use log::trace;
-use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty;
use rustc_span::{source_map::DUMMY_SP, Span, SpanData, Symbol};
+use crate::helpers::HexRange;
+use crate::stacked_borrows::{diagnostics::TagHistory, AccessKind, SbTag};
use crate::*;
/// Details of premature program termination.
Exit(i64),
Abort(String),
UnsupportedInIsolation(String),
- ExperimentalUb {
+ StackedBorrowsUb {
msg: String,
- url: String,
+ help: Option<String>,
+ history: Option<TagHistory>,
},
Deadlock,
MultipleSymbolDefinitions {
Exit(code) => write!(f, "the evaluated program completed with exit code {}", code),
Abort(msg) => write!(f, "{}", msg),
UnsupportedInIsolation(msg) => write!(f, "{}", msg),
- ExperimentalUb { msg, .. } => write!(f, "{}", msg),
+ StackedBorrowsUb { msg, .. } => write!(f, "{}", msg),
Deadlock => write!(f, "the evaluated program deadlocked"),
MultipleSymbolDefinitions { link_name, .. } =>
write!(f, "multiple definitions of symbol `{}`", link_name),
- SymbolShimClashing { link_name, .. } => write!(
- f,
- "found `{}` symbol definition that clashes with a built-in shim",
- link_name
- ),
+ SymbolShimClashing { link_name, .. } =>
+ write!(
+ f,
+ "found `{}` symbol definition that clashes with a built-in shim",
+ link_name
+ ),
}
}
}
/// Miri specific diagnostics
pub enum NonHaltingDiagnostic {
CreatedPointerTag(NonZeroU64),
- PoppedPointerTag(Item),
+ /// This `Item` was popped from the borrow stack, either due to a grant of
+ /// `AccessKind` to `SbTag` or a deallocation when the second argument is `None`.
+ PoppedPointerTag(Item, Option<(SbTag, AccessKind)>),
CreatedCallId(CallId),
CreatedAlloc(AllocId),
FreedAlloc(AllocId),
Note,
}
+/// Attempts to prune a stacktrace to omit the Rust runtime, and returns a bool indicating if any
+/// frames were pruned. If the stacktrace does not have any local frames, we conclude that it must
+/// be pointing to a problem in the Rust runtime itself, and do not prune it at all.
+fn prune_stacktrace<'mir, 'tcx>(
+ ecx: &InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
+ mut stacktrace: Vec<FrameInfo<'tcx>>,
+) -> (Vec<FrameInfo<'tcx>>, bool) {
+ match ecx.machine.backtrace_style {
+ BacktraceStyle::Off => {
+ // Retain one frame so that we can print a span for the error itself
+ stacktrace.truncate(1);
+ (stacktrace, false)
+ }
+ BacktraceStyle::Short => {
+ let original_len = stacktrace.len();
+ // Only prune frames if there is at least one local frame. This check ensures that if
+ // we get a backtrace that never makes it to the user code because it has detected a
+ // bug in the Rust runtime, we don't prune away every frame.
+ let has_local_frame = stacktrace.iter().any(|frame| ecx.machine.is_local(frame));
+ if has_local_frame {
+ // This is part of the logic that `std` uses to select the relevant part of a
+ // backtrace. But here, we only look for __rust_begin_short_backtrace, not
+ // __rust_end_short_backtrace because the end symbol comes from a call to the default
+ // panic handler.
+ stacktrace = stacktrace
+ .into_iter()
+ .take_while(|frame| {
+ let def_id = frame.instance.def_id();
+ let path = ecx.tcx.tcx.def_path_str(def_id);
+ !path.contains("__rust_begin_short_backtrace")
+ })
+ .collect::<Vec<_>>();
+
+ // After we prune frames from the bottom, there are a few left that are part of the
+ // Rust runtime. So we remove frames until we get to a local symbol, which should be
+ // main or a test.
+ // This len check ensures that we don't somehow remove every frame, as doing so breaks
+ // the primary error message.
