Summary: Experimental feature: Use memcached for summaries as a look-aside cache during analysis.
Reviewed By: jvillard
Differential Revision: D12939311
fbshipit-source-id: 9f78994e2
Summary:
Currently, if there are several reports on the same line, the most important one is reported together with a message containing how many reports were suppressed.
This is sometimes causing the bug hash we use believe that a report is introduced (eg if the number of suppressed reports changes).
Reviewed By: mbouaziz
Differential Revision: D13067306
fbshipit-source-id: 1cc0c6d3a
Summary:
Messages emitted by cost-analysis now look like the following:
Complexity of this function has **increased** from `O(1)` to `O(n)`.
Reviewed By: mbouaziz
Differential Revision: D13058008
fbshipit-source-id: 119037703
Summary:
It turns out keeping attributes (such as invalidation facts) separate
from the memory is a bad idea and leads to loss of precision and false
positives, as seen in the new test (which previously generated a
report).
Allow me to illustrate on this example, which is a stylised version of
the issue in the added test: previously we'd have:
```
state1 = { x = 1; invalids={} }
state2 = { x = 2; invalids ={1} }
join(state1, state2) = { x = {1, 2}; invalids={{1, 2}} }
```
So even though none of the states said that `x` pointed to an invalid
location, the join state says it does because `1` and `2` have been
glommed together. The fact `x=1` from `state1` and the fact "1 is
invalid" from `state2` conspire together and `x` is now invalid even
though it shouldn't.
Instead, if we record attributes as part of the memory we get that `x`
is still valid after the join:
```
state1 = { x = (1, {}) }
state2 = { x = (2, {}) }
join(state1, state2) = { x = ({1, 2}, {}) }
```
Reviewed By: mbouaziz
Differential Revision: D12958130
fbshipit-source-id: 53dc81cc7
Summary:
I hear that this scheduler is better. I want the best scheduler
possible. Also pulse's join is a bit complex so it might matter one day.
whydididothis
Reviewed By: mbouaziz
Differential Revision: D12958131
fbshipit-source-id: 3bd77ccba
Summary: The aligned width of bool should be 1-byte, while the range of bool [0,1].
Reviewed By: jvillard
Differential Revision: D12932394
fbshipit-source-id: be1a5d6d1
Summary: For a general case of `operator=` we want to create a fresh location for the first parameter as `operator=` behaves as copy assignment.
Reviewed By: jvillard
Differential Revision: D12940635
fbshipit-source-id: 89c6e530d
Summary:
Whenever `vec.reserve(n)` is called, remember that the vector is
"reserved". When doing `vec.push_back(x)` on a reserved vector, assume
enough size has been reserved in advance and do not invalidate the
underlying array.
This gets rid of false positives.
Reviewed By: mbouaziz
Differential Revision: D12939837
fbshipit-source-id: ce6354fc5
Summary:
Instead of keeping at most one invalidation fact for each address, keep
a set of them and call them "attributes". Keeping a set of invalidation
facts is redundant since we always only want the smallest one, but
makes the implementation simpler, especially once we add more kinds of
attributes (used for modelling, see next diffs).
Reviewed By: mbouaziz
Differential Revision: D12939839
fbshipit-source-id: 4a54c2132
Summary:
Copied on the ownership checker logic: return the initial value of the
domain as return. This can probably be improved.
Reviewed By: mbouaziz
Differential Revision: D12888102
fbshipit-source-id: 9e2dac7fc
Summary:
When initialising a variable via semi-exotic means, the frontend loses
the information that the variable was initialised. For instance, it
translates:
```
struct Foo { int i; };
...
Foo s = {42};
```
as:
```
s.i := 42
```
This can be confusing for backends that need to know that `s` actually
got initialised, eg pulse.
The solution implemented here is to insert of dummy call to
`__variable_initiazition`:
```
__variable_initialization(&s);
s.i := 42;
```
Then checkers can recognise that this builtin function does what its
name says.
Reviewed By: mbouaziz
Differential Revision: D12887122
fbshipit-source-id: 6e7214438
Summary:
Now that arrays are dealt with separately (see previous diff), we can
turn the join back into an over-approximation as far as invalid
locations are concerned.
Reviewed By: skcho
Differential Revision: D12881989
fbshipit-source-id: fd85e49c0
Summary:
Arrays are the main source of false positives that prevent us from
having a better (less under-approximate) join in general. The next diff
improves join and I split this off to make it easier to review.
Reviewed By: mbouaziz
Differential Revision: D12881986
fbshipit-source-id: 5f52dea27
Summary:
This prevents the join from wrongly assuming that we haven't seen a
variable on one side of the join.
