModule)
-#else
-#define CONTENT_PROCESS_WIDGET_MODULES
-#endif
-
-#ifdef ICON_DECODER
-#define ICON_MODULE MODULE(nsIconDecoderModule)
-#else
-#define ICON_MODULE
-#endif
-
-#ifdef MOZ_ENABLE_XREMOTE
-#define XREMOTE_MODULES MODULE(RemoteServiceModule)
-#else
-#define XREMOTE_MODULES
-#endif
-
-#ifdef MOZ_PREF_EXTENSIONS
-#define SYSTEMPREF_MODULES MODULE(nsAutoConfigModule)
-#else
-#define SYSTEMPREF_MODULES
-#endif
-
-#ifdef ENABLE_LAYOUTDEBUG
-#define LAYOUT_DEBUG_MODULE MODULE(nsLayoutDebugModule)
-#else
-#define LAYOUT_DEBUG_MODULE
-#endif
-
-#ifdef MOZ_JSDEBUGGER
-#define JSDEBUGGER_MODULES \
-    MODULE(JavaScript_Debugger)
-#else
-#define JSDEBUGGER_MODULES
-#endif
-
-#if defined(MOZ_FILEVIEW) && defined(MOZ_XUL)
-#define FILEVIEW_MODULE MODULE(nsFileViewModule)
-#else
-#define FILEVIEW_MODULE
-#endif
-
-#ifdef MOZ_ZIPWRITER
-#define ZIPWRITER_MODULE MODULE(ZipWriterModule)
-#else
-#define ZIPWRITER_MODULE
-#endif
-
-#ifdef MOZ_PLACES
-#define PLACES_MODULES \
-    MODULE(nsPlacesModule)
-#else
-#define PLACES_MODULES
-#endif
-
-#ifdef MOZ_XUL
-#define XULENABLED_MODULES                   \
-    MODULE(tkAutoCompleteModule)             \
-    MODULE(satchel)                          \
-    MODULE(PKI)
-#else
-#define XULENABLED_MODULES
-#endif
-
-#ifdef MOZ_SPELLCHECK
-#define SPELLCHECK_MODULE MODULE(mozSpellCheckerModule)
-#else
-#define SPELLCHECK_MODULE
-#endif
-
-#ifdef MOZ_XUL
-#ifdef MOZ_WIDGET_GTK
-#define UNIXPROXY_MODULE MODULE(nsUnixProxyModule)
-#endif
-#if defined(MOZ_WIDGET_QT)
-#define UNIXPROXY_MODULE MODULE(nsUnixProxyModule)
-#endif
-#endif
-#ifndef UNIXPROXY_MODULE
-#define UNIXPROXY_MODULE
-#endif
-
-#if defined(XP_MACOSX)
-#define OSXPROXY_MODULE MODULE(nsOSXProxyModule)
-#else
-#define OSXPROXY_MODULE
-#endif
-
-#if defined(XP_WIN)
-#define WINDOWSPROXY_MODULE MODULE(nsWindowsProxyModule)
-#else
-#define WINDOWSPROXY_MODULE
-#endif
-
-#if defined(MOZ_WIDGET_ANDROID)
-#define ANDROIDPROXY_MODULE MODULE(nsAndroidProxyModule)
-#else
-#define ANDROIDPROXY_MODULE
-#endif
-
-#if defined(BUILD_CTYPES)
-#define JSCTYPES_MODULE MODULE(jsctypes)
-#else
-#define JSCTYPES_MODULE
-#endif
-
-#ifndef MOZ_APP_COMPONENT_MODULES
-#if defined(MOZ_APP_COMPONENT_INCLUDE)
-#include MOZ_APP_COMPONENT_INCLUDE
-#define MOZ_APP_COMPONENT_MODULES APP_COMPONENT_MODULES
-#else
-#define MOZ_APP_COMPONENT_MODULES
-#endif
-#endif
-
-#if defined(MOZ_ENABLE_PROFILER_SPS)
-#define PROFILER_MODULE MODULE(nsProfilerModule)
-#else
-#define PROFILER_MODULE
-#endif
-
-#if defined(MOZ_WEBRTC)
-#define PEERCONNECTION_MODULE MODULE(peerconnection)
-#else
-#define PEERCONNECTION_MODULE
-#endif
-
-#if defined(MOZ_GIO_COMPONENT)
-#define GIO_MODULE MODULE(nsGIOModule)
-#else
-#define GIO_MODULE
-#endif
-
-#if defined(MOZ_SYNTH_PICO)
-#define SYNTH_PICO_MODULE MODULE(synthpico)
-#else
-#define SYNTH_PICO_MODULE
-#endif
-
-#define XUL_MODULES                          \
-    MODULE(nsUConvModule)                    \
-    MODULE(nsI18nModule)                     \
-    MODULE(nsChardetModule)                  \
-    UNIVERSALCHARDET_MODULE                  \
-    MODULE(necko)                            \
-    PERMISSIONS_MODULES                      \
