How can I ignore some warning of VSCode's clangd plugin? - c++

I installed a clangd plugin in VSCode to develop C++.
This plugin works well, but it shows some code error/waring in our project because we use a deprecated function in <zstd.h>.
include <zstd.h>
deprecated function
How can I mask this error without changing the code?
For example, I can ignore some warning in the VSCode's cpplint plugin by modifying .vscode/settings.json:
ignore some error on cpplint plugin
Can I do something like that to the VSCode's clangd plugin? thanks~
I try to use clang diagnostic, but it seems not work.
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-attributes"
#include <zstd.h>
#pragma clang diagnostic pop
clang diagnostic don't work

First, note that the reason for the error is not the function being deprecated, it's a parsing error ("an attribute list cannot appear here"). The note related to deprecation is just a comment that shows up in the hover, unrelated to the error diagnostic.
If you'd like to suppress the error, you can do it using https://clangd.llvm.org/config.html#suppress. For example, you could create a .clangd file in your project root containing:
Diagnostics:
Suppress: attributes_not_allowed
(Note, attributes_not_allowed is the diagnostic code of the error from the first screenshot.)
However, suppressing the diagnostic is likely to just paper over an underlying problem that's likely related to your project's configuration. A better approach would be to fix the underlying issue. To do that, please review the project setup instructions and ensure your project has a compile_commands.json and clangd is finding it; if that doesn't resolve the issue, feel free to post clangd logs for further diagnosis.

Related

CLion warning without any way to disable it

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?

[[deprecated]] results in error instead of warning in Visual Studio

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)

Cannot disable warnings caused by the Boost Library

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: ... ).

Erroneous "Unable to resolve identifier" in Netbeans

My program compiles fine, but Netbeans tells me "Unable to resolve identifier to_string."
I tried everything in "Netbeans 7.2 shows "Unable to resolve identifier" , although build is successful" and I set the "C++ standard" to "C++11" in the code assistance options.
This is the only function giving this problem so far. It is however also the first C++11 feature I am using, which leads me to believe it has something to do with Netbeans not understanding that I am using C++11, although I specify it explicitly in the code assistance menu.
Minimal example:
#include <string>
int main() {
std::to_string(1);
}
EDIT: the same problem arises where using nullptr
EDIT2: I suddenly realized it might be important to mention that I do not use a generated Makefile, but SCons.
I know this question is seven months old but since it came up as the second result to a google search I'll tell the answer I came up with. For Netbeans at least. Go to your project properties and make sure you have you "C Compiler"->"C Standard" set to C11, and your "C++ compiler"->"C++ Standard" set to C++11. You have to set BOTH or it will still give false errors!
This will solve the problem:
Right click on "Project".
Select "Code Assistance".
Clean C/C++ cache.
Restart IDE.
Autocomplete and sometimes even syntax highlighting are always faulty with C++. The more you go in depth with C++ and C++11, the more Eclipse and Netbeans will start underlining everything with a red wavy line. Some of my (correct and perfectly compiling) programs are a huge red wavy line. I suggest you disable error markers altogether and you keep autocomplete, but in many cases it just won't work and you have to make the best of it.
I had the same situation. This was occurred because I used .c file instead of .cpp
for Netbeans 8.2 (on Linux) only the following worked for me: Tools -> Options -> Code Assistance -> Macro Definitions:
change:__cplusplus=199711L
to:__cplusplus=201402L
for C++14
or to __cplusplus=201103L
for C++11
I did all the above but what did the trick for me was recognizing that the Makefile had g++ rather than g++ -std=c++11.
To resolve c++17 related 'Unable to resolve identifier' in latest netbeans 8.2 or 9 version, one may need to set the macro definition __cplusplus=201703L as the default C++14 standard macro definition unable to resolve those unexpected error messages appeared in the editor.

How can I inhibit warning 4200 in Visual Studio 2005?

I can inhibit many warnings in Visual Studio 2005 SP1 in the C/C++ Advanced property page, which causes the IDE to use the /wd switch on the command line which invokes the compiler. However, when I try to inhibit warning 4200 (nonstandard extension used : zero-sized array in struct/union), it still appears when I compile. (Of course it's justified; I'm just not in a position to fix the code, nor would it be worth bothering, because it's generated, and the warning is entirely benign under the circumstances.) Does anybody happen to know if this is a bug in the compiler? Or might there be something I can do about it?
To completely disable the warning in the file you can add the following to the top of the file
#pragma warning(disable:2400)
If you want some more flexibility other than a blanket disable for the file, the following page lists several other more fine grained options.
http://msdn.microsoft.com/en-us/library/2c8f766e(VS.80).aspx
It's unclear based on your information as to whether or not it's a bug in the compiler or a configuration issue. I would lean towards a configuration issue, specifically conflicting compiler options that is making it difficult to suppress the warning.
EDIT
OP mentioned they can't control the generated code so they can't directly include the pragma. If that's the case then try this trick. Say the file name is Generated.cpp. No longer include Generated.cpp as one of the files to compile. Instead create a new file called Example.cpp with the following contents
#pragma warning(disable:2400)
#include "Generated.cpp"
Now you'll get the text of Generated.cpp with the disabled warning by only compiling Example.cpp.
You mean like with pragma?
#pragma warning( disable : 2400 )