use std::cell::RefCell;
use std::fmt;
+use std::num::NonZeroU64;
use log::trace;
-use rustc_span::DUMMY_SP;
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::{source_map::DUMMY_SP, Span, SpanData, Symbol};
use crate::*;
/// Details of premature program termination.
pub enum TerminationInfo {
Exit(i64),
- Abort(Option<String>),
+ Abort(String),
UnsupportedInIsolation(String),
- ExperimentalUb { msg: String, url: String },
+ ExperimentalUb {
+ msg: String,
+ url: String,
+ },
Deadlock,
+ MultipleSymbolDefinitions {
+ link_name: Symbol,
+ first: SpanData,
+ first_crate: Symbol,
+ second: SpanData,
+ second_crate: Symbol,
+ },
+ SymbolShimClashing {
+ link_name: Symbol,
+ span: SpanData,
+ },
}
-impl fmt::Debug for TerminationInfo {
+impl fmt::Display for TerminationInfo {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use TerminationInfo::*;
match self {
- Exit(code) =>
- write!(f, "the evaluated program completed with exit code {}", code),
- Abort(None) =>
- write!(f, "the evaluated program aborted execution"),
- Abort(Some(msg)) =>
- write!(f, "the evaluated program aborted execution: {}", msg),
- UnsupportedInIsolation(msg) =>
- write!(f, "{}", msg),
- ExperimentalUb { msg, .. } =>
- write!(f, "{}", msg),
- Deadlock =>
- write!(f, "the evaluated program deadlocked"),
+ 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),
+ 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
+ ),
}
}
}
/// Miri specific diagnostics
pub enum NonHaltingDiagnostic {
- PoppedTrackedPointerTag(Item),
+ CreatedPointerTag(NonZeroU64),
+ PoppedPointerTag(Item),
+ CreatedCallId(CallId),
CreatedAlloc(AllocId),
FreedAlloc(AllocId),
+ RejectedIsolatedOp(String),
+}
+
+/// Level of Miri specific diagnostics
+enum DiagLevel {
+ Error,
+ Warning,
+ Note,
}
/// Emit a custom diagnostic without going through the miri-engine machinery
pub fn report_error<'tcx, 'mir>(
- ecx: &InterpCx<'mir, 'tcx, Evaluator<'tcx>>,
- mut e: InterpErrorInfo<'tcx>,
+ ecx: &InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
+ e: InterpErrorInfo<'tcx>,
) -> Option<i64> {
use InterpError::*;
- let (title, helps) = match &e.kind {
+ let (title, helps) = match &e.kind() {
MachineStop(info) => {
let info = info.downcast_ref::<TerminationInfo>().expect("invalid MachineStop payload");
use TerminationInfo::*;
let title = match info {
Exit(code) => return Some(*code),
- Abort(_) =>
- "abnormal termination",
- UnsupportedInIsolation(_) =>
- "unsupported operation",
- ExperimentalUb { .. } =>
- "Undefined Behavior",
- Deadlock => "deadlock",
+ Abort(_) => Some("abnormal termination"),
+ UnsupportedInIsolation(_) => Some("unsupported operation"),
+ ExperimentalUb { .. } => Some("Undefined Behavior"),
+ Deadlock => Some("deadlock"),
+ MultipleSymbolDefinitions { .. } | SymbolShimClashing { .. } => None,
};
+ #[rustfmt::skip]
let helps = match info {
UnsupportedInIsolation(_) =>
- vec![format!("pass the flag `-Zmiri-disable-isolation` to disable isolation")],
+ 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![
- format!("this indicates a potential bug in the program: it performed an invalid operation, but the rules it violated are still experimental"),
- format!("see {} for further information", url),
+ (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)),
],
+ MultipleSymbolDefinitions { first, first_crate, second, second_crate, .. } =>
+ vec![
+ (Some(*first), format!("it's first defined here, in crate `{}`", first_crate)),
+ (Some(*second), format!("then it's defined here again, in crate `{}`", second_crate)),
+ ],
+ SymbolShimClashing { link_name, span } =>
+ vec![(Some(*span), format!("the `{}` symbol is defined here", link_name))],
_ => vec![],
};
(title, helps)
}
_ => {
- let title = match e.kind {
+ #[rustfmt::skip]
+ let title = match e.kind() {
Unsupported(_) =>
"unsupported operation",
UndefinedBehavior(_) =>
"Undefined Behavior",
ResourceExhaustion(_) =>
"resource exhaustion",
- _ =>
