Using clang-tidy on LLVM itself (the proverbial eating your own dogfood) is
a little different from using a clang-tidy installation on another source
tree. clang-tidy needs to know where to find include files within the LLVM
source tree itself.
This is a Python script, tidy-llvm, which finds the root of the llvm tree,
verifies LLVM build requirements
(LLVM_ENABLE_PROJECTS:STRING=clang;clang-tools-extra and
CMAKE_EXPORT_COMPILE_COMMANDS:UNINITIALIZED=On), constructs llvm and
current directory include paths, concatenates up an argument list and then
runs clang-tidy on the .h and .cpp files on the command line.
tidy-llvm XXAsmPrinter.cpp generates a clang-tidy command line that looks
like:
clang-tidy -checks="llvm-*" -p .../build XXAsmPrinter.cpp -- -I.
-IAsmParser -IGISel -IDisassembler -ITargetInfo -IXX -IMCTargetDesc
-I.../libcxx/include -I.../build/include -I.../llvm/include
I'm pretty sure that the llvm include directories (-I.../libcxx/include
-I.../build/include -I.../llvm/include others?) have to be enumerated
rather than simply inheriting where clang-tidy thinks they are in the
installation. Unless I manually specified them, clang-tidy wasn't finding
them.
I think someone more expert in the build machinery could improve it
greatly. For example, it currently gets a strange error about __config_site
(which doesn't prevent the rest of the clang-tidy checking):
Error while processing path to XXAsmPrinter.cpp.
path/libcxx/include/__config:13:10: error: '__config_site' file not
found
[clang-diagnostic-error]
#include <__config_site>
__config_site is indeed not in my build tree. There is a file
libcxx/include/__config_site.in but that's it. Again, someone more
knowledgable in the build machinery might understand why this is the case.
clang-tidy still interprets its .clang_tidy file wherever it finds it. It's
better to leave most of the -checks there. The tidy-llvm Python script
itself is currently set to -checks=\"llvm-*\". I set modernize in the
.clang_tidy file for my backend. I can imagine having a .clang-tidy file at
the root of the llvm tree.
Adding support for run-clang-tidy would be nice but for tidying individual
files it really won't matter.
https://reviews.llvm.org/D115848
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Can you use a compilation database? Generate one from your LLVM build tree, symlink it into the root of your source tree & I'd think clang-tidy would find it there & use it & should be good to go? On Wed, Dec 15, 2021 at 10:46 PM Chris Sears via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Using clang-tidy on LLVM itself (the proverbial eating your own dogfood) > is a little different from using a clang-tidy installation on another > source tree. clang-tidy needs to know where to find include files within > the LLVM source tree itself. > > This is a Python script, tidy-llvm, which finds the root of the llvm tree, > verifies LLVM build requirements > (LLVM_ENABLE_PROJECTS:STRING=clang;clang-tools-extra and > CMAKE_EXPORT_COMPILE_COMMANDS:UNINITIALIZED=On), constructs llvm and > current directory include paths, concatenates up an argument list and then > runs clang-tidy on the .h and .cpp files on the command line. > > tidy-llvm XXAsmPrinter.cpp generates a clang-tidy command line that looks > like: > > clang-tidy -checks="llvm-*" -p .../build XXAsmPrinter.cpp -- -I. > -IAsmParser -IGISel -IDisassembler -ITargetInfo -IXX -IMCTargetDesc > -I.../libcxx/include -I.../build/include -I.../llvm/include > > I'm pretty sure that the llvm include directories (-I.../libcxx/include > -I.../build/include -I.../llvm/include others?) have to be enumerated > rather than simply inheriting where clang-tidy thinks they are in the > installation. Unless I manually specified them, clang-tidy wasn't finding > them. > > I think someone more expert in the build machinery could improve it > greatly. For example, it currently gets a strange error about __config_site > (which doesn't prevent the rest of the clang-tidy checking): > > Error while processing path to XXAsmPrinter.cpp. > path/libcxx/include/__config:13:10: error: '__config_site' file not > found [clang-diagnostic-error] > #include <__config_site> > > __config_site is indeed not in my build tree. There is a file > libcxx/include/__config_site.in but that's it. Again, someone more > knowledgable in the build machinery might understand why this is the case. > > clang-tidy still interprets its .clang_tidy file wherever it finds it. > It's better to leave most of the -checks there. The tidy-llvm Python script > itself is currently set to -checks=\"llvm-*\". I set modernize in the > .clang_tidy file for my backend. I can imagine having a .clang-tidy file at > the root of the llvm tree. > > Adding support for run-clang-tidy would be nice but for tidying individual > files it really won't matter. > > https://reviews.llvm.org/D115848 > _______________________________________________ > 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/20211215/29e10a1b/attachment.html>
Hi Chris, Thx for looking into this. The use case I was thinking about for a while was: Can we add clang-tidy to the linters run during arc diff to check my modifications, so similar to clang-format? A couple of thoughts around that. - Only trigger this linter if the user enabled it (at least until we know it works well). So we would need some mechanism to enable/disable this per user. - Ensure we have a compile_commands.json and the include files were generated. I suppose this is what your script takes care of. - Check only the modified files (everything else would be too slow) and filter the findings to your modified lines only. This is covered by clang-tidy-diff.py - I don't know if we want to offer to apply fix-its at this point. They might be too noisy. What do you think? Best, Christian On Thu, Dec 16, 2021 at 7:46 AM Chris Sears via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Using clang-tidy on LLVM itself (the proverbial eating your own dogfood) > is a little different from using a clang-tidy installation on another > source tree. clang-tidy needs to know where to find include files within > the LLVM source tree itself. > > This is a Python script, tidy-llvm, which finds the root of the llvm tree, > verifies LLVM build requirements > (LLVM_ENABLE_PROJECTS:STRING=clang;clang-tools-extra and > CMAKE_EXPORT_COMPILE_COMMANDS:UNINITIALIZED=On), constructs llvm and > current directory include paths, concatenates up an argument list and then > runs clang-tidy on the .h and .cpp files on the command line. > > tidy-llvm XXAsmPrinter.cpp generates a clang-tidy command line that looks > like: > > clang-tidy -checks="llvm-*" -p .../build XXAsmPrinter.cpp -- -I. > -IAsmParser -IGISel -IDisassembler -ITargetInfo -IXX -IMCTargetDesc > -I.../libcxx/include -I.../build/include -I.../llvm/include > > I'm pretty sure that the llvm include directories (-I.../libcxx/include > -I.../build/include -I.../llvm/include others?) have to be enumerated > rather than simply inheriting where clang-tidy thinks they are in the > installation. Unless I manually specified them, clang-tidy wasn't finding > them. > > I think someone more expert in the build machinery could improve it > greatly. For example, it currently gets a strange error about __config_site > (which doesn't prevent the rest of the clang-tidy checking): > > Error while processing path to XXAsmPrinter.cpp. > path/libcxx/include/__config:13:10: error: '__config_site' file not > found [clang-diagnostic-error] > #include <__config_site> > > __config_site is indeed not in my build tree. There is a file > libcxx/include/__config_site.in but that's it. Again, someone more > knowledgable in the build machinery might understand why this is the case. > > clang-tidy still interprets its .clang_tidy file wherever it finds it. > It's better to leave most of the -checks there. The tidy-llvm Python script > itself is currently set to -checks=\"llvm-*\". I set modernize in the > .clang_tidy file for my backend. I can imagine having a .clang-tidy file at > the root of the llvm tree. > > Adding support for run-clang-tidy would be nice but for tidying individual > files it really won't matter. > > https://reviews.llvm.org/D115848 > _______________________________________________ > 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/20211216/9e30a7d9/attachment.html>