From: Josh Stone <jistone@redhat.com>
Date: Fri, 26 Apr 2019 15:58:14 +0000 (-0700)
Subject: [PATCH] Limit internalization in LLVM 8 ThinLTO
X-Git-Tag: archive/raspbian/1.34.2+dfsg1-1+rpi1^2~24
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=c79e94f685a2366f4ae966a92c1a89ed0880d968;p=rustc.git

[PATCH] Limit internalization in LLVM 8 ThinLTO


Gbp-Pq: Name u-0001-Limit-internalization-in-LLVM-8-ThinLTO.patch
---

diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp
index 25595e1498..95ff95312a 100644
--- a/src/rustllvm/PassWrapper.cpp
+++ b/src/rustllvm/PassWrapper.cpp
@@ -866,8 +866,11 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
     return PrevailingType::Unknown;
   };
 #if LLVM_VERSION_GE(8, 0)
+  // We don't have a complete picture in our use of ThinLTO, just our immediate
+  // crate, so we need `ImportEnabled = false` to limit internalization.
+  // Otherwise, we sometimes lose `static` values -- see #60184.
   computeDeadSymbolsWithConstProp(Ret->Index, Ret->GUIDPreservedSymbols,
-                                  deadIsPrevailing, /* ImportEnabled = */ true);
+                                  deadIsPrevailing, /* ImportEnabled = */ false);
 #else
   computeDeadSymbols(Ret->Index, Ret->GUIDPreservedSymbols, deadIsPrevailing);
 #endif