bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/mir/eval/shim.rs')
-rw-r--r--crates/hir-ty/src/mir/eval/shim.rs47
1 files changed, 43 insertions, 4 deletions
diff --git a/crates/hir-ty/src/mir/eval/shim.rs b/crates/hir-ty/src/mir/eval/shim.rs
index ac295b5837..9ff58b27bb 100644
--- a/crates/hir-ty/src/mir/eval/shim.rs
+++ b/crates/hir-ty/src/mir/eval/shim.rs
@@ -153,10 +153,49 @@ impl Evaluator<'_> {
use LangItem::*;
let mut args = args.iter();
match x {
- // FIXME: we want to find the panic message from arguments, but it wouldn't work
- // currently even if we do that, since macro expansion of panic related macros
- // is dummy.
- PanicFmt | BeginPanic => Err(MirEvalError::Panic("<format-args>".to_string())),
+ BeginPanic => Err(MirEvalError::Panic("<unknown-panic-payload>".to_string())),
+ PanicFmt => {
+ let message = (|| {
+ let arguments_struct =
+ self.db.lang_item(self.crate_id, LangItem::FormatArguments)?.as_struct()?;
+ let arguments_layout = self
+ .layout_adt(arguments_struct.into(), Substitution::empty(Interner))
+ .ok()?;
+ let arguments_field_pieces =
+ self.db.struct_data(arguments_struct).variant_data.field(&name![pieces])?;
+ let pieces_offset = arguments_layout
+ .fields
+ .offset(u32::from(arguments_field_pieces.into_raw()) as usize)
+ .bytes_usize();
+ let ptr_size = self.ptr_size();
+ let arg = args.next()?;
+ let pieces_array_addr =
+ Address::from_bytes(&arg[pieces_offset..pieces_offset + ptr_size]).ok()?;
+ let pieces_array_len = usize::from_le_bytes(
+ (&arg[pieces_offset + ptr_size..pieces_offset + 2 * ptr_size])
+ .try_into()
+ .ok()?,
+ );
+ let mut message = "".to_string();
+ for i in 0..pieces_array_len {
+ let piece_ptr_addr = pieces_array_addr.offset(2 * i * ptr_size);
+ let piece_addr =
+ Address::from_bytes(self.read_memory(piece_ptr_addr, ptr_size).ok()?)
+ .ok()?;
+ let piece_len = usize::from_le_bytes(
+ self.read_memory(piece_ptr_addr.offset(ptr_size), ptr_size)
+ .ok()?
+ .try_into()
+ .ok()?,
+ );
+ let piece_data = self.read_memory(piece_addr, piece_len).ok()?;
+ message += &std::string::String::from_utf8_lossy(piece_data);
+ }
+ Some(message)
+ })()
+ .unwrap_or_else(|| "<format-args-evaluation-failed>".to_string());
+ Err(MirEvalError::Panic(message))
+ }
SliceLen => {
let arg = args
.next()