[clang++-18] Unexpected `deprecated-declarations` warning, when this warning is explicitly suppressed

[ralfkonrad]

clang-18 shows an unexpected deprecated-declarations warning when a deprecated constructor is used in std::make_shared<T>(args from deprecated constructor...) while the warning is turned off using _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"").

On the other hand using std::shared_ptr<T>(new T(args from deprecated constructor...)) does not emit any warning as expected when it off.

Neiter clang-16 and clang-17 nor gcc on ubuntu-24.04 and msvc emit a warning.

The same behaviour can be seen with boost::shared_ptr instead of std::shared_ptr.

To reproduce this issue, see https://github.com/ralfkonrad/clang_deprecation_warning and its workflow results.

[shafik]

Seems we don't have access to the repo but a gotbolt link w/ a minimal reproducer is almost always a better option.

[ralfkonrad]

Sorry, @shafik. The repo was private. Can you have a look again please.

I'll also try to provide a gotbolt link as well.

[ralfkonrad]

I have reproduced the warning in a small example: https://godbolt.org/z/vd5vP6c4P

I do not understand the warning warning: 'Data' is deprecated [-Wdeprecated-declarations] emitted from line 31 as it is guarded by

_Pragma("clang diagnostic push")
    _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")
        Class ::Class(int i)
    : data_(std::make_shared<Data>(i)) {}
_Pragma("clang diagnostic pop")

However, line 73

_Pragma("clang diagnostic push")
    _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")
        Class ::Class(int i)
    : data_(std::shared_ptr<Data>(new Data(i))) {}
_Pragma("clang diagnostic pop")

does not emit a warning.

I would expect that std::make_shared<Data>(i) and the "traditional" std::shared_ptr<Data>(new Data(i)) behave the same way here.

This behavior is there in clang++-18 and clang++-19, but older version do not emit a deprecation warning.