Summary: This will be more useful later when adding another one.
Reviewed By: ezgicicek, jberdine
Differential Revision: D18115231
fbshipit-source-id: a0a01901a
Summary:
The business of translating `Top/True/False` to `true/false` can be
hidden more.
Reviewed By: skcho
Differential Revision: D18115228
fbshipit-source-id: 071fcbddf
Summary:
Warning 33 (unused open) is enabled but the module open is not really
unused, it's just also opened at the top of the file...
Reviewed By: skcho
Differential Revision: D18114385
fbshipit-source-id: 2a8f9512a
Summary:
This diff avoids making top values on unknown non-static function,
such as abstract function, calls. This is necessary because the
generated top values ruin the precision of the cost checker.
Reviewed By: ezgicicek
Differential Revision: D17418611
fbshipit-source-id: aeb759bdd
Summary:
The wrong function was used when we tried to see if the class is
annotated with NullsafeStrict. This made it work only for non-static
methods.
Now we use the proper way.
Reviewed By: ngorogiannis
Differential Revision: D18113848
fbshipit-source-id: 02b7555be
Summary:
Previously, we considered a function which modifies its parameters to be impure even though it might not be modifying the underlying value. This resulted in FPs like the following program in Java:
```
void fresh_pure(int[] a) {
a = new int[1];
}
```
Similarly, in C++, we considered the following program as impure because it was writing to `s`:
```
Simple* reassign_pure(Simple* s) {
s = new Simple{2};
return s;
}
```
This diff fixes that issue by starting the check for address equivalnce in pre-post not directly from the addresses of the stack variables, but from the addresses pointed to by these stack variables. That means, we only consider things to be impure if the actual values pointed by the parameters change.
Reviewed By: skcho
Differential Revision: D18113846
fbshipit-source-id: 3d7c712f3
Summary: As suggested by artempyanykh, this will make it bit more clear
Reviewed By: artempyanykh
Differential Revision: D18037204
fbshipit-source-id: 65cb96815
Summary: We stop tracking at builder boundaries. Let's tract create methods as well so that trace is more informative.
Reviewed By: skcho
Differential Revision: D18038637
fbshipit-source-id: a99b6431f
Summary: Adding support to matching block names. We match mangled block names. We also needed to extend the function for extracting the range for each method, to also traverse the stmts to be able to find the block declarations.
Reviewed By: skcho
Differential Revision: D17956931
fbshipit-source-id: 707908812
Summary:
This is the first take on strict mode semantics.
The main invariant of strict mode is the following:
If the function passes `NullsafeStrict` check and its return value is
NOT annotated as Nullable, then the function does not indeed return
nulls, subject to unsoundness issues (which should either be fixed, or
should rarely happen in practice).
This invariant helps the caller in two ways:
1. Dangerous usages of non strict functions are visible, so the caller is enforced to check them (via assertions or conditions), or strictify them.
2. When the function is strict, the caller does not need to worry about
being defensive.
Biggest known issues so far:
1. Condition redundant and over-annotated warnings don't fully
respect strict mode, and this leads to stupid false positives. (There is
so much more stupid false positives in condition redundant anyway, so
not particularly a big deal for now).
2. Error reporting is not specific to mode. (E.g. we don't distinct real nullables and non-trusted non-nulls, which can be misleading). To be
improved as a follow up.
Reviewed By: artempyanykh
Differential Revision: D17978166
fbshipit-source-id: d6146ad71
Summary:
This is an intermediate nullability type powering future Strict mode.
See the next diff.
Reviewed By: artempyanykh
Differential Revision: D17977909
fbshipit-source-id: 2d5ab66d4
Summary:
Currently, we have NullsafeRules.ml responsible for detecting the
violation fact. All other logic: what should be the error type,
severity, and error message, is in TypeErr.ml.
In this diff, we move logic from NullsafeRules.ml and TypeErr.ml to
dedicated modules like AssignmentRule.ml etc.
Each such module is responsible for:
- detecting the violation fact (this is moved from NullsafeRules.ml)
- rendering the violation error (this is moved from TypeErr.ml).
This approach makes sense for two reasons:
1. The violation fact and the way we show error are logically related to
each other.
2. In future diffs, we will support more features guiding rule behavior,
such as a) decision whether to hide or show the error depending on type
information and mode; b) the way we render error depending on type
information and role.
Having dedicated modules incapsulating knowledge about rules is a natural way to support 2.
Reviewed By: artempyanykh
Differential Revision: D17977891
fbshipit-source-id: a53d916d3
Summary:
1. For each Nullsafe Rule, lets have a dedicated IssueType.
2. Split error reporting to three subfunctions: description, field type,
and infer issue.
This allows to introduce additional capabilities in a consolidated
manner. Example of such capabilities is should we hide or show an error,
what should be error severity depending on strictness mode, and how
exactly the error should be reported depending on how exactly
nullability is violated.
