Segmentation fault when running binary executable compiled from LLVM bitcode on Linux

Using Swift
1

Hi swift team,

I download the prebuilt swift 4.0 from here
<Swift.org - Not Found;
and
try to do some work on the generated LLVM BC. However, I got a seg fault
when running the binary executable compiled from bitcode as shown below:

$ cat hello.swift
print("Hello World")
$ swiftc hello.swift -emit-bc -o hello.bc
$ clang++ hello.bc -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Segmentation fault (core dumped)

It works fine if no bitcode file is involved here.

$ swiftc hello.swift -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Hello World

I am running Ubuntu 14.04.3 (kernel 4.8.0). I also encountered the same seg
fault if I use the prebuilt swift 3.1.1

Is it the right way to compile the bitcode generated from swift? Or is it a
bug in swift ?

Thanks a lot in advance!

Best regards,
Jeffrey

2

Hm, I don’t see any inherent problems with splitting compilation like this, although it’s not something we test. The only thing I could think of is that Swift uses a custom calling convention on some platforms, but I would expect clang++ to refuse to compile the bc file at all if that were the issue. Mind filing a bug at https://bugs.swift.org <Issues · apple/swift · GitHub; ?

Thanks,
Jordan

···

On Sep 21, 2017, at 13:42, Jeffrey W via swift-users <swift-users@swift.org> wrote:

Hi swift team,

I download the prebuilt swift 4.0 from here <https://swift.org/builds/swift-4.0-release/ubuntu1404/swift-4.0-RELEASE/swift-4.0-RELEASE-ubuntu14.04.tar.gz&gt; and try to do some work on the generated LLVM BC. However, I got a seg fault when running the binary executable compiled from bitcode as shown below:

$ cat hello.swift
print("Hello World")
$ swiftc hello.swift -emit-bc -o hello.bc
$ clang++ hello.bc -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Segmentation fault (core dumped)

It works fine if no bitcode file is involved here.

$ swiftc hello.swift -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Hello World

I am running Ubuntu 14.04.3 (kernel 4.8.0). I also encountered the same seg fault if I use the prebuilt swift 3.1.1

Is it the right way to compile the bitcode generated from swift? Or is it a bug in swift ?

Thanks a lot in advance!

Best regards,
Jeffrey

_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users

3

Thanks a lot, Jordan!

I have filed a bug here <https://bugs.swift.org/browse/SR-5962&gt;\.

Jeffrey

···

2017-09-21 19:05 GMT-04:00 Jordan Rose <jordan_rose@apple.com>:

Hm, I don’t see any inherent problems with splitting compilation like
this, although it’s not something we test. The only thing I could think of
is that Swift uses a custom calling convention on some platforms, but I
would expect clang++ to refuse to compile the bc file at all if that were
the issue. Mind filing a bug at https://bugs.swift.org ?

Thanks,
Jordan

On Sep 21, 2017, at 13:42, Jeffrey W via swift-users < > swift-users@swift.org> wrote:

Hi swift team,

I download the prebuilt swift 4.0 from here
<https://swift.org/builds/swift-4.0-release/ubuntu1404/swift-4.0-RELEASE/swift-4.0-RELEASE-ubuntu14.04.tar.gz&gt; and
try to do some work on the generated LLVM BC. However, I got a seg fault
when running the binary executable compiled from bitcode as shown below:

$ cat hello.swift
print("Hello World")
$ swiftc hello.swift -emit-bc -o hello.bc
$ clang++ hello.bc -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Segmentation fault (core dumped)

It works fine if no bitcode file is involved here.

$ swiftc hello.swift -c -o hello.o
$ swiftc hello.o -o hello
$ ./hello
Hello World

I am running Ubuntu 14.04.3 (kernel 4.8.0). I also encountered the same
seg fault if I use the prebuilt swift 3.1.1

Is it the right way to compile the bitcode generated from swift? Or is it
a bug in swift ?

Thanks a lot in advance!

Best regards,
Jeffrey

_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users