today I faced trouble - android's ndk does not have SUN_LEN macro (sys/un.h || linux/un.h ), I don't want to patch android's headers, what is better to do?
Don't patch the headers, define it in your own file.
#ifndef SUN_LEN //In case they fix it down the road
#define SUN_LEN(ptr) ((size_t) (((struct sockaddr_un *) 0)->sun_path) + strlen((ptr)->sun_path))
#endif
SUN_LEN macro is a non-portable (aka not a part of POSIX standard) extension.
It is completely safe to use sizeof(struct sockaddr_un) instead.
Related
First off, my app has a file named Android.hpp. This is part of the tmxlite library. Compiling tmxlite on windows works fine. However, when I move the code to android studio and compile it (with the NDK), I get an error.
Android.hpp:
/*********************************************************************
Matt Marchant 2016
http://trederia.blogspot.com
tmxlite - Zlib license.
This software is provided 'as-is', without any express or
implied warranty. In no event will the authors be held
liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute
it freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented;
you must not claim that you wrote the original software.
If you use this software in a product, an acknowledgment
in the product documentation would be appreciated but
is not required.
2. Altered source versions must be plainly marked as such,
and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any
source distribution.
*********************************************************************/
#ifndef ANDROID_INC_HPP_
#define ANDROID_INC_HPP_
#ifdef __ANDROID__
#include <string>
#include <sstream>
#include <cstdlib>
namespace std
{
template <typename T>
std::string to_string(T value)
{
std::ostringstream os;
os << value;
return os.str();
}
}
#define STOI(str) std::strtol(str.c_str(), 0, 10)
#else
#define STOI(str) std::stoi(str)
#endif // __ANDROID__
#endif // ANDROID_INC_HPP_
The error:
In file included from E:\max\android_libs\tmxliteOG\tmxlite\src\FreeFuncs.cpp:28:
In file included from E:\max\android_libs\tmxliteOG\tmxlite\include\tmxlite\FreeFuncs.hpp:54:
E:\max\android_libs\tmxliteOG\tmxlite\include\tmxlite\detail\Android.hpp:37:11: error: expected '{'
Why is this happening? I was under the impression that this was how namespaces were supposed to be declared and I don't see what is wrong with it. I mean, I didn't even write the code :-).
help is greatly appreciated.
I'm trying to compile libfuse with NDK, my environment:
Win10(64bit) + NDK(r14b,64bit) + libfuse(3.1.0)
Error occurs in fuse_common.h, it checks size of off_t:
$ ndk-build
[armeabi-v7a] Compile thumb : fuse <= buffer.c
In file included from jni/../../libfuse/lib/buffer.c:15:
In file included from jni/../../libfuse/lib/fuse_i.h:9:
In file included from jni/../../libfuse/include\fuse.h:19:
jni/../../libfuse/include/fuse_common.h:745:13: error: bit-field
'_fuse_off_t_must_be_64bit' has negative width (-1)
{ unsigned _fuse_off_t_must_be_64bit:((sizeof(off_t) == 8) ? 1 : -1); };
^
1 error generated.
make: *** [obj/local/armeabi-v7a/objs/fuse/__/__/libfuse/lib/buffer.o] Error 1
here's the check in fuse_common.h:
struct _fuse_off_t_must_be_64bit_dummy_struct \
{ unsigned _fuse_off_t_must_be_64bit:((sizeof(off_t) == 8) ? 1 : -1); };
I searched on google, there's _FILE_OFFSET_BITS=64 definition, which can be used to change the size of off_t, I have this defined my 'Android.mk' file:
LOCAL_CFLAGS := \
....
-D_FILE_OFFSET_BITS=64 \
....
And even add this line at the beginning of fuse_common.h
#define _FILE_OFFSET_BITS 64
Still not working, how to fix it?
Update to NDK r15c. _FILE_OFFSET_BITS=64 works from there on out.
Note that most off64_t system calls weren't available until android-21. If your minSdkVersion is set below that and you use _FILE_OFFSET_BITS=64, many functions will not be available.