-    AUTH_MODULE                              \
-    MODULE(nsJarModule)                      \
-    ZIPWRITER_MODULE                         \
-    MODULE(StartupCacheModule)               \
-    MODULE(nsPrefModule)                     \
-    MODULE(nsRDFModule)                      \
-    MODULE(nsWindowDataSourceModule)         \
-    MODULE(nsParserModule)                   \
-    MODULE(nsImageLib2Module)                \
-    MODULE(nsMediaSnifferModule)             \
-    MODULE(nsGfxModule)                      \
-    PROFILER_MODULE                          \
-    WIDGET_MODULES                           \
-    CONTENT_PROCESS_WIDGET_MODULES           \
-    ICON_MODULE                              \
-    MODULE(nsPluginModule)                   \
-    MODULE(nsLayoutModule)                   \
-    MODULE(docshell_provider)                \
-    MODULE(embedcomponents)                  \
-    MODULE(Browser_Embedding_Module)         \
-    MODULE(appshell)                         \
-    MODULE(nsTransactionManagerModule)       \
-    MODULE(nsComposerModule)                 \
-    MODULE(application)                      \
-    MODULE(Apprunner)                        \
-    MODULE(CommandLineModule)                \
-    FILEVIEW_MODULE                          \
-    MODULE(mozStorageModule)                 \
-    PLACES_MODULES                           \
-    XULENABLED_MODULES                       \
-    MODULE(nsToolkitCompsModule)             \
-    XREMOTE_MODULES                          \
-    JSDEBUGGER_MODULES                       \
-    MODULE(BOOT)                             \
-    MODULE(NSS)                              \
-    SYSTEMPREF_MODULES                       \
-    SPELLCHECK_MODULE                        \
-    LAYOUT_DEBUG_MODULE                      \
-    UNIXPROXY_MODULE                         \
-    OSXPROXY_MODULE                          \
-    WINDOWSPROXY_MODULE                      \
-    ANDROIDPROXY_MODULE                      \
-    JSCTYPES_MODULE                          \
-    MODULE(jsreflect)                        \
-    MODULE(jsperf)                           \
-    MODULE(identity)                         \
-    MODULE(nsServicesCryptoModule)           \
-    MOZ_APP_COMPONENT_MODULES                \
-    MODULE(nsTelemetryModule)                \
-    MODULE(jsinspector)                      \
-    MODULE(jsdebugger)                       \
-    PEERCONNECTION_MODULE                    \
-    GIO_MODULE                               \
-    SYNTH_PICO_MODULE                        \
-    MODULE(DiskSpaceWatcherModule)           \
-    /* end of list */
-
-#define MODULE(_name) \
-  NSMODULE_DECL(_name);
-
-XUL_MODULES
-
-#ifdef MOZ_WIDGET_GONK
-MODULE(WifiCertServiceModule)
-MODULE(WifiProxyServiceModule)
-MODULE(NetworkWorkerModule)
-#endif
-
-#undef MODULE
-
-#define MODULE(_name) \
-    &NSMODULE_NAME(_name),
-
-extern const mozilla::Module *const *const kPStaticModules[] = {
-  XUL_MODULES
-#ifdef MOZ_WIDGET_GONK
-MODULE(WifiCertServiceModule)
-MODULE(WifiProxyServiceModule)
-MODULE(NetworkWorkerModule)
-#endif
-  nullptr
-};
-
-#undef MODULE

