Looks like <stacktrace> is already part of C++23 [0]. But if you must use an older C++, why link the entire Swift runtime rather than something GCC's builtin backtraces [1] or libbacktrace [2]?
If you're on the Mac, your process is probably linking the Swift runtime anyway. Foundation.framework is being reimplemented in Swift, so if your process links Foundation (or even just CF), you've got the Swift runtime.
Part of Swift 5.9 which is in Xcode 15, so, I think so, but it's opt-in:
> This feature is also available on macOS but is disabled by default. To enable it, set SWIFT_BACKTRACE=enable=yes and sign your program with the com.apple.security.get-task-allow entitlement.
Hah that's funny, I recently ported the Swift compiler to a Debian package using the Ubuntu package (aside: why is Debian not supported, that baffles me, especially for Swift on Linux server? But Ubuntu is?).
I thought I did something wrong when the crash reported looked so different. I was unaware, that since the last time I did this (ubuntu->debian .deb), the compiler had changed its error reporting.
Props to the Swift team doing the good work, and please add a .deb to the binaries artefacts!
I'm not so keen on programs trying to be clever like this. How about making the system debugger better, which will benefit all programs? Actually that's not even necessary as abrt / coredumpctl on Linux are pretty good these days, even being able to automatically file a bug report with your distro.
> On Apple platforms or on Windows, you could look at the crash logs captured by the operating system’s built-in crash reporter, but on Linux that’s typically all you had to go on.
On modern linux distros, simply typing `coredumpctl debug` puts you right into gdb with the core dump loaded. If debuginfod is set up (not sure what the defaults look like there across distros), it will even automatically download debug symbols for all libraries loaded at the time of the crash.
I'll be interested in seeing how this gets integrated into the Xcode IDE, as I rarely find the need to go into the CLI, to debug, these days (although I had to, just a couple of days ago, to find a weird Apple crash, but I could work around it).
Looks cool. Glad they thought enough to only make 30s timeout happen if you're attached to a terminal. (unless they tried it the other way first, and their whole CI system locked up.)
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[ 3.4 ms ] story [ 64.7 ms ] threadJust link your C++ (or whatever) project with The Swift runtime (swiftrt.o and libswiftCore.so), and there you have it without writing any Swift.
-lswift_Backtracing also works, but dunno if that's "public API"
$ codesign --force --sign - --entitlements entitlements.plist foo
https://github.com/apple/swift/blob/main/docs/Backtracing.rs...
$ SWIFT_BACKTRACE="enable=yes" ./foo
Very cool!
[0] https://www.sandordargo.com/blog/2022/09/21/cpp23-stacktrace...
[1] https://www.gnu.org/software/libc/manual/html_node/Backtrace...
[2] https://github.com/ianlancetaylor/libbacktrace
Swift Backtracing is not only about the symbols, it’s also interactive and lets you attach the debugger after the process crashes, which is neat.
Boo! Show me my system frames!
(Also, is this available in the Xcode toolchain yet?)
> This feature is also available on macOS but is disabled by default. To enable it, set SWIFT_BACKTRACE=enable=yes and sign your program with the com.apple.security.get-task-allow entitlement.
https://www.swift.org/blog/swift-5.9-released/
I thought I did something wrong when the crash reported looked so different. I was unaware, that since the last time I did this (ubuntu->debian .deb), the compiler had changed its error reporting.
Props to the Swift team doing the good work, and please add a .deb to the binaries artefacts!
Does that get you a full Swift REPL like Python's debugger does?
https://forums.swift.org/t/backtraces-in-swift/61736
https://forums.swift.org/t/pitch-swift-backtracing-api/62741
I found the backtracing API design discussions in the second link especially illuminating
On modern linux distros, simply typing `coredumpctl debug` puts you right into gdb with the core dump loaded. If debuginfod is set up (not sure what the defaults look like there across distros), it will even automatically download debug symbols for all libraries loaded at the time of the crash.
I'll be interested in seeing how this gets integrated into the Xcode IDE, as I rarely find the need to go into the CLI, to debug, these days (although I had to, just a couple of days ago, to find a weird Apple crash, but I could work around it).