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: Refactor `ondemand.ml` so that the function `analyze_proc` does not need to be passed around as a function argument
Reviewed By: ngorogiannis, jvillard
Differential Revision: D16089689
fbshipit-source-id: 97ba07619
Summary:
javalib 3.0 adds more support for lambdas and instance methods in interfaces.
Java constant type has 2 more constructors. We don't handle them when
generating SIL (as before) but at least we are compatible with
javalib 3.0
Reviewed By: jvillard
Differential Revision: D16030479
fbshipit-source-id: 0b1508482
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:
Previously it was required to provide SDKROOT during configure on Mojave
hosts to `make` the project which in scripts was messing up local clang
and somewhat error-prone. Instead we could use xcrun to find required SDK
paths automatically.
Reviewed By: jvillard
Differential Revision: D16072354
fbshipit-source-id: 93cbf3980
Summary:
Move control of the number of remaining task from the taskbar [1] to each task generator [2]. This means that the call graph scheduler can count all procedures in mutually-recursive cycles as dealt with when only those procedures are left.
[1] : `infer/src/base/TaskBar.ml`
[2] : type defined in `/infer/src/base/ProcessPool.ml`
Reviewed By: ngorogiannis
Differential Revision: D16071497
fbshipit-source-id: aa9436638
Summary: Could be made better for cycles but not used and not unit tested, let's remove it.
Reviewed By: ngorogiannis
Differential Revision: D16017744
fbshipit-source-id: 6f7ae95c1
Summary: Do not fail on cycles, normalize values issuing from cycles, but do not try to recognize equal cycles like `let rec x = 1 :: x` and `let rec y = 1 :: 1 :: y`. This is unlikely to happen in our code.
Reviewed By: ngorogiannis
Differential Revision: D16017365
fbshipit-source-id: 691bb756c
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:
Previously we would union them with the previous attributes. I don't
think that makes sense.
Also change the interface a bit in preparation for the next commit.
Reviewed By: mbouaziz
Differential Revision: D16050051
fbshipit-source-id: 2e8f88f4e
Summary:
Noticed that:
- some option was always `Some _`
- recording the post never raises `Aliasing` (only exploring the pre does)
- a mutual recursion was unused
Reviewed By: mbouaziz
Differential Revision: D16050052
fbshipit-source-id: 7f77aae08
Summary:
Currently, `Callbacks.analyze_procedures` creates a function to call the method `Callbacks.iterate_procedure_callbacks`. This is supplied as an argument to functions in `ondemand.ml`, so that it can be invoked. This is done to avoid a cyclic dependancy.
This diff moves the functions that `ondemand.ml` needs to call into `ondemand.ml`, avoiding the need to supply them as arguments.
Reviewed By: ngorogiannis
Differential Revision: D16028836
fbshipit-source-id: 16ae27a3e
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:
Similar to D16005395: `folly::Optional` has a boolean field to know if
it needs to destroy the wrapped object and pulse ignores that
completely, causing false positives each time an `Optional` is created
around something with a non-trivial destructor.
Reviewed By: mbouaziz
Differential Revision: D16030149
fbshipit-source-id: aeed4a0b3
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:
The previous version had a potentially exponential behavior on values with already lots of sharing.
This is fixed here at the price of a multiplicative constant factor (cost of `Hashtbl.hash`).
It also prepares for the handling of cycles.
Reviewed By: ngorogiannis
Differential Revision: D16016906
fbshipit-source-id: 611287917
Summary:
In light of Pulse's misadventures with HIL, leave a warning for future
checkers writers. Comment mostly taken from summary of D15824961.
Reviewed By: ngorogiannis
Differential Revision: D16005392
fbshipit-source-id: 805f17584
Summary:
This can take a minute or so during which the user would have no idea
what infer is doing.
Reviewed By: ngorogiannis
Differential Revision: D16005393
fbshipit-source-id: 586812527
Summary:
No need to hide the real reason for the crash behind another crash when
trying to print the error message.
Reviewed By: mbouaziz, ngorogiannis
Differential Revision: D16005394
fbshipit-source-id: dc3d9437e
Summary:
The constructor of `folly::SocketAddress` conditionally deletes some
object and then makes that condition false. The destructor then does the
same. Pulse ignores conditionals so will see a double delete.
Just skip that function for now, but it should be easy for pulse to be
more correct here if it knew how to compare constant values.
Reviewed By: mbouaziz
Differential Revision: D16005395
fbshipit-source-id: 036f5091b
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:
Replace Hashtbl.clear with Hashtbl.reset
This saves memory because the reset method shrinks the hash-table, whereas the clear method just empties it
Reviewed By: jvillard
Differential Revision: D16004966
fbshipit-source-id: f32b00b0f
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:
Passing an absolute project path as buck config flag makes buck caching almost impossible for infer artefacts, since on every host/run that directory can be different.
