How to build Python-4-Android for the ARM Neon

Currently the Py4A project does not compile for the ARM Neon architecture. If you try to run ndk-build on the project by setting the APP_ABI to armeabi-v7a and setting the LOCAL_ARM_NEON variable to true, you get the following error:





libffi/src/arm/sysv.S: Assembler messages:
libffi/src/arm/sysv.S:203: Error: selected processor does not support ARM mode `stfeqs f0,[r2]'
libffi/src/arm/sysv.S:208: Error: selected processor does not support ARM mode `stfeqd f0,[r2]'
libffi/src/arm/sysv.S:283: Error: selected processor does not support ARM mode `ldfs f0,[sp]'
libffi/src/arm/sysv.S:286: Error: selected processor does not support ARM mode `ldfd f0,[sp]'
libffi/src/arm/sysv.S:289: Error: selected processor does not support ARM mode `ldfd f0,[sp]'
make: *** [obj/local/armeabi-v7a/objs/ffi/src/arm/sysv.o] Error 1

The following patch for the python-build/libffi/src/asm/sysv.S file allows you to cross-compile Py4A for the armeabi-v7a ABI and also for the Neon instruction set. The patch consists in appropriately changing the conditionals containing __SOFTFP__ and adding __SOFTFP__ || __ARM_EABI__.
For example to build for the ARM Neon instruction set, the ndk-build command line in build.sh should be the following:

ndk-build APP_ABI:=armeabi-v7a LOCAL_ARM_NEON:=true

--- libffi/src/arm/a/sysv.S    2013-01-30 14:49:29.711595414 -0500
+++ libffi/src/arm/sysv.S    2013-01-31 18:05:07.376178842 -0500
@@ -189,7 +189,7 @@ ARM_FUNC_START ffi_call_SYSV
 
 @ return INT
     cmp    r3, #FFI_TYPE_INT
-#ifdef __SOFTFP__
+#if defined(__SOFTFP__) || defined(__ARM_EABI__)
     cmpne    r3, #FFI_TYPE_FLOAT
 #endif
     streq    r0, [r2]
@@ -197,12 +197,12 @@ ARM_FUNC_START ffi_call_SYSV
 
     @ return INT64
     cmp    r3, #FFI_TYPE_SINT64
-#ifdef __SOFTFP__
+#if defined(__SOFTFP__) || defined(__ARM_EABI__)
     cmpne    r3, #FFI_TYPE_DOUBLE
 #endif
     stmeqia    r2, {r0, r1}
 
-#ifndef __SOFTFP__
+#if !defined(__SOFTFP__) && !defined(__ARM_EABI__)
     beq    LSYM(Lepilogue)
 
 @ return FLOAT
@@ -245,21 +245,21 @@ ARM_FUNC_START ffi_closure_SYSV
     beq    .Lretint
 
     cmp    r0, #FFI_TYPE_FLOAT
-#ifdef __SOFTFP__
+#if defined(__SOFTFP__) || defined(__ARM_EABI__)
     beq    .Lretint
 #else
     beq    .Lretfloat
 #endif
 
     cmp    r0, #FFI_TYPE_DOUBLE
-#ifdef __SOFTFP__
+#if defined(__SOFTFP__) || defined(__ARM_EABI__)
     beq    .Lretlonglong
 #else
     beq    .Lretdouble
 #endif
 
     cmp    r0, #FFI_TYPE_LONGDOUBLE
-#ifdef __SOFTFP__
+#if defined(__SOFTFP__) || defined(__ARM_EABI__)
     beq    .Lretlonglong
 #else
     beq    .Lretlongdouble
@@ -278,7 +278,7 @@ ARM_FUNC_START ffi_closure_SYSV
     ldr    r1, [sp, #4]
     b    .Lclosure_epilogue
 
-#ifndef __SOFTFP__
+#if !defined(__SOFTFP__) && !defined(__ARM_EABI__)
 .Lretfloat:
     ldfs    f0, [sp]
     b    .Lclosure_epilogue

How to build Python-4-Android for the x86

Currently the Py4A project only compiles for the ARM architecture.

