I’m building a Cocos2d-x game for Android on a Mac, using Android NDK, and I get many warnings like this when compiling the C++ part:
/usr/include/module.map:1662:22: warning: unknown attribute 'extern_c' [-Wignored-attributes]
Is it dangerous? How can I fix it?
I'm guessing that extern_c is a compiler directive for the module map saying it is referencing functions from C++ that were written in the C language (different call frame structure).
The LLVM portion of the CLANG compiler is probably having a version mismatch.
http://clang.llvm.org/docs/Modules.html#module-maps
Try a command line $ clang -v
You may have to verify the compiler library version
xcode->preferences->locations->command line tools.
Ultimately you will want to clear this up so your stack frames match the arguments and your not referencing a C language function.
Related
Trying to build Tink library (https://github.com/google/tink) with Bazel. Bazel installed, gcc version 7.2.0, Windows 10 x64. Visual C++ 2017.
At first, there were errors like "C++ compilation of rule '#boringssl//:crypto' failed" - I commented these lines (with compilation flags I think) in boringssl/BUILD file (sections boringssl_copts, boringssl_copts_c11) and they disappeared.
But after that, bazel said, that error is in errors.h file (https://github.com/google/tink/blob/master/cc/util/errors.h)
// from #include "absl/base/port.h"
#define PRINTF_ATTRIBUTE(string_index, first_to_check) \
__attribute__((__format__ (__printf__, string_index, first_to_check)))
// Constructs a Status object given a printf-style va list.
crypto::tink::util::Status ToStatusF(
crypto::tink::util::error::Code code, const char* format, ...)
PRINTF_ATTRIBUTE(2, 3);
} // namespace tink
} // namespace crypto
enter code here
Error C3646: unknown override specifier on line 32 (line with "PRINTF_ATTRIBUTE(2, 3);"). The most frightening thing is that in another files the same code (defining same attribute) is working.
There are another errors in this file, but mentioned is the first (and another are about the same line, so they are consequences of the first I guess).
I'm nearly a total newbie in cpp, but only cpp should be used, not java-version of library.
Thank you for your help, and sorry for possible misformatting and broken english - this is my first question here.
Unfortunately, we don't support Windows for now. It's something that we plan to support next year, please see our feature roadmap.
I am trying to work through this tutorial on OpenCL, on a Windows 10 dev system which has integrated Intel HD graphics. I have installed Intel's OpenCL SDK. I have added the include directory from the SDK install into Properties > C/C++ General > Paths and Symbols > Includes. I am using MinGW as my compiler for Eclipse
In response to a number of linker errors that popped up when I first tried to compile the project, I set up the linker in eclipse to point to opencl.lib as outlined in this answer.
That took care of the linker errors, but there's an offending line from the tutorial which makes it impossible for the tutorial boiler-plate to compile:
87 cl_int result = program.build({ device }, "");
Set up as I am, this gives me the following warning and error:
..\src\main.cpp:93:32: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
..\src\main.cpp:93:45: error: no matching function for call to 'cl::Program::build(<brace-enclosed initializer list>, const char [1])'
If I'm reading this correctly (I haven't used C++ since before C++11 was a thing), the compiler is first warning me that it doesn't properly recognize what {device} is supposed to be (a vector of devices which has only one entry in it, initialized earlier in the code). Then, since it doesn't recognize {device}, the compiler errors out because it can't find a signature for cl::Program::build with arguments that match whatever-the-heck it's interpreting {device} to be.
Following the warning's advice, I followed the instructions given in this answer to add the -std=c++11 option for the compiler. However, when I do that the linker errors come back. Trying to compile with these options results in about thirty errors which all basically say they can't find any reference for the CL calls in the library files. For example:
C:/Program Files (x86)/Intel/OpenCL SDK/6.3/include/CL/cl.hpp:1753: undefined reference to `clGetPlatformInfo#20'
How do I make the compiler behave? I think I remember reading somewhere that the order of compiler options in the command line matters withe regards to linking, could that be messing up my compile since I added the -std=c++11 option?
I (sort of) figured out why the compiler was unhappy--the library I was linking was the x64 library for OpenCL installed in [base Intel dir]\OpenCL SDK\6.3\lib\x64, but (I think?) my compiler is not set up to create x64 apps. When I link to the .lib file in OpenCL SDK\6.3\lib\x86 my linker errors disappeared.
I am trying to compile the boost log library and I keep getting this error from the dump_avx2.cpp file
error: always_inline function '_mm256_set1_epi32' requires target feature 'sse4.2', but would be inlined into function 'dump_data_avx2' that is compiled without support for 'sse4.2'
boost/boost/libs/log/src/dump_avx2.cpp:71:31: note: expanded from macro 'BOOST_LOG_AUX_MM_CONSTANTS'
const __m256i mm_char_0 = _mm256_set1_epi32(0x30303030);\
^
I get a lot of errors that are very similar to the one above, all of them have the same error message but different locations in the file where they occur, for reference I am on the commit hash 68701167a1020b0b4c47b76e31d3a3da9e2faf3f for the Boost.Log submodule as fetched from the github repo (https://github.com/boostorg/boost)
Does anyone know how I can go about resolving this issue? I am building with a C++14 compiler and this is what I get when I type g++ --version
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Thanks!