Eliminate that and rely on shell commands to find the project root, executed within the genrule.
Reviewed By: jvillard
Differential Revision: D15963807
fbshipit-source-id: b6e590029
Summary:
Some functions exposed in ScubaLogging interface were not
used outside of ScubaLogging and caused deadcode to fail.
Reviewed By: ngorogiannis
Differential Revision: D15964204
fbshipit-source-id: d823dbf8b
Summary:
Reduces the size of the `tenv` by sharing values as most as possible, in an untyped - but supposedly safe - way, by using black magic on objects.
Can be reused for other things later.
Reviewed By: ngorogiannis
Differential Revision: D15855870
fbshipit-source-id: 169a4b86b
Summary:
Using `Marshal.to_string` to create SQLite values used in comparisons is brittle as there is no guarantee that it will return the same value for structurally equal values.
When adding sharing, this will definitely break.
From the SQLite queries I found, only `SourceFile` and `Procname` are used in comparisons.
I haven't tested performance.
It shouldn't change anything for `SourceFile` as there is no possible sharing.
It shouldn't change much for `Procname` as they are pretty small anyway.
Reviewed By: ngorogiannis
Differential Revision: D15923122
fbshipit-source-id: ce4af1fe3
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:
Just moving code around.
This is needed later to make some types in `PulseTrace` depend on
a new that I'll have to define in `PulseDomain`.
Also, this gives better names all around I think
Reviewed By: mbouaziz
Differential Revision: D15881281
fbshipit-source-id: e86c1472e
Summary:
Just moving code around.
This is needed later to make some types in `PulseInvalidation` depend on
a new type that I'll have to define in `PulseDomain`.
Reviewed By: mbouaziz
Differential Revision: D15824962
fbshipit-source-id: 86cba2bfb
Summary:
Make it possible to re-use the graph visitor to compute all sorts of
things with a flexible API where you can pass a function that folds over
all addresses reachable from certain stack variables (specified with a
filter) and gets passed the access path that leads to each address.
This is used in later commits.
Reviewed By: mbouaziz
Differential Revision: D15824960
fbshipit-source-id: c424a71cb
Summary: Preanalysis is performed at the frontend now. Hence, we don't need to repeatedly check/set when/if it is performed.
Reviewed By: mbouaziz
Differential Revision: D15863175
fbshipit-source-id: f9c6b7ae1
Summary:
One "interesting" feature of the approach of merging the captured targets in Java, is that we union their type environments, as opposed to store partial tenvs together with each source file, which is the case for Clang.
This means
- the final global type environment is potentially huge because it contains all the types in all targets.
- all analysis workers start by loading that tenv in memory, meaning we consume `|size of tenv| x #cpus` memory, which can tip the balance towards OOMs
This diff attempts to economise on global tenv size. This is done by increasing sharing which is then preserved by marshalling. It's done in a brute force way, with hashtables for each struct component, and is not fully effective due to the recursion amongst types and types names, as well types appearing inside other constructs such as procnames.
This is done when calling `Tenv.store` so that
- the computation can be parallelised somewhat (capture is parallel, merging is not)
- buck caching will benefit from smaller tenvs.
This saves about 24% of total memory devoted to the type environment.
Reviewed By: mbouaziz
Differential Revision: D15840054
fbshipit-source-id: 6f03be1a4
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:
Needed for next diff: we'll need to do 2 passes on the AST to collect
the temporaries to destroy at the end of an `ExprWithCleanups`, but the
SIL names of these temporaries are generated freshly on the fly so they
would get different names if we do it naively.
This adds a hashmap to the translation context so the temporary
corresponding to a given `MaterializeTemporyExpr` is only generated once
and then reused.
Reviewed By: mbouaziz
Differential Revision: D15674212
fbshipit-source-id: 0e16062d9
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 allows to match `foo<int_&>` and many other horrible names.
Reviewed By: mbouaziz
Differential Revision: D15825403
fbshipit-source-id: c892033aa
Summary:
I realized that there was a discrepancy in the # of instructions between whether we run a single analysis or multiple analyses at the same time. It turns out that in biabduction, bufferoverrun and other HIL analyses we did Preanalysis step (which adds scope instructions and invokes liveness etc.) but not in others. This discrepancy results in inconsistent analysis results (e.g. in the new inefficient-keyset-iterator) that rely on instructions. We should be consistent. Hence, we now invoke Preanalysis in the frontend and remove all other uses in the rest of the checkers.
Consequently, I had to update the inefficient-keyset-checker to take the CFG resulting from Preanalysis with extra scoping instructions.
