Summary:
It terminates narrowing when new and old states are not comparable.
Since current narrowing does not use meet operations guaranteeing
termination of narrowing, it tries to terminate narrowing more
conservatively.
Reviewed By: mbouaziz
Differential Revision: D12815419
fbshipit-source-id: e8b45199e
Summary: It tries division on minmax value approximately, rather than just returning infinities. For example, `[0,2+min(6,s)] / 2` returns `[0,4]`.
Reviewed By: mbouaziz
Differential Revision: D10867091
fbshipit-source-id: d3f49987b
Summary:
This diff preserves values of offset and index separately, rather than
one value of their addition, because premature addition results in
imprecise FPs by the limited expressiveness of the domain.
Reviewed By: mbouaziz
Differential Revision: D10851393
fbshipit-source-id: 1685ead36
Summary:
It avoids checking integer overflow when it definitely cannot happen.
For example, it does not check integer overflow of addition when one
of parameters is a negative number, or underflow of subtraction when
its first parameter is a positive number.
Reviewed By: mbouaziz
Differential Revision: D10446161
fbshipit-source-id: b8c86e1b2
Summary: We assume multiplication of 1 is safe. It happens sometimes by multiplying `sizeof(char)`.
Reviewed By: mbouaziz
Differential Revision: D10444680
fbshipit-source-id: 2f33be280
Summary: This diff changes pp of binary operation condition in order to avoid a `make test` failure. For the same `uint64_t` type, it is translated to `unsigned long long` in 64bit mac, but `unsigned long` in 64bit linux, which made a `make test` failure.
Reviewed By: mbouaziz
Differential Revision: D10459466
fbshipit-source-id: 449ab548e
Summary:
Fix the logic for computing duplicate symbols. It was broken at some point and some duplicate symbols creeped into our tests. Fix these, and add a test to avoid duplicate symbols detection to regress again.
Also, this removes one use of `Cfg.load`, on the way to removing file-wide CFGs from the database.
Reviewed By: ngorogiannis
Differential Revision: D10173349
fbshipit-source-id: a0d2365b3
Summary: It uses big int, instead of 63bits int of OCaml, in the interval domain in order to get preciser numeric values in the future.
Reviewed By: jvillard
Differential Revision: D10123364
fbshipit-source-id: c217f4366
Summary:
Goal of the stack: deprecate the `--analyzer` option in favour of turning
individual features on and off. This option is a mess: some of the options are
now subcommands (compile, capture), others are aliases (infer and checkers),
and they can all be replicated using some straightforward combination of other
options.
This diff: stop using `--analyzer` in tests. It's mostly `checkers` everywhere,
which is already the default. `linters` becomes `--no-capture --linters-only`.
`infer` is supposed to be `checkers` already. `crashcontext` is
`--crashcontext-only`.
Reviewed By: mbouaziz
Differential Revision: D9942689
fbshipit-source-id: 048281761
Summary:
The model for `getcwd` assumes the first argument should be non-null when in fact a NULL pointer is legitimate and results in allocation:
> As an extension to the POSIX.1-2001 standard, glibc's getcwd() allocates the buffer dynamically using mal‐
> loc(3) if buf is NULL. In this case, the allocated buffer has the length size unless size is zero, when buf
> is allocated as big as necessary. The caller should free(3) the returned buffer.
I suggest this glibc extension be used for the getcwd model to reduce false positives.
Pull Request resolved: https://github.com/facebook/infer/pull/925
Reviewed By: mbouaziz
Differential Revision: D9830450
Pulled By: jvillard
fbshipit-source-id: 95c4862b1
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: When a typedef-ed structure is defined in another source file, `tenv` returns a structure with empty fields.
Reviewed By: mbouaziz
Differential Revision: D9629200
fbshipit-source-id: 8859803f9
Summary:
It returns unknown values on non-const function calls like on unknown
function calls.
Reviewed By: mbouaziz
Differential Revision: D9478862
fbshipit-source-id: 4b795ec55
Summary: `CONDITION_ALWAYS_**` can be introduced by global constants.
Reviewed By: ezgicicek, mbouaziz
Differential Revision: D9478528
fbshipit-source-id: 7b1a46e7a
Summary:
When we see `pthread_create(..., ..., foo, ...)`, we want to call the function
`foo` to check that its precondition is met. The initial goal was to get rid
of the uncouth call to `Summary.get` when what we really want is to analyse
`foo` instead of just betting on the fact that it has been analysed already.
Besides switching to `Ondemand.analyze_proc_name`, this also changes the
matching of the function pointer in the arguments of `pthread_create()` to
detect the common case of a constant function name. I also added tests.
Reviewed By: jeremydubreil
Differential Revision: D9195159
fbshipit-source-id: dfec79f14
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:
Infer does the right thing now, make sure it doesn't regress.
https://github.com/facebook/infer/issues/86
Reviewed By: mbouaziz, dulmarod
Differential Revision: D8442855
fbshipit-source-id: 3df29b88c
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 frontend got better and now `assert` is correctly translated.
Reviewed By: dulmarod
Differential Revision: D8731877
fbshipit-source-id: ba11b0c
Summary: Record that it is not supported: https://github.com/facebook/infer/issues/8
Reviewed By: mbouaziz, dulmarod
Differential Revision: D8442762
fbshipit-source-id: fa271cb
Summary:
I realized that control variable analysis was broken when we had multiple back-edges for the same loop. This is often the case when we have a switch statement combined with continue in a loop (see `test_switch` in `switch_continue.c`) or when we have disjunctive guards in do-while loops.
This diff fixes that by
- defining a loop by its loophead (the target of its backedges) rather than its back-edges. Then it converts back-edge list to a map from loop_head to sources of the loop's back-edges.
