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:
The purpose of DefinitelyNotNullable currently is bit unclear; let's
rename it so that the intention is obvious.
Reviewed By: artempyanykh
Differential Revision: D16984529
fbshipit-source-id: 696d58315
Summary:
`nullsafe` currently allows the following:
```
public void Nonnull Object willBeOK() { return null; }
```
But disallows the following:
```
public void Object willBeAnIssue() { return null; }
```
This was a deliberate choice made back in 2014.
The motivation was to provide a way to tell the checker "I know it can not be null, trust me".
A huge problem with that approach is that it is extremely non-intuitive and surprising, and contradicts with pretty much everything when Nonnull or similar annotations are used in external world.
This is not the way how checkers should be supressed.
We do provide 2 options to express this intention, namely `assertNotNull` and `assumeNotNull` would do the thing.
This is a much better approach for additional reason: assertNotNull is
granular and applies only to the exact expression that is under
question. In contrast, suppressing the check on the whole function level
make any modifications of a function dangerous.
Reviewed By: artempyanykh
Differential Revision: D16984213
fbshipit-source-id: 0ba0f623b
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 is more powerful than `"symbols"` for more advanced use-cases. Keep
`"symbols"` unchanged to make migrating easier.
Differential Revision: D16985756
fbshipit-source-id: dfbb09393
Summary: Adding new predicate for checking whether a variable is defined as extern. May be useful in AL rules.
Reviewed By: jvillard
Differential Revision: D16961690
fbshipit-source-id: 0677077dc
Summary: This diff prunes array sizes in Java by adding the size alias on the `get_array_length` function calls.
Reviewed By: ezgicicek
Differential Revision: D16983501
fbshipit-source-id: a924af09d
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:
Use whatever information we can to decide whether to use C or Java
syntax when outputting an access expression, now that we store them as
such.
Also, make cluster callbacks explicitly set the language, as this was not done before and led to some confusion (Clang being set when analysing a Java file).
Reviewed By: skcho
Differential Revision: D16884160
fbshipit-source-id: 40adf9f35
Summary: Ideally, we should be able to handle them like pruning if statements but for now, let's add the test.
Reviewed By: skcho
Differential Revision: D16938842
fbshipit-source-id: 04fae9559
Summary:
Change the logic of the annotation reachability checker in the following
ways:
1. Sanitizers take priority over sinks, i.e. a procedure that is both a
sink and a sanitizer is not a sink. This changes the existing tests
that seemed to assume the opposite. However I think that way is more
useful and goes better with the fact that sanitizers are specified as
"overrides".
2. When applying a summary, check again that we are not in a sanitizer
for the corresponding sink.
Without (2) this there was a subtle bug when several rules were
specified. For example, if `sink_wrapper()` wraps `sink()` for a rule
`R` then the summary of `sink_wrapper()` will be: `R-sink : call to sink()`.
Then, suppose `sanitizer()` calls `sink_wrapper()` and `sanitizer()` is
a sanitizer for `R` but not for another rule `R'`. The previous code
would add the call to `sink()` to the summary of `sanitizer()` because
it's not a sanitizer for `R'`, even though `sink()` is not a sink for
`R'`!
The current code will re-apply the rules correctly so that sinks are
matched only against the right sanitizers.
Reviewed By: skcho
Differential Revision: D16895577
fbshipit-source-id: 266cc4940
Summary:
- run the tests! they weren't hooked up to the main Makefile :/
- add some html debug messages
- formatting
Reviewed By: skcho
Differential Revision: D16895578
fbshipit-source-id: e96d737cc
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: Functions with empty body have unit cost, not zero. The unit cost comes from the start node.
Reviewed By: skcho
Differential Revision: D16855642
fbshipit-source-id: 6b5181faf
Summary:
Before this diff it returned `[0,size-1]`, but which became bottom
when size was given by 0. As a result, it made the both branches of
`if(iterator.hasNext())` unreachable. Similarly, if the size was 1,
it only visited the false branch of the if condition because the
condition value was `[0,0]` at that time.
This diff changes it to return `[0,size]`, so that
* the false branch is reachable when the size is 0
* the both branches are reachable when the size is 1
Reviewed By: ezgicicek
Differential Revision: D16803000
fbshipit-source-id: f8772be27
Summary: We want to keep big O notation as simple as possible in cost analysis reports (especially in diff time). Therefore, let's not show constants/min/max in big O notations even though the resulting asymptotic bound might be inaccurate. Developers can click on the trace and see the actual cost.
