C++: error: no member named 'signbit' in the global namespace

Question

TL;DR: #include <cmath> headers yield no member named 'signbit' in the global space when attempting to compile

Goal: Compile a pure C++ gRPC client-server application

Errors:

g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o  client `pkg-config --libs --cflags protobuf grpc++`
In file included from client.cpp:3:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpc++/grpc++.h:26:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/grpcpp.h:52:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/channel.h:28:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/completion_queue.h:45:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/sync.h:32:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/mutex.h:72:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/internal/kernel_timeout.h:34:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/clock.h:26:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/time.h:78:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:321:9: error: no member named 'signbit' in the global namespace
using ::signbit;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:322:9: error: no member named 'fpclassify' in the global namespace
using ::fpclassify;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:323:9: error: no member named 'isfinite' in the global namespace
using ::isfinite;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:324:9: error: no member named 'isinf' in the global namespace
using ::isinf;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:325:9: error: no member named 'isnan' in the global namespace
using ::isnan;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:326:9: error: no member named 'isnormal' in the global namespace
using ::isnormal;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:327:7: error: no member named 'isgreater' in the global namespace; did you mean '::std::greater'?
using ::isgreater;
      ^~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/functional:742:29: note: '::std::greater' declared here
struct _LIBCPP_TEMPLATE_VIS greater : binary_function<_Tp, _Tp, bool>
                            ^
In file included from client.cpp:3:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpc++/grpc++.h:26:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/grpcpp.h:52:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/channel.h:28:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/completion_queue.h:45:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/sync.h:32:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/mutex.h:72:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/internal/kernel_timeout.h:34:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/clock.h:26:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/time.h:78:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:328:7: error: no member named 'isgreaterequal' in the global namespace; did you mean '::std::greater_equal'?
using ::isgreaterequal;
      ^~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/functional:771:29: note: '::std::greater_equal' declared here
struct _LIBCPP_TEMPLATE_VIS greater_equal : binary_function<_Tp, _Tp, bool>
                            ^
In file included from client.cpp:3:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpc++/grpc++.h:26:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/grpcpp.h:52:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/channel.h:28:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/completion_queue.h:45:
In file included from /opt/homebrew/Cellar/grpc/1.41.1/include/grpcpp/impl/codegen/sync.h:32:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/mutex.h:72:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/synchronization/internal/kernel_timeout.h:34:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/clock.h:26:
In file included from /opt/homebrew/Cellar/abseil/20210324.2_1/include/absl/time/time.h:78:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:329:9: error: no member named 'isless' in the global namespace
using ::isless;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:330:9: error: no member named 'islessequal' in the global namespace
using ::islessequal;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:331:9: error: no member named 'islessgreater' in the global namespace
using ::islessgreater;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:332:9: error: no member named 'isunordered' in the global namespace
using ::isunordered;
      ~~^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cmath:333:9: error: no member named 'isunordered' in the global namespace
using ::isunordered;
      ~~^

This is just a small snippet of what else is cropping up. There are a few more errors with cmath but I assume the majority (if not all) will be cleared up once a solution is implemented.

What I've Tried:

Using different SDK paths

#Check the current sdk
xcrun --show-sdk-path

#Change sdk
sudo xcode-select -s /Library/Developer/CommandLineTools          #Using CommandLineTools SDK
sudo xcode-select -s /Applications/Xcode.app/Contents/Developer   #Using XCode.app SDK

Changing the #include <math.h> link in CMath file as described in this post.

The fix:

If we can alter the search order of #include<...> to search >/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/inclu>de/c++/v1 at first, it can be fixed.

Using #include</Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/math.h> instead of <math.h> in /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/cmath

Adding in -isysroot /sdk/path flag to my compilation command (full command below)

g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk 'pkg-config --libs --cflags protobuf grpc++'

Uninstalled, reinstalled, and update Xcode command line tools
Reinstalled gcc

Configuration:

                 ,xNMM.          ---------------------------------
               .OMMMMo           OS: macOS 12.0.1 21A559 arm64
               OMMM0,            Host: MacBookPro18,3
     .;loddo:' loolloddol;.      Kernel: 21.1.0
   cKMMMMMMMMMMNWMMMMMMMMMM0:    Uptime: 12 days, 22 hours, 41 mins
 .KMMMMMMMMMMMMMMMMMMMMMMMWd.    Packages: 53 (brew)
 XMMMMMMMMMMMMMMMMMMMMMMMX.      Shell: zsh 5.8
;MMMMMMMMMMMMMMMMMMMMMMMM:       Resolution: 1512x982
:MMMMMMMMMMMMMMMMMMMMMMMM:       DE: Aqua
.MMMMMMMMMMMMMMMMMMMMMMMMX.      WM: Quartz Compositor
 kMMMMMMMMMMMMMMMMMMMMMMMMWd.    WM Theme: Blue (Dark)
 .XMMMMMMMMMMMMMMMMMMMMMMMMMMk   Terminal: iTerm2
  .XMMMMMMMMMMMMMMMMMMMMMMMMK.   Terminal Font: Monaco 12
    kMMMMMMMMMMMMMMMMMMMMMMd     CPU: Apple M1 Pro
     ;KMMMMMMMWXXWMMMMMMMk.      GPU: Apple M1 Pro
       .cooc,.    .,coo:.        Memory: 3551MiB / 32768MiB

Not entirely sure what else I can find on this. From the few hours of research I have done, it seems to be a MacOS issue rather than a configuration/setup issue. Any assistance would be greatly appreciated.

Does this answer your question? [Catalina C++: Using headers yield error: no member named 'signbit' in the global namespace](https://stackoverflow.com/questions/58628377/catalina-c-using-cmath-headers-yield-error-no-member-named-signbit-in-th) — kiner_shah, Dec 07 '21 at 08:12
I tried the majority of these solutions, but one seems to have done the trick for me. I answered below. — zebra14, Dec 08 '21 at 07:21

zebra14 · Accepted Answer · 2021-12-08T07:55:04.183

After some digging I found what was most likely going wrong...

I executed gcc -Wp,-v -E - in my terminal to see what paths were being searched in what order.

Here was the output:

#include <...> search starts here:
 /usr/local/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/13.0.0/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks (framework directory)

As you may see, the first thing searched is /usr/local/include which did hold a version of 'math.h'.

After identifying this, I edited the #include line in 'cmath' to point directly to the one in the same directory as explained below:

// this was here before
#include <math.h>

// and I changed it to this
#include </Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/math.h>

After this, the compilation line g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client 'pkg-config --libs --cflags protobuf grpc++' now returns the following error:

ld: library not found for -lre2
clang: error: linker command failed with exit code 1 (use -v to see invocation)

So it seems as though I have fixed the math.h issues, and have found more to explore. yay.

Someone please chime in if you believe this is a bad idea. I know it isn't the brightest decision considering it may affect other things down the road, but I couldn't find anything on changing the order of search directories.

FINAL UPDATE:

Got the server to work finally. Just needed to add 're2' and 'libcares' to my compilation command bringing it to this:

g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client 'pkg-config --libs --cflags protobuf grpc++ re2 libcares'

What an amazing feeling to have built something from scratch after two months...

***I couldn't find anything on changing the order of search directories*** Does this help? https://stackoverflow.com/a/558819/4688321 — kiner_shah, Dec 08 '21 at 08:14

C++: error: no member named 'signbit' in the global namespace

1 Answers1