Summary: Similarly to Enum.name, we model Class.getCanonicalName as returning an arbitrary non-empty string.
Reviewed By: ngorogiannis
Differential Revision: D21207120
fbshipit-source-id: 1e2dbd1fd
Summary:
We model Enum.name as returing a constant name, rather than getting real field names. We did this
because we couldn't think of any big gains, in terms of analysis precision/performance, from getting
the real names.
Reviewed By: ezgicicek
Differential Revision: D21201730
fbshipit-source-id: a2dc01a44
Summary: This diff revises the models of Collection.set and get to handle its elements.
Reviewed By: ezgicicek
Differential Revision: D21201242
fbshipit-source-id: 9c248453d
Summary:
This diff revises how to handle the unknown location in inferbo in two ways:
* stop appending field to the `Unknown` location, e.g. `Unknown.x.a` is evaluated to `Unknown`
* redesign the abstract of multiple locations, like `Bottom` < `Unknown` < `Known` locations
I am doing them in one diff since applying only one of them showed bad results.
Background: `Unknown` was adopted for abstracting all unknown concrete locations, so we could avoid missing semantics of assignments to unknown locations. We tried to keep soundness. However, it brought some other problems related to precision and performance.
1. Sometimes especially when Inferbo failed to reason precise pointer values, `Unknown` may point to many other abstract locations.
2. At that time, value assignments to `*Unknown` makes the situation worse: many abstract locations are updated with imprecise values.
This problem harmed not only its precision, but also its performance since it introduced more location entries in the abstract memory.
Reviewed By: jvillard
Differential Revision: D21017789
fbshipit-source-id: 0bb6bd8b5
Summary: The pruning location of array size was dummy. This diff gives a right location to traces in the pruning.
Reviewed By: ezgicicek
Differential Revision: D20915167
fbshipit-source-id: 55cc583df
Summary:
In Inferbo, the bottom memory is introduced when a node is unreachable by pruning, i.e.
`[[e]] <= [0,0]` on `prune(e)`. This diff distinguishes whether `[[e]]` is `[0,0]` (unreachable)
or bottom (it could not evaluate `e` by some unknown reasons).
Reviewed By: ezgicicek
Differential Revision: D19902046
fbshipit-source-id: 7706017d6
Summary:
This diff introduces two issue types: `BUFFER_OVERRUN_T1` and `INFERBO_ALLOC_IS_TAINTED`, which
denotes tainted values are used in array accesses and memory allocations, respectively.
Note that the taint analysis is intra-procedural for now.
Reviewed By: ezgicicek
Differential Revision: D19410536
fbshipit-source-id: af85148ec
Summary:
`String` and `StringBuilder` both implement `CharSequence`. Let's generalize the model for `String` to `CharSequence` wherever possible and add missing models for
- `StringBuilder.append`
- `StringBuilder.toString`
Reviewed By: skcho
Differential Revision: D19558009
fbshipit-source-id: 0dfdb21af
Summary:
Java's String models were broken for
- initializing a String object with a locally defined constant string (which is an `Object*` in SIL).
- initializing a String object with a `char`/`byte` array
This diff fixes them and also adds models for `new String ()`.
Reviewed By: skcho
Differential Revision: D19662180
fbshipit-source-id: 23968d0aa
Summary: `String.split(regexp)` returns an array that is split by the given regexp. If the regexp doesn't match, the original string is returned. Hence, the resulting array's length must be in `[1, max(1, n_u -1)]` where`n_u` is the upper bound of the string's length.
Reviewed By: dulmarod
Differential Revision: D19578318
fbshipit-source-id: 675af7376
Summary:
This diff revises the generation of unknown value. If the type of the unknown value generating is
int, it does not add the "Unknown" pointer/array value.
Reviewed By: ngorogiannis
Differential Revision: D19392696
fbshipit-source-id: e1b3c9a3a
Summary: This diff extends the domain to express the relation between iterator's offset and integer value.
Reviewed By: ezgicicek
Differential Revision: D19143670
fbshipit-source-id: 6223bc934
Summary:
Move most of IR/Sil.ml into a new file biabduction/Predicates.ml to
reflect the fact that they are only useful for the biabduction analysis.
Unfortunately this is a huge change.
I tried to keep the change to a minimum, it's mostly about doing
s/Sil/Predicates/ in lots of places but sometimes I used the trick of
specifying parameters or return value types to avoid specifying the
module altogether. This isn't done consistently because there were just
too many places to change for poor me.
Reviewed By: ngorogiannis
Differential Revision: D19158530
fbshipit-source-id: d6dbcfe72
Summary:
Inferbo does not use the external relational domains, apron and elina. At some point, the parts of
inferbo using them were broken and they do not seem to be fixed easily in the near future. Let's
remove them and keep the code base cleaner.
Reviewed By: jvillard
Differential Revision: D19022905
fbshipit-source-id: e0eafe79f
Summary:
Remove Clang and Java submodules of Typ.Fieldname. They are unnecessary and they reflect a fake dichotomy: there is only one fieldname type. To distinguish between fields of Java classes and other C constructs, there is a helper function provided, but the idea is simple: obtain the class type the field belongs to, and check if it's a Java class.
This diff still preserves behaviour, but removes as many functions as possible from the interface, to leave a small surface.
Reviewed By: mityal
Differential Revision: D18962423
fbshipit-source-id: ffe6933ee
Summary:
This diff enables parsing and auto-formatting documentation
comments (aka docstrings).