Reviewed By: skcho
Differential Revision: D12881987
fbshipit-source-id: 42a776adb
Summary:
Smaller numbers are easier to read and abstract addresses should never
be shared across functions anyway.
Reviewed By: da319
Differential Revision: D12881988
fbshipit-source-id: f9bcfa343
Summary:
As explained in the added comment, clang started adding `-faddrsig` at the end
of every `-cc1` command, which trumps our heuristic for finding the file name
(thus we would write debug scripts to `-faddrsig.ast.sh`, do filename-based
filtering on `-faddrsig` instead of the source path, and more...). We rely on
the file name being the last argument in `-cc1` commands because so far that's
always been the case, and we don't want to parse the clang command line and
have to know about all the clang options...
Thanks martinoluca for the trick of simply passing `-fno-addrsig`!
Reviewed By: martinoluca
Differential Revision: D12921987
fbshipit-source-id: 28bebe647
Summary:
The upcoming ocamlformat has the ability to parse and format
docstrings. This requires that the docstrings conform to the ocamldoc
spec a bit more strongly. If a docstring does not parse, it is left
alone, but if it is morally ill-formed but parses by chance, it can be
reformatted incorrectly. This patch fixes the existing instances of
this problem.
Reviewed By: mbouaziz
Differential Revision: D12911937
fbshipit-source-id: 1c2eb590b
Summary:
For more deduplications of issues, this diff loosens the condition of
similar bounds. The previous condition of similar bounds was too
strict, so [0,0] and [0,+oo] were not similar.
Depends on D10851762
Reviewed By: mbouaziz
Differential Revision: D10866127
fbshipit-source-id: 4ba912a88
Summary: For `operator=(lhs, rhs)` we want to model it as an assignment if rhs is materialized temporary created in the constructor.
Reviewed By: jvillard
Differential Revision: D10462510
fbshipit-source-id: 998341e69
Summary: Do not create a new location for placement new argument if it already exists.
Reviewed By: jvillard
Differential Revision: D12839942
fbshipit-source-id: 758b67a82
Summary:
In order to know whether a global variable is an integral constant
expression in C, this diff adds a field for the results of isInitICE.
The controller you requested could not be found.: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D12838521
fbshipit-source-id: 388bff1f3
Summary:
This may help running the id map bookkeeping on its own in the future
and makes the code slightly more readable in my opinion.
Reviewed By: mbouaziz
Differential Revision: D12858066
fbshipit-source-id: fea4aea63
Summary:
HIL wanted to do its own HTML printing, causing code duplication and hacks to
avoid double opening/closing files. Instead, pass a hook to print SIL
instructions or not.
This also makes the debug HTML be printed even in case of raised exceptions,
which is invaluable to debug crashes or even just reports in the case of
checkers that can raise `Stop_analysis` (pulse only for now).
This also print intermediate abstract states between instructions instead of
only at the start and end of nodes, for moar debugging.
Reviewed By: mbouaziz
Differential Revision: D12857425
fbshipit-source-id: 4ee6c88d6
Summary:
Get rid of `USE_AFTER_LIFETIME`. This could be useful to deploy pulse
alongside the ownership checker too.
Reviewed By: da319
Differential Revision: D12857477
fbshipit-source-id: 8e2a2a37c
Summary: Make the whole type private, introduce constructors for each variant, and deal with the consequences.
Reviewed By: da319
Differential Revision: D12825810
fbshipit-source-id: a01922812
Summary:
Keep `USE_AFTER_LIFETIME` for unclassified errors (for now it contains
vector invalidation too because I can't think of a good name for
them, and maybe it makes sense to wait until we have more types of them
to decide on a name).
Reviewed By: da319
Differential Revision: D12825060
fbshipit-source-id: bd75ef698
Summary:
Getting this right will be long and complex so for now the easiest is to
underreport and only consider as invalid the addresses we know to be invalid on
both sides of a join. In fact the condition for an address to be invalid after
a join is more complex than this: it is invalid only if *all* the addresses in
its equivalence class as discovered by the join are invalid.
Reviewed By: skcho
Differential Revision: D12823925
fbshipit-source-id: 2ca109356
Summary: Similarly as for destructors, we provide an address of an object as a first parameter to constructors. When constructor is called we want to create a fresh location for a new object.
Reviewed By: jvillard
Differential Revision: D10868433
fbshipit-source-id: b60f32953
Summary:
There were several lists constructed unnecessarily -- replaced them with find_maps
and hopefully simplified the logic.