+ while stacktrace.len() > 1
+ && stacktrace.last().map_or(false, |frame| !ecx.machine.is_local(frame))
+ {
+ stacktrace.pop();
+ }
+ }
+ let was_pruned = stacktrace.len() != original_len;
+ (stacktrace, was_pruned)
+ }
+ BacktraceStyle::Full => (stacktrace, false),
+ }
+}
+
/// Emit a custom diagnostic without going through the miri-engine machinery
pub fn report_error<'tcx, 'mir>(
ecx: &InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
) -> Option<i64> {
use InterpError::*;
+ let mut msg = vec![];
+
let (title, helps) = match &e.kind() {
MachineStop(info) => {
let info = info.downcast_ref::<TerminationInfo>().expect("invalid MachineStop payload");
Exit(code) => return Some(*code),
Abort(_) => Some("abnormal termination"),
UnsupportedInIsolation(_) => Some("unsupported operation"),
- ExperimentalUb { .. } => Some("Undefined Behavior"),
+ StackedBorrowsUb { .. } => Some("Undefined Behavior"),
Deadlock => Some("deadlock"),
MultipleSymbolDefinitions { .. } | SymbolShimClashing { .. } => None,
};
UnsupportedInIsolation(_) =>
vec![
(None, format!("pass the flag `-Zmiri-disable-isolation` to disable isolation;")),
- (None, format!("or pass `-Zmiri-isolation-error=warn to configure Miri to return an error code from isolated operations (if supported for that operation) and continue with a warning")),
- ],
- ExperimentalUb { url, .. } =>
- vec![
- (None, format!("this indicates a potential bug in the program: it performed an invalid operation, but the rules it violated are still experimental")),
- (None, format!("see {} for further information", url)),
+ (None, format!("or pass `-Zmiri-isolation-error=warn` to configure Miri to return an error code from isolated operations (if supported for that operation) and continue with a warning")),
],
+ StackedBorrowsUb { help, history, .. } => {
+ let url = "https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md";
+ msg.extend(help.clone());
+ let mut helps = vec![
+ (None, format!("this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental")),
+ (None, format!("see {url} for further information")),
+ ];
+ match history {
+ Some(TagHistory::Tagged {tag, created: (created_range, created_span), invalidated, protected }) => {
+ let msg = format!("{:?} was created by a retag at offsets {}", tag, HexRange(*created_range));
+ helps.push((Some(*created_span), msg));
+ if let Some((invalidated_range, invalidated_span)) = invalidated {
+ let msg = format!("{:?} was later invalidated at offsets {}", tag, HexRange(*invalidated_range));
+ helps.push((Some(*invalidated_span), msg));
+ }
+ if let Some((protecting_tag, protecting_tag_span, protection_span)) = protected {
+ helps.push((Some(*protecting_tag_span), format!("{:?} was protected due to {:?} which was created here", tag, protecting_tag)));
+ helps.push((Some(*protection_span), "this protector is live for this call".to_string()));
+ }
+ }
+ Some(TagHistory::Untagged{ recently_created, recently_invalidated, matching_created, protected }) => {
+ if let Some((range, span)) = recently_created {
+ let msg = format!("tag was most recently created at offsets {}", HexRange(*range));
+ helps.push((Some(*span), msg));
+ }
+ if let Some((range, span)) = recently_invalidated {
+ let msg = format!("tag was later invalidated at offsets {}", HexRange(*range));
+ helps.push((Some(*span), msg));
+ }
+ if let Some((range, span)) = matching_created {
+ let msg = format!("this tag was also created here at offsets {}", HexRange(*range));
+ helps.push((Some(*span), msg));
+ }
+ if let Some((protecting_tag, protecting_tag_span, protection_span)) = protected {