I have looked at this entire diff and manually made some changes to
improve the formatting. In some cases it looked like it would take too
much time, or benefit from someone more familiar with the code doing
it, and I instead disabled auto-formatting docstrings in those files.
Also, there are some source files where the docstrings are invalid,
and some where the structure detected by the parser appears not to
match what was intended. Auto-formatting has been disabled for these
files.
Reviewed By: ezgicicek
Differential Revision: D18755888
fbshipit-source-id: 68d72465d
Summary: This diff removes `'markers` and `'captured_types` from the procname dispatcher. They are for checking an integrity when a type is captured from template parameters then it is used to match in parameters. However, we have not used that feature, so which simply complicates the types in the dispatcher without any gain at the moment.
Reviewed By: jvillard
Differential Revision: D18706254
fbshipit-source-id: f493778d7
Summary: Preperation diff to use `ProcnameDispatcher` for Pulse: it changes function arguments, i.e. `ProcnameDispatcher.Call.FuncArg`, to a record in order to track the value of arguments. To do that, it changes `ProcnameDispatcher.Call` into a functor so that we can parametrize over the type of the value without making changes upwards.
Reviewed By: jvillard
Differential Revision: D18590224
fbshipit-source-id: 6a13fbc1a
Summary:
This diff extends bound domain to express Min/Max of another bounds, so it can keep some more
precision in `Math.min/max`.
limitation: `MinMaxB`, the constructor of the bound, can contain only linear expressions or
previous min/max expressions.
Reviewed By: ezgicicek
Differential Revision: D18395365
fbshipit-source-id: fc90d27fd
Summary:
This diff extends the alias domain, so each variable can have multiple aliases.
It changed `KeyLhs` can be mapped to multiple alias targets in the `AliasMap` domain:
```
before : KeyLhs.t -> KeyRhs.t * AliasTarget.t
after : KeyLhs.t -> KeyRhs.t -> AliasTarget.t
```
Reviewed By: ezgicicek
Differential Revision: D18062178
fbshipit-source-id: b325a6055
Summary:
It extracts RHS of alias from `AliasTarget.t`, so it changes the `AliasMap` domain:
```
before : KeyLhs.t -> AliasTarget.t // AliasTarget.t includes KeyRhs.t
after : KeyLhs.t -> KeyRhs.t * AliasTarget.t
```
Reviewed By: ezgicicek
Differential Revision: D18299537
fbshipit-source-id: 1446580a8
Summary:
This diff adopts an array length evaluation function that is conservative. It is useful when our
domain cannot express length result precisely.
For example, suppose there is an array pointer `arr_locs` that may point to two arrays `a` and `b`,
and their lengths are `a.length` and `b.length` (symbols), respectively. Using the usual
evaluation, our current domain cannot express `a.length join b.length` (join of two symbolic
values), so it returns top.
In this case, we can use the conservative function intead. It evaluates the length as `[0,
a.length.ub + b.length.ub]`, since we know every array length is positive. The result is not
precise, but better than top.
Reviewed By: ezgicicek
Differential Revision: D17908859
fbshipit-source-id: 7c0b1591b
Summary:
This diff revises the semantics of hasNext model to add the lengths of
arrays, rather than join them to top.
Reviewed By: ezgicicek
Differential Revision: D17882388
fbshipit-source-id: f5edaedb3
Summary:
This diff extends the alias domain to analyze loop with list comprehensions form in Java precisely.
```
list2 = new List();
for (Element e : list1) {
list2.add(e);
}
```
1. `IteratorOffset` is a relation between a iterator offset and a length of another array. For example, in the above example, after n-times of iterations, the offset of the iterator (if it exists) and the length of `list2` are the same as `n`.
2. `IteratorHasNext` is a relation between iterator and its `hasNext` result.
3. At the conditional nodes, it prunes the alias list length of `list2` by that of `list1`.
* if `hasNext(list1's iterator)` is true, `list2`'s length is pruned by `< list1's length`
* if `hasNext(list1's iterator)` is false, `list2`'s length is pruned by `= list1's length`
Reviewed By: ezgicicek
Differential Revision: D17667128
fbshipit-source-id: 41fb23a45
Summary:
This diff generates a symbolic value when a function returns only
exceptions. Previously, the exception expression is evaluated to top,
thus it was propagated to other functions, which made those costs as
top. For preventing that situation, this diff changed:
* exception expressions are evaluated to bottom, and
* if callee's return value is bottom, it generates a symbolic value
for it.
Reviewed By: ezgicicek
Differential Revision: D17500386
fbshipit-source-id: 0fdcc710d
Summary:
This diff is to refactoring some stuffs for the following diff.
* revised pretty print of the alias domain
* moved `eval_array_locs_length` to `BufferOverrunSemantics`.
Reviewed By: jvillard
Differential Revision: D17667123
fbshipit-source-id: c95611df5
Summary:
In the cost checker, the range of selected control variables are used to estimate the number of loop iteration. However, sometimes the ranges of control variables are not related to how many times the loop iteration. This diff strengthens the condition for them as:
1. integers from `size` models
2. integers constructed from `+` or `-`
3. integers constructed from `*`
For the last one, the loop iteration is likely to be log scale of the range of the control variable:
```
while (i < c) {
i *= 2;
}
```
We will address this in the future.
Reviewed By: ezgicicek
Differential Revision: D17365796
fbshipit-source-id: c1e709ae8
Sungkeun Cho
Ezgi Çiçek
Nikos Gorogiannis
Jules Villard
Josh Berdine