Reviewed By: skcho
Differential Revision: D16731351
fbshipit-source-id: 2e16f7eca
Summary: In order to test changes to bigO notation, let's record them in test results.
Reviewed By: skcho
Differential Revision: D16763972
fbshipit-source-id: c1376909b
Summary:
Correct the models of ArrayList initialization. Basically, there are two ways to initialize:
- by setting an initial capacity, which creates an empty list
- by passing another collection as an argument
Before, we had only modeled the second case which was resulting in wrong memory model for the first case. This diff fixes that.
Reviewed By: skcho
Differential Revision: D16711055
fbshipit-source-id: e82faf191
Summary:
It adds a vector model of `data` method.
Depends on D16687280
Reviewed By: ezgicicek
Differential Revision: D16689400
fbshipit-source-id: 156016b3c
Summary:
It adds a model of vector::push_back
Depends on D16687225
Reviewed By: ezgicicek
Differential Revision: D16687269
fbshipit-source-id: 9d2a73fca
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:
These have proved to be too fragile to maintain as they would often break
compilation of user code. They have been off by default for more than a year
now (D7350715).
Removing the include models shows a more accurate picture of what infer results
look like in production. As such, lots of tests have changed, mostly
biabduction but also in inferbo. SIOF was using include-based models too but
now libc++ is better and iostreams are implemented in a way that SIOF
understands (instead of being magical creatures) so nothing changed there.
Reviewed By: skcho
Differential Revision: D16602171
fbshipit-source-id: ce38f045b
Summary: Models of Java's Collection mistakenly assumed that there was an argument for empty set whereas `Collections.emptySet()` doesn't have any actuals. This diff fixes that an also removes the type argument from the corresponding model definition.
Reviewed By: skcho
Differential Revision: D16582314
fbshipit-source-id: d4304dc60
Summary: Sometimes programmers use integer underflow to get a maximum number of that type. This diff assumes that integer underflows from the syntactical form `(unsigned 0) - constant` is intended by the programmer, and suppresses the alarms of which.
Reviewed By: ezgicicek
Differential Revision: D16560639
fbshipit-source-id: 206f30dbc
Summary:
Before this diff, it gave up pruning of linear bound by minmax bound.
For example, `overapprox_min (x+c1, c2+min(d1,y))` was `x+c1`.
However, we can get a bit more preciser value as follows.
```
overapprox_min (x+c1, c2+min(d1,y))
<= min (x+c1, c2+d1)
= c1+min(c2+d1-c1, x)
```
Reviewed By: ezgicicek
Differential Revision: D16543837
fbshipit-source-id: 8fdbce097
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 improves the precision of the mod operator.
For example, result of x % c (when x>=0 and c>0) is
(before) [0, c-1]
(after) [0, min(c-1,x)]
Reviewed By: ezgicicek
Differential Revision: D16518578
fbshipit-source-id: a68660ee7
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:
Pulse didn't treat local variables going out of scope as invalidating the corresponding address in memory. This diff fixes that by
- marking all local variables that exits the scope with the attribute `AddressOfStackVariable`
- before we write the summary for the proc, we make sure to invalidate all such addresses local to the procedure as `Invalid.` If such an address is read, then we would raise a use-after-lifetime issue.
Reviewed By: jvillard
Differential Revision: D16458355
fbshipit-source-id: 3686524cb
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: The method defined in the interface didn't match the implementation. Caught by ulyssesr.
Differential Revision: D16339179
fbshipit-source-id: 9cbb1dc74
Summary:
A common gotcha is the new test. Model the minimum amount of
`std::basic_string` to catch it.
Reviewed By: mbouaziz, ngorogiannis
Differential Revision: D16121090
fbshipit-source-id: 66f06cb43
Summary:
Be more flexible in what type of function calls are allowed in `ViaCall ...` actions to be able to include models.
Also get rid of `here here` in traces /o\
As a side-effect, get more precise (=qualified) procedure names in
traces (but not in messages so as not to be too verbose).
Reviewed By: mbouaziz, ngorogiannis
Differential Revision: D16121092
fbshipit-source-id: fb51b02f8
Summary:
The domain supported path sensitivity wrt to a specific boolean guard `Branch.unlikely`. This isn't used in actual code, so remove it.
Also
- add an .mli to the domain;
- unabbreviate domain name to match analyser name;
- use Payload.read instead of calling Ondemand directly;
- adjust tests.