Reviewed By: mbouaziz, jvillard
Differential Revision: D12823559
fbshipit-source-id: 1f06b20f3
Summary:
Sometimes in debug mode, the condition set is too big to print in the
log file. This diff limits the maximum number of conditions to print
as 30.
Reviewed By: mbouaziz
Differential Revision: D12836661
fbshipit-source-id: 8ddfe64a7
Summary: We provide an address of an object as a parameter to destructor. When destructor is called the object itself is invalidated, but not the address.
Reviewed By: jvillard
Differential Revision: D12824032
fbshipit-source-id: 516eebcf8
Summary:
Seems useful to know when we're printing one instruction only, but not when we
print lots of them for readability.
Reviewed By: mbouaziz
Differential Revision: D12823481
fbshipit-source-id: 2beb339f2
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:
Turns out once a vector array became invalid it stayed that way, instead
of the vector getting a new valid internal array.
Reviewed By: skcho
Differential Revision: D10853532
fbshipit-source-id: f6f22407f
Summary:
Now the domain can reason about `&` and `*` too. When recording `&`
between two locations also record a back-edge `*`, and vice-versa.
Reviewed By: mbouaziz
Differential Revision: D10509335
fbshipit-source-id: 8091b6ec0
Summary: This is more flexible and allows us to give more details when reporting.
Reviewed By: mbouaziz
Differential Revision: D10509336
fbshipit-source-id: 79c3ac1c8
Summary: Just to organise PulseDomain a bit more since it's quite big.
Reviewed By: mbouaziz
Differential Revision: D10509334
fbshipit-source-id: a81b36aa6
Summary: This should stop the bleeding until we get a better solution like shared memory + single writer process.
Reviewed By: mbouaziz
Differential Revision: D10868360
fbshipit-source-id: a4d0b064e
Summary: To avoid reporting on private methods, ignore those starting with underscore. Other cleanups.
Reviewed By: jvillard
Differential Revision: D10558970
fbshipit-source-id: 0572f1e70
Summary:
Invalidating addresses for destructors to catch use after destructor errors.
To pass ownership tests for use after destructor errors, we still need to:
(1) fix pointer arithmetic false positives
(2) add model for placement new to fix false positives
(3) add model for operator= to fix false positives
(4) support inter-procedural analysis for destructor_order_bad test
Reviewed By: jvillard
Differential Revision: D10450912
fbshipit-source-id: 2d9b1ee68
Summary:
It uses platform-dependent integer type widths information when
constructing Sizeof expressions which have a field(`nbytes`)
representing the static results of the evaluation of `sizeof(typ)`.
Reviewed By: mbouaziz
Differential Revision: D10504715
fbshipit-source-id: 0c79d37d8
Summary: Reports will now be issued for the class loads of the methods specified by the option `--class-loads-roots`.
Reviewed By: jvillard
Differential Revision: D10466492
fbshipit-source-id: 91456d723
Summary:
Instead of the non-sensical piecewise join we had until now write
a proper one. Hopefully the comments explain what it does. Main one:
```
(* high-level idea: maintain some union-find data structure to identify locations in one heap
with locations in the other heap. Build the initial join state as follows:
- equate all locations that correspond to identical variables in both stacks, eg joining
stacks {x=1} and {x=2} adds "1=2" to the unification.
- add all addresses reachable from stack variables to the join state heap
This gives us an abstract state that is the union of both abstract states, but more states
can still be made equal. For instance, if 1 points to 3 in the first heap and 2 points to 4
in the second heap and we deduced "1 = 2" from the stacks already (as in the example just
above) then we can deduce "3 = 4". Proceed in this fashion until no more equalities are
discovered, and return the abstract state where a canonical representative has been chosen
consistently for each equivalence class (this is what the union-find data structure gives
us). *)
```
Reviewed By: mbouaziz
Differential Revision: D10483978
fbshipit-source-id: f6ffd7528
Summary:
Instead of propagating a partial state give up the analysis of the
function entirely on error. The state after an error is mostly
non-sensical so until we know better just giving up makes sure the
analysis remains sensible and produce fewer spurious warnings.
Reviewed By: mbouaziz
Differential Revision: D10483979
fbshipit-source-id: 171ec8469
Summary: Since we only care about reachability, drop the interpreter and just fold over all instructions in the procdesc.
Reviewed By: mbouaziz
Differential Revision: D10461783
fbshipit-source-id: 3e0b42a48
Summary: We don't need the machinery of HIL, or its complexity for this analysis.
