This is another PR towards the goal of getting Z3 to compile cleanly
when included via FetchContents into clang-tidy, which uses a pretty
strict set of warnings.
The PR adds
```
"-Wsuggest-override"
"-Winconsistent-missing-override"
```
to the CLANG_ONLY_WARNINGS. This exposes a relatively small number of places where method overrides did not use the "override" keyword. The PR fixes those.
(In cmd_util.h, I also made the *_CMD macros be uniform in not ending the class they define with a semicolon; the invocation of the macro can add the semicolon.)
MSVC ASan reports showed a container-overflow in LP tableau pivoting,
reproducible from both examples and solver tests (issue #9781). The
failure came from reading a `column_cell` through a reference after
pivoting removed that entry from the backing column.
- **Root cause**
- `pivot_column_tableau` and the analogous Diophantine elimination loop
both held `auto& c = column.back()` across a call
(`pivot_row_to_row_given_cell`) that immediately removes that very cell
from the column via `remove_element`.
- After the mutation, the subsequent read `c.var()` used for bookkeeping
observed invalid memory.
- **Change**
- Record the affected row in the bookkeeping set (`m_touched_rows` /
`m_changed_rows`) by reading `c.var()` **before** the pivot call, while
the back cell is still valid.
- Make `static_matrix::pivot_row_to_row_given_cell` return `void`
instead of `bool`. Its result (`!rowii.empty()`) was always `true`: both
callers keep the matrix at full row rank (the tableau basis columns form
an identity submatrix; the Diophantine `m_l_matrix` stays invertible),
so an elementary row operation can never empty a row. The dead `if
(!...) return false;` early-exit in `pivot_column_tableau` is removed
and replaced with a `SASSERT(!rowii.empty())` documenting the invariant.
- **Affected code paths**
- `src/math/lp/static_matrix.h`, `src/math/lp/static_matrix.cpp`,
`src/math/lp/static_matrix_def.h`
- `src/math/lp/lp_core_solver_base_def.h`
- `src/math/lp/dioph_eq.cpp`
- **Behavioral impact**
- No algorithmic change to pivoting.
- Removes the stale-reference hazard in the loops that repeatedly
eliminate entries from a column.
```c++
while (column.size() > 1) {
auto& c = column.back();
SASSERT(c.var() != piv_row_index);
if (m_touched_rows != nullptr)
m_touched_rows->insert(c.var());
m_A.pivot_row_to_row_given_cell(piv_row_index, c, j);
}
```
- **Verification**
- Reproduced the exact issue #9781 failure on a local ASan build
(`container-overflow` in `pivot_column_tableau`) using the pre-fix code,
and confirmed it is gone with this change.
- The 4 reported tests pass clean under ASan: `c_example`,
`cpp_example`, `test-z3 get_implied_equalities`, `test-z3 quant_solve`.
- Full `test-z3 /a` suite: 89 passed, 0 failed, 0 ASan errors.
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Nikolaj Bjorner <nbjorner@microsoft.com>
Co-authored-by: Lev Nachmanson <levnach@hotmail.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* rename ul_pair to column
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* t
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* simple test passed
* remove an assert
* relax an assertion
* remove an obsolete function
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
* access a term by the term column
* remove the column index from colunm.h
* remove an unused method
* remove debug code
* fix the build of lp_tst
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
---------
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
Co-authored-by: Lev Nachmanson <levnach@hotmail.com>