Reviewed By: mbouaziz
Differential Revision: D16203953
fbshipit-source-id: 743aa4400
Summary:
Move annotation reachability tests to their own directory.
Clean up and complete the tests.
Reviewed By: jvillard
Differential Revision: D16201387
fbshipit-source-id: 8a87a25b7
Summary:
Treat `MainThread` and `WorkerThread` annotations.
Fix wrong test (`AnyThread` cannot call a UI-only method, because it can be called by ANY thread ;) ) See https://developer.android.com/reference/android/support/annotation/AnyThread
Clean up the code a bit.
Reviewed By: jvillard
Differential Revision: D16183798
fbshipit-source-id: 6b7e3b27e
Summary: There were FNs caused by only looking for the immediate predecessors when we were checking the pattern. This diff heuristically chases 4 more predecessors to reduce the number of FNs.
Reviewed By: ngorogiannis
Differential Revision: D16149983
fbshipit-source-id: f65c57a0a
Summary: Adding typechecks to prevent potential FPs like the added test
Reviewed By: ngorogiannis
Differential Revision: D16149511
fbshipit-source-id: 6d3fe0ad4
Summary:
Replaced by pulse. `--ownership` is now a deprecated form of `--pulse`.
The ownership checker is starting to give wrong answers due to changes in the
clang frontend, so it's better to remove it in favour of pulse.
there_goes_my_hero
Reviewed By: ngorogiannis
Differential Revision: D16107650
fbshipit-source-id: bb2446a19
Summary:
So it turns out we need to translate even more cases. Pulse had a FP
before that this fixes.
Reviewed By: ezgicicek
Differential Revision: D16073629
fbshipit-source-id: c03460b5a
Summary:
This is needed to test some functionality in the next diff. Only one
test changes (no longer a FN), which is now documented. Also, stop
including the "header models" meant for biabduction!
Maybe one day we'll need to have several test modes for different C++
versions. Seems overkill for now, so let's wait until we see some actual
issues (eg FPs) that manifest in one version but not the other.
Reviewed By: mbouaziz
Differential Revision: D16073630
fbshipit-source-id: 1cfdfc933
Summary:
Sometimes the post of a function call has attributes on addresses that
were mentioned in the pre but are no longer reachable in the post. We
don't want to forget these, see added test.
Reviewed By: mbouaziz
Differential Revision: D16050050
fbshipit-source-id: 1ce522b97
Summary:
The previous code would call the destructor for the C++ temporary
*before* the prune nodes, which then try to dereference it. Wrong.
Quick fix: don't destroy temporaries in conditionals.
Reviewed By: mbouaziz
Differential Revision: D16030735
fbshipit-source-id: e11abad58
Summary:
We were skipping some instructions before and that was a problem for
pulse. See added pulse test.
Reviewed By: mbouaziz
Differential Revision: D16030150
fbshipit-source-id: 9c62e6213
Summary: Not sure if anyone uses this but there, now it's modelled.
Reviewed By: mbouaziz
Differential Revision: D16008162
fbshipit-source-id: f4795dcba
Summary:
Prevent false positives about variables captured by value gone out of
scope.
Reviewed By: ezgicicek
Differential Revision: D16008165
fbshipit-source-id: d70e47db4
Summary: We know how to do interprocedural calls so let's use that!
Reviewed By: mbouaziz
Differential Revision: D16008164
fbshipit-source-id: 4c34bf704
Summary:
`function::operator=` is called whenever we assign a literal lambda to a
variable, so it's pretty useful to be able to report anything on
lambdas.
Reviewed By: mbouaziz
Differential Revision: D16008163
fbshipit-source-id: a9d07668d
Summary:
Printing `Exp.Const (Cfun proc_name)` adds `_fun_` in front of the
procedure name, eg `_fun_foo` instead of `foo`. This showed up in pulse
traces.
Reviewed By: mbouaziz
Differential Revision: D16004606
fbshipit-source-id: 72ac6866f
Summary:
Fixes a false positive where the address of a C++ temporary is bound to
a static const reference variable then returned. The fix doesn't try to
establish that the variable is a const reference so could lead to false
negatives but that can be addressed later.
Reviewed By: ezgicicek
Differential Revision: D16004538
fbshipit-source-id: e403dbefe
Summary:
[apologies for the unreviewable diff...]
