[SR-12001] Swift 5.2 toolchain ObjC Availability API crash

[Agarunov]

Previous ID	SR-12001
Radar	rdar://problem/57837918
Original Reporter	@Agarunov
Type	Bug
Status	Reopened
Resolution

Attachment: Download

Environment

Xcode 11.3

Toolchain: Swift 5.2 Snapshot 2020-01-06 (a)

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug, 5.2Regression
Assignee	None
Priority	Medium

Watchers: @shahmishal

md5: 8b5bac5d2fb7aa52431d9bb6bd0d5418

Issue Description:

This code produces compiler crash:

#import <Foundation/Foundation.h>

@interface Foo : NSObject

@end

#import "Foo.h"

@implementation Foo

- (instancetype)init {
    self = [super init];
    if (self) {
        if (@available(iOS 9.0, *)) {
            /*
            Undefined symbols for architecture arm64:
              "___isOSVersionAtLeast", referenced from:
                  -[Foo init] in Foo.o
            ld: symbol(s) not found for architecture arm64
            clang-7: error: linker command failed with exit code 1 (use -v to see invocation)
             */
        }
    }
    return self;
}

@end

Project minimum deployment target - iOS 8

[beccadax]

@swift-ci create

[mikeash]

This happens because the toolchains don't include compiler-rt libraries for iOS. We're looking into this, but in the meantime you can work around the problem by copying the compiler-rt libraries from Xcode. A command like this will take care of it (adjust the toolchain path as needed):

sudo cp `xcode-select -p`/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang//lib/darwin/libclang_rt..a /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2019-12-03-a.xctoolchain/usr/lib/clang/7.0.0/lib/darwin

[Agarunov]

@mikeash looks like it fixed in Xcode 10.4b1 toolchain ?

[mikeash]

Xcode toolchains get built a bit differently so I think that's expected. This problem would show up with swift.org toolchains.

[swift-ci]

Comment by Peter Steinberger (JIRA)

This is still a problem with the June 9 Trunk Toolchain. Fix via:

sudo cp `xcode-select -p`/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/*/lib/darwin/libclang_rt.STAR.a /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-06-09-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin

Replace STAR with * (comment formatting issue)

[keith]

Hrm even with the cp workaround the original sample project still fails for me in the same way. I wonder if that isn't enough anymore?

Notes: swift-5.3-DEVELOPMENT-SNAPSHOT-2020-08-10-a installed locally in ~/Library/Developer/Toolchains instead of globally.

Passing the library forcibly still works as expected.

[keith]

Ok so the issue is that this call https://github.com/apple/llvm-project/blob/8cbcb6870920db32b52367504902b9bd8456ff91/clang/lib/Driver/ToolChains/Darwin.cpp#L1083 uses the default IgnoreSim = false value. So the derived library name is `libclang_rt.iossim.a` https://github.com/apple/llvm-project/blob/8cbcb6870920db32b52367504902b9bd8456ff91/clang/lib/Driver/ToolChains/Darwin.cpp#L1155-L1156 which doesn't exist in Xcode 11.5, but does exist in 12.x. Copying `libclang_rt.ios.a` to that path fixes the issue.

[edymtt]

This has now been merged to main as part of

#31247

[edymtt]

This is also merged as part of release/5.3

#34236

[shahmishal]

Please verify the fix with this 5.3 development build (nightly): https://swift.org/builds/swift-5.3-branch/xcode/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a-osx.pkg

[edymtt]

Verified that with that toolchain I'm able to compile the sample program – also manually inspected the toolchain to ensure the files are there

> ls /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.{ios,tvos,watchos}*
-rw-r--r--@ 1 root  wheel  265776 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.ios.a
-rw-r--r--@ 1 root  wheel  265776 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.iossim.a
-rw-r--r--@ 1 root  wheel  225664 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.tvos.a
-rw-r--r--@ 1 root  wheel  225664 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.tvossim.a
-rw-r--r--@ 1 root  wheel  366152 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.watchos.a
-rw-r--r--@ 1 root  wheel  366152 Oct 12 22:52 /Library/Developer/Toolchains/swift-5.3-DEVELOPMENT-SNAPSHOT-2020-10-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.watchossim.a

[edymtt]

Also downloaded https://swift.org/builds/development/xcode/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a-osx.pkg

Test application builds and the builtins are in there

> ls /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.{ios,tvos,watchos}*
-rw-r--r--@ 1 root  wheel  265776 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.ios.a
-rw-r--r--@ 1 root  wheel  265776 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.iossim.a
-rw-r--r--@ 1 root  wheel  225664 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.tvos.a
-rw-r--r--@ 1 root  wheel  225664 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.tvossim.a
-rw-r--r--@ 1 root  wheel  366152 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.watchos.a
-rw-r--r--@ 1 root  wheel  366152 Oct 15 17:53 /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-10-15-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.watchossim.a

[swift-ci]

Comment by Peter Steinberger (JIRA)

This is not yet resolved. I downloaded the trunk development from November 12, 2020 and got this error:

ld: file not found: /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-11-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.profile_iossim.a``clang-10: error: linker command failed with exit code 1 (use -v to see invocation)

I had to apply the same workaround:

https://steipete.com/posts/building-with-swift-trunk/#libclang_rtprofile_iossima-not-found

`sudo cp `xcode-select -p`/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang//lib/darwin/libclang_rt..a /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-11-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin`

After copying above, it works.

[nikolaykasyanov]

I confirm this is not resolved, just tried the snapshot from 12th December with Xcode 12.3 Release Candidate:

ld: file not found: /Users/username/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2020-12-12-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.profile_iossim.a

[drewcrawford]

This is unresolved in swift-DEVELOPMENT-SNAPSHOT-2021-03-25-a.

After installing the toolchain, ls finds only one (osx) lib matching profile below

ls /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2021-03-25-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.*profile*
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2021-03-25-a.xctoolchain/usr/lib/clang/10.0.0/lib/darwin/libclang_rt.profile_osx.a 

Compare this output with the xcode toolchain which has profile lib for all OS:

sudo ls /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.*profile*
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_ios.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_iossim.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_osx.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_tvos.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_tvossim.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_watchos.a
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.profile_watchossim.a 

The confusion here seems partly because there are a lot of libs in the toolchain but Xcode (ld) is looking specifically for libs with profile. So the presence of other libs in the toolchain is not sufficient to build with xcode.