The following patch for the python-build sub-directory allows you to cross-compile Py4A for the x86 architecture. The patch consists in:

1. Adding a set of new files to support the x86 architecture (including creating a new libffi/linux-x86/ directory):
   
   libffi/linux-x86/ffi.h
   libffi/linux-x86/fficonfig.h
   setup-x86.cfg
2. changing the build.sh script to accept a new parameter - the Android ABI (for example 'armeabi' or 'x86') - so that the script can call
   
   ndk-build APP_ABI:=x86
   
   to trigger the cross-compilation for the x86 processor;
3. changing the build.py script to parametrize the GCC strip command and the selection of the setup.cfg configuration file based on the input ABI;
4. changing the libffi/Android.mk makefile to select the right set of source files based on the input ABI;
5. changing the libffi/include/ffi_real.h header file to redefine FFI_TYPE_LONGDOUBLE to 4;
6. changing the openssl/crypto/Android.mk and openssl/ssl/Android.mk makefiles to strip down the openssl library with only the bare minimum set that allows you to cross-compile the source code;
7. changing the  python/jni/modules.mk makefile to add the -fno-stack-protector compiler and linker option when building the _socket module and exclude the openssl module.

After applying the patch, to cross-compile Py4A for the x86 architecture you should run the following:

$ cd python-build

$ ./build.sh x86

Binaries for the x86 can be downloaded here:

• python_extras_r14.zip
• python-lib_r16.zip
• python_r16.zip
• python_scripts_r13.zip

--- orig/python/jni/modules.mk    2013-01-21 14:39:56.000000000 -0500
+++ python/jni/modules.mk    2013-01-29 14:58:52.922096000 -0500
@@ -58,7 +58,7 @@ $(call build-module,  syslog ,  Modules/
 $(call build-module,  audioop ,  Modules/audioop.c )
 $(call build-module,  imageop ,  Modules/imageop.c )
 $(call build-module,  _csv ,  Modules/_csv.c )
-$(call build-module,  _socket ,  Modules/socketmodule.c, libc, -lc, -nostdlib )
+$(call build-module,  _socket ,  Modules/socketmodule.c, libc, -lc -fno-stack-protector, -nostdlib -fno-stack-protector )
 $(call build-module,  _sha ,  Modules/shamodule.c )
 $(call build-module,  _md5 ,  Modules/md5module.c Modules/md5.c )
 $(call build-module,  _sha256 ,  Modules/sha256module.c )
@@ -125,6 +125,7 @@ include $(BUILD_SHARED_LIBRARY)
 
 #$(call build-module,  _ssl ,  Modules/_ssl.c, ssl crypto )
 
+ifneq ($(APP_ABI), x86)
 $(call import-module, openssl)
 LOCAL_PATH :=  $(PYTHON_SRC_PATH)
 LOCAL_C_INCLUDES += $(PYTHON_SRC_PATH) $(PYTHON_SRC_PATH)/Include $(OPENSSL)/include $(OPENSSL)
@@ -133,6 +134,7 @@ LOCAL_MODULE_FILENAME := _ssl
 LOCAL_SRC_FILES := Modules/_ssl.c
 LOCAL_SHARED_LIBRARIES := libpython2.6 libcrypto libssl
 include $(BUILD_SHARED_LIBRARY)
+endif
 
 
 $(call import-module, libffi)
--- orig/setup-x86.cfg    1969-12-31 19:00:00.000000000 -0500
+++ setup-x86.cfg    2013-01-28 16:09:49.004463929 -0500
@@ -0,0 +1,2 @@
+[bdist_egg]
+plat-name=linux-x86
--- orig/openssl/ssl/Android.mk    2013-01-21 14:42:17.000000000 -0500
+++ openssl/ssl/Android.mk    2013-01-28 16:33:35.563643087 -0500
@@ -7,6 +7,10 @@ local_c_includes := \
 
 include $(CLEAR_VARS)
 
+ifeq ($(APP_ABI), x86)
+LOCAL_SRC_FILES:= \
+    kssl.c
+else
 LOCAL_SRC_FILES:= \
     s2_meth.c \
     s2_srvr.c \
@@ -45,6 +49,7 @@ LOCAL_SRC_FILES:= \
     bio_ssl.c \
     ssl_err.c \
     kssl.c
+endif
 
