Compilation fails when Address Sanitizer enabled

[davidrothera]

Platform

iOS

Installed

Swift Package Manager

Version

7.21.0

Steps to Reproduce

• Enable Address Sanitizer on build
• Try to build
• Observe compilation fails with:

ld: Assertion failed: (index < orderedInitOffsetAtoms.size()), function doPass, file inits.cpp, line 131.

Simple repro at https://github.com/davidrothera/CrashTest with ASAN enabled

Expected Result

Compilation works

Actual Result

Compilation fails

[davidrothera]

Confirmed that rolling back to 7.2.0 fixes the issue.

[bruno-garcia]

Does it work on the latest? 7.21.0?

[davidrothera]

Sorry I got the versions wrong:

• Working: 7.20.0
• Broken: 7.21.0

[philipphofmann]

Thanks for reporting this, @davidrothera. I can reproduce this with your sample project and have to look into what's causing this. I'm surprised that our CI didn't catch this.

[davidrothera]

It took me a while to catch it myself as it's not super clear what causes it and I wasn't seeing it in all projects or in all build modes and it wasn't until I went over them with a magnifying glass that I remembered I had ASAN enabled the one which was failing.

I'm guessing most of your CI projects don't have ASAN enabled.

[bruno-garcia]

I'm guessing most of your CI projects don't have ASAN enabled.

If we enable it in one of our samples, would that do the job @philipphofmann @brustolin ?

[davidrothera]

If we enable it in one of our samples, would that do the job @philipphofmann @brustolin ?

It should do, enabling ASAN usually should have no impact other than to surface issues and then even this is abnormal for ASAN but I'm guessing it could be related to the C++ module init functions which were added?

[philipphofmann]

Yep, it's related to

sentry-cocoa/Sources/Sentry/SentrySysctl.m

Lines 14 to 20 in 6781721

	/**
	* Module initialization functions. The C++ compiler places static constructors here. For more info
	* visit:
	* https://github.com/aidansteele/osx-abi-macho-file-format-reference#table-2-the-sections-of-a__datasegment
	*/
	__attribute__((section("__DATA,__mod_init_func"))) typeof(sentryModuleInitializationHook) *__init
	= sentryModuleInitializationHook;

I just removed this code, and it compiles again. I wonder why that is.

We have ASAN enabled in CI for the Sentry project, but not for the samples. Enabling it for our sample projects doesn't fail the build.

Maybe we can use

__used __attribute__((constructor)) static void recordProcessStartTime() {
    moduleInitializationTimestamp = [NSDate date];
}

Instead of the __mod_init_func.

[philipphofmann]

The detailed error is

Assertion failed: (index < orderedInitOffsetAtoms.size()), function doPass, file inits.cpp, line 131.
0  0x10a2ee0ee  __assert_rtn + 127
1  0x10a2ac2ef  ld::passes::inits::doPass(Options&, ld::Internal&) + 1169
2  0x10a1a2325  main + 419

The assertion error is coming from here assert(index < orderedInitOffsetAtoms.size());.

Here is the linker snapshot. It's bigger than 25MB, so I couldn't upload it here.