[Pkg-rust-maintainers] Bug#930598: rustc: Please backport upstream patch to fix ABI breakage on sparc64

[John Paul Adrian Glaubitz]

Source: rustc
Version: 1.34.2+dfsg1-1
Severity: normal
Tags: patch
User: debian-sparc at lists.debian.org
Usertags: sparc64

Hi!

Rust 1.34.0 introduced a regression which broke the compiler on
sparc64 [1]. There is now an upstream patch which has already
been acked by upstream and should therefore be backported to
all Debian versions of rustc >= 1.34.0.

Thanks,
Adrian

> [1] https://github.com/rust-lang/rust/issues/61306
> [2] https://github.com/rust-lang/rust/pull/61881

--
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913
-------------- next part --------------
>From 3fa7411050e5f712c28b6e97346e9da3833407bb Mon Sep 17 00:00:00 2001
From: John Paul Adrian Glaubitz <glaubitz at physik.fu-berlin.de>
Date: Sun, 16 Jun 2019 02:53:33 +0200
Subject: [PATCH] librustc_codegen_llvm: Use repr(transparent) for bitflags
 over repr(C) (#61306)

In order to make sure that Rust's bitflags types are passed the same
way in the Rust ABI as they are in the C ABI, we need to use the attribute
repr(transparent) over the repr(C) attribute for the single-field bitflags
structs in in order to prevent ABI mismatches. Thanks to Michael Karcher
for finding this bug.
---
 src/librustc_codegen_llvm/llvm/ffi.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
index a71243c7c8..a5c295cd45 100644
--- a/src/librustc_codegen_llvm/llvm/ffi.rs
+++ b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -564,7 +564,7 @@ pub mod debuginfo {
 
     // These values **must** match with LLVMRustDIFlags!!
     bitflags! {
-        #[repr(C)]
+        #[repr(transparent)]
         #[derive(Default)]
         pub struct DIFlags: ::libc::uint32_t {
             const FlagZero                = 0;
@@ -593,7 +593,7 @@ pub mod debuginfo {
 
     // These values **must** match with LLVMRustDISPFlags!!
     bitflags! {
-        #[repr(C)]
+        #[repr(transparent)]
         #[derive(Default)]
         pub struct DISPFlags: ::libc::uint32_t {
             const SPFlagZero              = 0;
-- 
2.20.1