Bug 1598196 - Support disabling the linker on Android in the code. r=froydnj

For now, there is no flag to actually allow it, but this is the
code-side changes to allow the linker being disabled.

Differential Revision: https://phabricator.services.mozilla.com/D54074

--HG--
extra : moz-landing-system : lando

mozglue/android/APKOpen.cpp

@@ -31,7 +31,7 @@
 #include "sqlite3.h"
 #include "SQLiteBridge.h"
 #include "NSSBridge.h"
-#include "ElfLoader.h"
+#include "Linker.h"
 #include "application.ini.h"
 
 #include "mozilla/arm.h"
@@ -99,7 +99,7 @@ JavaVM* sJavaVM;
 
 void abortThroughJava(const char* msg) {
   struct sigaction sigact = {};
-  if (SEGVHandler::__wrap_sigaction(SIGSEGV, nullptr, &sigact)) {
+  if (__wrap_sigaction(SIGSEGV, nullptr, &sigact)) {
     return;  // sigaction call failed.
   }
 
@@ -373,9 +373,13 @@ Java_org_mozilla_gecko_mozglue_GeckoLoader_nativeRun(JNIEnv* jenv, jclass jc,
       return;
     }
 
+#ifdef MOZ_LINKER
     ElfLoader::Singleton.ExpectShutdown(false);
+#endif
     gBootstrap->GeckoStart(jenv, argv, argc, sAppData);
+#ifdef MOZ_LINKER
     ElfLoader::Singleton.ExpectShutdown(true);
+#endif
   } else {
     gBootstrap->XRE_SetAndroidChildFds(
         jenv, {prefsFd, prefMapFd, ipcFd, crashFd, crashAnnotationFd});

mozglue/android/NSSBridge.cpp

@@ -11,7 +11,7 @@
 #  include <android/log.h>
 #endif
 
-#include "ElfLoader.h"
+#include "Linker.h"
 
 #ifdef DEBUG
 #  define LOG(x...) __android_log_print(ANDROID_LOG_INFO, "GeckoJNI", x)

mozglue/android/SQLiteBridge.cpp

@@ -4,11 +4,12 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <jni.h>
 #include <android/log.h>
 #include "dlfcn.h"
 #include "APKOpen.h"
-#include "ElfLoader.h"
+#include "Linker.h"
 #include "SQLiteBridge.h"
 
 #ifdef DEBUG

mozglue/baseprofiler/core/shared-libraries-linux.cc

@@ -35,7 +35,7 @@
 
 #  if defined(MOZ_LINKER)
 #    include "AutoObjectMapper.h"
-#    include "ElfLoader.h"  // dl_phdr_info
+#    include "Linker.h"  // dl_phdr_info
 #  elif defined(GP_OS_linux) || defined(GP_OS_android)
 #    include <link.h>  // dl_phdr_info
 #  else

mozglue/linker/ElfLoader.cpp

@@ -1322,5 +1322,3 @@ int SEGVHandler::__wrap_sigaction(int signum, const struct sigaction* act,
   if (act) that.action = *act;
   return 0;
 }
-
-Logging Logging::Singleton;

mozglue/linker/Linker.h

@@ -0,0 +1,24 @@
+/* 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 Linker_h
+#define Linker_h
+
+#ifdef MOZ_LINKER
+#  include "ElfLoader.h"
+#  define __wrap_sigaction SEGVHandler::__wrap_sigaction
+#else
+#  include <dlfcn.h>
+#  include <link.h>
+#  include <signal.h>
+#  define __wrap_sigaction sigaction
+#  define __wrap_dlopen dlopen
+#  define __wrap_dlerror dlerror
+#  define __wrap_dlsym dlsym
+#  define __wrap_dlclose dlclose
+#  define __wrap_dladdr dladdr
+#  define __wrap_dl_iterate_phdr dl_iterate_phdr
+#endif
+
+#endif

mozglue/linker/Logging.cpp

@@ -0,0 +1,7 @@
+/* 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 "Logging.h"
+
+Logging Logging::Singleton;

mozglue/linker/Logging.h

@@ -5,6 +5,7 @@
 #ifndef Logging_h
 #define Logging_h
 
+#include <cstdlib>
 #include "mozilla/Likely.h"
 #include "mozilla/MacroArgs.h"
 

mozglue/linker/moz.build

@@ -4,12 +4,19 @@
 # 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/.
 