 include $(LOCAL_PATH)/../android-config.mk
 
--- orig/openssl/crypto/Android.mk    2013-01-21 14:42:08.000000000 -0500
+++ openssl/crypto/Android.mk    2013-01-29 14:49:00.334324159 -0500
@@ -2,27 +2,17 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_CFLAGS += -DOPENSSL_BN_ASM_MONT -DAES_ASM -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DOPENSSL_NO_STATIC_ENGINE
+ifneq ($(APP_ABI), x86)
 LOCAL_SRC_FILES:= 0.9.9-dev/bn/armv4-mont.s \
                   0.9.9-dev/aes/aes-armv4.s \
                   0.9.9-dev/sha/sha1-armv4-large.s \
                   0.9.9-dev/sha/sha256-armv4.s \
                   0.9.9-dev/sha/sha512-armv4.s
-
 LOCAL_SRC_FILES+= \
-    cryptlib.c \
-    mem.c \
-    mem_clr.c \
     mem_dbg.c \
-    cversion.c \
     dyn_lck.c \
     ex_data.c \
-    tmdiff.c \
     cpt_err.c \
-    ebcdic.c \
-    uid.c \
-    o_time.c \
-    o_str.c \
-    o_dir.c \
     aes/aes_misc.c \
     aes/aes_ecb.c \
     aes/aes_cbc.c \
@@ -474,6 +464,19 @@ LOCAL_SRC_FILES+= \
     ripemd/rmd_dgst.c \
     ripemd/rmd_one.c \
     evp/m_ripemd.c
+endif
+
+LOCAL_SRC_FILES+= \
+    cryptlib.c \
+    mem.c \
+    mem_clr.c \
+    cversion.c \
+    tmdiff.c \
+    ebcdic.c \
+    uid.c \
+    o_time.c \
+    o_str.c \
+    o_dir.c
 
 LOCAL_CFLAGS += -DNO_WINDOWS_BRAINDEATH
 
--- orig/build.py    2013-01-21 14:44:17.000000000 -0500
+++ build.py    2013-01-28 16:19:35.088015089 -0500
@@ -82,6 +82,10 @@ def rm(path):
 
 
 def strip(path):
+  if len(sys.argv) > 1:
+    if sys.argv[1] == "x86":
+      run('i686-linux-android-strip %s' % path)
+    else:
   run('arm-linux-androideabi-strip %s' % path)
 
 
@@ -153,6 +157,12 @@ map(rm, find('output.temp/usr/lib/python
 map(rm, find('output.temp', 'python$', exclude=['setuptools', 'distutils'])[0])
 run("mkdir python", cwd="output.temp/usr")
 run("cp -r %s/python-libs/py4a python" % pwd, cwd="output.temp/usr")
+if len(sys.argv) > 1:
+    if sys.argv[1] == "x86":
+        run("cp %s/setup-x86.cfg ." % pwd, cwd="output.temp/usr")
+    else:
+        run("cp %s/setup.cfg ." % pwd, cwd="output.temp/usr")
+else:
 run("cp %s/setup.cfg ." % pwd, cwd="output.temp/usr")
 run("cp %s/prepare_setuptools.sh setup.sh" % pwd, cwd="output.temp/usr")
 run("cp %s/standalone_python.sh python.sh" % pwd, cwd="output.temp/usr")
--- orig/libffi/include/ffi_real.h    2013-01-21 14:42:35.000000000 -0500
+++ libffi/include/ffi_real.h    2013-01-29 10:27:30.664550823 -0500
@@ -371,8 +371,12 @@ void ffi_call(ffi_cif *cif,
 #if CONF_HAVE_LONG_DOUBLE       // android changed
 #define FFI_TYPE_LONGDOUBLE 4
 #else
+#ifdef x86
+#define FFI_TYPE_LONGDOUBLE 4
+#else
 #define FFI_TYPE_LONGDOUBLE FFI_TYPE_DOUBLE
 #endif
+#endif
 #define FFI_TYPE_UINT8      5  
 #define FFI_TYPE_SINT8      6
 #define FFI_TYPE_UINT16     7
--- orig/libffi/Android.mk    2013-01-21 14:42:42.000000000 -0500
+++ libffi/Android.mk    2013-01-28 17:00:21.190897854 -0500
@@ -21,6 +21,17 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE := ffi
 LOCAL_MODULE_FILENAME :=
+ifeq ($(APP_ABI), x86)
+    LOCAL_SRC_FILES := src/x86/sysv.S \
+    src/x86/ffi.c \
+    src/debug.c \
+    src/java_raw_api.c \
+    src/prep_cif.c \
+    src/raw_api.c \
+    src/types.c
+
+    LOCAL_C_INCLUDES := $(LOCAL_PATH)/include $(LOCAL_PATH)/linux-x86
+else
 LOCAL_SRC_FILES := src/arm/sysv.S \
     src/arm/ffi.c \
     src/debug.c \
@@ -30,6 +41,7 @@ LOCAL_SRC_FILES := src/arm/sysv.S \
     src/types.c
 
