thr3ads.net - llvm dev - [llvm-dev] Miscellaneous warnings in code using Visual Studio [Jan 2021]

If this information is useful, please help other people find it:
Share via:

Paul C. Anagnostopoulos via llvm-dev

2021-Jan-12 17:14 UTC

[llvm-dev] Miscellaneous warnings in code using Visual Studio

When I build on Windows 7 with Visual Studio, I get various warnings that were
ignored until I recently set

LLVM_ENABLE_WERROR:BOOL=ON

One example is shown below. Should I take the time to hunt these down and fix
them?


**********************************************************************
** Visual Studio 2019 Developer Command Prompt v16.8.1
** Copyright (c) 2020 Microsoft Corporation
**********************************************************************

D:\LLVM\build>build-targets.bat
        1 file(s) copied.
[363/1578] Building CXX object
lib\CodeGen\...LLVMGlobalISel.dir\MachineIRBuilder.cpp.obj
FAILED:
lib/CodeGen/GlobalISel/CMakeFiles/LLVMGlobalISel.dir/MachineIRBuilder.cpp.obj
C:\PROGRA~2\MIB055~1\2019\COMMUN~1\VC\Tools\MSVC\1428~1.293\bin\Hostx86\x86\cl.exe
/nolog
o /TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE
-D_CRT_NONSTDC_NO_WARNINGS
-D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_FILE_OFFSET_BITS=64
-D_HAS_EXCEPTI
ONS=0 -D_LARGEFILE_SOURCE -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS
-D_UNICODE
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
-Ilib\CodeGen\Global
ISel -IC:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel -Iinclude
-IC:\LLVM\llvm-project\l
lvm\include /DWIN32 /D_WINDOWS   /WX /Zc:inline /Zc:__cplusplus
/Zc:strictStrings /Oi /Zc:
rvalueCast /bigobj /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456
-wd4457 -wd
4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610
-wd4510 -wd47
02 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204
-wd4577 -wd4091
 -wd4592 -wd4319 -wd4709 -wd4324 -w14062 -we4238 /MDd /Zi /Ob0 /Od /RTC1 
/EHs-c- /GR- -st
d:c++14 /showIncludes
/Folib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\MachineIRBui
lder.cpp.obj
/Fdlib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\LLVMGlobalISel.pdb /F
S -c C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp
C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
error C2220: t
he following warning is treated as an error
C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
warning C4018:
 '>=': signed/unsigned mismatch
[366/1578] Building CXX object
lib\CodeGen\...CMakeFiles\LLVMGlobalISel.dir\Utils.cpp.obj
ninja: build stopped: subcommand failed.

David Blaikie via llvm-dev

2021-Jan-12 17:17 UTC

head link

[llvm-dev] Miscellaneous warnings in code using Visual Studio

If they prove to be good cleanup/improvements to the code in general - but
we don't try too hard to be -Werror clean on every compiler, mostly just
self-hosted clang. The line is fuzzy - if a warning isn't /too/ bad (ie:
doesn't require extreme contortions to the code to address the warning)
then fixing instances seems ok. If it's unhelpful (eg: a warning has a high
false positive rate and/or clang's equivalent warning is more nuanced and
avoids the need to touch false positives) we may disable warnings in LLVM.
(this doesn't address the issue of warnings in LLVM's public headers -
not
every downstream consumer of LLVM is going to disable the same set of
warnings, so sometimes it's necessary to do some warning cleanup even for
undesirable warnings)

On Tue, Jan 12, 2021 at 9:14 AM Paul C. Anagnostopoulos via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> When I build on Windows 7 with Visual Studio, I get various warnings that
> were ignored until I recently set
>
> LLVM_ENABLE_WERROR:BOOL=ON
>
> One example is shown below. Should I take the time to hunt these down and
> fix them?
>
>
> **********************************************************************
> ** Visual Studio 2019 Developer Command Prompt v16.8.1
> ** Copyright (c) 2020 Microsoft Corporation
> **********************************************************************
>
> D:\LLVM\build>build-targets.bat
>         1 file(s) copied.
> [363/1578] Building CXX object
> lib\CodeGen\...LLVMGlobalISel.dir\MachineIRBuilder.cpp.obj
> FAILED:
>
lib/CodeGen/GlobalISel/CMakeFiles/LLVMGlobalISel.dir/MachineIRBuilder.cpp.obj
>
C:\PROGRA~2\MIB055~1\2019\COMMUN~1\VC\Tools\MSVC\1428~1.293\bin\Hostx86\x86\cl.exe
> /nolog
> o /TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE
> -D_CRT_NONSTDC_NO_WARNINGS
> -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS
> -D_FILE_OFFSET_BITS=64 -D_HAS_EXCEPTI
> ONS=0 -D_LARGEFILE_SOURCE -D_SCL_SECURE_NO_DEPRECATE
> -D_SCL_SECURE_NO_WARNINGS -D_UNICODE
> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
> -Ilib\CodeGen\Global
> ISel -IC:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel -Iinclude
> -IC:\LLVM\llvm-project\l
> lvm\include /DWIN32 /D_WINDOWS   /WX /Zc:inline /Zc:__cplusplus
> /Zc:strictStrings /Oi /Zc:
> rvalueCast /bigobj /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351
> -wd4456 -wd4457 -wd
> 4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505
> -wd4610 -wd4510 -wd47
> 02 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204
> -wd4577 -wd4091
>  -wd4592 -wd4319 -wd4709 -wd4324 -w14062 -we4238 /MDd /Zi /Ob0 /Od /RTC1
> /EHs-c- /GR- -st
> d:c++14 /showIncludes
> /Folib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\MachineIRBui
> lder.cpp.obj
> /Fdlib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\LLVMGlobalISel.pdb
> /F
> S -c C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp
> C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
> error C2220: t
> he following warning is treated as an error
> C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
> warning C4018:
>  '>=': signed/unsigned mismatch
> [366/1578] Building CXX object
> lib\CodeGen\...CMakeFiles\LLVMGlobalISel.dir\Utils.cpp.obj
> ninja: build stopped: subcommand failed.
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20210112/7703347d/attachment.html>

