From 826141359132123d7498a9fccf3b50742ce74ff7 Mon Sep 17 00:00:00 2001
From: Michael Woerister <michaelwoerister@posteo>
Date: Wed, 21 Jun 2017 17:38:22 +0300
Subject: [PATCH] debuginfo: Work around crash-bug in MSDIA library
---
src/librustc_trans/debuginfo/mod.rs | 30 ++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)
diff --git a/src/librustc_trans/debuginfo/mod.rs b/src/librustc_trans/debuginfo/mod.rs
index d4d098ee5e7..68432c22f81 100644
--- a/src/librustc_trans/debuginfo/mod.rs
+++ b/src/librustc_trans/debuginfo/mod.rs
@@ -43,7 +43,7 @@ use std::ptr;
use syntax_pos::{self, Span, Pos};
use syntax::ast;
use syntax::symbol::Symbol;
-use rustc::ty::layout;
+use rustc::ty::layout::{self, LayoutTyper};
pub mod gdb;
mod utils;
@@ -320,8 +320,32 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
};
// Arguments types
- for &argument_type in inputs {
- signature.push(type_metadata(cx, argument_type, syntax_pos::DUMMY_SP));
+ if cx.sess().target.target.options.is_like_msvc {
+ // FIXME(#42800):
+ // There is a bug in MSDIA that leads to a crash when it encounters
+ // a fixed-size array of `u8` or something zero-sized in a
+ // function-type (see #40477).
+ // As a workaround, we replace those fixed-size arrays with a
+ // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
+ // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
+ // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
+ // This transformed type is wrong, but these function types are
+ // already inaccurate due to ABI adjustments (see #42800).
+ signature.extend(inputs.iter().map(|&t| {
+ let t = match t.sty {
+ ty::TyArray(ct, _)
+ if (ct == cx.tcx().types.u8) ||
+ (cx.layout_of(ct).size(cx).bytes() == 0) => {
+ cx.tcx().mk_imm_ptr(ct)
+ }
+ _ => t
+ };
+ type_metadata(cx, t, syntax_pos::DUMMY_SP)
+ }));
+ } else {
+ signature.extend(inputs.iter().map(|t| {
+ type_metadata(cx, t, syntax_pos::DUMMY_SP)
+ }));
}
if sig.abi == Abi::RustCall && !sig.inputs().is_empty() {