Author Topic: something about M_PI  (Read 6009 times)

Offline coutnut

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something about M_PI
« on: September 07, 2021, 11:04:16 am »
Hi! Guys, nice to meet u all here.
     I am really new to CBs. and I am learning programing in the structure of OpenCASCADE. Typically, I should use VS2019. However my computer is a little bit old, if I use the VS2019,  sometimes it'll crash. So I aim to program with CBs, language is cpp.

    Here is the problem. I got a gp_Dir2d.lxx which uses M_PI.
    I defineed ||#define D_USE_MATH_DEFINES   || and ||  #define _USE_MATH_DEFINES || ,||   #include <math.h> ||   but error came out  : 'M_PI' was not declared in this scope.

    I am really confused. What should I do to fix it? (PS:this works in VS2019,BUT I really need a lighter IDE!)

Offline stahta01

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Re: something about M_PI
« Reply #1 on: September 07, 2021, 05:49:02 pm »
Sounds like an Compiler and Code::Blocks (C::B) configuration related issue.

Therefore the Compiler Toolchain info is needed.  NOTE: C::B is not an Compiler.

Operating System (OS) including 64 or 32 bit might also be needed.

Example info expected is:

Compiler: GCC (Rev5, Built by MSYS2 project) 10.3.0
C::B Version: svn-r12452
OS Info: Microsoft Windows 7 64 bit

From C::B Help -> About (Information Tab)

Code
Name                    : Code::Blocks
Version                 : svn-r12452
SDK Version             : 2.9.0
Scintilla Version       : 3.7.5
Author                  : The Code::Blocks Team
E-mail                  : info@codeblocks.org
Website                 : http://www.codeblocks.org
OS                      : Windows 7 (build 7601, Service Pack 1), 64-bit edition
Scaling factor          : 1.000000
Detected scaling factor : 1.000000
Display PPI             : 96x96
Display count           : 1
Display 0 (\\.\DISPLAY1): XY=[0,0]; Size=[1366,768]; Primary

wxWidgets Library (wxMSW port)
Version 3.1.5 (Unicode: wchar_t, debug level: 1),
compiled at Apr 25 2021 09:56:34

Runtime version of toolkit used is 6.1.

I am 80 percent sure the problem is caused by using GCC with a non standard file extension of "lxx".

But, I have no idea about how to fix the problem.

Posting the build log might help an expert to help you. NOTE: Build Log not Build messages

Edit: Add example build log
Code
-------------- Build: Debug in testpi (compiler: GNU GCC Compiler)---------------

x86_64-w64-mingw32-g++.exe -Wall -fexceptions -pedantic -std=c++17 -g  -c C:/Users/stahta01/test/testpi/main.cpp -o obj/Debug/main.o
x86_64-w64-mingw32-g++.exe  -o bin/Debug/testpi.exe obj/Debug/main.o   
Output file is bin\Debug\testpi.exe with size 143.26 KB
Process terminated with status 0 (0 minute(s), 5 second(s))
0 error(s), 0 warning(s) (0 minute(s), 5 second(s))
 

Tim S.

« Last Edit: September 07, 2021, 05:51:42 pm by stahta01 »
C Programmer working to learn more about C++ and Git.
On Windows 7 64 bit and Windows 10 32 bit.
On Debian Stretch, compiling CB Trunk against wxWidgets 3.0.
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When in doubt, read the CB WiKi FAQ. http://wiki.codeblocks.org

Offline stahta01

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Re: something about M_PI
« Reply #2 on: September 07, 2021, 11:45:49 pm »
The file "gp_Dir2d.lxx" that I found in opencascade project was never meant to be treated as a source file as in being compiled.
Instead it should be treated as a header file and the compiling and linking turned off for the file.

So, the file extension of "lxx" should not be a problem. Still waiting for a build log!

Tim S.
 
C Programmer working to learn more about C++ and Git.
On Windows 7 64 bit and Windows 10 32 bit.
On Debian Stretch, compiling CB Trunk against wxWidgets 3.0.
--
When in doubt, read the CB WiKi FAQ. http://wiki.codeblocks.org

Offline sodev

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Re: something about M_PI
« Reply #3 on: September 08, 2021, 04:30:47 pm »
M_PI is not part of the C standard but part of POSIX. Most probably the OP is using GCC and that one is more strict regarding the standard. Using a C standard with GNU extensions does help in that case, e.g. instead of using --std=c11 use --std=gnu11.