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include $(LOCAL_PATH)/linux-arm
+endif
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
 
 $(call __ndk_info, Building libffi)
--- orig/libffi/linux-x86/ffi.h    1969-12-31 19:00:00.000000000 -0500
+++ libffi/linux-x86/ffi.h    2013-01-28 16:24:28.975890002 -0500
@@ -0,0 +1,10 @@
+/*
+ * Copyright 2008 The Android Open Source Project
+ */
+#ifndef LIBFFI_H
+
+#define x86
+#include "../src/x86/ffitarget.h"
+#include "../include/ffi_real.h"
+
+#endif
--- orig/libffi/linux-x86/fficonfig.h    1969-12-31 19:00:00.000000000 -0500
+++ libffi/linux-x86/fficonfig.h    2013-01-28 16:23:04.047926730 -0500
@@ -0,0 +1,160 @@
+/* fficonfig.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to one of `_getb67', `GETB67', `getb67' for Cray-2 and Cray-YMP
+   systems. This function is required for `alloca.c' support on those systems.
+   */
+#undef CRAY_STACKSEG_END
+
+/* Define to 1 if using `alloca.c'. */
+#undef C_ALLOCA
+
+/* Define to the flags needed for the .section .eh_frame directive. */
+#define EH_FRAME_FLAGS "aw"
+
+/* Define this if you want extra debugging. */
+#undef FFI_DEBUG
+
+/* Define this is you do not want support for the raw API. */
+#undef FFI_NO_RAW_API
+
+/* Define this is you do not want support for aggregate types. */
+#undef FFI_NO_STRUCTS
+
+/* Define to 1 if you have `alloca', as a function or macro. */
+#define HAVE_ALLOCA 1
+
+/* Define to 1 if you have <alloca.h> and it should be used (not on Ultrix).
+   */
+#define HAVE_ALLOCA_H 1
+
+/* Define if your assembler supports .cfi_* directives. */
+#undef HAVE_AS_CFI_PSEUDO_OP
+
+/* Define if your assembler supports .register. */
+#undef HAVE_AS_REGISTER_PSEUDO_OP
+
+/* Define if your assembler and linker support unaligned PC relative relocs.
+   */
+#undef HAVE_AS_SPARC_UA_PCREL
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define if __attribute__((visibility("hidden"))) is supported. */
+#undef HAVE_HIDDEN_VISIBILITY_ATTRIBUTE
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define if you have the long double type and it is bigger than a double */
+#undef HAVE_LONG_DOUBLE
+
+/* Define to 1 if you have the `memcpy' function. */
+#define HAVE_MEMCPY 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the `mmap' function. */
+#define HAVE_MMAP 1
+
+/* Define if mmap with MAP_ANON(YMOUS) works. */
+#define HAVE_MMAP_ANON 1
+
+/* Define if mmap of /dev/zero works. */
+#define HAVE_MMAP_DEV_ZERO 1
+
+/* Define if read-only mmap of a plain file works. */
+#define HAVE_MMAP_FILE 1
+
+/* Define if .eh_frame sections should be read-only. */
+#undef HAVE_RO_EH_FRAME
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if you have the <sys/mman.h> header file. */
+#define HAVE_SYS_MMAN_H 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to 1 if your C compiler doesn't accept -c and -o together. */
+#undef NO_MINUS_C_MINUS_O
+
+/* Name of package */
+#define PACKAGE "libffi"
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* The size of `double', as computed by sizeof. */
+#define SIZEOF_DOUBLE 8
+
+/* The size of `long double', as computed by sizeof. */
+#undef SIZEOF_LONG_DOUBLE
+
+/* If using the C implementation of alloca, define if you know the
+   direction of stack growth for your system; otherwise it will be
+   automatically deduced at runtime.
+    STACK_DIRECTION > 0 => grows toward higher addresses
+    STACK_DIRECTION < 0 => grows toward lower addresses
+    STACK_DIRECTION = 0 => direction of growth unknown */
+#undef STACK_DIRECTION
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Define this if you are using Purify and want to suppress spurious messages.
+   */
+#undef USING_PURIFY
+
+/* Version number of package */
+#undef VERSION
+
+/* Define to 1 if your processor stores words with the most significant byte
+   first (like Motorola and SPARC, unlike Intel and VAX). */
+#undef WORDS_BIGENDIAN
+
+
+#ifdef HAVE_HIDDEN_VISIBILITY_ATTRIBUTE
+#ifdef LIBFFI_ASM
+#define FFI_HIDDEN(name) .hidden name
+#else
+#define FFI_HIDDEN __attribute__ ((visibility ("hidden")))
+#endif
+#else
+#ifdef LIBFFI_ASM
+#define FFI_HIDDEN(name)
+#else
+#define FFI_HIDDEN
+#endif
+#endif
+

