clang-tidy 20 crashes in RegionStoreManager

[BobIsOnFire]

The best I could minimize is this, repro crashes on line 7 (*m_ptr = '\0'):

class A
{
public:
    A()
    : m_ptr(m_buf)
    {
        *m_ptr = '\0';
    }

private:
    char m_buf[64] = {0};
    char * m_ptr;
};

A a;

crash.log

Reproduces in godbolt as well (with trunk clang-tidy): https://godbolt.org/z/PMaToWrWG

Using 20.1.7 compiled with assertions, I get following assertion error with the same stack:

clang-tidy: /export/home/nikita.akatiev/llvm-project/llvm/include/llvm/Support/Casting.h:566: decltype(auto) llvm::cast(const From&) [with To = clang::ento::nonloc::CompoundVal; From = clang::ento::SVal]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

I've also ran a git-bisect, which led me to this commit 820403c.

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Nikita Akatyev (BobIsOnFire)

The best I could minimize is this, repro crashes on line 7 (`*m_ptr = '\0'`):

class A
{
public:
    A()
    : m_ptr(m_buf)
    {
        *m_ptr = '\0';
    }

private:
    char m_buf[64] = {0};
    char * m_ptr;
};

A a;

crash.log

Reproduces in godbolt as well (with trunk clang-tidy): https://godbolt.org/z/PMaToWrWG

Using 20.1.7 compiled with assertions, I get following assertion error with the same stack:

clang-tidy: /export/home/nikita.akatiev/llvm-project/llvm/include/llvm/Support/Casting.h:566: decltype(auto) llvm::cast(const From&) [with To = clang::ento::nonloc::CompoundVal; From = clang::ento::SVal]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

I've also ran a git-bisect, which led me to this commit 820403c. Somewhat surprisingly, clang --analyze doesn't seem to crash on this code.

[BobIsOnFire]

clang --analyze also crashes with same stack: https://godbolt.org/z/7846jK6n4

crash.log

[llvmbot]

@llvm/issue-subscribers-clang-static-analyzer

Author: Nikita Akatyev (BobIsOnFire)

The best I could minimize is this, repro crashes on line 7 (`*m_ptr = '\0'`):

class A
{
public:
    A()
    : m_ptr(m_buf)
    {
        *m_ptr = '\0';
    }

private:
    char m_buf[64] = {0};
    char * m_ptr;
};

A a;

crash.log

Reproduces in godbolt as well (with trunk clang-tidy): https://godbolt.org/z/PMaToWrWG

Using 20.1.7 compiled with assertions, I get following assertion error with the same stack:

clang-tidy: /export/home/nikita.akatiev/llvm-project/llvm/include/llvm/Support/Casting.h:566: decltype(auto) llvm::cast(const From&) [with To = clang::ento::nonloc::CompoundVal; From = clang::ento::SVal]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

I've also ran a git-bisect, which led me to this commit 820403c.

[steakhal]

Thanks for the great reproducer. As I was the author of the blamed patch, I'll have a look (at some point) at the crash.