Summary: This diff get static value with `EMPTY` field from class initializer.
Reviewed By: ngorogiannis
Differential Revision: D18616588
fbshipit-source-id: 26414c9b2
Summary: Following D18351867, this diff adds more size alias: when initial array size is one.
Reviewed By: ezgicicek
Differential Revision: D18530598
fbshipit-source-id: 26d57fe30
Summary:
This diff avoids unqualified variables by `ItvUpdatedBy` are qualified later. For example,
```
z = x & y;
z = z + 1;
```
While `z` should not be selected as a control variable, it wasn't, because it was qualified by the addition. This pattern introduces FPs in many cases.
Reviewed By: ngorogiannis
Differential Revision: D18505894
fbshipit-source-id: 13aec3008
Summary: Sometimes there is a code like `for(int i = 1; i < x; i++){ l.add(); }`, where the first element in a list is addressed specifically. This case was not analyzed precisely, because the alias value is added only when `i` is initialized by 0 by heuristic. This diff extends the heuristic, so it adds a size alias between `i` and `l.size()` when `i` is initialized by 0 or 1.
Reviewed By: ezgicicek
Differential Revision: D18351867
fbshipit-source-id: e7d19a4ec
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: The way `<=` is used in `AbstractDomain` prevents infix use and forces bracketing it everywhere. Replace with simple `leq`.
Reviewed By: jvillard
Differential Revision: D18201854
fbshipit-source-id: 8175224e4
Summary:
This diff adds SafeInvertedMap, which is similar to InvertedMap but it
guarantees that there is no top elements in the tree of the map.
Reviewed By: ezgicicek
Differential Revision: D18062174
fbshipit-source-id: 2fbc51f31
Summary:
This diff introduces inequality for the iterator alias target, as we
did for the size target before.
Reviewed By: ezgicicek
Differential Revision: D17879208
fbshipit-source-id: cc2f6a723
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 introduces an inequality for the size alias targets, in order to get preciser array lengths after loops. The alias domain in inferbo was able to express strict equality between alias source and its targets, e.g. x=size(array). Now, for the size alias target, it can express less than or equal relations, e.g. x>=size(array).
Reviewed By: ezgicicek
Differential Revision: D17606222
fbshipit-source-id: 2557d3bd0
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
Summary:
`ModeledRange` represents how many times the interval value can be updated by modeled functions. This
domain is to support the case where there are mismatches between value of a control variable and
actual number of loop iterations. For example,
```
while((c = file_channel.read(buf)) != -1) { ... }
```
the loop will iterates as the file size, but the control variable `c` does not have that value. In
these cases, it assigns a symbolic value of the file size to the modeled range of `c`, then which
is used when calculating the overall cost.
Reviewed By: jvillard
Differential Revision: D17476621
fbshipit-source-id: 9a81376e8
Summary:
This diff extends the `Simple` alias domain to address Java's
temporary variables better. It now has an additional field to denote
an alias temporary variable.
Reviewed By: jvillard
Differential Revision: D17421907
fbshipit-source-id: 8b8b47461
Summary:
This diff simplifies two similar alias targets: AliasTarget.Simple and
AliasTarget.SimplePlusA. Since the latter is simply extended version
of the former, they are better to have a common constructor.
Reviewed By: jvillard
Differential Revision: D17421416
fbshipit-source-id: e0946a73b
Summary:
This diff addresses collection adds in loop. For example,
```
ArrayList<...> a = new ArrayList<>();
for (int i = 0; i < size; i++) {
a.add(...);
}
// we want to know the size of `a` here!
```
This is a common pattern on initializing a collection in Java.
How we did: Instead of adopting general (but complicated) solutions such as relational domain, we
extended the current alias domain of inferbo, to be able to handle this specific case:
* An array `a` should have size 0, at the entry of the loop.
* The iterating variable `i` should start with 0.
* `add` should be called once inside the loop.
Reviewed By: jvillard
Differential Revision: D17319350
fbshipit-source-id: 99b6acae1
Summary: It prints debug information when top values is generated.
Reviewed By: ngorogiannis
Differential Revision: D17285448
fbshipit-source-id: 0621fd36d
Summary:
This diff ignores character symbols in the cost results, in order to
avoid FPs from parser code.
Reviewed By: ezgicicek
Differential Revision: D17132053
fbshipit-source-id: d9cf8bd26
Summary:
Since it does not make sense to get ranges of non-integer values and
use them as approximate iteration numbers, this diff ignores control
values that only contain non-integer symbols.
Reviewed By: ezgicicek
Differential Revision: D17130967
fbshipit-source-id: f5ba58d52
Summary: This diff extends size alias domain for keeping one more alias of a Java temporary variable.
Reviewed By: ezgicicek
Differential Revision: D16984082
fbshipit-source-id: 244bbd0ee
Summary:
`__inferbo_empty`, `__inferbo_min`, and `__inferbo_set_size` were in the
"include-based" cpp model.
Reviewed By: jvillard
Differential Revision: D17072034
fbshipit-source-id: dd840331f
Summary:
This diff uses the models of vector for modelling string in Cpp.
Depends on D16963153
Reviewed By: ezgicicek
Differential Revision: D16963166
fbshipit-source-id: 5effe2d72
Summary:
This diff avoids that an integer value is pruned to the bottom by
comparing to a pointer.
For example, before this diff,
assume((int*)x == p);
assume((int*)x != p);
where x is an integer, x is pruned to the bottom in both of the assume
cases. So, there were some, unintentional and false, unreachable
code.