+ helps.push((Some(*protecting_tag_span), format!("{:?} was protected due to a tag which was created here", protecting_tag)));
+ helps.push((Some(*protection_span), "this protector is live for this call".to_string()));
+ }
+ }
+ None => {}
+ }
+ helps
+ }
MultipleSymbolDefinitions { first, first_crate, second, second_crate, .. } =>
vec![
(Some(*first), format!("it's first defined here, in crate `{}`", first_crate)),
"Undefined Behavior",
ResourceExhaustion(_) =>
"resource exhaustion",
- InvalidProgram(InvalidProgramInfo::ReferencedConstant) =>
+ InvalidProgram(
+ InvalidProgramInfo::AlreadyReported(_) |
+ InvalidProgramInfo::Layout(..) |
+ InvalidProgramInfo::ReferencedConstant
+ ) =>
"post-monomorphization error",
- InvalidProgram(InvalidProgramInfo::AlreadyReported(_)) =>
- "error occurred",
kind =>
bug!("This error should be impossible in Miri: {:?}", kind),
};
#[rustfmt::skip]
let helps = match e.kind() {
- Unsupported(UnsupportedOpInfo::NoMirFor(..)) =>
- vec![(None, format!("make sure to use a Miri sysroot, which you can prepare with `cargo miri setup`"))],
- Unsupported(UnsupportedOpInfo::ReadBytesAsPointer | UnsupportedOpInfo::ThreadLocalStatic(_) | UnsupportedOpInfo::ReadExternStatic(_)) =>
+ Unsupported(
+ UnsupportedOpInfo::ThreadLocalStatic(_) |
+ UnsupportedOpInfo::ReadExternStatic(_)
+ ) =>
panic!("Error should never be raised by Miri: {:?}", e.kind()),
- Unsupported(_) =>
+ Unsupported(
+ UnsupportedOpInfo::Unsupported(_) |
+ UnsupportedOpInfo::PartialPointerOverwrite(_) |
+ UnsupportedOpInfo::ReadPointerAsBytes
+ ) =>
vec![(None, format!("this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support"))],
UndefinedBehavior(UndefinedBehaviorInfo::AlignmentCheckFailed { .. })
- if ecx.memory.extra.check_alignment == AlignmentCheck::Symbolic
+ if ecx.machine.check_alignment == AlignmentCheck::Symbolic
=>
vec![
(None, format!("this usually indicates that your program performed an invalid operation and caused Undefined Behavior")),
(None, format!("this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior")),
(None, format!("see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information")),
],
- _ => vec![],
+ InvalidProgram(_) | ResourceExhaustion(_) | MachineStop(_) =>
+ vec![],
};
(Some(title), helps)
}
};
+ let stacktrace = ecx.generate_stacktrace();
+ let (stacktrace, was_pruned) = prune_stacktrace(ecx, stacktrace);
e.print_backtrace();
- let msg = e.to_string();
+ msg.insert(0, e.to_string());
report_msg(
- *ecx.tcx,
+ ecx,
DiagLevel::Error,
- &if let Some(title) = title { format!("{}: {}", title, msg) } else { msg.clone() },
+ &if let Some(title) = title { format!("{}: {}", title, msg[0]) } else { msg[0].clone() },
msg,
helps,
- &ecx.generate_stacktrace(),
+ &stacktrace,
);
+ // Include a note like `std` does when we omit frames from a backtrace
+ if was_pruned {
+ ecx.tcx.sess.diagnostic().note_without_error(
+ "some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace",
+ );
+ }
+
// Debug-dump all locals.
for (i, frame) in ecx.active_thread_stack().iter().enumerate() {
trace!("-------------------");
trace!("Frame {}", i);
- trace!(" return: {:?}", frame.return_place.map(|p| *p));
+ trace!(" return: {:?}", *frame.return_place);
for (i, local) in frame.locals.iter().enumerate() {
trace!(" local {}: {:?}", i, local.value);
}
access.uninit_offset.bytes(),
access.uninit_offset.bytes() + access.uninit_size.bytes(),
);
- eprintln!("{:?}", ecx.memory.dump_alloc(*alloc_id));
+ eprintln!("{:?}", ecx.dump_alloc(*alloc_id));
}
_ => {}
}
/// Report an error or note (depending on the `error` argument) with the given stacktrace.
/// Also emits a full stacktrace of the interpreter stack.