Reviewed By: artempyanykh
Differential Revision: D17977887
fbshipit-source-id: 860d67d2f
Summary:
This function can return `None` if the result is equal to the first
argument of join (why first?). It is unclear if it was an optimization
attempt of over-complicated logic.
Reviewed By: artempyanykh
Differential Revision: D17876561
fbshipit-source-id: 9628fb86e
Summary:
The goal of this logic is unclear:
1/ See the comments
2/ I can not see the scenario where classes and proper types can be
joined in a legit Java program
3/ Even it if was the case, I don't see how this heuristic is justified.
So I assume it is not.
Reviewed By: artempyanykh
Differential Revision: D17876568
fbshipit-source-id: c9c6cd604
Summary:
It is unclear what is the purpose of doing so, and it adds complexity to
codebase.
1/ The semantics of this is not clear, it more or less corresponds to
"where are all original locations that contributed to the type
calculation", but many branches in CFG have nothing to do with
nullability; also it was used not always consistently.
2/ The only place where this was used is logs, so this is no-ops. It is
unclear how seeing all locations can help debugging, given 3/ - see
below
3/ We have the right place to store such informatin, namely TypeOrigin,
where we store locations associated with types where we merge them in
CFG. Currently, we store only "winner" - the most relevant locations
that contributed to nullability in the most informative way. We show
this to the user when we report an error.
4/ If we want to support more things (e.g. show something more to the user), TypeOrigin
seems to be the right place. Or, alternatively, we might still merge
locations in `range`, but this will be better to organize in a tree form
instead of flat list that is not really informative and helpful. It is
all speculative though since need to support things like that seems
unclear.
Reviewed By: artempyanykh
Differential Revision: D17857198
fbshipit-source-id: 6cf6e48a2
Summary:
That module's interface was repeated twice to avoid exposing its
internals to PulseDomain itself. It's also quite long so it makes sense
to move it to its own file.
Reviewed By: ezgicicek
Differential Revision: D17977209
fbshipit-source-id: 56a2dac24
Summary:
Another poorman's library, this time about Pulse Domains. Also renames
`PulseDomain` to `PulseBaseDomain`.
Reviewed By: ezgicicek
Differential Revision: D17955287
fbshipit-source-id: 9c947cf98
Summary:
The name had rotten: it should be `AddrHistPair`. There is little value
of exposing the type of the pair `AbstractValue.t * ValueHistory.t`,
just inline its definition everywhere.
Reviewed By: ezgicicek
Differential Revision: D17955283
fbshipit-source-id: d145251e0
Summary:
See explanations in D17955104.
This renames `AbstractAddress` to `AbstractValue` since they are not
necessarily addresses.
Reviewed By: ezgicicek
Differential Revision: D17955290
fbshipit-source-id: 8bb4c61f2
Summary:
See explanations in D17955104. I put Attributes inside PulseAttribute
instead of creating a new file to avoid exposing more internals about
ranks.
Reviewed By: ezgicicek
Differential Revision: D17955284
fbshipit-source-id: a8719a58f
Summary:
Problem: PulseDomain.ml is pretty big, and contains lots of small
modules. The Infer build being a bit monolithic at the moment, it is
hard to split all these small modules off without creating some
confusion about which abstraction barries lay where. For instance, it's
fine to use `PulseDomain.ValueHistory` anywhere, but using `PulseDomain`
itself is sometimes bad when one should use `PulseAbductiveDomain`
instead.
Proposal: a poorman's library mechanism based on module aliasing. This
stack of diffs creates new Pulse* modules for all these small, safe to
use modules, together with `PulseBasicInterface.ml`, which aliases these
modules to remove the `Pulse` prefix. At the end of the stack, it will
contain:
```
module AbstractValue = PulseAbstractValue
module Attribute = PulseAttribute
module Attributes = PulseAttribute.Attributes
module CallEvent = PulseCallEvent
module Diagnostic = PulseDiagnostic
module Invalidation = PulseInvalidation
module Trace = PulseTrace
module ValueHistory = PulseValueHistory
```
This "interface" module can be opened in other pulse modules freely.
Reviewed By: ezgicicek
Differential Revision: D17955104
fbshipit-source-id: 13d3aa2b5
Summary:
Domain for thread-type. The main goals are
- Track code paths that are explicitly on UI thread (via annotations, or assertions).
- Maintain UI-thread-ness through the call stack (if a callee is on UI thread then the
trace any call site must be on the UI thread too).
- If we are not on the UI thread we assume we are on a background thread.
- Traces with "UI-thread" status cannot interleave but all other combinations can.
- We do not track other annotations (eg WorkerThread or AnyThread) as they can be
erroneously applied -- other checkers should catch those errors (annotation reachability).
- Top is AnyThread, and is used as the initial state for analysis.