Note I should clarify that in this context it is required that I compile this library separately.
Note There seem to be two related source files dump_ssse3.cpp and the mentioned dump_avx2.cpp file, do I have to compile only one of them? I cannot make out what to do from the Jamfile in the build folder :(
That looks like a bug in clang (LLVM). First, the intrinsic belongs to AVX2, not SSE4.2. Second, the whole dump_avx2.cpp file is compiled with -mavx2, so the required extensions are enabled. You can see the compiler switches in the error message from b2. And no, both dump_ssse3.cpp and dump_avx2.cpp should be compiled. The library does runtime detection of the available instructions in the CPU and selects the proper implementation.
I want to run an example plugin for CLANG/LLVM. Specifically llvm\tools\clang\examples\PrintFunctionNames. I managed to build it and i see an PrintFunctionNames.exports but i dont think visual studios supports it. The file is simply _ZN4llvm8Registry*. I have no idea what that is but i suspect its namespace llvm, class Registry which is defined as
template <typename T, typename U = RegistryTraits<T> >
class Registry {
I suspect the key line is at the end of the example file
static FrontendPluginRegistry::Add<PrintFunctionNamesAction> X("print-fns", "print function names");
print-fns is the name while the 2nd param is the desc. When i try loading/running the dll via
clang -cc1 -load printFunctionNames.dll -plugin print-fns a.c
I get an error about not finding print-fns. I suspect its because the static variable is never being initialize thus it never registers the plugin. A wrong dll name would get an error loading module msg.
I created a def file and added it to my project. It compiled but still no luck. Here is my def file
LIBRARY printFunctionNames
EXPORTS
X DATA
How do i register the plugin or get this example working?
Ok, becoming slightly more clear. To summarize: Visual Studio has nothing to do with it, really. This is a plugin for the clang executable. Therefore, there must be a method to communicate between them (the plugin interface). This appears to be an undocumented interface, so it's taking a bit off guesswork.
Troubleshooting DLL issues is done with "Dependency Walker" aka "Depends". It offers a profiling mode, in which all symbol lookups can be profiled. I.e. if you profile clang -cc1 -load printFunctionNames.dll -plugin print-fns a.c, you will see what symbols clang expects from your DLL, and in what order.
It looks like you're trying to mix C++ code built with two different, incompatible compilers. That's not supported, and the error you're seeing is a typical sign of that: C++ compilers usually use a "name mangling scheme", and if two compilers are incompatible then their name mangling schemes don't line up. One compiler may mangle llvm::Registry as _ZN4llvm8Registry* while another refers to it as llvm__Registry.
I'm currently writing a very simple game engine for an assignment and to make the code a lot nicer I've decided to use a vector math library. One of my lecturers showed me the Sony Vector Math library which is used in the Bullet Physics engine and it's great as far as I can see. I've got it working on Linux nicely but I'm having problems porting it to work on OS X (intel, Snow Leopard). I have included the files correctly in my project but the C++ version of the library doesn't seem to compile. I can get the C version of the library working but it has a fairly nasty API compared to the C++ version and the whole reason of using this library was to neaten the code in the first place.
http://glosx.blogspot.com/2008/07/sony-vector-math-library.html
This blog post that I've stumbled upon seems to suggest something's up with the compiler? It's fairly short so I couldn't take a lot of information from it.
When I try to use the C++ version I get the following errors (expanded view of each error):
/usr/include/vectormath/cpp/../SSE/cpp/vectormath_aos.h:156:0
/usr/include/vectormath/cpp/../SSE/cpp/vectormath_aos.h:156:
error: '__forceinline' does not name a type
second error:
/Developer/apps/gl test/main.cpp:7:0 In file included from /Developer/apps/gl test/main.cpp
/usr/include/vectormath/cpp/vectormath_aos.h:38:0 In file included from
/usr/include/vectormath/cpp/vectormath_aos.h
/usr/include/vectormath/cpp/../SSE/cpp/vectormath_aos.h:330:0 In file included from
/usr/include/vectormath/cpp/../SSE/cpp/vectormath_aos.h
/usr/include/vectormath/cpp/../SSE/cpp/vecidx_aos.h:45:0 Expected constructor, destructor,
or type conversion before '(' token in /usr/include/vectormath/cpp/../SSE/cpp/vecidx_aos.h
Finally two errors at the end of the main.cpp file:
Expected '}' at the end of input
Expected '}' at the end of input
I've Googled my heart out but I can't seem to find any answers or anything to point me in the right direction so any help will be greatly received.
Thanks,
__forceinline is a reserved word that is supported by only a couple compilers. Clearly, your compiler does not support the __forceinline keyword and the code in question is non-portable.
A very poor workaround would be to pass a new define to your compiler that gives the keyword the correct meaning. E.g.: -D__forceinline=inline or -D__forceinline=__attribute__((always_inline)) (Thanks Paul!)
The SSE version was assumed to be only for Microsoft Visual Studio. For other platforms (Mac etc) you can use the scalar version.
Bullet\Extras\vectormathlibrary\include\vectormath\scalar\cpp
It looks like someone's fixed this up and posted a patched version in response to this very issue.
Now GCC compliant.
Which compiler are you using on OS X ? There are 4 to choose from in the standard Xcode 3.2 install and the default is gcc 4.2. You might be better off trying gcc 4.0.