Summary:
It simplifies abstract memory instantiations of function calls. Now it instantiates callee memories by directly evaluating symbol paths, rather than constructing `subst_map`.
main changes are:
- no construction of `subst_map` and `trace_map`
- no symbol table in Inferbo's summary
- no `Symbol_not_found` exception (for when a required symbol was unavailable in `subst_map`)
Reviewed By: mbouaziz
Differential Revision: D9495597
fbshipit-source-id: 18cdcd6f7
Summary: It uses a SymbolPath map to Symbol in Inferbo's summary instead of an entry memory of callee, which is used for instantiations of the abstract memories on function calls.
Reviewed By: mbouaziz
Differential Revision: D9081631
fbshipit-source-id: 478cda0de
Summary:
It adds relational domains to Inferbo: octagon of Apron and polyhedra of Elina.
- Each Mem domain value includes one relational value containing relations among symbols. The relational values are modified by the `Prune` and `Store` commands.
- Each abstract value includes three symbols, which represent integer value, array offset, and array size of an abstract value.
The relational domain is deactivated by default. Use the `--bo-relational-domain {oct, poly}` option for the activation, though Inferbo with the relational domains does not work at this point because some modifications of Apron and Elina we made has not been applied to their opam repositories yet.
Reviewed By: jvillard
Differential Revision: D8874102
fbshipit-source-id: 08e5883cb
Summary: `IntLit.to_int` could raise, was not documented until recently and was not named `_exn`. Switch to option type and fix uses.
Reviewed By: jeremydubreil
Differential Revision: D8865525
fbshipit-source-id: f5ec2f221
Summary:
It adds relational domains to Inferbo: octagon of Apron and polyhedra of Elina.
- Each `Mem` domain value includes one relational value containing relations among *symbols*. The relational values are modified by the `Prune` and `Store` commands.
- Each abstract value includes three *symbols*, which represent integer value, array offset, and array size of an abstract value.
The relational domain is deactivated by default, so this diff should not make any differences in CI.
Use `--bo-relational-domain {oct, poly}` for the activation, though Inferbo with the relational domains does not work at this point because some modifications of Apron and Elina we made has not been applied to their opam repositories yet.
Reviewed By: mbouaziz, jvillard
Differential Revision: D8478542
fbshipit-source-id: 510ff53
Summary:
The motivation is in a following diff: ensuring symbols do not cross procedure boundaries.
- This diff rewrites `Bound.subst` to be based on the substituted bound rather than folding on the symbol map.
- This way we are sure all symbols are substituted and no symbols from another procedure remains in the result.
- All cases from the previous version should still be here, I think I added a few constant approximations of minmax substituted with minmax (that would be return Top).
Side-effects (good):
- `mult_const` has also more constant approximations for minmax,
- substitution should be faster
Reviewed By: jvillard
Differential Revision: D8369993
fbshipit-source-id: 6ed8be8
Summary:
Change the license of the source code from BSD + PATENTS to MIT.
Change `checkCopyright` to reflect the new license and learn some new file
types.
Generated with:
```
git grep BSD | xargs -n 1 ./scripts/checkCopyright -i
```
Reviewed By: jeremydubreil, mbouaziz, jberdine
Differential Revision: D8071249
fbshipit-source-id: 97ca23a
Summary:
It improves the precision of widening operations of interval:
upper_bound_widen (min(n, s), s) = s
lower_bound_widen (max(n, s), s) = s
Reviewed By: mbouaziz
Differential Revision: D8038941
fbshipit-source-id: 61b10cb
Summary:
Before we were computing the size of an abstract state (`range`) using the `NonNegativeBound` domain but it wasn't able to express product of symbolic values.
This diff introduces a domain for that.
The range of an interval is still computed in `NonNegativeBound` but then the product is done in `TopLiftedPolynomial` so all costs end up being of that type.
The //symbols// of a polynomial are `NonNegativeBound` (so the polynomial only represent non-negative values, perfect for a cost), which handles substitution correctly, i.e. it gives zero instead of negative values.
Reviewed By: ddino
Differential Revision: D7397229
fbshipit-source-id: 6868bb7
Summary:
This is an attempt to make things more consistent, and maybe save some work
from the `Format` module in case flambda doesn't have our backs.
Reviewed By: jberdine
Differential Revision: D7775496
fbshipit-source-id: 59a6314
Summary:
The Cost analysis uses `Bound` for non-negative values only, let's make it a separate module (and abstract type).
This also separates the abstract domain part of `Bound` which we wanted anyway.
