https://bugs.llvm.org/show_bug.cgi?id=42096

            Bug ID: 42096
           Summary: Inplace new-ing an array overwrites the square of the
                    memory
           Product: clang
           Version: 8.0
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: C++
          Assignee: [email protected]
          Reporter: [email protected]
                CC: [email protected], [email protected],
                    [email protected], [email protected],
                    [email protected]

When in-place new-ing a local variable of an array of trivial type, the
generated code calls 'memset' with the square of the size of the array,
corrupting the stack.

Quick example:

#include <new>

template <typename TYPE>
void f()
{
    typedef TYPE TArray[7];

    TArray x;
    new(&x) TArray();
}

int main()
{
    f<char>();
    f<int>();
}


Sample code generation can be seen for Clang 7 and 8 via godbolt:
https://godbolt.org/z/WjhFrc

-- 
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs

Reply via email to