Reviewed By: mbouaziz, ngorogiannis, jvillard
Differential Revision: D15803492
fbshipit-source-id: 4e21eb610
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:
Move genrule capture integration logic from shell to OCaml.
Also, stop relying on side-effects of buck compilation for constructing the infer-deps.txt file used for merging. Now this is obtained by passing `--show-output` to buck, which spits out the `buck-out` output paths to the targets we asked to build.
Reviewed By: ezgicicek
Differential Revision: D15715608
fbshipit-source-id: 8fa896ba6
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:
When multiple buck java tests use the same `buck-out` they sometimes fail. This isn't surprising, as they presumably clobber each other's output when running on the same files.
Since there is no reason to have this global, shared buck repo, create one for each test, inside the test directory. Also, clean up the Makefiles a bit -- they provide bogus compile targets, for example, and have mostly wrong source dependencies.
That done, remove the `testlock` crutch which enforces mutual exclusion between tests, from the buck/java tests.
I do not understand why the buck clang tests can share the global repo without failure, but there you go.
Reviewed By: jvillard
Differential Revision: D15579133
fbshipit-source-id: 7eff79173
Summary: Not sure how that happens but it does. Instead of crashing, log the error and continue.
Reviewed By: martintrojer
Differential Revision: D15660008
fbshipit-source-id: c87e724d4
Summary: The previous commit broke the `--foo arg` case because it matched `--foo` in the case looking for `--foo=`.
Reviewed By: mbouaziz
Differential Revision: D15670472
fbshipit-source-id: ab81c7357
Summary: There's currently no way to skip these when they are passed to clang.
Reviewed By: martintrojer
Differential Revision: D15669132
fbshipit-source-id: be97d2638
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:
Somehow clang now chooses slightly different arguments to pass to `ld`
in the invocation that `ndk-build` makes to link:
```
--- clang7 2019-05-28 07:47:19.214949009 -0700
+++ clang8 2019-05-28 07:46:55.095924374 -0700
@@ -1,6 +1,15 @@
"/opt/android_ndk/r15c/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/lib/gcc/aarch64-linux-android/4.9.x/../../../../aarch64-linux-android/bin/ld"
"--sysroot=/opt/android_ndk/r15c/platforms/android-21/arch-arm64"
+"-EL"
"--fix-cortex-a53-843419"
+"-z"
+"now"
+"-z"
+"relro"
+"-z"
+"max-page-size=4096"
+"--hash-style=gnu"
+"--hash-style=both"
"--no-add-needed"
"--enable-new-dtags"
"--eh-frame-hdr"
@@ -32,7 +41,7 @@
"--fatal-warnings"
"-lc"
"-lm"
-"-lstdc++"
+"-lc++"
"-lm"
"-lgcc"
"-ldl"
```
In particular:
- `lc++` results in `libc++.so` not found from the toolchain
- the forced relocation `-z relro` fails with "/..//bin/ld: ./obj/local/arm64-v8a/objs/hello/__/hello.o: Relocations in generic ELF (EM: 183)" and other weirder errors
Somehow pretending the C++ compiler is `clang` instead of `clang++` stops the insanity.
Also add an Application.mk file to specify some sane defaults.
Also add `V=1` to the `ndk-build` invocation in our tests so that when it fails we have a bit more to work with.
Reviewed By: mbouaziz, martintrojer
Differential Revision: D15518447
fbshipit-source-id: 40203814b
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:
Infer was complaining about a parameter not null checked, which was failing the
model compilation since no errors are allowed on models.
Reviewed By: ezgicicek
Differential Revision: D15453573
fbshipit-source-id: 3bd0df715
Summary:
`infer_events` table is a key-value storage that also have list of fields common for entire infer run.
Infer should be agnostic of many of such fields (e.g. diff number).
Hence we will pass such extra fields through CI.
Note that only "normals" (strings in scuba terminology) are currently supported.
Reason being: most of things that are technically ints (like IDs) should actually be normals (because average etc does not make sense for them; and group by, in contrast, does).
Reviewed By: jvillard
Differential Revision: D15376636
fbshipit-source-id: 729eaabfc
Summary: There can be A LOT of procedures -- currently we log two lines (started/done) for each one, when doing call graph scheduling. This leads to ridiculously long log files. Switch to only log these messages in the log file and only if we are verbose logging.
Reviewed By: jvillard
Differential Revision: D15413330
fbshipit-source-id: 6e26693e8
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:
I was wondering what were the empty sessions and why inferbo was running twice.
Answer: the empty sessions were 'compute pre' and the second run of inferbo was the narrowing phase.
Reviewed By: ngorogiannis
Differential Revision: D15378138
fbshipit-source-id: 507a3df42
Summary:
This was hardcoded to `true` and its purpose is unclear to me. I kill
what confuses me.