Depends on D7844267
Depends on D7843351
Depends on D7782184
Reviewed By: ddino
Differential Revision: D7844572
fbshipit-source-id: 0e6b620
Summary: We were wrongly using the underapproximation of `min` rather than the overapproximation
Reviewed By: ddino
Differential Revision: D7844267
fbshipit-source-id: c9d9247
Summary:
Upgrade ocamlformat, and base which needs to be done in sync in order to build
ocamlformat, and the other deps can come for the ride.
Reviewed By: jvillard
Differential Revision: D7663537
fbshipit-source-id: 3e90970
Summary:
Got rid of `Itv.equal` which was ambiguous and use an abstract boolean type for abstract comparison results
Depends on D7568573
Reviewed By: jvillard
Differential Revision: D7568583
fbshipit-source-id: 0e897e9
Summary:
Convenience function for `prune_eq` with zero (needed for stacked diffs).
Renamed `prune_zero` to `prune_ne_zero` to avoid ambiguity.
Reviewed By: jvillard
Differential Revision: D7568556
fbshipit-source-id: b95ab6d
Summary: It adds an issue type, `BUFFER_OVERRUN_U5`, for alarms involving unknown values, i.e., when the trace set includes an unknown function call.
Reviewed By: mbouaziz
Differential Revision: D7178841
fbshipit-source-id: bfe857b
Summary: It corrects a precision bug in the interval domain, with adding some test cases.
Reviewed By: mbouaziz
Differential Revision: D7230918
fbshipit-source-id: 3ec641a
Summary:
This commit improves precision of symbol instantiations.
When a return value of a callee is `[s1 + s2, _]` and if we want to
instantiate `s1` to `c3 + max(c4, s5)`, the lower bound was
substituted to `-oo` because our domain cannot express `c3 + max(c4,
s5) + s2`.
However, we can have instantiations that are preciser than `-oo`:
(1) `c3 + c4 + s2`
(2) or `c3 + s5 + s2`
because they are smaller than the ideal instantiation, `c3 + max(c4,
s5) + s2` and it is on the lower bound position.
For now, the implementation instantiates to (1) between the two ones,
because constant values introduced by `assert` or `assume`(`if`)
command are often used as safety conditions, e.g., `assert(index >=
0);` can place before array accesses. (We can change the stratege
later if we find that it doesn't work on some other cases.)
Reviewed By: mbouaziz
Differential Revision: D7020063
fbshipit-source-id: 62fb390
Summary:
- `NonZeroInt` for added guarantees on the invariants of `SymLinear` coefficients
- some simplifications
- some optimizations
Reviewed By: jvillard
Differential Revision: D6833968
fbshipit-source-id: 39e28a0
Summary:
Found the dead code with the script in the next commit, iteratively until no
warnings remained.
Methodology:
1. I kept pretty-printers for values, which can be useful to use from infer's REPL (or
when printf-debugging infer in general)
2. I kept functions that formed some consistent API (but not often, so YMMV), for instance if it looked like `Set.S`, or if it provides utility functions for stuff in development (mostly the procname dispatcher functions)
3. I tried not to lose comments associated with values no longer exported: if the value is commented in the .mli and not the .ml, I moved the comment
4. Some comments needed updating (not claiming I caught all of those)
5. Sometimes I rewrote the comments a bit when I noticed mis-attached comments
Reviewed By: mbouaziz
Differential Revision: D6723482
fbshipit-source-id: eabaafd
Summary:
Upgrade ocamlformat to 0.3, and (necessarily) base to v0.10.0.
- Fix accumulated mis-formatting
- Update opam.lock to unbreak clean build
- Update to base v0.10.0
- Update opam.lock for base
- Update offline opam repo
- Everyone should already have removed their ocamlformat pin
- ocamlformat 0.3 supports output to stdout natively
- bump version of ocamlformat
Reviewed By: jeremydubreil
Differential Revision: D6636741
fbshipit-source-id: 41a56a8
Summary:
Model for `folly::split` that handles the representation in the cpp model.
Depends on D6544992
Reviewed By: jvillard
Differential Revision: D6545006
fbshipit-source-id: 2b7a139
Summary:
- Plug model checkers
- Add alloc size safety condition on alloc of negative, zero or big size
Reviewed By: sblackshear
Differential Revision: D6375144
fbshipit-source-id: bbea6f3
Summary:
Change ocamlformat installation procedure to use opam instead of
pinning.
Reformat all code with v0.2, which has a few improvements.
Reviewed By: jvillard
Differential Revision: D6292057
fbshipit-source-id: 759967f
Summary:
Install ocamlformat from github as part of `make devsetup`, and use it
for formatting OCaml (and jbuild) code.