Get rid of HIL expressions in pulse. This finishes the HIL -> SIL
migration. The first step made pulse start from SIL instructions but
would translate most accesses to HIL to re-use most of the existing
pulse code. This diff gets rid of the intermediate translation of SIL
expressions to HIL expressions.
Big changes:
1. `PulseOperations` mostly rewritten, driven by using `Exp.t` instead of `HilExp.AccessExpression.t` for everything.
2. Stop trying to reverse-engineer what addresses mean in terms of
access paths from program variables. Rely on the trace pointing at
the right places in the code to be enough. This is because it wasn't
that useful (and could even be misleading when wrong) but could be
prohibitively expensive in degenerate cases (eg nodes with tens of
thousands of successive array accesses...)
3. `PulseAbductiveDomain.apply_post` now returns the computed return
value instead of recording it itself.
4. Change of vocabulary: `materialize` -> `eval`, `crumb` -> `event`
5. Function calls arguments are now evaluated prior to doing anything
else, which saves everything else from having to (remember to) do
that. In particular, this changes how models look quite a bit.
Reviewed By: mbouaziz
Differential Revision: D15986373
fbshipit-source-id: 1d79935de
Summary: Inject destructor calls to destroy a temporary when its lifetime ends.
Reviewed By: mbouaziz
Differential Revision: D15674209
fbshipit-source-id: 0f783a906
Summary:
Now that HIL doesn't help us anymore we need to reconstruct its mapping
"SIL logical var -> program access path". We already have everything we
need in pulse: it suffices to walk the current memory graph starting
from program variables until we find the value of the temporary we are
interested in.
This diff also builds some type machinery to make sure all accesses are
explained.
Reviewed By: mbouaziz
Differential Revision: D15824959
fbshipit-source-id: 722c81b39
Summary:
It turns out HIL gets in the way of a precise heap analysis. For
instance, instead of:
```
n$0 = *&x.f
_ = delete(&x)
*&y = n$0
```
HIL tries hard to forget about intermediate variables and shows instead
```
_ = delete(&x)
*&y = *&x.f
```
Oops, that's a use-after-delete, whereas the original code was safe.
While it's easy to write SIL programs that are completely unsound for
HIL, they are not generated very often from the frontends. In fact, the
problem became apparent only when making the clang frontend translate
C++ temporaries destructors, which produces the situation above
routinely.
This diff makes the minimal amount of change to make Pulse build and
produce equivalent results (minus HIL bugs) starting from SIL instead of
HIL. The reporting sucks for now because we need to translate SIL
temporaries back into program access paths. This is done in the next
diff.
Reviewed By: mbouaziz
Differential Revision: D15824961
fbshipit-source-id: 8e4e2a3ed
Summary:
- Add allocation costs to `costs-report.json` and enable diffing over allocation costs.
- Also, let's be more consistent and modular in naming our cost issues.
- introduce a generic issue type `X_TIME_COMPLEXITY_INCREASE` where `X` can be one of the cost kinds. If the function is on the cold start, issue can have the `COLD_START` suffix. Similarly for infinite/zero/expensive calls.
- Change `PERFORMANCE_VARIATION` -> `EXECUTION_TIME_COMPLEXITY_INCREASE`
- Add new issue type for `ALLOCATION_COMPLEXITY_INCREASE_COLD_START` which will be enabled by default
- Refactor cost issues to be more modular and succinct. This also makes addition of a new cost kind very easy by adding the kind into the `enabled_cost_kinds` list in `CostKind.ml`
Reviewed By: mbouaziz
Differential Revision: D15822681
fbshipit-source-id: cf89ece59
Summary:
This one isn't caught because we don't destruct temporaries that are
bound to a const reference. According to the C++ standard these should
get destroyed when the const reference gets destroyed but instead we
just don't destroy them for now.
Reviewed By: mbouaziz
Differential Revision: D15760209
fbshipit-source-id: 32c935ec0
Summary:
In a next diff temporaries will get destructed at the end of their
lifetimes and that naive model would be causing false positives.
The flipside is that we lose all reports on closures for now, will need
to model them separately later.
Reviewed By: mbouaziz
Differential Revision: D15695943
fbshipit-source-id: c2c482c02
Summary:
This started as an attempt to understand how to modify the frontend to
inject destructors for C++ temporaries (see next diffs).
This diff rewrites the existing logic for computing the list of
variables that should be destroyed at the end of each statement, either
because it's the end of their syntactic scope or because control flow
branches outside of their syntactic scope.
