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'clang-diagnostic-' checks not considered as enabled #34763

Open llvmbot opened 6 years ago

llvmbot commented 6 years ago
Bugzilla Link 35415
Version unspecified
OS Linux
Attachments sample project to recreate the undesired behavior
Reporter LLVM Bugzilla Contributor
CC @dawagner

Extended Description

'clang-diagnostic-' checks family cannot be the only one enabled for running clang-tidy due to 'no checks enabled' error: $ clang-tidy -checks='-*,clang-diagnostic-unused-variable' main.cpp Error: no checks enabled.

Extending check list by any other works fine for 'clang-diagnostic-' also: $ clang-tidy -checks='-*,cert-err34-c,clang-diagnostic-unused-variable' main.cpp 1 error generated.

What's worse, 'clang-diagnostic-' checks are not printed by listing all available checks: $ clang-tidy -checks='*' -list-checks | grep clang-diagnostic | wc -l 0

This is really counter-intuitive and makes the user doubt, whether 'clang-diagnostic' checks does still exist.

I've tested that on clang-tidy-5.0. There is a sample project attached to easily recreate the issue, with clang-tidy calls prepared.

4316e653-256d-4475-aad9-719268272d34 commented 6 years ago

I can confirm this with clang-tidy-5.0.1. It generates false negatives on files that will not compile:

I compile my code with GCC and do static analysis with clang-tidy. Because of varying implementation, GCC may accept code that clang doesn't. In such a case, clang-tidy will print something like:

file:line:col: error: ... [clang-diagnostic-error]

clang-tidy will then fail to analyse the file but will return a success code.

​34930 seems related.

chaitanyav commented 3 months ago

i checked this on git version

./clang-tidy --version
LLVM (http://llvm.org/):  
  LLVM version 19.0.0git  
  Optimized build with assertions.

I see that it does not list clang-diagnostic-* in the checks

./clang-tidy --list-checks --checks='clang-diagnostic-*'
Enabled checks:
    llvm-else-after-return
    llvm-header-guard
    llvm-include-order
    llvm-namespace-comment
    llvm-prefer-isa-or-dyn-cast-in-conditionals
    llvm-prefer-register-over-unsigned
    llvm-qualified-auto
    llvm-twine-local
    misc-confusable-identifiers
    misc-coroutine-hostile-raii
    misc-definitions-in-headers
    misc-header-include-cycle
    misc-misleading-bidirectional
    misc-misleading-identifier
    misc-misplaced-const
    misc-new-delete-overloads
    misc-non-copyable-objects
    misc-redundant-expression
    misc-static-assert
    misc-throw-by-value-catch-by-reference
    misc-unconventional-assign-operator
    misc-uniqueptr-reset-release
    misc-unused-alias-decls
    misc-unused-using-decls
    misc-use-internal-linkage
    readability-identifier-naming

The clang-analyzer-* checks are created programmatically in ClangTidy.cpp using clang/lib/StaticAnalyzer/Checkers /*

/clang-tidy --list-checks --checks='clang-analyzer-*'
Enabled checks:
    clang-analyzer-apiModeling.Errno
    clang-analyzer-apiModeling.TrustNonnull
    clang-analyzer-apiModeling.TrustReturnsNonnull
    clang-analyzer-apiModeling.google.GTest
    clang-analyzer-apiModeling.llvm.CastValue
    clang-analyzer-apiModeling.llvm.ReturnValue
    clang-analyzer-core.BitwiseShift
    clang-analyzer-core.CallAndMessage
    clang-analyzer-core.CallAndMessageModeling
    clang-analyzer-core.DivideZero
    clang-analyzer-core.DynamicTypePropagation
    clang-analyzer-core.NonNullParamChecker
    clang-analyzer-core.NonnilStringConstants
    clang-analyzer-core.NullDereference
    clang-analyzer-core.StackAddrEscapeBase
    clang-analyzer-core.StackAddressEscape
....

Is there a way to obtain clang-diagnostic-* in a similar way?. cc @llvm/pr-subscribers-clang-tidy

PiotrZSL commented 3 months ago

No, clang-diagnostic is just an proxy to compiler warnings, those are not a checks but a way to present compiler warnings.