NOTE Provided solution is much like workaround, see #Dan's answer for reliable and official way to get 64-bit off_t.
On Android off_t is always 32-bit length, and there is no preprocessor macro that controls its size. (Though it is true only for NDK development since modern bionic allow to configure off_t size at compile time). And because of this you cannot compile your library directly.
But I guess there is some way to workaround it. Android NDK offers non-POSIX extended type - off64_t, and also it provides a complementary set of library functions that accept it instead of off_t. They are distinguished by 64 suffix, i.e. lseek64(), mmap64(). So to make things work you may try to add global configuration header to your project:
/* let off_t to be a 64-bit length */
typedef off64_t off_t;
/* use appropriate versions of system functions */
/* list here only functions that have off_t parameters and are used by your library */
#define mmap mmap64
#define lseek lseek64
And of course keep in mind that compiled code now is linked against *64() functions instead of regular ones and any public interfaces expect off64_t instead of off_t.
Im trying to build an Ubuntu Touch tree, based on an Aosp tree I already correctly built.
It fails with this error
CAPEWrapper.cpp:16: error: undefined reference to '__xlog_buf_printf'
this is the header that file includes
#include "CAPEWrapper.h"
which on cascade includes
#include <cutils/xlog.h>
which in turn defines
#if defined(__cplusplus)
extern "C" {
#endif
int __xlog_buf_printf(int bufid, const struct xlog_record *rec, ...);
#if defined(__cplusplus)
}
#endif
I suspect that my g++ doesn't set __cplusplus macro. Could it be a realistic scenario with this kind of error? If this could be the problem, should I need to specify a standard implementation with "stdc=something" to solve it?
Any other idea is welcome.
Make sure that your project is linking libcutils, and that it's linking it in the correct order (i.e. that -lcutils appears in the linker command line after any module that depends on it).
In the end, I found that the modules was listed inside a macro called LOCAL_WHOLE_STATIC_LIBRARIES, that in Android environment passes its content to the --whole-archive flag of GCC linker.
I'm building a demo with bullet physics engine library for android phone(NDK).
From 2.81 version, Bullet physics engine supports arm neon optimization, but only for apple devices.
My question is how to enable arm neon for android?
The flag for arm neon is defined in btScalar.h file, code is as below:
#if (defined (__APPLE__) && (!defined (BT_USE_DOUBLE_PRECISION)))
#if defined (__i386__) || defined (__x86_64__)
#define BT_USE_SSE
#define BT_USE_SSE_IN_AP
#elif defined( __armv7__ )
#ifdef __clang__
#define BT_USE_NEON 1
#if defined BT_USE_NEON && defined (__clang__)
#include <arm_neon.h>
……
As we can see in the code, flag BT_USE_NEON is defined in the condition of it is compiled for apple device, if I drop this code and define this flag by myself, some error occurs when compiling, something like bad alignment--vld1.f32 {d26},[r4:128].
What should I do for my demo to enable arm neon?
I had the same issues few days ago:)
The problem was assembly code defined in btVector3 (vld1q_f32_aligned_postincrement). As far as I know, syntax such as [r3, :128] is used in GAS - I guess it is used in iOS environment, but not sure. Modifying it to [%1, #128] may remove those errors.
By the way, from my experience, it is usually slow than plain implementation. I think the bullet neon intrinsics are not optimized for android, as you can see an assembly code(probably optimized) on the other side(defined as APPLE).
I got a macro I am using for debugging/logging, simply:
MY_DEBUG_INFO(msg...)
this works fine on say android:
#ifdef ANDROID
#define MY_DEBUG_INFO(msg...) __android_log(ANDROID_INFO,"TEST",msg...) (roughly)
However, how do I make the same macro apply to iOS logging? With the new data types and all
#ifdef IOS
#define MY_DEBUG_INFO(msg...) NSLog(????)
#define MY_DEBUG_INFO(...) NSLog(#__VA_ARGS__)