The frontend translates a function from the last instructions to the
first, but scope computation needs to be done in the other direction, so
it's done in a separate pass *before* the main translation happens. That
first pass creates a map from statements in the AST to the list of
variables that should be destroyed at the end of these statements. This
is still the case now.
Before, that map would be computed in a bit of a weird way: scopes are
naturally a stack but instead of that the structure maintained was a
flat list + a counter to know where the current scope ended in that
list.
In this diff, redo the computation maintaining a stack of scopes
instead, which is a bit cleaner. Also treat more instructions as
introducing a new scope, eg if, for, ...
Reviewed By: mbouaziz
Differential Revision: D15674208
fbshipit-source-id: c92429e82
Summary:
Somewhat trivial: add a string to "Destruction" nodes to indicate why
they were created. Rename the main `instruction_aux` function into
`instruction_translate` (see next diff for why).
Reviewed By: mbouaziz
Differential Revision: D15674211
fbshipit-source-id: 8a7eda72c
Summary:
I rewrote the test so it doesn't need any C++ headers so that:
- it's easier to see what's going on
- it's easier to debug: the whole AST is now somewhat readable vs before
the headers made it impossibly long
Reviewed By: ezgicicek
Differential Revision: D15674213
fbshipit-source-id: d98941983
Summary:
This is a simple checker that identifies inefficient uses of `keySet` iterator where (not only the key but also) the value is accessed via `get(key)`. It is more efficient to use `entrySet` iterator which already returns both key-value pairs. This optimization would get rid of many extra lookups which can be expensive.
We simply traverse the CFG starting from the loop head upwards and pick up the map that is iterated over. Then, we check in the loop nodes if there is a call to `get(...)` over this map. If, so we report.
Reviewed By: ngorogiannis
Differential Revision: D15737779
fbshipit-source-id: 702465b4e
Summary:
The synthetic methods from `topl.Property` are now nonempty: they
simulate a nondeterministic automaton.
Reviewed By: jvillard
Differential Revision: D15668471
fbshipit-source-id: 050408283
Summary:
Instrument SIL according to TOPL properties. Roughly, the
instrumentation is a set of calls into procedures that simulate a
nondeterministic automaton. For now, those procedures are NOP dummies.
Reviewed By: jvillard
Differential Revision: D15063942
fbshipit-source-id: d22c2f6fa
Summary:
It is unsafe to call protocol methods defined optional. Before calling them we should check it
the implementation exists by calling
`if ([object respondsToSelector:selector(...)]) ...`
Without the above check we get run time crashes.
Reviewed By: jvillard
Differential Revision: D15554951
fbshipit-source-id: f0560971b
Summary: In its new form it actually tests that infer takes the correct branch.
Reviewed By: mbouaziz
Differential Revision: D15494297
fbshipit-source-id: 7b9bb8f75
Summary:
- take advantage more structured attributes in the exported AST
- circumvent new format of `if` and `switch`
- a few new features/nodes but nothing major there
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz, martintrojer
Differential Revision: D15453572
fbshipit-source-id: c0c24345f
Summary:
- Rename `invariantModels` to `purityModels`
- Track which arguments are modified in purity models. Before we were invalidating all arguments of impure modeled functions. Instead, now we only invalidate modified args given in the model. This should ideally result in more precision in the analysis.
- Add some more purity models for :`cast`, `new`, `new_array` and `Math.random`
Reviewed By: mbouaziz
Differential Revision: D15535332
fbshipit-source-id: 5395800d9
Summary:
That test wasn't hooked up to `make test` and so regressed at some
unknown time in the past. Just recording the new state of things for
now.
Reviewed By: ngorogiannis
Differential Revision: D15495234
fbshipit-source-id: 14fb112de
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:
This messes with the deduplication heuristic when templated function
names show up in the error messages, since the heuristic demands that
the error messages are the same.
Reviewed By: mbouaziz
Differential Revision: D15374333
fbshipit-source-id: 70232d254
Summary:
Improve the error messages, change is more or less documented in the
code.
Reviewed By: mbouaziz
Differential Revision: D15374334
fbshipit-source-id: f1dd54180
Summary:
Some edge case involving casting field pointers to the structure type itself generated arbitrarily long paths when used in a loop.
Without changing the widening, this diff avoids repetitions of fields in paths by abstracting them with a star.
E.g. `x.a.b.c.b` will become `x.a.b.c*.b`, and so will `x.a.b.c.a.b`, `x.a.b.c.c.b`, or `x.a.b.c.b.b`.