+if CONFIG['MOZ_LINKER']:
+    SOURCES += [
+        'BaseElf.cpp',
+        'CustomElf.cpp',
+        'ElfLoader.cpp',
+        'Mappable.cpp',
+        'XZStream.cpp',
+    ]
+
+# When the linker is disabled, we still need Zip for mozglue/android.
+# Logging is a required dependency.
 SOURCES += [
-    'BaseElf.cpp',
-    'CustomElf.cpp',
-    'ElfLoader.cpp',
-    'Mappable.cpp',
-    'XZStream.cpp',
+    'Logging.cpp',
     'Zip.cpp',
 ]
 

mozglue/misc/StackWalk.cpp

@@ -15,7 +15,7 @@
 #include <string.h>
 
 #if defined(ANDROID) && defined(MOZ_LINKER)
-#  include "ElfLoader.h"
+#  include "Linker.h"
 #  include <android/log.h>
 #endif
 

mozglue/misc/moz.build

@@ -82,7 +82,7 @@ else:
         'Mutex_posix.cpp',
     ]
 
-if CONFIG['MOZ_LINKER']:
+if CONFIG['MOZ_LINKER'] or CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
     LOCAL_INCLUDES += [
         '/mozglue/linker',
     ]

mozglue/moz.build

@@ -7,7 +7,7 @@
 with Files("**"):
     BUG_COMPONENT = ("Core", "mozglue")
 
-if CONFIG['MOZ_LINKER']:
+if CONFIG['MOZ_LINKER'] or CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
     DIRS += ['linker']
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':

old-configure.in

@@ -2556,7 +2556,7 @@ dnl ========================================================
 MOZ_ARG_HEADER(Static build options)
 
 if test -z "$MOZ_SYSTEM_ZLIB"; then
-if test -n "$JS_SHARED_LIBRARY" -o -n "$MOZ_LINKER"; then
+if test -n "$JS_SHARED_LIBRARY" -o -n "$MOZ_LINKER" -o "$MOZ_WIDGET_TOOLKIT" = android; then
   ZLIB_IN_MOZGLUE=1
   AC_DEFINE(ZLIB_IN_MOZGLUE)
 fi

tools/profiler/core/shared-libraries-linux.cc

@@ -30,7 +30,7 @@
 
 #if defined(MOZ_LINKER)
 #  include "AutoObjectMapper.h"
-#  include "ElfLoader.h"  // dl_phdr_info
+#  include "Linker.h"  // dl_phdr_info
 #elif defined(GP_OS_linux) || defined(GP_OS_android)
 #  include <link.h>  // dl_phdr_info
 #else

xpcom/glue/standalone/nsXPCOMGlue.cpp

@@ -99,7 +99,7 @@ static NSFuncPtr GetSymbol(LibHandleType aLibHandle, const char* aSymbol) {
   return (NSFuncPtr)dlsym(aLibHandle, aSymbol);
 }
 
-#  ifndef MOZ_LINKER
+#  if !defined(MOZ_LINKER) && !defined(__ANDROID__)
 static void CloseLibHandle(LibHandleType aLibHandle) { dlclose(aLibHandle); }
 #  endif
 #endif
@@ -125,7 +125,7 @@ static void AppendDependentLib(LibHandleType aLibHandle) {
 
 static bool ReadDependentCB(pathstr_t aDependentLib,
                             LibLoadingStrategy aLibLoadingStrategy) {
-#ifndef MOZ_LINKER
+#if !defined(MOZ_LINKER) && !defined(__ANDROID__)
   // Don't bother doing a ReadAhead if we're not in the parent process.
   // What we need from the library should already be in the system file
   // cache.
@@ -173,7 +173,7 @@ struct ScopedCloseFileTraits {
 };
 typedef Scoped<ScopedCloseFileTraits> ScopedCloseFile;
 
-#ifndef MOZ_LINKER
+#if !defined(MOZ_LINKER) && !defined(__ANDROID__)
 static void XPCOMGlueUnload() {
   while (sTop) {
     CloseLibHandle(sTop->libHandle);
@@ -206,7 +206,7 @@ static const char* ns_strrpbrk(const char* string, const char* strCharSet) {
 
 static nsresult XPCOMGlueLoad(const char* aXPCOMFile,
                               LibLoadingStrategy aLibLoadingStrategy) {
-#ifdef MOZ_LINKER
+#if defined(MOZ_LINKER) || defined(__ANDROID__)
   if (!ReadDependentCB(aXPCOMFile, aLibLoadingStrategy)) {
     return NS_ERROR_FAILURE;
   }