With the following MCVE:
import std.core;
int main()
{
__int64 t = time(nullptr);
return 0;
}
I get the complaint that
C:\...\main.cpp(9,1): error C2129: static function '__int64 time(__int64 *const )' declared but not defined
I'm compiling Debug/Win32. Runtime library is /MDd. I have /std:c++latest and /experimental:module set; command-line options are
/JMC /experimental:module /permissive- /GS /analyze- /W3 /Zc:wchar_t /I"../../external/fmt-master/include" /ZI /Gm- /Od /Fd"Debug\vc142.pdb" /Zc:inline /fp:precise /D "_MBCS" /errorReport:prompt /WX- /Zc:forScope /RTC1 /Gd /Oy- /MDd /std:c++latest /FC /Fa"Debug\" /EHsc /nologo /Fo"Debug\" /Fp"Debug\modules.pch" /diagnostics:column
Not having problems accessing std::cout, std::string, srand, or sin. What can tell Visual Studio to find the time function too?
std.core provides everything else in the C++ Standard Library. However, as of Visual Studio 2019 version 16.2, Draft C++20 Standard modules are not fully implemented in the Microsoft C++ compiler. You can use the modules feature to create single-partition modules and to import the Standard Library modules provided by Microsoft. You could refer to this link for more information.
Also, You could see Overview of modules in C++ about how to create modules.
Related
Consider code:
#include <stdio.h>
int main() {
int a = 4;
#if 1
printf("Hello world\n");
#endif a++;
printf("a is %d\n", a);
}
Inadvertently, statement a++; is on the same line as a #endif and is not evaluated. As a result, the final output is:
Hello world
a is 4
On x86-64 clang 12, this is captured as a warning with using option -Wextra-tokens. See here.
I tried compiling this on Visual Studio 2019 MSVC, with command line options:
/JMC /permissive- /ifcOutput "Debug\" /GS /analyze- /W3 /Zc:wchar_t /I"../include/" /ZI /Gm- /Od /sdl /Fd"Debug\vc142.pdb" /Zc:inline /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_UNICODE" /D "UNICODE" /errorReport:prompt /WX- /Zc:forScope /RTC1 /Gd /Oy- /MDd /FC /Fa"Debug\" /EHsc /nologo /Fo"Debug\" /Fp"Debug\windows.pch" /diagnostics:column
There is no warning of any sort on compilation. Is there a setting that can be passed to the compiler in MSVC that detects extra tokens?
Edited to add:
As answered by user Nathan Pierson, it was indeed option /Za that worked. It does not seem to be on by default. I was also unable to use the Visual Studio Project Properties dialog to find out the option to set. Yet, one can feed in extra options manually thus:
There's compiler warning C4067. It looks like you need to set the flag /Za for it to apply to #endif directives.
In the Visual Studio properties page, this flag is controlled by the setting "Disable Language Extensions" in the Language subsection of the C/C++ section.
To accurately profile an application, under linux, it is recommended to have optimizations on and debug symbols on via compile options -O2 -g for gcc or g++. This enables profiling to include the user's C++ code and not point to assembly code instead as possible hotspots, for instance. See for instance, here.
In Visual Studio IDE, for usage of profilers, what are the equivalent compile/linking options?
In Release mode of Visual Studio, under "Whole Program Optimization" property sheet that comes loaded by default, the Debug Information Format gets set to Program Database with command line option /Zi. See image:
Is this the Visual Studio/Windows/MSVC (Cl.exe, MSBuild.exe) equivalent of -O2 -g? Or are there any other equivalent settings?
ETA: Under the default Visual Studio 2019 release mode settings, the following flags are set:
/permissive- /ifcOutput "x64\Release\" /GS /GL /W3 /Gy /Zc:wchar_t /I"E:\local\boost_1_72_0" /Zi /Gm- /O2 /sdl /Fd"x64\Release\vc142.pdb" /Zc:inline /D "_MBCS" /errorReport:prompt /WX- /Zc:forScope /Gd /Oi /MD /FC /Fa"x64\Release\" /EHsc /nologo /Fo"x64\Release\" /FA /Fp"x64\Release\windows.pch" /diagnostics:column
Have a look at the project properties, under C++ optimization. The IDE tells you everything.
According to Microsoft ( https://learn.microsoft.com/en-us/cpp/overview/visual-cpp-language-conformance?view=msvc-160 ), it implemented P1502R1 Standard library header units for C++20:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1502r1.html
in the latest Visual Studio 2019.
So one can write, e.g.:
import <vector>;
But if I do it in my Visual Studio 2019 16.10.3 (with /std:c++latest switch), the following compilation error arises:
error C7612: could not find header unit for 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\vector'
The complete command-line in Debug configuration:
/JMC /experimental:module /external:env:"EXTERNAL_INCLUDE" /permissive- /ifcOutput "x64\Debug\" /GS /W4 /Zc:wchar_t /ZI /Gm- /Od /sdl /Fd"x64\Debug\vc142.pdb" /Zc:inline /fp:precise /D "_DEBUG" /D "_CONSOLE" /D "_UNICODE" /D "UNICODE" /errorReport:prompt /WX- /Zc:forScope /RTC1 /Gd /MDd /std:c++latest /FC /Fa"x64\Debug\" /EHsc /nologo /Fo"x64\Debug\" /Fp"x64\Debug\Project1.pch" /diagnostics:column
Please help how to activate this new feature in MSVC?
