From 45d5a37787accac8bd4276ea47872a561069109c Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 11 Mar 2020 20:05:44 +0100
Subject: [PATCH 1/2] rustup+fix

---
 rust-version       |  2 +-
 src/machine.rs     |  3 +--
 src/shims/panic.rs | 10 +++-------
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/rust-version b/rust-version
index fb138448f9..66d096c0a0 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-303d8aff6092709edd4dbd35b1c88e9aa40bf6d8
+c20d7eecbc0928b57da8fe30b2ef8528e2bdd5be
diff --git a/src/machine.rs b/src/machine.rs
index f69606e48f..bd5884786c 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -265,11 +265,10 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
     #[inline(always)]
     fn assert_panic(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
-        span: Span,
         msg: &mir::AssertMessage<'tcx>,
         unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx> {
-        ecx.assert_panic(span, msg, unwind)
+        ecx.assert_panic(msg, unwind)
     }
 
     #[inline(always)]
diff --git a/src/shims/panic.rs b/src/shims/panic.rs
index 2968bd9b58..d6f563deb0 100644
--- a/src/shims/panic.rs
+++ b/src/shims/panic.rs
@@ -14,7 +14,6 @@
 use rustc::mir;
 use rustc::ty::{self, layout::LayoutOf};
 use rustc_target::spec::PanicStrategy;
-use rustc_span::source_map::Span;
 
 use crate::*;
 
@@ -176,7 +175,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
     fn assert_panic(
         &mut self,
-        span: Span,
         msg: &mir::AssertMessage<'tcx>,
         unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx> {
@@ -187,11 +185,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             BoundsCheck { ref index, ref len } => {
                 // Forward to `panic_bounds_check` lang item.
 
-                // First arg: Caller location.
-                let location = this.alloc_caller_location_for_span(span);
-                // Second arg: index.
+                // First arg: index.
                 let index = this.read_scalar(this.eval_operand(index, None)?)?;
-                // Third arg: len.
+                // Second arg: len.
                 let len = this.read_scalar(this.eval_operand(len, None)?)?;
 
                 // Call the lang item.
@@ -199,7 +195,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 let panic_bounds_check = ty::Instance::mono(this.tcx.tcx, panic_bounds_check);
                 this.call_function(
                     panic_bounds_check,
-                    &[location.ptr.into(), index.into(), len.into()],
+                    &[index.into(), len.into()],
                     None,
                     StackPopCleanup::Goto { ret: None, unwind },
                 )?;

From 76ee8ff4589b5085c68c5efbebd8d3fb07b8a00d Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 11 Mar 2020 20:21:44 +0100
Subject: [PATCH 2/2] use ctfe_backtracte variable for backtrace control

---
 src/bin/miri.rs | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/bin/miri.rs b/src/bin/miri.rs
index d270964323..e40bfcf627 100644
--- a/src/bin/miri.rs
+++ b/src/bin/miri.rs
@@ -7,13 +7,10 @@ extern crate log;
 extern crate log_settings;
 extern crate miri;
 extern crate rustc;
-extern crate rustc_codegen_utils;
 extern crate rustc_driver;
-extern crate rustc_errors;
 extern crate rustc_hir;
 extern crate rustc_interface;
-extern crate rustc_metadata;
-extern crate rustc_span;
+extern crate rustc_session;
 
 use std::convert::TryFrom;
 use std::env;
@@ -21,9 +18,11 @@ use std::str::FromStr;
 
 use hex::FromHexError;
 
+use rustc_session::CtfeBacktrace;
 use rustc_driver::Compilation;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_interface::{interface, Queries};
+use rustc::ty::TyCtxt;
 
 struct MiriCompilerCalls {
     miri_config: miri::MiriConfig,
@@ -35,10 +34,10 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
         compiler: &interface::Compiler,
         queries: &'tcx Queries<'tcx>,
     ) -> Compilation {
-        init_late_loggers();
         compiler.session().abort_if_errors();
 
         queries.global_ctxt().unwrap().peek_mut().enter(|tcx| {
+            init_late_loggers(tcx);
             let (entry_def_id, _) = tcx.entry_fn(LOCAL_CRATE).expect("no main function found!");
             let mut config = self.miri_config.clone();
 
@@ -72,7 +71,7 @@ fn init_early_loggers() {
     }
 }
 
-fn init_late_loggers() {
+fn init_late_loggers(tcx: TyCtxt<'_>) {
     // We initialize loggers right before we start evaluation. We overwrite the `RUSTC_LOG`
     // env var if it is not set, control it based on `MIRI_LOG`.
     if let Ok(var) = env::var("MIRI_LOG") {
@@ -96,10 +95,13 @@ fn init_late_loggers() {
 
     // If `MIRI_BACKTRACE` is set and `RUSTC_CTFE_BACKTRACE` is not, set `RUSTC_CTFE_BACKTRACE`.
     // Do this late, so we ideally only apply this to Miri's errors.
-    if let Ok(var) = env::var("MIRI_BACKTRACE") {
-        if env::var("RUSTC_CTFE_BACKTRACE") == Err(env::VarError::NotPresent) {
-            env::set_var("RUSTC_CTFE_BACKTRACE", &var);
-        }
+    if let Ok(val) = env::var("MIRI_BACKTRACE") {
+        let ctfe_backtrace = match &*val {
+            "immediate" => CtfeBacktrace::Immediate,
+            "0" => CtfeBacktrace::Disabled,
+            _ => CtfeBacktrace::Capture,
+        };
+        *tcx.sess.ctfe_backtrace.borrow_mut() = ctfe_backtrace;
     }
 }