Depends on D16960199
Reviewed By: ezgicicek
Differential Revision: D16964735
fbshipit-source-id: 90a3c8c80
Summary:
It prunes the size of collections when the size function is called in the condition expression. The diff extended the alias domain to understand temporary variables of SIL from Java.
Depends on D16761461
Reviewed By: ezgicicek
Differential Revision: D16761611
fbshipit-source-id: 849c5c71c
Summary:
It revises Java's cast model to keep type in the location when it has a field.
The type information is useful especially when generating ondemand values of Collection elements.
Depends on D16807299
Reviewed By: ezgicicek
Differential Revision: D16807378
fbshipit-source-id: 636e54429
Summary:
Since it is non-sense to get ranges of boolean values, this diff
ignores control values that only contain boolean symbols.
Depends on D16804802
Reviewed By: ezgicicek
Differential Revision: D16804808
fbshipit-source-id: ccb25db4d
Summary:
It renames a function to make it clear what it does.
Depends on D16761451
Reviewed By: ezgicicek
Differential Revision: D16761461
fbshipit-source-id: b989cc274
Summary: We do not need to keep the elements type of vector in the field.
Reviewed By: ezgicicek
Differential Revision: D16761451
fbshipit-source-id: 6d5384662
Summary:
It enables pruning of vector's size when the return value of the function call of `vector::size` is pruned.
Depends on D16687167
Reviewed By: ezgicicek
Differential Revision: D16687225
fbshipit-source-id: 793a21b3a
Summary:
It generates vector value ondemand when it is given as a parameter.
Depends on D16645589
Reviewed By: ezgicicek
Differential Revision: D16645624
fbshipit-source-id: 7498c8ab2
Summary:
This diff prevents that the latest prune value is overwritten as top
from callees.
Reviewed By: jvillard
Differential Revision: D16540391
fbshipit-source-id: bdd5b42ed
Summary: This diff tries to do weak update for the abstract locations by pointer arithmetic, e.g. `p[n]` or `p+n`, even if the type of `p` is declared as a simple pointer, not an array.
Reviewed By: ezgicicek
Differential Revision: D16458367
fbshipit-source-id: 3b4cdd7e4
Summary:
The `represents_multiple_values` flag was adopted to decide whether updating abstract value strongly or weakly. However, the flag was included in the `Val` domain, which is strange, because it is a property of abstract locations, rather than abstract values. This makes the behavior of memory update function depend on the abstract value to update, making its code complicated.
This diff detach the `represents_multiple_values` flag from the `Value` domain, thus the memory update does not depend on the abstract value. Since this is a refactoring, I believe the diff should not make many semantic changes.
Reviewed By: ezgicicek
Differential Revision: D16441734
fbshipit-source-id: 4c10779d7
Summary:
It downgrades issues of void pointer to L5, because of its impreciseness. This is not
ideal but Inferbo cannot analyze arrays pointed by void pointers precisely at the moment.
Reviewed By: jvillard
Differential Revision: D16379911
fbshipit-source-id: f2c016aba
Summary:
Thanks to the newly added `StarField`, path length is better controlled before ondemand is used.
Hence there is no need to (unsoundly) canonicalize paths then anymore.
Reviewed By: ezgicicek
Differential Revision: D15409716
fbshipit-source-id: 9ea7b4717
Summary: Remove from inferbo summary locations that are unreachable from callers
Reviewed By: ezgicicek
Differential Revision: D15064518
fbshipit-source-id: 734e79b4a
Summary: The name was misleading, the function only forget locs for relations.
Reviewed By: ezgicicek
Differential Revision: D15045933
fbshipit-source-id: 7f41a55e7
Summary:
This diff propagates LatestPrune on function calls.
Depends on D14321605
Reviewed By: mbouaziz
Differential Revision: D14321618
fbshipit-source-id: cb2e1b547
Summary:
Given a pointer-typed parameter, Inferbo assumes that it is an array
block. However, when a pointer is given as an actual parameter, it
failed the substitution of the array block value of the parameter, thus
which made some return values to bottom unexpectedly.
This diff revises the substitution of array block, so it can
substitute array block values with actual pointers correctly when it
is possible.
Reviewed By: mbouaziz
Differential Revision: D14663475
fbshipit-source-id: 0477de1ba
Summary:
It does more reachability checks on prunings. Before the diff, it checked the reachability only by the condition expression of prune commands, but now also uses PrunePairs.
Depends on D14321575
Reviewed By: mbouaziz
Differential Revision: D14321605
fbshipit-source-id: f630de842
Summary:
This diff accumulates LatestPrune in sequential prunings. It should be sound since Inferbo invalidates some data of LatestPrune if they are updated.
Depends on D14321534
Reviewed By: mbouaziz
Differential Revision: D14321575
fbshipit-source-id: 233dbae32
Summary:
This diff changes a LatestPrune to use a return variable instead of another local variable, when the function returns a conditional value. This is a preparation to propagate LatestPrune inter-procedurally in the following diffs.
context: If a function returns a conditional value, e.g. `return x == y`, the LatestPrune value includes a temporary local variable introduced by the SIL translation. This diff is to avoid propagating the temporary local variables to its caller.
Reviewed By: mbouaziz
Differential Revision: D14321534
fbshipit-source-id: d157bfdd0
Summary: Unknown locations in the alias domain resulted in unexpected unreachable code.
Reviewed By: mbouaziz
Differential Revision: D14339412
fbshipit-source-id: a5dca6489
Sungkeun Cho
Josh Berdine
Nikos Gorogiannis
Ezgi Çiçek
Mehdi Bouaziz