- collecting multiple guard nodes that come from potentially multiple exit nodes per loop head
In addition, it also removes the wrong assumption that an exit node belongs to a single loop head.
Reviewed By: mbouaziz
Differential Revision: D8398061
fbshipit-source-id: abaf288
Summary: There is a number of dangling pointer dereference false positives coming from our treatment of union in c/cpp. For now, do not treat union fields as uninitialised.
Reviewed By: mbouaziz
Differential Revision: D8279802
fbshipit-source-id: a339b0e
Summary:
It's useful to test that the bucket a given error is classified as doesn't
change over time without notice.
This records the bucket for *all* the tests, even though some never produce a
bucket. This is to be on the safe size instead of risking to forget adding the
bucket information when the test changes, or when copy/pasting from a test that
doesn't have buckets to one that does.
The implementation is pretty crude: it greps the beginning of the qualifier
string for a `[bucket]`.
Reviewed By: mbouaziz
Differential Revision: D8236393
fbshipit-source-id: b3b1eb9
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: Set arguments of pointer type as initialised for indirect function calls.
Reviewed By: mbouaziz
Differential Revision: D8097895
fbshipit-source-id: 830f568
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:
Labels inside switch statements were causing havoc (see test), and the translation of switch statements in general could be improved to handle more cases.
It turns out that `case` (and `default`) statements are more or less fancy labels into the code. In other words, if you erase all the `case XXX:` and `default:` strings in the `switch` statement you get the real structure of the program, and `switch` just jumps straight to the first `case` directives (and to the second if the first one is not satisfied, etc. until all `case`/`default` have been considered).
This suggests an alternative implementation: translate the body of the `switch` and simply record the list of switch cases inside that body, along with where they point to. Then post-process this list to construct the control flow of the `switch`, which points into the control-flow of the `body`. In order not to modify every function in `CTrans` to propagate the current list of cases, I created an ugly `ref` inside `SwitchCase` instead (but it cannot be directly accessed and it's guaranteed to be well-parenthesised wrt nested switches by the `SwitchCase` API so it's not too bad).
[unrelated] Also make translation failures output more information about what exactly in the source code is causing the crash, and the ancestors in the AST that lead to the crash site.
Reviewed By: martinoluca
Differential Revision: D8011046
fbshipit-source-id: 8455090
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:
Previously, the type of `trans_result` contained a list of SIL expressions.
However, most of the time we expect to get exactly one, and getting a different
number is a soft(!) error, usually returning `-1`.
This splits `trans_result` into `control`, which contains the information
needed for temporary computation (hence when we don't necessarily know the
return value yet), and a new version of `trans_result` that includes `control`,
the previous `exps` list but replaced by a single `return` expression instead,
and a couple other values that made sense to move out of `control`. This allows
some flexibility in the frontend compared to enforcing exactly one return
expression always: if they are not known yet we stick to `control` instead (see
eg `compute_controls_to_parent`).
This creates more garbage temporary identifiers, however they do not show up in
the final cfg. Instead, we see that temporary IDs are now often not
consecutive...
The most painful complication is in the treatment of `DeclRefExpr`, which was
actually returning *two* expressions: the method name and the `this` object.
Now the method name is a separate (optional) field in `trans_result`.
Reviewed By: mbouaziz
Differential Revision: D7881088
fbshipit-source-id: 41ad3b5
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: We were wrongly using the underapproximation of `min` rather than the overapproximation
Reviewed By: ddino
Differential Revision: D7844267
fbshipit-source-id: c9d9247
Summary:
This simplifies the frontends and backends in most cases. Before this diff,
returning `void` could be modelled either with a `None` return, or a dummy
return variable with type `Tvoid`. Now it's always the latter.
Reviewed By: sblackshear, dulmarod
Differential Revision: D7832938
fbshipit-source-id: 0a403d1
Summary:
We want instr-granular invariant maps so let's use the OneInstrPerNode CFG in the AI analyzers.
This requires specializing the TransferFunctions.
Keep using the normal CFG where we only need node-granular informations.
Depends on D7587241
Depends on D7608526
Reviewed By: sblackshear
Differential Revision: D7618320
fbshipit-source-id: 73918f0
Summary:
When looking at large CFGs, at least in `xdot`, it's often difficult to find
the procedure you're looking for. Sorting the proc names puts them in
alphabetical order, which makes searching one procedure easier.
Reviewed By: mbouaziz
Differential Revision: D7758521
fbshipit-source-id: 8e9997f
Summary:
This information is already available in the trace, and can contain absolute
paths to system includes (or infer's own clang runtime), which confuses the
diff analysis.
Reviewed By: mbouaziz
Differential Revision: D7534609
fbshipit-source-id: 5bd8f8b
Summary:
It renames `eval_locs` to `eval_arr` and we use it for getting array block values the given input expressions are pointing to. For example, when given a program variable `x` as an input, `eval_arr` returns array blocks that `x` is pointing to, on the other hand, `eval` returns an abstract location of `x`.
Depends on D7471891
Reviewed By: mbouaziz
Differential Revision: D7471915
fbshipit-source-id: b994944
Summary: In the pointer arithmetics, it returns top, if we cannot precisely follow the physical memory model, e.g., (&x + 1).
Reviewed By: mbouaziz
Differential Revision: D7453510
fbshipit-source-id: db8738e
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
Sungkeun Cho
Mehdi Bouaziz
Dino Distefano
Jules Villard
Thomas M. DuBuisson
Julian Sutherland
Martino Luca
Ezgi Çiçek
Daiva Naudziuniene
Dulma Churchill