-use rustc_mir::interpret::InterpErrorInfo;
use std::cell::RefCell;
+use std::fmt;
+use std::num::NonZeroU64;
+
+use log::trace;
+
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::{source_map::DUMMY_SP, Span};
use crate::*;
+/// Details of premature program termination.
+pub enum TerminationInfo {
+ Exit(i64),
+ Abort(String),
+ UnsupportedInIsolation(String),
+ ExperimentalUb { msg: String, url: String },
+ Deadlock,
+}
+
+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(msg) =>
+ write!(f, "{}", msg),
+ UnsupportedInIsolation(msg) =>
+ write!(f, "{}", msg),
+ ExperimentalUb { msg, .. } =>
+ write!(f, "{}", msg),
+ Deadlock =>
+ write!(f, "the evaluated program deadlocked"),
+ }
+ }
+}
+
+impl MachineStopType for TerminationInfo {}
+
/// Miri specific diagnostics
pub enum NonHaltingDiagnostic {
- PoppedTrackedPointerTag(Item),
+ CreatedPointerTag(NonZeroU64),
+ PoppedPointerTag(Item),
+ CreatedCallId(CallId),
CreatedAlloc(AllocId),
+ FreedAlloc(AllocId),
}
/// Emit a custom diagnostic without going through the miri-engine machinery
-pub fn report_diagnostic<'tcx, 'mir>(
- ecx: &InterpCx<'mir, 'tcx, Evaluator<'tcx>>,
- mut e: InterpErrorInfo<'tcx>,
+pub fn report_error<'tcx, 'mir>(
+ ecx: &InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
+ e: InterpErrorInfo<'tcx>,
) -> Option<i64> {
- // Special treatment for some error kinds
- let msg = match e.kind {
- InterpError::MachineStop(ref info) => {
+ use InterpError::*;
+
+ let (title, helps) = match &e.kind() {
+ MachineStop(info) => {
let info = info.downcast_ref::<TerminationInfo>().expect("invalid MachineStop payload");
- match info {
- TerminationInfo::Exit(code) => return Some(*code),
- TerminationInfo::Abort(None) => format!("the evaluated program aborted execution"),
- TerminationInfo::Abort(Some(msg)) => format!("the evaluated program aborted execution: {}", msg),
- }
+ use TerminationInfo::*;
+ let title = match info {
+ Exit(code) => return Some(*code),
+ Abort(_) =>
+ "abnormal termination",
+ UnsupportedInIsolation(_) =>
+ "unsupported operation",
+ ExperimentalUb { .. } =>
+ "Undefined Behavior",
+ Deadlock => "deadlock",
+ };
+ let helps = match info {
+ UnsupportedInIsolation(_) =>
+ vec![format!("pass the flag `-Zmiri-disable-isolation` to disable isolation")],
+ 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),
+ ],
+ _ => vec![],
+ };
+ (title, helps)
+ }
+ _ => {
+ let title = match e.kind() {
+ Unsupported(_) =>
+ "unsupported operation",
+ UndefinedBehavior(_) =>
+ "Undefined Behavior",
+ ResourceExhaustion(_) =>
+ "resource exhaustion",
+ InvalidProgram(InvalidProgramInfo::ReferencedConstant) =>
+ "post-monomorphization error",
+ _ =>
+ bug!("This error should be impossible in Miri: {}", e),
+ };
+ 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 | 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 { .. })
+ 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 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"),
+ ],
+ _ => vec![],
+ };
+ (title, helps)
}
- err_unsup!(NoMirFor(..)) => format!(
- "{}. Did you set `MIRI_SYSROOT` to a Miri-enabled sysroot? You can prepare one with `cargo miri setup`.",
- e
- ),
- InterpError::InvalidProgram(_) => bug!("This error should be impossible in Miri: {}", e),
- _ => e.to_string(),
};
- e.print_backtrace();
- report_msg(ecx, msg, true)
-}
-/// Report an error or note (depending on the `error` argument) at the current frame's current statement.
-/// Also emits a full stacktrace of the interpreter stack.
-pub fn report_msg<'tcx, 'mir>(
- ecx: &InterpCx<'mir, 'tcx, Evaluator<'tcx>>,
- msg: String,
- error: bool,
-) -> Option<i64> {
- if let Some(frame) = ecx.stack().last() {
- let span = frame.current_source_info().unwrap().span;
-
- let mut err = if error {
- let msg = format!("Miri evaluation error: {}", msg);
- ecx.tcx.sess.struct_span_err(span, msg.as_str())
- } else {
- ecx.tcx.sess.diagnostic().span_note_diag(span, msg.as_str())
- };
- let frames = ecx.generate_stacktrace(None);
- err.span_label(span, msg);
- // We iterate with indices because we need to look at the next frame (the caller).
- for idx in 0..frames.len() {
- let frame_info = &frames[idx];
- let call_site_is_local = frames
- .get(idx + 1)
- .map_or(false, |caller_info| caller_info.instance.def_id().is_local());
- if call_site_is_local {
- err.span_note(frame_info.call_site, &frame_info.to_string());
- } else {
- err.note(&frame_info.to_string());
- }
- }
- err.emit();
- } else {
- ecx.tcx.sess.err(&msg);
- }
+ e.print_backtrace();
+ let msg = e.to_string();
+ report_msg(*ecx.tcx, /*error*/true, &format!("{}: {}", title, msg), msg, helps, &ecx.generate_stacktrace());
- for (i, frame) in ecx.stack().iter().enumerate() {
+ // 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!(" local {}: {:?}", i, local.value);
}
}
- // Let the reported error determine the return code.
- return None;
+
+ // Extra output to help debug specific issues.
+ match e.kind() {
+ UndefinedBehavior(UndefinedBehaviorInfo::InvalidUninitBytes(Some(access))) => {
+ eprintln!(
+ "Uninitialized read occurred at offsets 0x{:x}..0x{:x} into this allocation:",
+ access.uninit_ptr.offset.bytes(),
+ access.uninit_ptr.offset.bytes() + access.uninit_size.bytes(),
+ );
+ eprintln!("{:?}", ecx.memory.dump_alloc(access.uninit_ptr.alloc_id));
+ }
+ _ => {}
+ }
+
+ None
+}
+
+/// 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>,
+ error: bool,
+ title: &str,
+ span_msg: String,
+ mut helps: Vec<String>,
+ stacktrace: &[FrameInfo<'tcx>],
+) {
+ let span = stacktrace.first().map_or(DUMMY_SP, |fi| fi.span);
+ let mut err = if error {
+ tcx.sess.struct_span_err(span, title)
+ } else {
+ tcx.sess.diagnostic().span_note_diag(span, title)
+ };
+ // Show main message.
+ if span != DUMMY_SP {
+ err.span_label(span, span_msg);
+ } else {
+ // 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);
+ }
+ }
+ // Add backtrace
+ 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.span_note(frame_info.span, &frame_info.to_string());
+ } else {
+ err.note(&frame_info.to_string());
+ }
+ }
+
+ err.emit();
}
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) =>
+ 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),
};
- report_msg(this, msg, false);
+ report_msg(*this.tcx, /*error*/false, "tracking was triggered", msg, vec![], &stacktrace);
}
});
}
projects / rust.git / blobdiff