Reviewed By: jeremydubreil
Differential Revision: D15294783
fbshipit-source-id: 3c1c469ee
Summary:
- Makes sure that `start_session` and `finish_session` are well parenthesized
- Avoids a try finally when debug is disabled
Reviewed By: ngorogiannis
Differential Revision: D15371841
fbshipit-source-id: 340203edb
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:
In preparation for the next diff that re-uses `PulseTrace.t` for a type
that combines breadcrumbs + action.
No change intended.
Reviewed By: mbouaziz, jberdine
Differential Revision: D15354437
fbshipit-source-id: cbb8757b4
Summary:
Before: no links to procedure summary and nodes in header file debug html
Now: some or all of them if you are lucky enough
Reviewed By: jvillard
Differential Revision: D15279379
fbshipit-source-id: a145f9e66
Summary:
Before: they are written only when the file is fully analyzed.
Now: a first version is written as soon as the file gets analyzed so that we get links to nodes, the final version overwrites it
Reviewed By: jvillard
Differential Revision: D15279351
fbshipit-source-id: a3120aa31
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:
API and stub implementation for real-time logging capabilities.
Low-level implementation requires interaction with FB-specific deployment of Scribe, hence it is stubbed out.
Reviewed By: jberdine
Differential Revision: D15259559
fbshipit-source-id: 712cb99e1
Summary:
Enabling starvation by default (D15158597) makes infer double report racerd
issues in these tests. The reason seems to be that both racerd and starvation
use `IssueLog` to record issues, so racerd records its issues there (using side
effects), then starvation adds its own (empty) set of issues and reports
whatever is there again. Since nothing cleans up the IssueLog in the middle,
racerd issues get reported twice: once as racerd issues and the other as
starvation issues.
Let's fix this later, for now just unbreak the test itself.
Reviewed By: mbouaziz, ngorogiannis
Differential Revision: D15277552
fbshipit-source-id: 3e7be8795
Summary: Previously there was no way of getting that list from the manual.
Reviewed By: jeremydubreil
Differential Revision: D15158598
fbshipit-source-id: 1705ed59d
Summary:
A more dynamic scheduling scheme will potentially run into the situation where no new work packets can be scheduled, but more work will be possible to schedule in the future, perhaps when some dependent work packet finishes being analysed.
The current implementation prevents that, as it expects that if a worker goes idle, it stays idle.
The changes here address this in two parts:
- the `select` call is always given a finite timeout. If given an infinite timeout, we will not be able to poll the task generator for more work, where none were previously possible.
- when the `select` call times out without updates, check if there is an idle child, and if so if the task generator has more work right now.
See also ProcessPool.mli for comments.
Reviewed By: mbouaziz
Differential Revision: D15197749
fbshipit-source-id: babe5da8e
Summary:
Before moving to any kind of non-trivial scheduling, we need to change the Tasks interface.
In particular, it's too restrictive to expect that the tasks to be scheduled are provided as a list before starting execution. For example, dynamic scheduling does not fit the bill here. Also, the list expectation means all scheduling work has to be done up front.
The solution here is to move to a `Sequence`-like interface with one difference:
- The function returning the next task expects a task option argument. That argument is the task that was just finished (if any) by the worker expecting new work. This will be useful for things like task dependencies (for instance, a procedure has been analysed, and can be marked so).
Reviewed By: mbouaziz
Differential Revision: D15181613
fbshipit-source-id: 21f3ba825
Summary:
Adds option `--summary-stats` to `infer report`.
The formatting is not perfect yet but it gives what I want.
Reviewed By: ngorogiannis
Differential Revision: D15064162
fbshipit-source-id: 56c4b4929
Summary: No reason to use custom function name and not implement `Hashable`.
Reviewed By: mbouaziz
Differential Revision: D15097603
fbshipit-source-id: 7303fc15e
Summary: Remove from inferbo summary locations that are unreachable from callers
Reviewed By: ezgicicek
Differential Revision: D15064518
fbshipit-source-id: 734e79b4a
Summary: Using `Fields.to_list` also makes sure we don't forget fields.
Reviewed By: ezgicicek
Differential Revision: D15062353
fbshipit-source-id: aaac9be99
Summary:
TOPL properties are essentially automata, which will be modeled as a set
of procedures. The code-to-analyze makes calls into these procedures,
thereby driving the automaton. In this commit, these calls do not do
anything. The point is to prepare the hook-up mechanism.
Reviewed By: jvillard
Differential Revision: D14819650
fbshipit-source-id: d95ecdb3d
Summary: The name was misleading, the function only forget locs for relations.
Reviewed By: ezgicicek
Differential Revision: D15045933
fbshipit-source-id: 7f41a55e7
Summary:
- `--source-files` was missing.