Reviewed By: ddino
Differential Revision: D10461641
fbshipit-source-id: 2e7d3ab8e
Summary: First version of an analyzer collecting classes transitively touched.
Reviewed By: mbouaziz
Differential Revision: D10448025
fbshipit-source-id: 0ddfefd46
Summary: Even though we recognize the lock/unlock methods of various classes in C++, to report we insist that the class must have a `mutex` member. Equalize the two sets of types recognized.
Reviewed By: da319
Differential Revision: D10446527
fbshipit-source-id: f42ae1a35
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:
`Location` was clashing with the `Location` module, so use `Address`
instead.
When invalidating an address, remember the "actor" of its invalidation,
i.e. the access expression leading to the address and the source
location of the corresponding instruction.
When checking accesses, also pass the actor responsible for the access,
so that when we raise an error we know:
1. when and why a location was invalidated
2. when and why we tried to read it after that
Reviewed By: mbouaziz
Differential Revision: D10446282
fbshipit-source-id: 3ca4fb3d4
Summary:
Model `x[y]` and `x.push_back(i)` to catch the classic bug of "take
reference inside vector, invalidate, then use again".
Reviewed By: da319
Differential Revision: D10445824
fbshipit-source-id: 21ffd9677
Summary:
Do the intersection of the heap and stack domains, and the union of the
invalid location sets. This forgets invalid locations that appear only
in one heap, unfortunately. We can start with this and improve later.
Reviewed By: mbouaziz
Differential Revision: D10445825
fbshipit-source-id: cc24460af
Summary:
It gets built-in integer type widths of C from the clang plugin. For Java, it uses fixed widths.
The controller you requested could not be found.: facebook-clang-plugins
Reviewed By: jvillard
Differential Revision: D10397409
fbshipit-source-id: 73958742e
Summary:
Store the correct version of the proc desc into the DB when specialising
it. This doesn't seem to be used but is useful for investigating after
the fact (eg, if we could print individual cfgs).
Reviewed By: mbouaziz
Differential Revision: D10380708
fbshipit-source-id: fd72dbfc2
Summary:
New analysis in foetal form to detect invalid use of C++ objects after their
lifetime has ended. For now it has:
- A domain consisting of a graph of abstract locations representing the heap, a map from program variables to abstract locations representing the stack, and a set of locations known to be invalid (their lifetime has ended)
- The heap graph is unfolded lazily when we resolve accesses to the heap down to an abstract location. When we traverse a memory location we check that it's not known to be invalid.
- A simple transfer function reads and updates the stack and heap in a rudimentary way for now
- C++ `delete` is modeled as adding the location that its argument resolves to to the set of invalid locations
- Also, the domain has a really crappy join and widening for now (see comments in the code)
With this we already pass most of the "use after delete" tests from the
Ownership checker. The ones we don't pass are only because we are missing
models.
Reviewed By: mbouaziz
Differential Revision: D10383249
fbshipit-source-id: f414664cb
Summary:
In some error paths we may end up querying the state for the instruction
being executed, but that is only populated by biabduction. Now it's
populated by AI checkers too.
Reviewed By: jberdine
Differential Revision: D10381068
fbshipit-source-id: dca1325d7
Summary:
When the backend crashes we print which instruction/file/... we were analysing,
but because of recursion we can end up repeating that information all
the way to the toplevel call.
This makes sure we only print the innermost one, we don't care about the
calling context because the analysis is compositional.
Reviewed By: mbouaziz
Differential Revision: D10381141
fbshipit-source-id: 1c92bb861
Summary:
Trace events would crash when infer subprocesses were spawned by the build
system because they didn't detect if the file was already initialised
correctly.
Also trace the clang capture.
Reviewed By: mbouaziz
Differential Revision: D10380745
fbshipit-source-id: 76e1d4d7e
Summary:
It avoids raising an exception when unexpected arguments are given to
placement new. We will revert this after fixing the frontend to parse
user defined `new` correctly in the future.
Reviewed By: mbouaziz
Differential Revision: D10378136
fbshipit-source-id: d494f781b
Summary:
Use same code for deciding whether two accesses conflict across java/clang, by adapting that of the clang version.
Eliminate/simplify some code.
Reviewed By: mbouaziz, jberdine
Differential Revision: D10217383
fbshipit-source-id: dc0986d05
Summary:
It unsets `var_exp_typ` of `trans_state` during the translations of
placement parameters, so they are translated independently against the
target variable and class of the `new` function.
Reviewed By: mbouaziz, jvillard
Differential Revision: D10161419
fbshipit-source-id: 7f588a91c
Summary: It enables placement_new to get three parameters, which happens when placement_new is overloaded (e.g. Boost).
