`d9bb467`

Fix parser infinite loop on implicit program followed by explicit unit

parse_implicit_program returned without consuming the END PROGRAM
tokens. parse_file re-entered parse_program_unit at the same
position, creating an infinite loop on inputs like:
type :: t / end type / program p / end program

Root cause: parse_unit_body breaks BEFORE the terminator tokens,
leaving them unconsumed. parse_program calls consume_end after
parse_unit_body, but parse_implicit_program did not.

Found by fuzz smoke test with randomized Fortran fragments.

Authored by mfwolffe <wolffemf@dukes.jmu.edu> 1 month ago

SHA: d9bb467d87ed84683013b141f1d6ab6043fa73ef
Parents: 08b0346
Tree: dc73bab

1 changed file

Status	File	+	-
M	`src/parser/unit.rs`	9	0

src/parser/unit.rsmodified

          // No PROGRAM keyword — implicit main program.
          let (uses, imports, implicit, decls, body, ifaces) = self.parse_unit_body(&["program"])?;
 +        // Consume the END [PROGRAM] if present — parse_unit_body breaks
 +        // *before* consuming the terminator, so we must advance past it
 +        // or parse_file will re-enter parse_program_unit at the same
 +        // position forever.
 +        self.skip_newlines();
 +        if self.peek() != &TokenKind::Eof {
 +            let _ = self.consume_end("program");
 +        }
++
          let span = span_from_to(start, self.prev_span());
          Ok(Spanned::new(ProgramUnit::Program {
              name: None, uses, imports, implicit, decls, body, contains: ifaces,