From 1c95f5a34c14f08d65cdd198827e3a2fcb63cf39 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 22 Jan 2019 11:13:53 -0700 Subject: [PATCH] Fix issue 57762 Issue 57762 points out a compiler crash when the compiler was built using a stock LLVM 7. LLVM 7 was released without a necessary fix for a bug in the DWARF discriminant code. This patch changes rustc to use the fallback mode on (non-Rust) LLVM 7. Closes #57762 --- src/librustc_codegen_llvm/debuginfo/metadata.rs | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs index 6deedd0b5ea3..a354eef6887a 100644 --- a/src/librustc_codegen_llvm/debuginfo/metadata.rs +++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs @@ -1164,7 +1164,11 @@ fn use_enum_fallback(cx: &CodegenCx) -> bool { // On MSVC we have to use the fallback mode, because LLVM doesn't // lower variant parts to PDB. return cx.sess().target.target.options.is_like_msvc - || llvm_util::get_major_version() < 7; + || llvm_util::get_major_version() < 7 + // LLVM version 7 did not release with an important bug fix; + // but the required patch is in the equivalent Rust LLVM. + // See https://github.com/rust-lang/rust/issues/57762. + || (llvm_util::get_major_version() == 7 && unsafe { !llvm::LLVMRustIsRustLLVM() }); } // Describes the members of an enum value: An enum is described as a union of