Reviewed By: mbouaziz
Differential Revision: D10100324
fbshipit-source-id: 0ecb0a404
Summary:
Using debugging on uninit raised an exception. A file was opened twice and closed twice.
This happened because the two abstract interpreters (SIL, LowerHIL) conflicted.
Let's use the LowerHIL-AI directly
Reviewed By: jvillard
Differential Revision: D10126442
fbshipit-source-id: 113c9e131
Summary:
Load proc descs from the "procedures" sqlite table instead of from
file-wide cfgs stored in the "source_files" table. This removes the need
for a cache of these file-wide CFGs, which was needed because loading
them is expensive and potentially needed in case we need to load the
proc descs of several procedures in the same file. Now we can just load
the proc descs one by one and not worry about caching.
Reviewed By: jberdine
Differential Revision: D10173355
fbshipit-source-id: 665636121
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:
First step: record the proc desc of each procedure in the "procedures"
table. Update them according to the attributes logic. Bonus: this
proc-desc for a procedure is now always in sync with its attributes.
For now nothing uses these per-procedure cfgs. Later diffs make more and
more use of them and eventually kill off file-wide CFGs from the
database.
Reviewed By: jberdine
Differential Revision: D10173350
fbshipit-source-id: b6d222bee
Summary:
There's nothing to analyse for declared procedures, and if there is then
that's because they are defined outside the source file and should not
be analysed unless ondemand needs them.
Reviewed By: ngorogiannis
Differential Revision: D10173353
fbshipit-source-id: 39c42eb7a
Summary:
In a future commit `Attributes` will depend on `Procdesc` and that
creates a cycle for the functions concerned with specialising proc
descs, which need `Attributes`.
Reviewed By: jberdine
Differential Revision: D10173354
fbshipit-source-id: 6c4ff82f0
Summary: The Nullsafe checker integration is filtering out the pre-existing warnings based on the bug hash only. However, there was a typo in the regexp and the bug hash for methods in anonymous classes was then depending on the name (in the bytecode) of the anonymous class, i.e. depending on the `N` in `ClassName$N.methodName()` where `N` is the occurrence of the anonymous class in `ClassName`. As a consequence, introducing a new anonymous class in a file was leading to all the reports in the subsequent anonymous classes to be marked as introduced.
Reviewed By: jberdine
Differential Revision: D10186651
fbshipit-source-id: 42e27c132
Summary:
An order constraint (A,B) means we take lock A and before releasing it we perform B (whatever that is).
Previously if a method call crossed class boundaries, we removed the callee's order constraints before integrating the callee's summary to that of the caller. The reasoning was that this may lead to reports blaming a caller for something they are very far from, plus a proliferation of reports with the same bad endpoint.
The first reason still applies, but this is a general problem. It may be better to report and let developers deal with it.
The second reason is moot, since in differential mode most of these reports are hidden.
Reviewed By: jberdine
Differential Revision: D10173200
fbshipit-source-id: 9afbf292c
Summary:
Instead of many successive implicit transactions to write each
attributes of the procedures in a file, write them all in a single
transaction.
Reviewed By: jberdine
Differential Revision: D10173351
fbshipit-source-id: 5f2a5ffb5
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:
Before storing attributes to disk, we fix their location information if needed.
Ideally we wouldn't be creating bogus attributes but sometimes the frontends
are built in a way that makes it difficult to do otherwise, thus we have to
live with this. However, what's aggravating is that attributes are also saved
in the proc descs of these procedures but in their wrong version. This makes
the two versions (inside the procedures sqlite table and inside the procdesc in
the cfg of the source_files table) agree.
Reviewed By: jeremydubreil
Differential Revision: D10084708
fbshipit-source-id: 5bfd5da3a
Summary:
Make distinct reports on strict mode violations.
For now, restrict to direct violations (UI threads calls transitively a violating method).
Will assess impact and enable indirect reports later (via locks).
Reviewed By: mbouaziz
Differential Revision: D10126780
fbshipit-source-id: 9c75930bc
Summary: Option is not needed, just set `default` record to agree with function default arguments.
Reviewed By: da319
Differential Revision: D10050463
fbshipit-source-id: e7d13bbd5
Mehdi Bouaziz
Ezgi Çiçek
Nikos Gorogiannis
Sungkeun Cho
Dino Distefano
Martino Luca
Jules Villard
Martin Trojer
Daiva Naudziuniene
Josh Berdine
Jeremy Dubreil