- The three modes are actually independent, make it clearer and group options by mode.
- Fail if `--procedures` and `--source-files` are used together.
Reviewed By: jeremydubreil
Differential Revision: D15049822
fbshipit-source-id: cc515cb56
Summary:
Replace `$(u,...)` with `$(i,...)` since `$(u,...)` doesn't exist.
Cmdliner was emitting a warning at runtime:
cmdliner error: Unknown cmdliner markup $(u,...) in "Specify classes where the destructor should be ignored when computing liveness. In other words, assignement to variables of these types (or common wrappers around these types such as $(u,unique_ptr<type>)) will count as dead stores when the variables are not read explicitly by the program. (default: $(i,[]))"
Reviewed By: mbouaziz
Differential Revision: D15045004
fbshipit-source-id: e03ece4f7
Summary:
A long-standing easter egg from infer error messages is the "object
`null` could be null and is dereferenced at line ...". I tried to fix
this but the part that generates the first "null" in the message and the
part that generates the second one are very far apart and it's hard to
see how to make the second part aware of the first in a clean way.
Instead, hack around it by detecting if the string representing the
value is literally `null` and in that case chop `could be null ` from
the error messages...
Reviewed By: jeremydubreil
Differential Revision: D14972324
fbshipit-source-id: ccc48ce6b
Summary:
We get messages like " object returned by `getArguments()` at line 101."
instead of " object returned by `getArguments()` could be null and is
dereferenced at line 101.". Tracking it down, it happens for
nullable-looking values, but I don't know why.
It seems that something regressed but I couldn't track it down.
So, just generate the error message in the same way as for non-nullable
objects in this case to fix the non-sensical message.
Reviewed By: jeremydubreil
Differential Revision: D14972325
fbshipit-source-id: 2a97501cc
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 is useful for the model of `exit` that returns 0 disjuncts. All
other models return 1 disjunct for now, but in the future things like
`malloc()` will need to return 2 possible states for instance.
Reviewed By: ngorogiannis
Differential Revision: D14753491
fbshipit-source-id: 3e7387d6d
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
Summary:
We see the magic function `__variable_initialization` at the point where
the variable is declared, eg `int x = foo()`. It's safe to reset `&x` at
that point. This circumvents an issue that pops up in some rare cases
where the ternary conditional operator `?:` and variable initialization
conspire to produce weird frontend results.
Some test becomes a FN again, but I think it was being reported for the
wrong reasons; will investigate more later.
Reviewed By: ngorogiannis
Differential Revision: D14747980
fbshipit-source-id: e75d6e30f
Summary:
This is ~2.5x wall clock faster, ~5x user time faster, and finds 98% of
the bugs. Not very scientific yet but seems better than the previous
non-scientific arbitrary default.
Reviewed By: ngorogiannis
Differential Revision: D14753494
fbshipit-source-id: b72cdd613
Summary:
Useful to know which disjunct is being executed. Reprinting them
wholesale is too spammy so compromise by outputting just enough to be
able to reconstruct the info "which disjunct was executed and which new
disjuncts were produced?".
Reviewed By: ngorogiannis
Differential Revision: D14753495
fbshipit-source-id: f5aa68160
Summary:
This isn't needed now that this information is recorded in
`PulseTrace.action` instead.
Reviewed By: mbouaziz
Differential Revision: D14645089
fbshipit-source-id: 9c3f38722
Summary:
This ensures that each attribute type can only be present once per
address. Makes ~80x time improvement on pathological cases such as
Duff's device.
This introduces a new kind of Set in `PrettyPrintable`.
Reviewed By: mbouaziz
Differential Revision: D14645091
fbshipit-source-id: c7f9b760c
Summary:
Detect when a variable goes out of scope. When that's the case, mark its
address *and* its contents as invalid.
Give subsequent uses a USE_AFTER_LIFETIME error type instead of
USE_AFTER_DESTRUCTOR.
Reviewed By: jberdine
Differential Revision: D14387147
fbshipit-source-id: a2c530fda
Summary:
This provides a way for AI checkers to read the formals of a procedure,
or other things related to its `Procdesc.t`.
Reviewed By: mbouaziz
Differential Revision: D14258483
fbshipit-source-id: a28e28d3c
Summary:
For each operation on the domain, try to record what it requires of the
precondition of the function. This is akin to what happens in the
biabduction backend, hence the terminology used.
Reviewed By: jberdine
Differential Revision: D14387148
fbshipit-source-id: a61fe30c8
Summary:
This is in preparation of interprocedural pulse. The abstract addresses
generator keeps a reference to create fresh addresses, but that's a
piece of global state that needs to persist across ondemand analyses.