Offline coutnut

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Re: something about M_PI
« Reply #4 on: March 11, 2022, 03:40:26 am »
The file "gp_Dir2d.lxx" that I found in opencascade project was never meant to be treated as a source file as in being compiled.
Instead it should be treated as a header file and the compiling and linking turned off for the file.

So, the file extension of "lxx" should not be a problem. Still waiting for a build log!

Tim S.
Thanks for you guys' replies!
I'm really appreciate that!
Sorry to response so late, I was temporarily working on some other stuff in the past months. Give me the pardon!
Also something wrong with my pc, so I rebuild the project. The error still exists.

Here is part of build log, and I using "..." to replace the fullpath
Also, the 12 errors are all the same.

Code
...\opencascade-7.5.0\inc/gp_Vec.lxx: In member function 'Standard_Boolean gp_Vec::IsParallel(const gp_Vec&, Standard_Real) const':
...\opencascade-7.5.0\inc/gp_Vec.lxx:111:39: error: 'M_PI' was not declared in this scope
   return   Ang <= AngularTolerance || M_PI - Ang <= AngularTolerance;
                                       ^
Process terminated with status 1 (0 minute(s), 1 second(s))
12 error(s), 0 warning(s) (0 minute(s), 1 second(s))
M_PI is not part of the C standard but part of POSIX. Most probably the OP is using GCC and that one is more strict regarding the standard. Using a C standard with GNU extensions does help in that case, e.g. instead of using --std=c11 use --std=gnu11.

Actually, I use the GNU GCC Compiler in the project.
As for the compiler flags, I picked the -std=c++11.
But error remains.

By the way, I tried to include math.h instead of cmath, this still happens.

Attachment is the pic of the compiler flags.
« Last Edit: March 11, 2022, 03:42:17 am by coutnut »

Offline stahta01

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Re: something about M_PI
« Reply #5 on: March 11, 2022, 05:34:05 am »
Please post a full re-build log or I will just add you to the list of people not worth helping!

NOTE: WE CAN NOT HELP YOU IF YOU REFUSE TO POST THE GCC COMMAND CAUSING THE ERROR!

https://wiki.codeblocks.org/index.php?title=FAQ-Compiling_%28general%29#Q:_How_do_I_report_a_compilation_problem_on_the_forums.3F

Tim S.
« Last Edit: March 11, 2022, 05:36:07 am by stahta01 »
C Programmer working to learn more about C++ and Git.
On Windows 7 64 bit and Windows 10 32 bit.
On Debian Stretch, compiling CB Trunk against wxWidgets 3.0.
--
When in doubt, read the CB WiKi FAQ. http://wiki.codeblocks.org

Offline sodev

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Re: something about M_PI
« Reply #6 on: March 11, 2022, 02:49:28 pm »
Actually, I use the GNU GCC Compiler in the project.
As for the compiler flags, I picked the -std=c++11.
But error remains.

Of course they remain because again you use C++11 without GNU extensions. Specify -std=gnu++11 instead.

Offline stahta01

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Re: something about M_PI
« Reply #7 on: March 12, 2022, 07:41:53 am »
Actually, I use the GNU GCC Compiler in the project.
As for the compiler flags, I picked the -std=c++11.
But error remains.

Of course they remain because again you use C++11 without GNU extensions. Specify -std=gnu++11 instead.

I would try this suggestion; but, since you will not post more information and the cause and solution seems to vary per my internet searches. A link that gives more things to try https://stackoverflow.com/questions/26065359/m-pi-flagged-as-undeclared-identifier

Tim S.
C Programmer working to learn more about C++ and Git.
On Windows 7 64 bit and Windows 10 32 bit.
On Debian Stretch, compiling CB Trunk against wxWidgets 3.0.
--
When in doubt, read the CB WiKi FAQ. http://wiki.codeblocks.org

Offline stahta01

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Re: something about M_PI
« Reply #8 on: March 12, 2022, 06:03:41 pm »
You may want to read the website rules: https://forums.codeblocks.org/index.php/topic,9996.0.html

Since, you refuse to supply the Code::Blocks information I requested that implies you do not think it is a Code::Blocks related question.

Tim S.

C Programmer working to learn more about C++ and Git.
On Windows 7 64 bit and Windows 10 32 bit.
On Debian Stretch, compiling CB Trunk against wxWidgets 3.0.
--
When in doubt, read the CB WiKi FAQ. http://wiki.codeblocks.org