[SR-12694] Swift does not link in the C++ standard library anymore

[swift-ci]

Previous ID	SR-12694
Radar	rdar://problem/62894492
Original Reporter	kencarroll (JIRA User)
Type	Bug

Environment

Linux Mint 19.1.

Swift 5.2.1

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug
Assignee	None
Priority	Medium

md5: f12fe375ba7b9ad5b139225df5684fb3

Issue Description:

Since moving to swift 5.2.1 my application no longer links. The following error is given (amongst) others:

error: undefined reference to 'std:: cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'.

[dan-zheng]

This issue seems unrelated to Swift for TensorFlow, so I'll move it to the Swift project (SR).

[beccadax]

@swift-ci create

[beccadax]

@gribozavr Any chance this might have something to do with C++ interop?

[gribozavr]

We haven't made any changes to the driver for the sake of C++ interop (yet).

The symbol mentioned in the error comes from libstdc+\. The Swift driver used to link in the default C+ standard library, but since #26110 it does not.

For C++ interop, we're trying to restore the old behavior in #30914 but it will be a while until it lands, and the current plan is to only link in the C++ standard library when C++ interop is enabled.

cc @compnerd

[compnerd]

If your application is using `{{C+`}}, you should explicitly link against the `{{C`}} runtime (and any supporting libraries that it may required such as the ABI library). Although, I do understand how you are adding C dependencies into Swift code currently.