Reviewed By: jberdine
Differential Revision: D14324760
fbshipit-source-id: 5cdb1d3f5
Summary:
Increases precision a bit. I didn't observe speed problems on what I tested. (But, who knows?)
Closes https://github.com/facebook/infer/pull/799
Reviewed By: jvillard
Differential Revision: D6284206
Pulled By: rgrig
fbshipit-source-id: 6f1e8631f
Summary:
Instead of emitting an ad-hoc builtin on variable declaration emit a new
metadata instruction. This allows us to remove the code matching on that
ad-hoc builtin that had to be inserted in several checkers.
Inferbo & pulse used that information meaningfully and had to undergo
some minor changes to cope with the new metada instruction.
Reviewed By: ezgicicek
Differential Revision: D14833100
fbshipit-source-id: 9b3009d22
Summary:
Bundle all non-semantic-bearing instructions into a `Metadata _`
instruction in SIL.
- On a documentation level this makes clearer the distinction between
instructions that encode the semantics of the program and those that are
just hints for the various backend analysis.
- This makes it easier to add more of these auxiliary instructions in
the future. For example, the next diff introduces a new `Skip` auxiliary
instruction to replace the hacky `ExitScope([], Location.dummy)`.
- It also makes it easier to surface all current and future such
auxiliary instructions to HIL as the datatype for these syntactic hints
can be shared between SIL and HIL. This diff brings `Nullify` and
`Abstract` to HIL for free.
Reviewed By: ngorogiannis
Differential Revision: D14827674
fbshipit-source-id: f68fe2110
Summary:
Several tools that use ocamlformat look for the "project root" in
order to find the config for a given file to format. The project root
is inferred by looking in ancestor directories of the input file until
one of .git, .hg, or dune-project is found. Since the .ocamlformat
config file is currently two directories higher than dune-project,
this fails. This diff moves the config file.
Reviewed By: jvillard
Differential Revision: D14694260
fbshipit-source-id: 2fb51bf30
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:
Some of these tests were wrong, eg `~lambda()` calls `lambda()` then...
takes the bitwise complement or something? The intent was to call the
destructor.
Add interprocedural tests for later.
Reviewed By: jberdine
Differential Revision: D14324762
fbshipit-source-id: 40d2c32f5
Summary:
Previously we would say that `lhs <= rhs` (or `lhs |- rhs`) when a
mapping existed between the abstract addresses of `lhs` and `rhs` such
that `mapping(lhs)` was a supergraph of `rhs`. In particular,
we had that `x |-> x' * x' |-> x'' |- x |-> x'`. This is not entirely
great, in particular once we get pairs of state representing footprint +
current state. I'm not sure I have an extremely compelling argument why
though, except that it's not the usual way we do implication in SL, but
there wasn't a compelling argument for the previous state of affairs
either.
This changes `|-` to be true only when `mapping(lhs) = rhs` (modulo only
considering the addresses reachable from the stack variables).
Reviewed By: jberdine
Differential Revision: D14568272
fbshipit-source-id: 1bb83950e
Summary: This helps convergence when `<=` is based on physical equality for example, and widening is implemented as `widen ~prev ~next = join prev next`.
Reviewed By: skcho
Differential Revision: D14568270
fbshipit-source-id: ded5ed296
Summary: It's all grown up now and taking quite some space in src/checkers/.
Reviewed By: skcho
Differential Revision: D14568273
fbshipit-source-id: b843c031e
Summary:
Open fewer sessions by wrapping AI operations together in the same HTML
node session. This allows us to also print more stuff, such as whether
the current loop computation has converged.
Reviewed By: skcho
Differential Revision: D14568274
fbshipit-source-id: d47110cf4
Summary:
Re-declarations of global variables sometimes hide constant
initializations in the original declaration, which caused FN before.
In this diff, it translates global variables to point to original
declarations, rather than following re-declarations, if possible.
Reviewed By: mbouaziz, jvillard
Differential Revision: D14596301
fbshipit-source-id: 55c3b5f95
Summary: In SIL, sometimes a return value is assigned to `__return_param`.
Reviewed By: ezgicicek, mbouaziz
Differential Revision: D14538590
fbshipit-source-id: dfbb74dc2
Summary: This diff substitutes symbolic values for unknown functions in proof obligations to top. The goal of the diff is to avoid generating too many number of proof obligations that cannot be concretized.
Reviewed By: ezgicicek
Differential Revision: D14537542
fbshipit-source-id: 7f8f3bb4b
Summary:
TOPL properties are essentially automata, which specify a bad pattern.
This commit is just a parser for them.
