Toolchain library errors when building C++ Swift Package

I'm trying to include a C++ Swift Package into an iOS app.

I'm completely new to xcode and I'm having a lot of trouble making my project build.


My code relies on c++14 features, and I depend on pthreads, security framework and some static libraries that I have already built (openssl).

This is my Package.swift:

// swift-tools-version:5.1
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyLibrary",
    products: [
        // Products define the executables and libraries produced by a package, and make them visible to other packages.
        .library(
            name: "MyLibrary",
            targets: ["MyLibrary"]),
    ],
    dependencies: [],
    targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
        .target(
            name: "MyLibrary",
            dependencies: [],
            path: "Sources/MyLibrary",
            cxxSettings: [
                .headerSearchPath("Dependencies/include/")
            ],
            linkerSettings: [
                .linkedFramework("Security"),
                .linkedLibrary("pthread"),
                .linkedLibrary("/Users/matteo/Documents/Workspace/C++/MyLibrary/Sources/MyLibrary/Dependencies/lib/libcrypto.a"),
                .linkedLibrary("/Users/matteo/Documents/Workspace/C++/MyLibrary/Sources/MyLibrary/Dependencies/lib/libssl.a"),
            ]),
    ],
    cxxLanguageStandard: CXXLanguageStandard.cxx14
)


The real problem begins when I try to build it.

I get hundreds of error like:

In file included from /Users/matteo/Documents/Workspace/C++/MyLibrary/Sources/MyLibrary/utils/SessionService.cpp:6:
In file included from /Users/matteo/Documents/Workspace/C++/MyLibrary/Sources/MyLibrary/include/protocol/utils/HttpClient.h:9:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/map:480:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__tree:73:35: error: expected ';' at end of declaration
__tree_is_left_child(_NodePtr __x) _NOEXCEPT
                                  ^
error: C++ requires a type specifier for all declarations
__tree_is_left_child(_NodePtr __x) _NOEXCEPT
                                   ^
note: expanded from macro '_NOEXCEPT'
#  define _NOEXCEPT noexcept
                    ^


or

In file included from /Users/matteo/Documents/Workspace/C++/MyLibrary/Sources/MyLibrary/protocol/data/LPrefixedString.cpp:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/codecvt:59:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__locale:18:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/mutex:191:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__mutex_base:15:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/chrono:932:67: error: expected ';' at end of declaration list
    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT {return _Rep(0);}





I have no idea the reason and if I messed up anything in the Package.swift

I followed the documentation at Target - Swift Package Manager | Apple Developer Documentation


Thanks

Up vote post of MatteCarra Down vote post of MatteCarra
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MatteCarra
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I'm still not sure about the reason of the issue, but I discovered that you can't include binaries in a Swift Package.


This is the correct Package.swift:

// swift-tools-version:5.1
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyLibrary",
    products: [
        // Products define the executables and libraries produced by a package, and make them visible to other packages.
        .library(
            name: "MyLibrary",
            targets: ["MyLibrary"]),
    ],
    dependencies: [],
    targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
        .target(
            name: "MyLibrary",
            dependencies: [],
            path: "Sources/MyLibrary",
            linkerSettings: [
                .linkedFramework("Security"),
                .linkedLibrary("pthread"),
                .linkedLibrary("crypto"),
                .linkedLibrary("ssl")
            ]),
    ],
    cxxLanguageStandard: CXXLanguageStandard.cxx14
)


I then placed the binaries in a directory and added the directory to the 'Library search paths' in Project->Build Settings

Posted by
MatteCarra
Up vote reply of MatteCarra Down vote reply of MatteCarra
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C++ is not compatible with Swift. If you want to create a Swift package from C++, you will need an additional target to wrap the C++ in either C or Objective-C++. Then that wrapper interface can be exposed via Swift.

Posted by
john daniel
Up vote reply of john daniel Down vote reply of john daniel
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I'm still not sure about the reason of the issue, but I discovered that you can't include binaries in a Swift Package.


This is the correct Package.swift:

// swift-tools-version:5.1
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyLibrary",
    products: [
        // Products define the executables and libraries produced by a package, and make them visible to other packages.
        .library(
            name: "MyLibrary",
            targets: ["MyLibrary"]),
    ],
    dependencies: [],
    targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
        .target(
            name: "MyLibrary",
            dependencies: [],
            path: "Sources/MyLibrary",
            linkerSettings: [
                .linkedFramework("Security"),
                .linkedLibrary("pthread"),
                .linkedLibrary("crypto"),
                .linkedLibrary("ssl")
            ]),
    ],
    cxxLanguageStandard: CXXLanguageStandard.cxx14
)


I then placed the binaries in a directory and added the directory to the 'Library search paths' in Project->Build Settings

Posted by
MatteCarra
Up vote reply of MatteCarra Down vote reply of MatteCarra
Post marked as solved
Add a Comment