- bug!("This error should be impossible in Miri: {}", e),
+ InvalidProgram(InvalidProgramInfo::ReferencedConstant) =>
+ "post-monomorphization error",
+ InvalidProgram(InvalidProgramInfo::AlreadyReported(_)) =>
+ "error occurred",
+ kind =>
+ bug!("This error should be impossible in Miri: {:?}", kind),
};
- let helps = match e.kind {
- Unsupported(UnsupportedOpInfo::NoMirFor(..)) =>
- vec![format!("make sure to use a Miri sysroot, which you can prepare with `cargo miri setup`")],
- Unsupported(UnsupportedOpInfo::ReadBytesAsPointer) =>
- panic!("`ReadBytesAsPointer` cannot be raised by Miri"),
+ #[rustfmt::skip]
+ let helps = match e.kind() {
+ Unsupported(UnsupportedOpInfo::ThreadLocalStatic(_) | UnsupportedOpInfo::ReadExternStatic(_)) =>
+ panic!("Error should never be raised by Miri: {:?}", e.kind()),
Unsupported(_) =>
- vec![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 { .. }) =>
+ 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
+ =>
vec![
- format!("this usually indicates that your program performed an invalid operation and caused Undefined Behavior"),
- format!("but alignment errors can also be false positives, see https://github.com/rust-lang/miri/issues/1074"),
- format!("you can disable the alignment check with `-Zmiri-disable-alignment-check`, but that could hide true bugs")
+ (None, format!("this usually indicates that your program performed an invalid operation and caused Undefined Behavior")),
+ (None, format!("but due to `-Zmiri-symbolic-alignment-check`, alignment errors can also be false positives")),
],
UndefinedBehavior(_) =>
vec![
- format!("this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior"),
- format!("see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information"),
+ (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![],
};
- (title, helps)
+ (Some(title), helps)
}
};
e.print_backtrace();
let msg = e.to_string();
- report_msg(ecx, &format!("{}: {}", title, msg), msg, helps, true)
+ report_msg(
+ *ecx.tcx,
+ DiagLevel::Error,
+ &if let Some(title) = title { format!("{}: {}", title, msg) } else { msg.clone() },
+ msg,
+ helps,
+ &ecx.generate_stacktrace(),
+ );
+
+ // 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));
+ for (i, local) in frame.locals.iter().enumerate() {
+ trace!(" local {}: {:?}", i, local.value);
+ }
+ }
+
+ // Extra output to help debug specific issues.
+ match e.kind() {
+ UndefinedBehavior(UndefinedBehaviorInfo::InvalidUninitBytes(Some((alloc_id, access)))) => {
+ eprintln!(
+ "Uninitialized read occurred at offsets 0x{:x}..0x{:x} into this allocation:",
+ access.uninit_offset.bytes(),
+ access.uninit_offset.bytes() + access.uninit_size.bytes(),
+ );
+ eprintln!("{:?}", ecx.memory.dump_alloc(*alloc_id));
+ }
+ _ => {}
+ }
+
+ None
}
-/// Report an error or note (depending on the `error` argument) at the current frame's current statement.
+/// 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, 'mir>(
- ecx: &InterpCx<'mir, 'tcx, Evaluator<'tcx>>,
+fn report_msg<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ diag_level: DiagLevel,
title: &str,
span_msg: String,
- mut helps: Vec<String>,
- error: bool,
-) -> Option<i64> {
- let span = if let Some(frame) = ecx.stack().last() {
- frame.current_source_info().unwrap().span
- } else {
- DUMMY_SP
+ mut helps: Vec<(Option<SpanData>, String)>,
+ stacktrace: &[FrameInfo<'tcx>],
+) {
+ let span = stacktrace.first().map_or(DUMMY_SP, |fi| fi.span);
+ 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),
};
- let mut err = if error {
- ecx.tcx.sess.struct_span_err(span, title)
+
+ // Show main message.
+ if span != DUMMY_SP {
+ err.span_label(span, span_msg);
} else {
- ecx.tcx.sess.diagnostic().span_note_diag(span, title)
- };
- err.span_label(span, span_msg);
+ // Make sure we show the message even when it is a dummy span.
+ err.note(&span_msg);
+ err.note("(no span available)");
+ }
+ // Show help messages.
if !helps.is_empty() {
// Add visual separator before backtrace.
