Clang builtins from Swift?


(Jean-Denis Muys) #1

Hi,

Xcode seems to think that [some] builtins can be used from Swift. It
autocompletes popcount for example, and command-clicking the function opens
a bona fide interface file, with the following declaration (among others):

public func __builtin_popcount(_: UInt32) -> Int32

However, when I try to compile code that uses that function, I get an
unresolved identifier compiler error.

I guess I need to import some module, but which one?

Generally speaking, how to find in which module some symbol is defined?

Thanks,

Jean-Denis


(Chris Lattner) #2

Huh, that is odd. It should not be made available to Swift code like that. Please file a jira or radar ticket, thank you!

-Chris

ยทยทยท

On Oct 2, 2016, at 6:24 PM, Jean-Denis Muys via swift-users <swift-users@swift.org> wrote:

Hi,

Xcode seems to think that [some] builtins can be used from Swift. It autocompletes popcount for example, and command-clicking the function opens a bona fide interface file, with the following declaration (among others):

public func __builtin_popcount(_: UInt32) -> Int32

However, when I try to compile code that uses that function, I get an unresolved identifier compiler error.

I guess I need to import some module, but which one?