Interestingly, by choosing the right strategy for choosing initial state and applying callee summaries gets rid of some false negatives in the tests even though we have not introduced any path sensitivity yet.
Reviewed By: jvillard
Differential Revision: D17929390
fbshipit-source-id: d72871034
Summary: For Objective-C methods we match the mangled names (the field is name in the profiler samples).
Reviewed By: skcho
Differential Revision: D17952552
fbshipit-source-id: 308d415f6
Summary:
bigmacro_bender
There are 3 ways pulse tracks history. This is at least one too many. So
far, we have:
1. "histories": a humble list of "events" like "assigned here", "returned from call", ...
2. "interproc actions": a structured nesting of calls with a final "action", eg "f calls g calls h which does blah"
3. "traces", which combine one history with one interproc action
This diff gets rid of interproc actions and makes histories include
"nested" callee histories too. This allows pulse to track and display
how a value got assigned across function calls.
Traces are now more powerful and interleave histories and interproc
actions. This allows pulse to track how a value is fed into an action,
for instance performed in callee, which itself creates some more
(potentially now interprocedural) history before going to the next step
of the action (either another call or the action itself).
This gives much better traces, and some examples are added to showcase
this.
There are a lot of changes when applying summaries to keep track of
histories more accurately than was done before, but also a few
simplifications that give additional evidence that this is the right
concept.
Reviewed By: skcho
Differential Revision: D17908942
fbshipit-source-id: 3b62eaf78
Summary:
Java method annotations are ambiguous in that there is no difference between
annotating the return value of a method, and annotating the method itself.
The disambiguation is done entirely based on the meaning of the annotation.
Here, while `UiThread`/`MainThread` are genuine method/class annotations
and not return annotations, the reverse is true for `ForUiThread`/`ForNonUiThread`.
This means that these latter annotations do not determine the thread status of
the method they are attached to.
Here we fix that misunderstanding.
Reviewed By: jvillard
Differential Revision: D17960994
fbshipit-source-id: 5aecfb124
Summary:
- Adds ATD file to parse the clang profiler samples
- Procnames don't help us here because we want to use mangled names, not the version of names that Infer needs, so passing in the RangeMap also ClangProc that just include the names and mangled names.
- First matching of c functions to have something in place to add a test, matching further method kinds to be done in next diff.
Reviewed By: skcho
Differential Revision: D17877071
fbshipit-source-id: b31d651a7
Summary:
I dunno, seemed wrong before. About to introduce another attribute with
similar arguments so making them consistent in advance.
Reviewed By: skcho
Differential Revision: D17930349
fbshipit-source-id: 944b58bac
Summary:
- add the variable being declared so we can report it back in the trace in addition to its location
- distinguish between local vars and formals
Reviewed By: skcho
Differential Revision: D17930348
fbshipit-source-id: a5b863e64
Summary:
- Putting test determinator in own directory
- Putting Java procname creation stuff in its own module
Reviewed By: skcho
Differential Revision: D17929885
fbshipit-source-id: 4f2578566
Summary:
Eventually thread status will be stored inside every critical pair so as to allow path sensitivity. That means that the status can no longer be a whole trace, as this will quickly become intractable, because each domain element would have to maintain its own trace as well as its own thread-status trace.
This is not great, as we lose information here, but I don't see any other way around it that is not super complicated/costly (sharing will be limited when moving from callee to caller).
Other diffs up the stack will clean up infrastructure no longer used meaningfully (ie models and domains).
Reviewed By: mityal
Differential Revision: D17908908
fbshipit-source-id: 3bf353e33
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 will avoid printing stuff like
"0$?%__sil_tmpSIL_materialize_temp__n$2 declared" to the poor
unsuspecting user. The non-verbose stuff is used only by pulse so far as
far I can tell so hopefully this doesn't break anything.
Reviewed By: ezgicicek
Differential Revision: D17908943
fbshipit-source-id: 8ef4f1a8f
Summary:
Instead of a string argument named `~str` pass `Formal | Global` and let
`add_to_errlog` figure out how to print it.
Reviewed By: ezgicicek
Differential Revision: D17907657
fbshipit-source-id: ed09aab72
Summary:
When we make the decision to go into a branch "v = N" where some
abstract value is compared to a constant, remember the corresponding
equality. This allows to prune simple infeasible paths
intra-procedurally.
Further work is needed to make this useful interprocedurally, for
instance either or both of these ideas could be explored:
- abduce v=N in the precondition and do not apply summaries when the
equalities in the pre are not satisfied
- prune post-conditions that lead to unsat states where a value has to
be equal to several different constants
Reviewed By: skcho
Differential Revision: D17906166
fbshipit-source-id: 5cc84abc2
Jules Villard
Dulma Churchill
Sungkeun Cho
Mitya Lyubarskiy
Ezgi Çiçek
Nikos Gorogiannis