- helps.last_mut().unwrap().push_str("\n");
- for help in helps {
- err.help(&help);
+ helps.last_mut().unwrap().1.push_str("\n");
+ for (span_data, help) in helps {
+ if let Some(span_data) = span_data {
+ err.span_help(span_data.span(), &help);
+ } else {
+ err.help(&help);
+ }
}
}
// Add backtrace
- let frames = ecx.generate_stacktrace();
- for (idx, frame_info) in frames.iter().enumerate() {
+ for (idx, frame_info) in stacktrace.iter().enumerate() {
let is_local = frame_info.instance.def_id().is_local();
// No span for non-local frames and the first frame (which is the error site).
if is_local && idx > 0 {
}
err.emit();
-
- for (i, frame) in ecx.stack().iter().enumerate() {
- trace!("-------------------");
- trace!("Frame {}", i);
- trace!(" return: {:?}", frame.return_place.map(|p| *p));
- for (i, local) in frame.locals.iter().enumerate() {
- trace!(" local {}: {:?}", i, local.value);
- }
- }
- // Let the reported error determine the return code.
- return None;
}
thread_local! {
DIAGNOSTICS.with(|diagnostics| diagnostics.borrow_mut().push(e));
}
-impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
+/// Remember enough about the topmost frame so that we can restore the stack
+/// after a step was taken.
+pub struct TopFrameInfo<'tcx> {
+ stack_size: usize,
+ instance: Option<ty::Instance<'tcx>>,
+ span: Span,
+}
+
+impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
+ fn preprocess_diagnostics(&self) -> TopFrameInfo<'tcx> {
+ // Ensure we have no lingering diagnostics.
+ DIAGNOSTICS.with(|diagnostics| assert!(diagnostics.borrow().is_empty()));
+
+ let this = self.eval_context_ref();
+ if this.active_thread_stack().is_empty() {
+ // Diagnostics can happen even with the empty stack (e.g. deallocation of thread-local statics).
+ return TopFrameInfo { stack_size: 0, instance: None, span: DUMMY_SP };
+ }
+ let frame = this.frame();
+
+ TopFrameInfo {
+ stack_size: this.active_thread_stack().len(),
+ instance: Some(frame.instance),
+ span: frame.current_span(),
+ }
+ }
+
/// Emit all diagnostics that were registed with `register_diagnostics`
- fn process_diagnostics(&self) {
+ fn process_diagnostics(&self, info: TopFrameInfo<'tcx>) {
let this = self.eval_context_ref();
DIAGNOSTICS.with(|diagnostics| {
- for e in diagnostics.borrow_mut().drain(..) {
+ let mut diagnostics = diagnostics.borrow_mut();
+ if diagnostics.is_empty() {
+ return;
+ }
+ // We need to fix up the stack trace, because the machine has already
+ // stepped to the next statement.
+ let mut stacktrace = this.generate_stacktrace();
+ // Remove newly pushed frames.
+ while stacktrace.len() > info.stack_size {
+ stacktrace.remove(0);
+ }
+ // Add popped frame back.
+ if stacktrace.len() < info.stack_size {
+ assert!(
+ stacktrace.len() == info.stack_size - 1,
+ "we should never pop more than one frame at once"
+ );
+ let frame_info = FrameInfo {
+ instance: info.instance.unwrap(),
+ span: info.span,
+ lint_root: None,
+ };
+ stacktrace.insert(0, frame_info);
+ } else if let Some(instance) = info.instance {
+ // Adjust topmost frame.
+ stacktrace[0].span = info.span;
+ assert_eq!(
+ stacktrace[0].instance, instance,
+ "we should not pop and push a frame in one step"
+ );
+ }
+
+ // Show diagnostics.
+ for e in diagnostics.drain(..) {
use NonHaltingDiagnostic::*;
let msg = match e {
- PoppedTrackedPointerTag(item) =>
- format!("popped tracked tag for item {:?}", item),
- CreatedAlloc(AllocId(id)) =>
- format!("created allocation with id {}", id),
- FreedAlloc(AllocId(id)) =>
- format!("freed allocation with id {}", id),
+ 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),
+ RejectedIsolatedOp(ref op) =>
+ format!("{} was made to return an error due to isolation", op),
};
- report_msg(this, "tracking was triggered", msg, vec![], false);
+
+ let (title, diag_level) = match e {
+ RejectedIsolatedOp(_) =>
+ ("operation rejected by isolation", DiagLevel::Warning),
+ _ => ("tracking was triggered", DiagLevel::Note),
+ };
+
+ report_msg(*this.tcx, diag_level, title, msg, vec![], &stacktrace);
}
});
}