mirror of
https://github.com/Z3Prover/z3
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1c8b6cfdb8
`scanner::scan()` was returning `EOF_TOKEN` when the underlying stream
had `badbit` set, making a failed read (EIO, ENOSPC, etc.)
indistinguishable from a clean end-of-file. Z3 would silently produce no
output with exit code 0.
## Root cause
`std::istream::gcount()` returns 0 for both normal EOF and I/O failure.
`read_char()` returned -1 in both cases, and `scan()`'s `-1` handler
unconditionally set `EOF_TOKEN`.
## Fix
### `src/parsers/util/scanner.cpp`
Check `m_stream.bad()` in the `-1` case; emit an error message and
`ERROR_TOKEN` on failure:
```cpp
case static_cast<char>(-1):
if (m_stream.bad()) {
m_err << "ERROR: I/O failure while reading input stream.\n";
m_state = ERROR_TOKEN;
} else {
m_state = EOF_TOKEN;
}
break;
```
### `src/test/scanner_io.cpp` (new)
Regression test (ported from the `io_test` branch) verifying:
1. A good stream scans to completion (`n > 0` tokens).
2. A stream with `badbit` pre-set produces `ERROR_TOKEN` or a non-empty
error message rather than silent EOF.
### `src/test/main.cpp` + `src/test/CMakeLists.txt`
Register `tst_scanner_io` in the `FOR_EACH_ALL_TEST` macro and add
`scanner_io.cpp` to the build.
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
Co-authored-by: Nikolaj Bjorner <nikolaj@cs.stanford.edu>
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| .. | ||
| ackermannization | ||
| api | ||
| ast | ||
| cmd_context | ||
| math | ||
| model | ||
| muz | ||
| nlsat | ||
| opt | ||
| params | ||
| parsers | ||
| qe | ||
| sat | ||
| shell | ||
| smt | ||
| solver | ||
| tactic | ||
| test | ||
| util | ||
| CMakeLists.txt | ||