Reviewed By: ngorogiannis
Differential Revision: D15352143
fbshipit-source-id: 5ea426c5e
Summary:
Before: the trace would explain how a value was invalidated and
accessed, but not how the value that was invalidated had been
constructed.
Now: `PulseTrace.t` records breadcrumbs of how the value was constructed
in addition to the interproc "action" trace leading to the invalidation
or access action.
Concretely:
```
void bad(X &x) {
X *y = x;
X *z = x;
delete y;
access(z);
}
```
will produce the trace:
Invalidation part:
y = x
delete y
Access part:
z = x
access(z)
access to z->f inside of access(z)
Before this diff the "Access part" would be missing the "z = x" part of
the trace, so it might be confusing why `z` has anything to do with `y`.
However, such "breadcrumbs" are not recorded in the inter-procedural
part, only the sequence of calls is. This is a trade-off for simplicity,
maybe it's enough for developers maybe it isn't, we'll find out later.
Reviewed By: jberdine
Differential Revision: D15354438
fbshipit-source-id: 8d0aed717
Summary:
update-submodule: facebook-clang-plugins
We used to translate `offsetof` by an unknown value.
This fixes it. It is now translated like an integer literal.
Reviewed By: ddino
Differential Revision: D15317799
fbshipit-source-id: ae89e0ec5
Summary:
Feedback from peterogithub:
- mention which access path is being invalidated and accessed in the message
- mention the line at which it was invalidated (the line at which it's accessed is already the line at which we report)
- traces for stack variable/C++ temporary address escapes
- delete double implementation of the same functionality in
`PulseTrace`: `location_of_action_start` is the same as
`outer_location_of_action`...
Reviewed By: jberdine
Differential Revision: D14800294
fbshipit-source-id: 3d9ab9b3d
Summary:
Similarly to function parameters (and the return value), we need to
apply the pre/post of a function call to the globals mentioned in its
summary.
- tigthen summaries further to remember only abducible variables in the
post (as well as in the pre)
- take globals into account when applying pre/post pairs
Reviewed By: jberdine
Differential Revision: D14780800
fbshipit-source-id: fc0d180bb
Summary:
The heuristic to detect variables going out of scope was to detect any
access expression passed as argument to an injected destructor call.
However destructor calls are also injected in destructor bodies to
destruct each field of an object, so the heuristic would detect fields
going out of scope, which, erm, doesn't make sense. Limit the heuristic
to local program variables.
Reviewed By: jberdine
Differential Revision: D14771454
fbshipit-source-id: ffa3c9fe3
Summary:
Only throw values to the pre if they can be followed from "abducible"
variables: formals of the current method and globals.
Because figuring out if a `Pvar.t` is a formal of the current procedure
is actually a giant pain, hack something not too bad instead:
pre-register all formals at the start of the analysis of the
procedure. Then the only other variables we care about in the
precondition are globals, which we can detect easily.
This is mostly an optimisation (summaries won't include irrelevant
"abduced" facts about the procedure's local variables anymore), but it
also fixes a bug where we would sometimes overwrite things in the pre. I
think that's why the tests improved.
Reviewed By: ngorogiannis
Differential Revision: D14753493
fbshipit-source-id: 08e73637f
Summary:
This mostly doesn't make sense. The only thing this would have been good
for was to give the most accurate result on access paths such as
`*(&(x.f))`, but these are normalised anyway (into `x.f`) so we actually
never see these. That said there might be some use to some similar logic
in the future, but in the meantime let's delete the current feature as
it wasn't thought through.
Reviewed By: ezgicicek
Differential Revision: D14753492
fbshipit-source-id: 597cec027
Summary:
The previous message formatting had regressed and produced non-sensical messages.
More importantly, remove template parameters from error messages to
trigger the heuristic in `InferPrint` that deduplicates errors that are
on the same line with the same error type and message. Without this we
get hundreds of reports that correspond to as many instantiations of the
same code.
Reviewed By: ngorogiannis
Differential Revision: D14747979
fbshipit-source-id: 3c4aad2b1
Sungkeun Cho
Mitya Lyubarskiy
Ezgi Çiçek
Jules Villard
Dulma Churchill
Nikos Gorogiannis
Martin Trojer
Dino Distefano
Radu Grigore
Josh Berdine
Peter O'Hearn
Jeremy Dubreil
Mehdi Bouaziz
Andrew Adams-Moran
David Lively
Lee Howes