std::array incorrect bounds

[Benjamin Combee]

I saw this last night checking some of our internal code and shrunk down to this test case:

#include <array>

constexpr int blockLen = 10;
void foo(std::array<uint8_t, blockLen * 2>& a) {
    a[2] = 2;
}

this gives the error arrayIndexOutOfBounds Array 'a[2]' accessed at index 2, which is out of bounds, because it looks like the code that computes the size of std::array doesn't handle the constexpr value correctly. However, changing that line to "#define blockLen 10" also gave the same error. This reproduces with 1.88 and top-of-tree from git.

[Paul Fultz]

This is related to this issue reported here:

https://trac.cppcheck.net/ticket/9202

[Barrett Lowe]

That link seems to be dead. Ticket 9202 doesn't exist, it seems. Any other thoughts?

[versat]

The Trac server has moved and https does not work yet. It should work like before sooner or later.
Meanwhile you can view the ticket here: http://trac.cppcheck.net/ticket/9202

[Steffen]

https://trac.cppcheck.net/ticket/9202 was closed but did not fix this particular issue.
With

std::array<uint8_t, blockLen>

1.89 and master work fine.

But with

std::array<uint8_t, blockLen * 2>

or

std::array<uint8_t, blockLen + 1>

they do not. The arrayIndexOutOfBounds false positive pops up again.

[versat]

Thanks!
@amai created a follow up ticket: https://trac.cppcheck.net/ticket/9386