--- build.sh (orig/build.sh)
+++ build.sh (build.sh)
@@ -5,6 +5,7 @@
 set -ex
 CWD=$(pwd)
 DEBUG=no
+android_abi="$1"

 RELEASE_VERSION=$(cat LATEST_VERSION)
 echo "Building Python VM For Android Release ${RELEASE_VERSION}"
@@ -78,12 +79,12 @@
 ${CWD}/host/pgen ${CWD}/python-src/Grammar/Grammar \
  ${CWD}/python-src/Include/graminit.h \
  ${CWD}/python-src/Python/graminit.c
-ndk-build
+ndk-build APP_ABI:=$android_abi

 # copy out all the needed files
-mv obj/local/armeabi/python ${OUT}/usr/bin
-mv obj/local/armeabi/lib*.so ${OUT}/usr/lib
-mv obj/local/armeabi/*.so ${OUT}/usr/lib/python2.6/lib-dynload
+mv obj/local/$android_abi/python ${OUT}/usr/bin
+mv obj/local/$android_abi/lib*.so ${OUT}/usr/lib
+mv obj/local/$android_abi/*.so ${OUT}/usr/lib/python2.6/lib-dynload
 popd

 pushd ${CWD}/python-libs
@@ -91,7 +92,7 @@
 popd

 ${CWD}/host/bin/python ${OUT}/usr/lib/python2.6/compileall.py ${OUT}/usr/lib/python2.6
-${CWD}/host/bin/python build.py
+${CWD}/host/bin/python build.py $android_abi

 if [ "$DEBUG" != "yes" ]; then
     rm -rf output*

Android: Trying to load native library results in a process terminated by signal (11)

Symptoms

You are trying to load your native C/C++ library in an Android application and when at runtime your app calls the System.loadLibrary() function - for example:

static {
        System.loadLibrary("mynativelib");

}

the application dies without core dumping, and the only message you see in LogCat is something like the following:

01-23 19:58:08.699: D/dalvikvm(4146): Trying to load lib /data/data/com.example.myapp/lib/libmynativelib.so 0x42341a50
01-23 19:58:08.709: I/ActivityManager(340): Process com.example.myapp (pid 4146) has died.
01-23 19:58:08.709: W/ActivityManager(340): Force removing ActivityRecord{211d37d0 com.example.myapp/.MyActivity}: app died, no saved state
01-23 19:58:08.719: D/Zygote(188): Process 4146 terminated by signal (11)

Causes

You native library is probably trying to dynamically load another library it depends upon.

Solution

Use the GCC readelf for your ABI to dump the dynamic section of your native library and find out which libraries it depends upon. For example if you are compiling for the x86 ABI:


$ android-ndk-r8d/toolchains/x86-4.7/prebuilt/linux-x86/bin/i686-linux-android-readelf -d libmynativelib.so | grep NEEDED
 0x00000001 (NEEDED)                     Shared library: [libgnustl_shared.so]
 0x00000001 (NEEDED)                     Shared library: [libiconv.so]
 0x00000001 (NEEDED)                     Shared library: [libdl.so]
 0x00000001 (NEEDED)                     Shared library: [libstdc++.so]
 0x00000001 (NEEDED)                     Shared library: [libm.so]
 0x00000001 (NEEDED)                     Shared library: [libc.so]


In this example you only need to load libgnustl_shared.so and libiconv.so before your libmynativelib.so to resolve the dependencies and make the System.loadLibrary() function call happy (the other standard libraries are already preloaded for you by Android). In your static section you will then include the following lines:

static {

        System.loadLibrary("gnustl_shared");

        System.loadLibrary("iconv");

        System.loadLibrary("mynativelib");

}

This should solve the problem.