-fn report_msg<'tcx>(
- tcx: TyCtxt<'tcx>,
+/// We want to present a multi-line span message for some errors. Diagnostics do not support this
+/// directly, so we pass the lines as a `Vec<String>` and display each line after the first with an
+/// additional `span_label` or `note` call.
+fn report_msg<'mir, 'tcx>(
+ ecx: &InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
diag_level: DiagLevel,
title: &str,
- span_msg: String,
+ span_msg: Vec<String>,
mut helps: Vec<(Option<SpanData>, String)>,
stacktrace: &[FrameInfo<'tcx>],
) {
let span = stacktrace.first().map_or(DUMMY_SP, |fi| fi.span);
+ let sess = ecx.tcx.sess;
let mut err = match diag_level {
- DiagLevel::Error => tcx.sess.struct_span_err(span, title),
- DiagLevel::Warning => tcx.sess.struct_span_warn(span, title),
- DiagLevel::Note => tcx.sess.diagnostic().span_note_diag(span, title),
+ DiagLevel::Error => sess.struct_span_err(span, title).forget_guarantee(),
+ DiagLevel::Warning => sess.struct_span_warn(span, title),
+ DiagLevel::Note => sess.diagnostic().span_note_diag(span, title),
};
// Show main message.
if span != DUMMY_SP {
- err.span_label(span, span_msg);
+ for line in span_msg {
+ err.span_label(span, line);
+ }
} else {
// Make sure we show the message even when it is a dummy span.
- err.note(&span_msg);
+ for line in span_msg {
+ err.note(&line);
+ }
err.note("(no span available)");
}
+
// Show help messages.
if !helps.is_empty() {
// Add visual separator before backtrace.
- helps.last_mut().unwrap().1.push_str("\n");
+ helps.last_mut().unwrap().1.push('\n');
for (span_data, help) in helps {
if let Some(span_data) = span_data {
err.span_help(span_data.span(), &help);
}
// Add backtrace
for (idx, frame_info) in stacktrace.iter().enumerate() {
- let is_local = frame_info.instance.def_id().is_local();
+ let is_local = ecx.machine.is_local(frame_info);
// No span for non-local frames and the first frame (which is the error site).
if is_local && idx > 0 {
err.span_note(frame_info.span, &frame_info.to_string());
);
}
+ let (stacktrace, _was_pruned) = prune_stacktrace(this, stacktrace);
+
// Show diagnostics.
for e in diagnostics.drain(..) {
use NonHaltingDiagnostic::*;
let msg = match e {
CreatedPointerTag(tag) => format!("created tag {:?}", tag),
- PoppedPointerTag(item) => format!("popped tracked tag for item {:?}", item),
- CreatedCallId(id) => format!("function call with id {}", id),
- CreatedAlloc(AllocId(id)) => format!("created allocation with id {}", id),
- FreedAlloc(AllocId(id)) => format!("freed allocation with id {}", id),
+ PoppedPointerTag(item, tag) =>
+ match tag {
+ None =>
+ format!(
+ "popped tracked tag for item {:?} due to deallocation",
+ item
+ ),
+ Some((tag, access)) => {
+ format!(
+ "popped tracked tag for item {:?} due to {:?} access for {:?}",
+ item, access, tag
+ )
+ }
+ },
+ CreatedCallId(id) => format!("function call with id {id}"),
+ CreatedAlloc(AllocId(id)) => format!("created allocation with id {id}"),
+ FreedAlloc(AllocId(id)) => format!("freed allocation with id {id}"),
RejectedIsolatedOp(ref op) =>
- format!("`{}` was made to return an error due to isolation", op),
+ format!("{op} was made to return an error due to isolation"),
};
let (title, diag_level) = match e {
_ => ("tracking was triggered", DiagLevel::Note),
};
- report_msg(*this.tcx, diag_level, title, msg, vec![], &stacktrace);
+ report_msg(this, diag_level, title, vec![msg], vec![], &stacktrace);
}
});
}
projects / rust.git / blobdiff