Bug 427651

Summary:	Static linking of LLVM libs breaks krita
Product:	[Frameworks and Libraries] SeExpr	Reporter:	Antonio Rojas <arojas>
Component:	General	Assignee:	amyspark <amy>
Status:	RESOLVED FIXED
Severity:	normal	CC:	halla
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:	https://invent.kde.org/graphics/kseexpr/-/commit/b57c3236f3c540b81d44c7ac77d77869f35d7c1a	Version Fixed In:
Sentry Crash Report:

Description Antonio Rojas 2020-10-13 18:35:53 UTC

SUMMARY
Krita's SeExpr links to the static LLVM libs (Interpreter, MCJIT, etc) instead of the shared libLLVM.so in [1]. This in turn makes krita itself link statically to the same libs again, which break krita at runtime due to double linking:

CommandLine Error: Option 'interpreter-print-volatile' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options 

Linking against the shared libLLVM library, like upstream seexpr does [2] fixes the problem.

[1] https://invent.kde.org/graphics/seexpr/-/blob/master/CMakeLists.txt#L192
[2] https://github.com/wdas/SeExpr/blob/main/CMakeLists.txt#L150

Comment 1 Halla Rempt 2020-10-14 07:41:24 UTC

Afaik, seexpr for Krita should be built with the following flags: -DENABLE_LLVM_BACKEND=OFF -DENABLE_SSE4=OFF -DBUILD_DOC=OFF -DBUILD_TESTS=OFF -DBUILD_UTILS=OFF -DUSE_PYTHON=OFF

so, that disables llvm and python.

Amyspark, is that correct?

Comment 2 amyspark 2020-10-14 18:04:46 UTC

This is correct. The SeExpr fork we use in Krita does not involve LLVM at all.

In the next point release, I will make it build without LLVM support by default.

In any case, I will have a look at this and make sure it works correctly.

Comment 3 amyspark 2020-10-15 01:25:53 UTC

FTR, linking against shared LLVM makes it impossible to use in systems that provide only static LLVM (like the Academy Software Foundation's Docker images, which I use for testing my changes in CI). 
I'm checking if the CMake modules provides any tooling to dynamically detect and use the shared lib if available (otherwise, I'll have to use llvm-config...)