--- a/xpcom/components/Module.h
+++ b/xpcom/components/Module.h
@@ -113,16 +113,29 @@ struct Module
   LoadFuncPtr loadProc;
   UnloadFuncPtr unloadProc;
 };
 
 } // namespace
 
 #if defined(MOZILLA_INTERNAL_API)
 #  define NSMODULE_NAME(_name) _name##_NSModule
-#  define NSMODULE_DECL(_name) extern mozilla::Module const *const NSMODULE_NAME(_name)
-#  define NSMODULE_DEFN(_name) NSMODULE_DECL(_name)
+#  if defined(_MSC_VER)
+#    pragma section(".kPStaticModules$M", read)
+#    pragma comment(linker, "/merge:.kPStaticModules=.rdata")
+#    define NSMODULE_SECTION __declspec(allocate(".kPStaticModules$M"), dllexport)
+#  elif defined(__GNUC__)
+#    if defined(__ELF__)
+#      define NSMODULE_SECTION __attribute__((section(".kPStaticModules"), visibility("protected")))
+#    elif defined(__MACH__)
+#      define NSMODULE_SECTION __attribute__((section("__DATA, .kPStaticModules"), visibility("default")))
+#    endif
+#  endif
+#  if !defined(NSMODULE_SECTION)
+#    error Do not know how to define sections.
+#  endif
+#  define NSMODULE_DEFN(_name) extern NSMODULE_SECTION mozilla::Module const *const NSMODULE_NAME(_name)
 #else
 #  define NSMODULE_NAME(_name) NSModule
 #  define NSMODULE_DEFN(_name) extern "C" NS_EXPORT mozilla::Module const *const NSModule
 #endif
 
 #endif // mozilla_Module_h

--- a/xpcom/components/nsComponentManager.cpp
+++ b/xpcom/components/nsComponentManager.cpp
@@ -76,20 +76,16 @@
 #include "mozilla/Omnijar.h"
 
 #include "prlog.h"
 
 using namespace mozilla;
 
 PRLogModuleInfo* nsComponentManagerLog = nullptr;
 
-// defined in nsStaticXULComponents.cpp to contain all the components in
-// libxul.
-extern mozilla::Module const *const *const kPStaticModules[];
-
 #if 0 || defined (DEBUG_timeless)
  #define SHOW_DENIED_ON_SHUTDOWN
  #define SHOW_CI_ON_EXISTING_SERVICE
 #endif
 
 // Bloated registry buffer size to improve startup performance -- needs to
 // be big enough to fit the entire file into memory or it'll thrash.
 // 512K is big enough to allow for some future growth in the registry.
@@ -273,26 +269,36 @@ nsComponentManagerImpl::nsComponentManag
     , mContractIDs(CONTRACTID_HASHTABLE_INITIAL_SIZE)
     , mLock("nsComponentManagerImpl.mLock")
     , mStatus(NOT_INITIALIZED)
 {
 }
 
 nsTArray<const mozilla::Module*>* nsComponentManagerImpl::sStaticModules;
 
+NSMODULE_DEFN(start_kPStaticModules);
+NSMODULE_DEFN(end_kPStaticModules);
+
+/* The content between start_kPStaticModules and end_kPStaticModules is gathered
+ * by the linker from various objects containing symbols in a specific section.
+ * ASAN considers (rightfully) the use of this content as a global buffer
+ * overflow. But this is a deliberate and well-considered choice, with no proper
+ * way to make ASAN happy. */
+MOZ_ASAN_BLACKLIST
 /* static */ void
 nsComponentManagerImpl::InitializeStaticModules()
 {
     if (sStaticModules)
         return;
 
     sStaticModules = new nsTArray<const mozilla::Module*>;
-    for (const mozilla::Module *const *const *staticModules = kPStaticModules;
-         *staticModules; ++staticModules)
-        sStaticModules->AppendElement(**staticModules);
+    for (const mozilla::Module *const *staticModules = &NSMODULE_NAME(start_kPStaticModules) + 1;
+         staticModules < &NSMODULE_NAME(end_kPStaticModules); ++staticModules)
+        if (*staticModules) // ASAN adds padding
+            sStaticModules->AppendElement(*staticModules);
 }
 
 nsTArray<nsComponentManagerImpl::ComponentLocation>*
 nsComponentManagerImpl::sModuleLocations;
 
 /* static */ void
 nsComponentManagerImpl::InitializeModuleLocations()
 {