Reviewed By: jvillard
Differential Revision: D14477671
fbshipit-source-id: c38a8ef37
Summary:
Add support for GuardedBy: we deviate from the spec as follows:
- No warnings issued for any access within a private method, unless that method is called from a public method and the lock isn't held when the access occurs.
- Warnings are suppressed with the general RacerD mechanism, ie `ThreadSafe(enableChecks=false)`
- GuardedBy warnings override thread-safety violation warnings on the same access, because GuardedBy has a clearer and simpler contract.
Also, some simplifications, cleanups and perf improvements (eg avoid unreportable procs at the top level as opposed to on each of their accesses).
Reviewed By: jeremydubreil
Differential Revision: D14506161
fbshipit-source-id: b7d794051
Summary:
While adding a footprint frame during rearrangement, the footprint
variables should be fresh with respect to the current state too, not
only with respect to he footprint, because the frame is added to the
state.
Reviewed By: jberdine
Differential Revision: D14401026
fbshipit-source-id: 20ea4485a
Summary:
Context: "quandary" traces optimise for space by only storing a call site (plus analysis element) in a summary, as opposed to a list of call sites plus the element (i.e., a trace). When forming a report, the trace is expanded to a full one by reading the summary of the called function, and then matching up the current element with one from the summary, iterating until the trace cannot be expanded any more. In the best case, this can give a quadratic saving, as a real trace gets longer the higher one goes in the call stack, and therefore the total cost of saving that trace in each summary is quadratic in the length of the trace. Quandary traces give a linear cost.
HOWEVER, these have been a source of many subtle bugs.
1. The trace expansion strategy is very arbitrary and cannot distinguish between expanded traces that are invalid (i.e., end with a call and not an originating point, such as a field access in RacerD). Plus the strategy does not explore all expansions, just the left-most one, meaning the left most may be invalid in the above sense, but another (not left-most) isn't even though it's not discovered by the expansion. This is fixable with major surgery.
2. All real traces that lead to the same endpoint are conflated -- this is to save space because there may be exponentially many such traces. That's OK, but these traces may have different locking contexts -- one may take the lock along the way, and another may not. The expansion cannot make sure that if we are reporting a trace we have recorded as taking the lock, will actually do so. This has resulted in very confusing race reports that are superficially false positives (even though they point to the existence of a real race).
3. Expansion completely breaks down in the java/buck integration when the trace goes through f -> g -> h and f,g,h are all in distinct buck targets F,G,H and F does not depend directly on H. In that case, the summary of h is simply not available when reporting/expanding in f, so the expanded trace comes out as truncated and invalid. These are filtered out, but the filtering is buggy and kills real races too.
This diff completely replaces quandary traces in RacerD with plain explicit traces.
- This will incur the quadratic space/time cost previously saved. See test plan: there is indeed a 30% increase in summary size, but there is no slowdown. In fact, on openssl there is a 10-20% perf increase.
- For each endpoint, up to a single trace is used, as before, so no exponential explosion. However, because there is no such thing as expansion, we cannot get it wrong and change the locking context of a trace.
- This diff is emulating the previous reporting format as much as possible to allow good signal from the CI. Further diffs up this stack will remove quandary-trace specific things, and simplify further the code.
- 2 is not fully addressed -- it will require pushing the `AccessSnapshot` structure inside `TraceElem`. Further diffs.
Reviewed By: jberdine
Differential Revision: D14405600
fbshipit-source-id: d239117aa
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:
To meet the pure parts of formulas, the process was to (a) call Rename.extend
with variables occuring in similar places and (b) extract substitutions out of
those. Two matching primed vars would both be replaced by some fresh primed var.
However, equivalence classes of primed variables would *not* be replaced by
one fresh (primed) variable. Now, that should work.
Reviewed By: mbouaziz
Differential Revision: D14150192
fbshipit-source-id: 90ca9216c
Summary:
This will be used in the future to determine what to do with destructors
in pulse.
Reviewed By: mbouaziz
Differential Revision: D14324759
fbshipit-source-id: bc3c34471
Summary:
This seems generally useful. Force people to do it in the future even if
they want to avoid having to update the frontend tests.
Reviewed By: mbouaziz
Differential Revision: D14324758
fbshipit-source-id: cdef3f72a
Summary:
Before: the abstract state represents heap addresses as a single map
from addresses to edges + attributes.
After: the heap is made of 2 maps: one mapping addresses to edges, and
one mapping an address to its attributes.
It turns out that edges and attributes are often not updated at the same
time, so keeping them in the same map was causing pressure on the OCaml
gc.
Reviewed By: mbouaziz
Differential Revision: D14147991
fbshipit-source-id: 6713eeb3c
Summary:
This is basically unused except for debugging and is going to cause
issues later.