Reviewed By: jvillard
Differential Revision: D6092464
fbshipit-source-id: 4ba0845
Summary: This commit adds unsigned symbol for preciser analysis results with less number of uses of min/max operators.
Reviewed By: mbouaziz
Differential Revision: D6040437
fbshipit-source-id: 999ca4c
Summary:
Next step to issue deduplication: do not keep safety conditions that are subsumed by others.
Only do it if they do not have infinite bound: replacing `0 < size` by `1 < size` is ok, but replacing it by `+oo < size` is not because it looks much more like a lack of precision.
Reviewed By: skcho
Differential Revision: D5978455
fbshipit-source-id: acc2384
Summary:
Move Inferbo safety conditions to their own file.
Split the old `Condition.t` to a condition together with a trace.
This will ease having: different kind of condition and several traces for the same condition (see following diff)
Reviewed By: jvillard
Differential Revision: D5942030
fbshipit-source-id: d74a612
Summary:
Bottom bounds do not make sense (what is the meaning of `[_|_; 1]`?), let's get rid of them.
`Bot` was useful for substitution though, with a special meaning, use `bottom_lifted` for that case.
Reviewed By: skcho
Differential Revision: D5941796
fbshipit-source-id: 5778255
Summary: A bottom interval in a safety condition doesn't make sense. Let's not allow it at all.
Reviewed By: skcho
Differential Revision: D5941552
fbshipit-source-id: 6bd2a65
Summary:
The interval bound of the abstract domain is extended.
`[min|max](int, symbol)` => `int [+|-] [min|max](int, symbol)`
As a result, `vector::empty` can be modelled to return a more precise value: `1 - min(1, size)`.
Reviewed By: mbouaziz
Differential Revision: D5899404
fbshipit-source-id: c8c3f49
Summary:
Read the documentation and it doesn't seem like these functions are guaranteed to choose the same value in different runs.
I hypothesize that these may be the source of flakiness in the thread-safety tests/smoke tests.
Reviewed By: jvillard
Differential Revision: D5794384
fbshipit-source-id: 02b7a96
Summary:
- failwith police: no more `failwith`. Instead, use `Logging.die`.
- Introduce the `SimpleLogging` module for dying from modules where `Logging`
cannot be used (usually because that would create a cyclic dependency).
- always log backtraces, and show backtraces on the console except for usage errors
- Also point out in the log file where the toplevel executions of infer happen
Reviewed By: jeremydubreil
Differential Revision: D5726362
fbshipit-source-id: d7a01fc
Summary:
Conversion and reformat of infer source using ocamlformat
auto-formatting tool.
Current status:
- Because Reason does not handle docstrings, the output of the
conversion is not 'Warning 50'-clean, meaning that there are
docstrings with ambiguous placement. I'll need to manually fix
them just before landing.
Reviewed By: jvillard
Differential Revision: D5225546
fbshipit-source-id: 3bd2786
Summary:
Previously all knowledge of the dynamic length of such arrays was lost to infer:
```
void foo(int len) {
int a[len];
}
```
The translation of this program would make no reference to `len` (except as a
param of `foo`).
Translate this "initialization" using the existing `__set_array_length` infer
builtin, as:
```
# Declare local a[_]
n$0 = len;
__set_array_length(a, len);
```
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D4969446
fbshipit-source-id: dff860f
Summary:
`[a, b] < [a, _]` and `[_, a] < [b, a]` are most probably false (it comes from size < size)
Mark definitely unsatisfied conditions as B1, others as B2+
Reviewed By: KihongHeo, jvillard
Differential Revision: D4962107
fbshipit-source-id: ba8f469
Summary:
- Bottom-lift abstract memory domain to express unreachable node
- Two cases to make a node unreachable
+ constant: when an evaluation result of condition expression is
bottom or false, e.g., "prune(0)".
+ alias: when the same structure e is compared to itself with "<",
">", and "!=", e.g., "prune(e < e)".
- Add test for the new prune (prune_constant.c, prune_alias.c)
- Debug the semantics of comparison
Reviewed By: mbouaziz
Differential Revision: D4938055
fbshipit-source-id: d0fadf0
Sungkeun Cho
Josh Berdine
Martino Luca
Ezgi Çiçek
Mehdi Bouaziz
Julian Sutherland
Nikos Gorogiannis
Jules Villard
Dino Distefano
Sam Blackshear
Jeremy Dubreil
Andrzej Kotulski
Cristiano Calcagno
Kihong Heo