[Github][CIR] Add CI/CD for clang tidy [1/N]

[badumbatish]

Part of #1912

This PR only fixes 1 file. Also added a CI file to see if it'd run correctly

[xlauko]

It would be better to split the PR, first setup an action and then add changes incrementally always checking it passes the new action.

The first one should have tag [Github][CIR]

[badumbatish]

about the hacky ninja -C build_pilot $(ninja -C build_pilot -t targets all | grep IncGen | sed 's/:.*//') clang-tablegen-targets, the reason is that we don't make these IncGen's in CIR be dependencies on mlir-headers via add_dependencies(mlir-headers ...).

For example, in clang/include/clang/CIR/Dialect/IR/CMakeLists.txt, MLIRCIREnumsGen is not added to mlir-headers' dependencies so when we build the mlir-headers target, clang-tidy's reporting compiler error.

# This replicates part of the add_mlir_dialect cmake function from MLIR that
# cannot be used here. This happens because it expects to be run inside MLIR
# directory which is not the case for CIR (and also FIR, both have similar
# workarounds).

# Equivalent to add_mlir_dialect(CIROps cir)
set(LLVM_TARGET_DEFINITIONS CIROps.td)
mlir_tablegen(CIROps.h.inc -gen-op-decls)
mlir_tablegen(CIROps.cpp.inc -gen-op-defs)
mlir_tablegen(CIROpsTypes.h.inc -gen-typedef-decls)
mlir_tablegen(CIROpsTypes.cpp.inc -gen-typedef-defs)
mlir_tablegen(CIROpsDialect.h.inc -gen-dialect-decls)
mlir_tablegen(CIROpsDialect.cpp.inc -gen-dialect-defs)
add_public_tablegen_target(MLIRCIROpsIncGen)
add_dependencies(mlir-headers MLIRCIROpsIncGen)

# Equivalent to add_mlir_doc
add_clang_mlir_doc(CIROps CIROps Dialects/ -gen-op-doc)
add_clang_mlir_doc(CIRAttrs CIRAttrs Dialects/ -gen-attrdef-doc)
add_clang_mlir_doc(CIRTypes CIRTypes Dialects/ -gen-typedef-doc)

# Generate extra headers for custom enum and attrs.
mlir_tablegen(CIROpsEnums.h.inc -gen-enum-decls)
mlir_tablegen(CIROpsEnums.cpp.inc -gen-enum-defs)
mlir_tablegen(CIROpsStructs.h.inc -gen-attrdef-decls)
mlir_tablegen(CIROpsStructs.cpp.inc -gen-attrdef-defs)
mlir_tablegen(CIROpsAttributes.h.inc -gen-attrdef-decls)
mlir_tablegen(CIROpsAttributes.cpp.inc -gen-attrdef-defs)
add_public_tablegen_target(MLIRCIREnumsGen)

clang_tablegen(CIRBuiltinsLowering.inc -gen-cir-builtins-lowering
               SOURCE CIROps.td
               TARGET CIRBuiltinsLowering)

set(LLVM_TARGET_DEFINITIONS CIRTypeConstraints.td)
mlir_tablegen(CIRTypeConstraints.h.inc -gen-type-constraint-decls)
mlir_tablegen(CIRTypeConstraints.cpp.inc -gen-type-constraint-defs)
add_public_tablegen_target(MLIRCIRTypeConstraintsIncGen)
add_dependencies(mlir-headers MLIRCIRTypeConstraintsIncGen)

if we depend on the ninja check-clang-cir job it wouldn't be much of a problem, but if we're aiming for a separate CI/CD completely then we probably should make a few PR to address these, so that we don't end up with the hacky ninja build command

[bcardosolopes]

the reason is that we don't make these IncGen's in CIR be dependencies on mlir-headers via add_dependencies(mlir-headers ...).

That was a great catch, fixing this dependency sounds like the way to go!

[badumbatish]

I've included the two other PRs into this one, we can now use mlir-headers. Run time is 11 minutes but can be reduced w/ ccache. Please let me know if you'd like me to add ccache to this PR (or another one)