I downloaded the source code for a library that resembles the processing library but for c++ called libxd. I used CMake to generate project files for Visual Studio 2019 which worked successfully. When trying to compile the solution for all of the provided build modes, I get the following errors:
The first error invlaid numeric argument '/Wno-narrowing' is what I'm concerned about for now. I'm trying to figure out why this argument is being provided to the compiler. When looking in the properties window for the xd project in the solution I can see the command line arguments that are supposed to be provided to the compiler in the C/C++ > Command Line tab. I verified that there is no /Wno-narrowing option provided. When looking at the build output it can be seen that the option -Wno-narrowing is being provided to the compiler. Can someone help me figure out why this argument is being passed? I looked throughout the compiler properties window to see if I could see anything that would be affecting it but I can't see anything that would affect this.
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\bin\HostX64\x64\CL.exe /c /IC:\dev\libxd\include /IC:\dev\libxd\lib\glad\include /IC:\dev\libxd\lib\glm /IC:\dev\libxd\lib\stb\include /IC:\dev\libxd\lib\glfw\include /Zi /nologo /W3 /WX- /diagnostics:column /Od /Ob0 /D WIN32 /D _WINDOWS /D "CMAKE_INTDIR=\"Debug\"" /D _MBCS /Gm- /EHsc /RTC1 /MDd /GS /fp:precise /Zc:wchar_t /Zc:forScope /Zc:inline /GR /Fo"xd.dir\Debug\\" /Fd"xd.dir\Debug\xd.pdb" /Gd /TP /errorReport:prompt -Wno-narrowing C:\dev\libxd\src\opensans.cpp
Tracking command:
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Tracker.exe /d "C:\Program Files (x86)\MSBuild\15.0\FileTracker\FileTracker32.dll" /i C:\dev\libxd\build\xd.dir\Debug\xd.tlog /r C:\DEV\LIBXD\SRC\OPENSANS.CPP /b MSBuildConsole_CancelEventfa83e1bb599743cfa0c02eb67d579e28 /c "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\bin\HostX64\x64\CL.exe" /c /IC:\dev\Users\olive\Downloads\libxd\include /IC:\dev\libxd\lib\glad\include /IC:\dev\libxd\lib\glm /IC:\dev\libxd\lib\stb\include /IC:\dev\libxd\lib\glfw\include /Zi /nologo /W3 /WX- /diagnostics:column /Od /Ob0 /D WIN32 /D _WINDOWS /D "CMAKE_INTDIR=\"Debug\"" /D _MBCS /Gm- /EHsc /RTC1 /MDd /GS /fp:precise /Zc:wchar_t /Zc:forScope /Zc:inline /GR /Fo"xd.dir\Debug\\" /Fd"xd.dir\Debug\xd.pdb" /Gd /TP /errorReport:prompt -Wno-narrowing C:\dev\libxd\src\opensans.cpp
cl : command line error D8021: invalid numeric argument '/Wno-narrowing'
The command exited with code 2.
The error is caused because that's not a valid MSVC flag. The flag is there because the CMakeLists.txt file demands it:
set_source_files_properties(src/opensans.cpp PROPERTIES COMPILE_FLAGS -Wno-narrowing)
That project specifies what it supports for building under Windows and it's not MSVC.
Windows Prerequisites: mingw-w64 version >= 4.8.1
So you either need to build it in the supported way, or modify the build scripts to allow for MSVC.
That would entail figuring out what the flag does in gcc (disables diagnostic messages about narrowing issues) and finding the equivalent in MSVC, probably a /disable:nnnn variant, once you figure out the nnnn. Figuring that out should be relatively painless since MSVC will tell you that when you compile it - lots of Cnnnn - something to do with narrowing warning messages.
Or you could just disable the line that adds the flag (for MSVC builds only) and see if it still builds. Of course, in the spirit of open source, you should then notify the author what it took to get it going, they may be happy to support MSVC if the effort is not too high.
I have a small test project that I want to build with TeamCity. In TeamCity I have created a build step with runner type 'Visual Studio' solution. The problem is it is not building. The error I get is:
error C1069: cannot read compiler command line
Here a part of the build log:
[16:55:05]ClCompile
[16:55:05]CL
[16:55:05]C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\CL.exe /c /ZI /nologo /W3 /WX- /sdl /Od /Oy- /D WIN32 /D _DEBUG /D _LIB /D _UNICODE /D UNICODE /Gm /EHsc /RTC1 /MDd /GS /fp:precise /Zc:wchar_t /Zc:forScope /Fo"Debug\\" /Fd"Debug\vc120.pdb" /Gd /TP /analyze- /errorReport:queue UnitTest.cpp
[16:55:05]UnitTest.cpp
[16:55:05]c:\data\teamcity buildagent\work\d8c46b39964cb4dc\testlibrary\unittest.cpp(27, 0): error C1069: cannot read compiler command line
Try removing the space in the TeamCity build agent path:
c:\data**teamcity buildagent**\work\d8c46b39964cb4dc\testlibrary\unittest.cpp
There is a bug with the VS2013 compiler as documented here:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/82304c15-37e2-4761-8928-0c67e074bf47/error-c1069-cannot-read-compiler-command-line-on-visual-studio-2013-rc?forum=vcgeneral
(Note, this is referring to the RC and could now be fixed)