Bug 741912

Summary:	sys-boot/lilo-24.2: edit.c:195:31: error: initializer element is not a compile-time constant
Product:	Gentoo Linux	Reporter:	Agostino Sarubbo <ago>
Component:	Current packages	Assignee:	Joshua Kinard <kumba>
Status:	CONFIRMED ---
Severity:	normal	CC:	base-system, peter
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	792567
Attachments:	build.log Patch to move the pointer calculation to runtime

Description Agostino Sarubbo gentoo-dev

2020-09-12 18:40:38 UTC

https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: sys-boot/lilo-24.2 fails to compile.
Discovered on: amd64 (internal ref: tinderbox)

NOTE:
This machine uses a clang/LLVM toolchain.
If you think that this issue is strictly related to clang/LLVM please block bug 408963. If you think that this issue is strictly related to the LLD linker, please block bug 731004.
This machine uses also GLIBC-2.32. If you think that this issue is strictly related to GLIBC please block bug 736174.

Comment 1 Agostino Sarubbo gentoo-dev

2020-09-12 18:40:41 UTC

Created attachment 659817 [details]
build.log

build log and emerge --info

Comment 2 Peter Stuge 2021-06-02 01:37:24 UTC

Created attachment 713217 [details, diff]
Patch to move the pointer calculation to runtime

Comment 3 Joshua Kinard gentoo-dev

2021-06-06 19:43:03 UTC

I am not convinced that the attached patch fully resolves the issue.  The patch makes the runtime calculation only happen in function `bmp_file_open', but the 'lh' pointer is also accessed in `bmp_file_close' and `main'.

Some quick research suggests two possible solutions:

- Remove the 'static' initializer from the 'lh' definition, per this StackOverflow answer: https://stackoverflow.com/a/34450315/ and this commit in someone's personal repo: https://git.sr.ht/~kqz/repo/commit/b8808d8

- Change the assignment to the following code, sourced from a Reddit comment on making lilo build with clang and musl:
(void*)((char*)&tm + (offsetof(MENUTABLE, row) - offsetof(BITMAPLILOHEADER, row)))
Source: https://www.reddit.com/r/Gentoo/comments/nmq5o1/help_with_installing_a_bootloader_on_a_clangmusl/

I don't have a working clang compiler installation, so I cannot reliably test either of these solutions (gcc-11 seems content with either of them).

Thoughts?