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Fix #15080 FP uninitMemberVarNoCtor for const and reference members - #8910

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Fix #15080 FP uninitMemberVarNoCtor for const and reference members#8910
autoantwort wants to merge 4 commits into
cppcheck-opensource:mainfrom
autoantwort:fix-noctor-const-member

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@autoantwort

@autoantwort autoantwort commented Oct 1, 2026

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https://trac.cppcheck.net/ticket/15080

struct S {
    const std::array<std::uint8_t, 2> a;
    const std::vector<std::uint8_t>::const_iterator it;
};
S f(const std::vector<std::uint8_t>& v) {
    return S{ {}, v.cbegin() };
}

gives Member variable 'S::it' has no initializer. [uninitMemberVarNoCtor], and struct S { int a = 0; const int b; int& c; }; warns for b and c.

A non-static const or reference member without default member initializer can't stay uninitialized: for trivial types the implicit default constructor is deleted, so every instance must initialize it, and a const class type is default-constructed. These members are now skipped by the no-constructor check.

Since f90a76f (#15072) this also shows up for class templates whose member type is a using alias.

This PR was created by Claude Code (an AI coding agent) on behalf of @autoantwort.

🤖 Generated with Claude Code

@autoantwort @claude
Fix #15080 FP uninitMemberVarNoCtor for const and reference members
ba74606 
A class without constructor whose non-static const or reference member has
no default member initializer is not default constructible (or, for a const
class type with a default constructor, default constructs it), so the member
can never be left uninitialized.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
chrchr-github
chrchr-github reviewed Oct 2, 2026
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Comment thread lib/checkclass.cpp Outdated
@autoantwort @claude
Const/reference member of non-class type inhibits uninitMemberVarNoCt…
b8fbea9 
…or for all members

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
chrchr-github
chrchr-github reviewed Oct 3, 2026
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Comment thread test/testconstructors.cpp
@autoantwort

autoantwort commented Oct 7, 2026

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Any further changes requested?

@danmar

danmar commented Oct 7, 2026

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@claude review

claude[bot]
claude Bot reviewed Oct 7, 2026
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Comment thread lib/checkclass.cpp Outdated
@claude

claude Bot commented Oct 7, 2026

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The approach makes sense: a const member of trivial type, or a reference member, with no initializer deletes the implicit default constructor, so every instance has to be initialized another way.

One issue (inline): static const and static reference members are in the usage list too. The new check doesn't exclude them, so a declaration like static const int N; turns off uninitMemberVarNoCtor for the whole class. That's a new false negative. It needs a !var.isStatic() guard and a regression test.

Minor: it would be good to add a test for a const pointer member (int* const p;).

🤖 Generated with Claude Code

@danmar

danmar commented Oct 7, 2026

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please check the results here:
http://ec2-16-170-140-253.eu-north-1.compute.amazonaws.com/

autoantwort and others added 2 commits October 8, 2026 14:47
@autoantwort @claude
Update lib/checkclass.cpp
325020d 
Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
@autoantwort @claude
Add tests for const pointer and static members
d9ff8a4 
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@dmcppcheck

dmcppcheck commented Oct 9, 2026

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Test results for commit d9ff8a4 (tools/test-my-pr.py, main compared to this PR):

Test: http://ec2-16-170-140-253.eu-north-1.compute.amazonaws.com/pr-8910/
packages: 200
Differing warnings: 31 (+0 -31)
AI review: 22 improvement, 8 regression, 1 unclear (http://ec2-16-170-140-253.eu-north-1.compute.amazonaws.com/pr-8910/2026-10-08_12-49-15-d9ff8a48bccd-review.txt)
Timing: -0.1% (http://ec2-16-170-140-253.eu-north-1.compute.amazonaws.com/pr-8910/2026-10-08_12-49-15-d9ff8a48bccd_timing.html)

Posted automatically by the cppcheck PR test runner. +N: warnings only with this PR, -N: warnings only with main. The AI review is written by Claude and can be wrong.

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@autoantwort @danmar @dmcppcheck @chrchr-github