[llvm-dev] llvm-link: Missing Dwarf DIE references (original) (raw)

Jack Carter via llvm-dev llvm-dev at lists.llvm.org
Mon Sep 18 13:28:52 PDT 2017


I am experiencing an issue combining bitcode files for the purpose of generating the combined bitcodes as a single bitcode file. I would like to have any pointers to help me debug this or maybe it has been seen before and a fix is either being worked on or is done.

I am using the Xcode 9.0 compiler. I believe the Swift code is 3.x. I have reproduced this using the tot llvm-link.

The input modules are from Swift (LucidDreams) and have been compiled -O. The problem doesn't seem to exist when they are compiled -Onone.

The llvm-link occurs without error and the subsequent compilation also seems to go fine, but when the resultant llvm-dwarfdump -verbose -verify is run I get a bunch of the following errors:

warning: could not find referenced DIE in DIE:

0x0000a33f: DW_TAG_inlined_subroutine [20] * DW_AT_abstract_origin [DW_FORM_ref4] (cu + 0x0c84 => {0x0000a40d}) DW_AT_ranges [DW_FORM_sec_offset] (0x00021960 [0x0000000000001878 - 0x000000000000187c) [0x00000000000018b0 - 0x0000000000001910) [0x0000000000001980 - 0x00000000000019e0)) DW_AT_call_file [DW_FORM_data1] ("/testprogram_lucidDreams/iOS_APP/LucidDreams/DreamListViewControllerModel.swift") DW_AT_call_line [DW_FORM_data1] (61) while processing /testprogram_lucidDreams/iOS_APP/DerivedData/iOS_APP/Build/Intermediates.noindex/iOS_APP.build/Debug-iphoneos/iOS_APP.build/Objects-normal/arm64/iOS_APP.bc.o:

All the errors reference DreamListViewControllerModel.swift and have todo with inlining, but if I remove enough of the input bitcode objects from the llvm-link the error goes away even though DreamListViewControllerModel is still included.

Here are the commands I used to generate the error (omitting the original Swift compile):

######################## ######################## llvm-link
-o /iOS_APP.bc
/DreamListViewController.o
/TextEntryCollectionViewCell.bc
/ImageDrawable.bc
/DreamScene.bc
/DreamListViewControllerModel.bc
/CreatureCollectionViewCell.bc
/RangeReplaceableCollection+IndexSet.bc
/DreamPreviewHeaderReusableView.bc
/Rendering.bc

######################## ######################## xcrun
--sdk iphoneos
/Xcode_9.0.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++
-fembed-bitcode
/iOS_APP.bc
-arch arm64
-O0
-c
-o /iOS_APP.bc.o

######################## ######################## llvm-dwarfdump -verbose -verify small.o > small.o.dwarfdump

Any insights would be appreciated. Input bitcode files are attached.

Thanks, Jack -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170918/9f66aaa6/attachment-0002.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: bitcode_files.tgz Type: application/octet-stream Size: 351685 bytes Desc: not available URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170918/9f66aaa6/attachment-0001.obj> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170918/9f66aaa6/attachment-0003.html>



More information about the llvm-dev mailing list