Tag: C++

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Encountering `::signbit` stuff not passing to `math.h` in MacOS 12.4

TL;DR

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:317:9: error: no member named 'signbit' in the global namespace
using ::signbit;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:318:9: error: no member named 'fpclassify' in the global namespace
using ::fpclassify;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:319:9: error: no member named 'isfinite' in the global namespace
using ::isfinite;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:320:9: error: no member named 'isinf' in the global namespace
using ::isinf;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:321:9: error: no member named 'isnan' in the global namespace
using ::isnan;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:322:9: error: no member named 'isnormal' in the global namespace
using ::isnormal;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:323:9: error: no member named 'isgreater' in the global namespace
using ::isgreater;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:324:9: error: no member named 'isgreaterequal' in the global namespace
using ::isgreaterequal;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:325:9: error: no member named 'isless' in the global namespace
using ::isless;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:326:9: error: no member named 'islessequal' in the global namespace
using ::islessequal;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:327:9: error: no member named 'islessgreater' in the global namespace
using ::islessgreater;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:328:9: error: no member named 'isunordered' in the global namespace
using ::isunordered;
      ~~^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:329:9: error: no member named 'isunordered' in the global namespace
using ::isunordered;
      ~~^

When I was compiling LLVM recently I found this, it may be because my CommandLineTool is outdated as described in stackoverflow. And I reinstalled it with following code added.

using ::signbit _LIBCPP_USING_IF_EXISTS;
using ::fpclassify _LIBCPP_USING_IF_EXISTS;
using ::isfinite _LIBCPP_USING_IF_EXISTS;
using ::isinf _LIBCPP_USING_IF_EXISTS;
using ::isnan _LIBCPP_USING_IF_EXISTS;
using ::isnormal _LIBCPP_USING_IF_EXISTS;
using ::isgreater _LIBCPP_USING_IF_EXISTS;
using ::isgreaterequal _LIBCPP_USING_IF_EXISTS;
using ::isless _LIBCPP_USING_IF_EXISTS;
using ::islessequal _LIBCPP_USING_IF_EXISTS;
using ::islessgreater _LIBCPP_USING_IF_EXISTS;
using ::isunordered _LIBCPP_USING_IF_EXISTS;
using ::isunordered _LIBCPP_USING_IF_EXISTS;

_LIBCPP_USING_IF_EXISTS is defined as # define _LIBCPP_USING_IF_EXISTS __attribute__((using_if_exists)), simply pass if no defined in the global namespace.

Then the following code output error

using _Lim = numeric_limits<_IntT>;

add another header in 

#include <limits>

Then comes to the std::isnan using bypassing no definition error in llvm/lib/Support/NativeFormatting.cpp.

error: expected unqualified-id for std::isnan(N)

just drop the std::

The full formula for riscv-rvv-llvm is located in https://github.com/victoryang00/homebrew-riscv, if anything above happens, do as the above specifies.

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A command line string to the class constructor.

There's the demand of passing a name and doing the class construction of this name. I don't want to make the switch case on the construct. Let's do the hack!

I found the base implementation in stackoverflow.

template <class T> void* constructor() { return (void*)new T(); }

struct factory
{
   typedef void*(*constructor_t)();
   typedef std::map<std::string, constructor_t> map_type;
   map_type m_classes;

   template <class T>
   void register_class(std::string const& n)
   { m_classes.insert(std::make_pair(n, &constructor<T>)); }

   void* construct(std::string const& n)
   {
      map_type::iterator i = m_classes.find(n);
      if (i == m_classes.end()) return 0; // or throw or whatever you want
      return i->second();
   }
};

factory g_factory;

#define REGISTER_CLASS(n) g_factory.register_class<n>(#n)

The problem is it does not allow the arg passing in construction. My class accepts the arguments module.

template <class T, typename M_> void *constructor(M_ *module_) {
    return (void *)new T{reinterpret_cast<M_ *>(module_)};
}
template <typename M_> struct arg_to_pass {
    typedef void *(*constructor_t)(M_ *);
    typedef std::map<std::string, constructor_t> map_type;
    map_type m_classes;
    M_ *module;

    template <class T> void register_class(std::string const &n, M_ *&module_) {
        module = module_;
        m_classes.insert(std::make_pair(n, &constructor<T, M_>));
    }

    void *construct(std::string const &n) {
        auto i = m_classes.find(n);
        if (i == m_classes.end())
            return nullptr; // or throw or whatever you want
        return i->second(module);
    }
};

arg_to_pass<Module> pass_factory;

#define REGISTER_CLASS(n, m_) pass_factory.register_class<n>(#n, m_)

This will resolve all the problem.

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高级语言 to LLVM 的解释层

最近在做编译原理课程设计的设计，看了很多到 LLVM 的编译器的想法，同时发现 Rust 类型体操作为黑魔法合集也能带给社区很多新鲜玩意，就把之前设计 Chocopy LLVM 层的一些小想法放在这，上科大的同学想玩可以加个piazza，invite code: CHOCOPY。有一部分参考 High Level Constructs to LLVM_IR, 范型的设计更多参考 rust 和 c。

Continue reading "高级语言 to LLVM 的解释层"

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A weird thing in arm64 of operator << in gcc-11

I'm trying to do some log stuff in a Compiler project. When I'm trying to use the fmt::format library.

It was safe and sound to run with apple-clang 13, but when it comes to gcc-11 for the following line:

if ((x.second)->is_list_type()) {
    LOG(INFO) << fmt::format("{} : [{}]", x.first,
            ((ClassValueType *)((ListValueType *)x.second)->elementType)->className);
}

LogStream is something like:

class LogStream {
public:
    LogStream() { sstream_ = new std::stringstream(); }
    ~LogStream() = default;

    template <typename T> LogStream &operator<<(const T &val) noexcept {
        (*sstream_) << val;
        return *this;
    }

    friend class LogWriter;

private:
    std::stringstream *sstream_;
};


The operator << gets error reading the memory byte from the fmt byte, possibly because the author of GCC is not aware the pointer passed do not fit in the following ldur style of stream out. On x86 OSX machine, the GCC have some _M_is_leaked() check in the same line and on Windows MSVC, the line has reported the memory leakage for doubly linked pointer.

The compiled code is:

There's trick to maintain a compiler that have a universal error code output.