How to port Mozilla SpiderMonkey 1.7 to Android

Another third-party package I needed to cross-compile for Android was Mozilla's SpiderMonkey 1.7 Javascript engine. I found two issues here:

1. When configuring SpiderMonkey the makefile tries to build two executables (jscpucfg and jskwgen) and then runs them to generate two  configuration header files (jsautocfg.h and jsautokw.h, respectively). The problem when using the Android NDK cross-compiler is that these two executables can only be run on the Android target (for example an ARM processor), while I'm cross-compiling my build from a Linux Ubuntu 12.04 machine with an x86_64 processor architecture. So you get an error that you cannot execute these files on the host machine.
   I solved this problem by copying the two executables to an Android device (Samsung Galaxy S III) using scp and the SSHDroid application, and generating the two header files there:
   
   $ jscpucfg > jsautocfg.h
   $ jskwgen > jsautokw.h
   
   then I copied the two files back to my node on my Ubuntu machine and saved in the source trunk under the config sub-directory. Then I changed the makefile to skip generating these two header files when cross-compiling for Android and get them instead from the config sub-directory.
2. The SpiderMonkey jsnum.c file generates the following error when cross-compiled for Android:
   
   js-1.7/jsnum.c: In function 'js_InitRuntimeNumberState':
   js-1.7/jsnum.c:578: error: 'struct lconv' has no member named 'thousands_sep'
   js-1.7/jsnum.c:578: error: 'struct lconv' has no member named 'thousands_sep'
   js-1.7/jsnum.c:580: error: 'struct lconv' has no member named 'decimal_point'
   js-1.7/jsnum.c:580: error: 'struct lconv' has no member named 'decimal_point'
   js-1.7/jsnum.c:582: error: 'struct lconv' has no member named 'grouping'
   js-1.7/jsnum.c:582: error: 'struct lconv' has no member named 'grouping'
   gmake[2]: *** [js-1.7.dir/jsnum.c.o] Error 1
   
   This is caused by the fact that the lconv structure in locale.h shipped with the Android NDK is stubbed with the following comment:
   
   #if 1 /* MISSING FROM BIONIC - DEFINED TO MAKE libstdc++-v3 happy */
   struct lconv { };
   struct lconv *localeconv(void);
   #endif /* MISSING */
   
   To solve this problem I applied the following patch to jsnum.c and I was able to successfully cross-compile SpiderMonkey 1.7 for Android.
   
   --- a/jsnum.c   2013-01-10 10:37:54.413800695 -0500
   +++ b/jsnum.c   2013-01-10 10:06:49.432752061 -0500
   @@ -573,13 +573,28 @@ js_InitRuntimeNumberState(JSContext *cx)
        u.s.lo = 1;
        number_constants[NC_MIN_VALUE].dval = u.d;
    
   -    locale = localeconv();
   -    rt->thousandsSeparator =
   -        JS_strdup(cx, locale->thousands_sep ? locale->thousands_sep : "'");
   -    rt->decimalSeparator =
   -        JS_strdup(cx, locale->decimal_point ? locale->decimal_point : ".");
   -    rt->numGrouping =
   -        JS_strdup(cx, locale->grouping ? locale->grouping : "\3\0");
   +    /* Copy locale-specific separators into the runtime strings. */
   +    const char *thousandsSeparator, *decimalPoint, *grouping;
   +#ifdef HAVE_LOCALECONV
   +    locale = localeconv();
   +    thousandsSeparator = locale->thousands_sep;
   +    decimalPoint = locale->decimal_point;
   +    grouping = locale->grouping;
   +#else
   +    thousandsSeparator = getenv("LOCALE_THOUSANDS_SEP");
   +    decimalPoint = getenv("LOCALE_DECIMAL_POINT");
   +    grouping = getenv("LOCALE_GROUPING");
   +#endif
   +    if (!thousandsSeparator)
   +        thousandsSeparator = "'";
   +    if (!decimalPoint)
   +        decimalPoint = ".";
   +    if (!grouping)
   +        grouping = "\3\0";
   +
   +    rt->thousandsSeparator = JS_strdup(cx, thousandsSeparator);
   +    rt->decimalSeparator = JS_strdup(cx, decimalPoint);
   +    rt->numGrouping = JS_strdup(cx, grouping);
    
        return rt->thousandsSeparator && rt->decimalSeparator && rt->numGrouping;
    }
   
   Of course you would define HAVE_LOCALECONV only for regular builds but not for Android cross-compilations, so that you could either pass your own definitions for the locale thousands separator, decimal point or locale grouping via environment variables, or use the above defaults.