Machiel van Hooren via llvm-dev

2021-Jan-19 15:30 UTC

head link

[llvm-dev] Miscellaneous warnings in code using Visual Studio

I've had similar issues with warnings from LLVM headers with Visual Studio.
The way I've dealt with this is this to use the experimental /external 
compiler flags within Visual Studio which allow control of warning 
levels from external headers.

For example adding these flags will set warning level to W0 for all 
include files that are included with angle brackets:

/experimental:external /external:anglebrackets /external:W0

This is a bit crude because you can't target specific libraries, but it 
might still be helpful depending on your application.

Regards,

Machiel van Hooren

On 12-Jan-21 18:14, Paul C. Anagnostopoulos via llvm-dev
wrote:> When I build on Windows 7 with Visual Studio, I get various warnings that
were ignored until I recently set
>
> LLVM_ENABLE_WERROR:BOOL=ON
>
> One example is shown below. Should I take the time to hunt these down and
fix them?
>
>
> **********************************************************************
> ** Visual Studio 2019 Developer Command Prompt v16.8.1
> ** Copyright (c) 2020 Microsoft Corporation
> **********************************************************************
>
> D:\LLVM\build>build-targets.bat
>          1 file(s) copied.
> [363/1578] Building CXX object
lib\CodeGen\...LLVMGlobalISel.dir\MachineIRBuilder.cpp.obj
> FAILED:
lib/CodeGen/GlobalISel/CMakeFiles/LLVMGlobalISel.dir/MachineIRBuilder.cpp.obj
>
C:\PROGRA~2\MIB055~1\2019\COMMUN~1\VC\Tools\MSVC\1428~1.293\bin\Hostx86\x86\cl.exe
/nolog
> o /TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE
-D_CRT_NONSTDC_NO_WARNINGS
> -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_FILE_OFFSET_BITS=64
-D_HAS_EXCEPTI
> ONS=0 -D_LARGEFILE_SOURCE -D_SCL_SECURE_NO_DEPRECATE
-D_SCL_SECURE_NO_WARNINGS -D_UNICODE
> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
-Ilib\CodeGen\Global
> ISel -IC:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel -Iinclude
-IC:\LLVM\llvm-project\l
> lvm\include /DWIN32 /D_WINDOWS   /WX /Zc:inline /Zc:__cplusplus
/Zc:strictStrings /Oi /Zc:
> rvalueCast /bigobj /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351
-wd4456 -wd4457 -wd
> 4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505
-wd4610 -wd4510 -wd47
> 02 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204
-wd4577 -wd4091
>   -wd4592 -wd4319 -wd4709 -wd4324 -w14062 -we4238 /MDd /Zi /Ob0 /Od /RTC1 
/EHs-c- /GR- -st
> d:c++14 /showIncludes
/Folib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\MachineIRBui
> lder.cpp.obj
/Fdlib\CodeGen\GlobalISel\CMakeFiles\LLVMGlobalISel.dir\LLVMGlobalISel.pdb /F
> S -c C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp
> C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
error C2220: t
> he following warning is treated as an error
> C:\LLVM\llvm-project\llvm\lib\CodeGen\GlobalISel\MachineIRBuilder.cpp(657):
warning C4018:
>   '>=': signed/unsigned mismatch
> [366/1578] Building CXX object
lib\CodeGen\...CMakeFiles\LLVMGlobalISel.dir\Utils.cpp.obj
> ninja: build stopped: subcommand failed.
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

llvm dev - Jan 2021 - Miscellaneous warnings in code using Visual Studio

[llvm-dev] Miscellaneous warnings in code using Visual Studio

[llvm-dev] Miscellaneous warnings in code using Visual Studio

[llvm-dev] Miscellaneous warnings in code using Visual Studio