From d59fa081ec272573ef560c4ea914466fce74db3c Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 25 May 2020 08:52:16 +0200 Subject: [PATCH] fix ICE when debug-printing MIR --- src/librustc_middle/ty/print/pretty.rs | 30 +++++++++++++++++--------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/src/librustc_middle/ty/print/pretty.rs b/src/librustc_middle/ty/print/pretty.rs index f03d91aa64b78..a47addf18044c 100644 --- a/src/librustc_middle/ty/print/pretty.rs +++ b/src/librustc_middle/ty/print/pretty.rs @@ -1,5 +1,7 @@ use crate::middle::cstore::{ExternCrate, ExternCrateSource}; -use crate::mir::interpret::{sign_extend, truncate, AllocId, ConstValue, Pointer, Scalar}; +use crate::mir::interpret::{ + sign_extend, truncate, AllocId, ConstValue, GlobalAlloc, Pointer, Scalar, +}; use crate::ty::layout::IntegerExt; use crate::ty::subst::{GenericArg, GenericArgKind, Subst}; use crate::ty::{self, DefIdTree, ParamConst, Ty, TyCtxt, TypeFoldable}; @@ -951,15 +953,20 @@ pub trait PrettyPrinter<'tcx>: }, _, ), - ) => { - let byte_str = self - .tcx() - .global_alloc(ptr.alloc_id) - .unwrap_memory() - .get_bytes(&self.tcx(), ptr, Size::from_bytes(*data)) - .unwrap(); - p!(pretty_print_byte_str(byte_str)); - } + ) => match self.tcx().get_global_alloc(ptr.alloc_id) { + Some(GlobalAlloc::Memory(alloc)) => { + if let Ok(byte_str) = alloc.get_bytes(&self.tcx(), ptr, Size::from_bytes(*data)) + { + p!(pretty_print_byte_str(byte_str)) + } else { + p!(write("")) + } + } + // FIXME: for statics and functions, we could in principle print more detail. + Some(GlobalAlloc::Static(def_id)) => p!(write("", def_id)), + Some(GlobalAlloc::Function(_)) => p!(write("")), + None => p!(write("")), + }, // Bool (Scalar::Raw { data: 0, .. }, ty::Bool) => p!(write("false")), (Scalar::Raw { data: 1, .. }, ty::Bool) => p!(write("true")), @@ -1018,6 +1025,9 @@ pub trait PrettyPrinter<'tcx>: )?; } (Scalar::Ptr(ptr), ty::FnPtr(_)) => { + // FIXME: this can ICE when the ptr is dangling or points to a non-function. + // We should probably have a helper method to share code with the "Byte strings" + // printing above (which also has to handle pointers to all sorts of things). let instance = self.tcx().global_alloc(ptr.alloc_id).unwrap_fn(); self = self.typed_value( |this| this.print_value_path(instance.def_id(), instance.substs),