Reviewed By: mbouaziz
Differential Revision: D14258490
fbshipit-source-id: b2800990e
Summary:
This fixes (if in a hackish way) an inherently quadratic behaviour in
the disjunctive domain when analysing loops: If you start with some
disjuncts `D1 \/ ... \/ Dn` and go once around the loop, you will end up
with disjuncts `(D1 \/ ... \/ Dn) \/ (D1' \/ ... \/ Dn')` assuming that
for all `i`, `{ Di } body of loop { Di' }` (in practice there is the
added difficulty that the post of the body of the loop can be a
disjunction too instead of a single abstract state). Assuming this isn't
a fixpoint, we would then go around the loop again from `D1`, ..., `Dn`,
`D1'`, ..., `Dn'`. However we already know what the posts of `D1` to `Dn`
are!
This attempts to curb duplicate work by marking the disjuncts in `prev`
as "visited" and instructing symbolic execution to skip visited states.
Then, once convergence is detected (from within `widen` for now) we mark
again all states as unvisited so that whatever is after the loop gets
symbolically executed.
This is a hack because ideally the AI scheduler would know about
disjunctive domain and schedule individual disjuncts for analysis.
However that would be a much bigger change. Let's see if the hack is
enough for now.
Reviewed By: mbouaziz
Differential Revision: D14258491
fbshipit-source-id: 21454398c
Summary:
When joining two lists of disjuncts we try to ensure there isn't a state
that under-approximates another already in the list. This helps reduce
the number of disjuncts that are generated by conditionals and loops.
Before we would always just add more disjuncts unless they were
physically equal but now we do a subgraph computation to assess
under-approximation.
We only do this half-heartedly for now however, only taking into
consideration the "new" disjuncts vs the "old" ones. It probably makes
sense to do a full quadratic search to minimise the number of disjuncts
from time to time but this isn't done here.
Reviewed By: mbouaziz
Differential Revision: D14258482
fbshipit-source-id: c2dad4889
Summary:
This removes the "abstract addresses" that used to be stored in the `Closure` attribute of pulse abstract addresses. There used to be a list of values recorded for each closure, each one representing one captured value. Instead these values are now recorded as fake edges in the memory graph.
Having addresses appear in attributes causes issues when trying to establish graph isomorphism between two memory states. Avoid it by rewriting the closures mechanism to encode captured addresses as fake edges in memory. This way captured addresses are automatically treated right by the graph algorithms (in the next diffs).
Reviewed By: mbouaziz
Differential Revision: D14323044
fbshipit-source-id: 413b4d989
Summary: Unknown locations in the alias domain resulted in unexpected unreachable code.
Reviewed By: mbouaziz
Differential Revision: D14339412
fbshipit-source-id: a5dca6489
Summary:
The disjunctive domain shouldn't really be a set in the first place as
comparing abstract states for equality is expensive to do naively
(walking the whole maps representing the abstract heap). Moreover in
practice these sets have a small max size (currently 50 for pulse, the
only client), so switching them to plain lists makes sense.
Reviewed By: mbouaziz
Differential Revision: D14258489
fbshipit-source-id: c512169eb
Summary:
It's useful to keep the size of states down, especially when humans are
trying to read it. It will also help keep the size of summaries down in
the inter-procedural pulse.
Reviewed By: mbouaziz
Differential Revision: D14258486
fbshipit-source-id: 45ebcac67
Summary:
You can only take the address of variables, field accesses, and array
accesses, the rest doesn't make sense.
Reviewed By: mbouaziz
Differential Revision: D14258484
fbshipit-source-id: 8ddcfe810
Summary: Spent some time staring at empty HTML output instead of seeing `<Some ...>` because I'm dumb. Now it's dumb proof.
Reviewed By: mbouaziz
Differential Revision: D14258492
fbshipit-source-id: d1368d212
Summary: After a redeclaration of a global constant, it is not parsed as ICE(integral constant expression), which results in FN.
Reviewed By: ezgicicek
Differential Revision: D14299288
fbshipit-source-id: 394afd595
Summary:
It assigns symbolic values for global variables in the load commands. However, it does not instantiate the symbols for the global variables yet, which will be addressed in another diff.
Depends on D14208643
Reviewed By: ezgicicek
Differential Revision: D14257619
fbshipit-source-id: f9113c8a3
Nikos Gorogiannis
Jules Villard
Phoebe Nichols
David Pichardie
Artem Pianykh
Mehdi Bouaziz
Ezgi Çiçek
Radu Grigore
Dino Distefano
Josh Berdine
Martin Trojer
Peter O'Hearn
Jeremy Dubreil
Mitya Lyubarskiy
Andrew Adams-Moran
David Lively
Lee Howes
Daniel Mercier
Radu Grigore
Katie Ots
Sungkeun Cho
Wenzhe Lu