I'm getting a compile-time error. It complains that I'm initializing a variable, but not referencing it. What's happening is that I initialize it then make a debug print statement that only get's compiled in for a debug build but not a release build. The error in question is warning c4189 (it's treated as an error and won't compile).
Is it possible to suppress this warning? How about warnings in general?
Don't suppress the warning, fix it! Wrap the declaration and initialization of the variable so it only exists in a debug build too.
Related
I'm getting the following (probably) inspection warning in CLion: warning: bitwise operation between different enumeration types is deprecated
There is no context menu option to disable it and I can't find it anywhere in the settings. I can see the warning popup window (see screenshot) when I hover over it with the mouse, but there isn't any information there except the warning text (no error code, intention name or anything at all that gives me a clue as to where this warning comes from)... very strange.
I thought it comes from C++20 compiler warning C5054 from the MSVC compiler so I tried to disable it in CMake with target_compile_options(engine PRIVATE -wd5054) but it didn't work.
Note: it bothers me since it appears all over my code and I fix the original code that causes it since it comes from in an external library.
Any idea how do I disable this annoyance?
According to cppreference [[deprecated("message string")]] we should be able to use the symbol but in VS results in error instead.
For example I wan't to issue a warning for ANSI methods in UNICODE builds and vice versa:
#ifdef UNICODE
[[deprecated("This method does not work well in UNICODE builds")]]
#endif // UNICODE
void f() {}
compiler doesn't let me compile, but standard says the attribute should allow usage but issue a warning message.
How to resolve this?, btw. my project is set to maximum conformance with the standard.
What ever the reason for VS going against the standard, is there a better way to issue a warning for above case?
Very much late to the party, but this cost me a couple of hours this morning.
By default, Visual Studio and the sdl (Security Development Lifecycle) compile flag treat
[[deprecated]] as an error. Whether or not you agree with this or not, that's how they do it.
To fix this go to Configuration Properties -> C/C++ -> Command Line and add /sdl /w34996
The /wX part represents the severity of the warning, and the rest is the error you want to report as a warning.
I hope this saves people some time.
I was able to get the compiler to treat [[deprecated]] as a warning by adding
/w34996
to the compiler options, as suggested in the responses in following link
https://developercommunity.visualstudio.com/content/problem/786502/cant-treat-deprecated-warning-as-warning-with-wx.html
is there a better way to issue a warning for above case?
There's no other way of warning about usage of a function than deprecation attribute in standard C++ at least that I know of.
Msvc has other alternatives such as #pragma deprecated(f), but those are not better.
How to resolve this?
Assuming you haven't configured your compiler to treat warnings as errors, you could proceed with writing a bug report to the maintainers.
I haven't tested it with Visual Studio, but in my case the following helped and probably is more generic:
On that error usually warnings are treated as errors with the compiler flag -Werror, that is automatically set in Visual Studio. That is the reason way a class or function marked with [[deprecated]] results in an error. To avoid explicitly that error and output it just as a warning, the compiler flag -Werror -Wno-error=deprecated-declarations can be set. In CMake it would look like:
add_compile_options(-Werror -Wno-error=deprecated-declarations)
I have a __forceinline function that cannot be inlined when compiled as CLI (probably due to the specific restrictions to inlining that apply with .NET).
In debug, it is a warning and does not prevent me from building. But in release, it comes up as an error:
error C4714: function '...' marked as __forceinline not inlined
In the project configuration, Treat Warnings As Errors is set to No (/WX-), Treat Specific Warnings As Errors is empty (no value and no inherited value) and there is no /We option in the Command Line of the C/C++ section.
Thus, I don't understand why this warning comes up as an error.
And as it is an error it prevents me from building the project in release.
Do you have any clue on why this comes up as an error?
Any idea of how I could get rid of it, considering I cannot change the function nor its use (it comes from a library I'm using and I'd like not to alter)?
Thank you very much!
I am trying to eliminate the warnings in my project so I can turn on the flag that treats warnings as errors. The project uses the boost library, specifically the Concept_check.hpp and cuthill_mckee_ordering.hpp files. The warnings 4510 and 4610 are shown in the concept_check.hpp file and I have tried to disable them using #pragma warning push and pop. The warnings are caused by the boost library trying to instantiate a class using the template found in concept_check.cpp when there is no constructor written for it.
My Question is this: Is there a more sure fire way that I can disable these warnings without modifying the boost code? I am using Visual studio 2010.
Perhaps you are looking in the wrong direction. As Alan Stokes pointed out, the warning is there for a reason. I have three hints that are perhaps not the answers you expect, but may bring an acceptable solution:
Instead of silencing the warning, just fix the error. I don't know your code, but there are other people that had a similar problem which was possible to fix by just declaring a variable.
Another question is: why do you want to turn all your warnings into errors? Is it really neccessary? I agree that normal code should always compile without warnings. But these warnings are not originating from your own code. Consider a static code-checker that warns you about issues where your compiler is blind about.
If you have to use -WX, move the offending code into a static object/library/module so you will be bothered about the warning only when you need to recompile this module. You could use specific compile options for this module, to get the warnings completely out of your way.
There is another possibility, but I'm not able to check whether it really works. According the Microsoft Documentation it is possible to set the warning level of specific warnings. (there are similar options for GCC). First, switch all warnings to error:
/WX
Then, set the warning level of the two offending warnings to zero:
/W04510 /W04610
A complete commandline would look like this:
cl source.cpp /WX /W04510 /W04610
The best solution would be to combine this with hint 3 above. This way, the specific compiler options are only used for the files that cause the warnings.
Maybe these solutions work.
You can disable specific warning from a .h file (#pragma warning( disable: ... ).
I'm on Ubuntu 13.04 32 platform. I'm trying to compile awn with latest vala. I get following error message.
vala-utils.cc: In function 'void awn::vala_array_destroy(gpointer, gint, GDestroyNotify)':
vala-utils.cc:358:6: error: no previous declaration for 'void awn::vala_array_destroy(gpointer, gint, GDestroyNotify)' [-Werror=missing-declarations]
cc1plus: some warnings being treated as errors
How can I fix that error?
At the top of vala-utils.cc insert the function prototype:
void vala_array_destroy(gpointer array, gint array_length, GDestroyNotify destroy_func);
This will silence the warning which is causing the build to fail due to -Werror defined in the Makefile. Consider raising a pull request for the benefit of the maintainers.
Alternatively modify ln.89 in configure.ac and remove the -Werror to stop the warning failing the build.
This actually a warning, and a rather pedantic one at that.
It's saying that the global function awn::vala_array_destroy has not been declared beforehand. Usually this is a sign of a programmer's mistake, but from the source it seems to me that:
this function is only supposed to be used by awn::vala_array_free directly below it (in which case it should really have been given internal linkage), or
a declaration is available in some header elsewhere (in which case it's probably in the wrong header, as it ought to be in vala-utils.h).
The long and short of it is that the code is probably fine, if a little strangely designed. This case is being treated as an error because you have -Werror turned on for this warning, turning it into an error.
I don't know how you're building the library, but you could adjust the compiler flags to avoid this; by default, GCC does not emit this warning, nor turn it into an error. Alternatively, you could add the function declaration into vala-utils.h yourself. You should also take up the issue with the library's maintainers.
Update: I found the culprit on line 89 of AWN's configure.ac. You should definitely take this up with the library maintainers. I'd be amazed if this had not already been reported as a bug; I believe it was introduced in this revision.