rust/0001-Let-LLVM-5-add-DW_OP_deref-to-indirect-args-itself.patch
2018-02-15 15:38:13 -08:00

54 lines
2.3 KiB
Diff

From 7eb7d45c0b0a9dc0454c5f3a3c5e911c7900bbea Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Tue, 23 Jan 2018 13:53:01 -0800
Subject: [PATCH] Let LLVM 5 add DW_OP_deref to indirect args itself
We needed to manually added the `DW_OP_deref` ourselves in earlier LLVM,
but starting with [D31439] in LLVM 5, it appears that LLVM will always
handle this itself. When we were still adding this manually, the
resulting `.debug_loc` had too many derefs, and this failed test
`debuginfo/by-value-self-argument-in-trait-impl.rs`.
[D31439]: https://reviews.llvm.org/D31439
Fixes #47611.
cc @alexcrichton
r? @michaelwoerister
---
src/librustc_trans/mir/mod.rs | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/src/librustc_trans/mir/mod.rs b/src/librustc_trans/mir/mod.rs
index b367eb6548d0..da01592d9118 100644
--- a/src/librustc_trans/mir/mod.rs
+++ b/src/librustc_trans/mir/mod.rs
@@ -487,16 +487,18 @@ fn arg_local_refs<'a, 'tcx>(bx: &Builder<'a, 'tcx>,
// The Rust ABI passes indirect variables using a pointer and a manual copy, so we
// need to insert a deref here, but the C ABI uses a pointer and a copy using the
// byval attribute, for which LLVM does the deref itself, so we must not add it.
+ // Starting with D31439 in LLVM 5, it *always* does the deref itself.
let mut variable_access = VariableAccess::DirectVariable {
alloca: place.llval
};
-
- if let PassMode::Indirect(ref attrs) = arg.mode {
- if !attrs.contains(ArgAttribute::ByVal) {
- variable_access = VariableAccess::IndirectVariable {
- alloca: place.llval,
- address_operations: &deref_op,
- };
+ if unsafe { llvm::LLVMRustVersionMajor() < 5 } {
+ if let PassMode::Indirect(ref attrs) = arg.mode {
+ if !attrs.contains(ArgAttribute::ByVal) {
+ variable_access = VariableAccess::IndirectVariable {
+ alloca: place.llval,
+ address_operations: &deref_op,
+ };
+ }
}
}
--
2.14.3