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:
The purpose these serve is unclear to me. From the comment I *think*
they were used to hint to the biabduction backend that smart pointers
are just pointers. That said, The tests still mostly pass even without
that (just a few `weak_ptr` tests changed from `NULL_DEREFERENCE` to
`Bad_footprint`).
Moreover, this extra dereference was added unreliably. For instance,
this piece of code:
```
auto x = std::make_unique<X>(some_X);
```
would either get the extra dereference or not depending on which headers
were picked for the C++ stdlib.
The extra dereference was tripping up the liveness checker (see later in
the stack), and probably most checkers too.
Reviewed By: mbouaziz
Differential Revision: D13991130
fbshipit-source-id: 462923595
Summary:
Before, the liveness pre-analysis would place extra instructions in the
CFG for either:
1. marking an `Ident.t` as dead, or
2. marking a `Pvar.t` as `= 0`
But we have no way of marking pvars dead without setting them to 0. This
is bad because setting pvars to 0 is not possible everywhere they are
dead. Indeed, we only do it when we haven't seen their address being
taken anyway. This prevents the following situation, recorded in our tests:
```
int address_taken() {
int** x;
int* y;
int i = 7;
y = &i;
x = &y;
// if we don't reason about taken addresses while adding nullify instructions,
// we'll add
// `nullify(y)` here and report a false NPE on the next line
return **x;
}
```
So we want to mark pvars as dead without nullifying them. This diff
extends the `Remove_temps` SIL instruction to accept pvars as well, and
so renames it to `ExitScope`.
Reviewed By: da319
Differential Revision: D13102953
fbshipit-source-id: aa7f03a52
Summary:
Useful to understand the changes in the pre-analysis, or to inspect the
CFG that checkers actually get.
This means that the pre-analysis always runs when we output the dotty,
but I don't really see a reason why not. In fact, we could probably
*always* store the CFGs as pre-analysed.
Reviewed By: mbouaziz
Differential Revision: D13102952
fbshipit-source-id: 89f3102ec
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:
Change the license of the source code from BSD + PATENTS to MIT.
Change `checkCopyright` to reflect the new license and learn some new file
types.
Generated with:
```
git grep BSD | xargs -n 1 ./scripts/checkCopyright -i
```
Reviewed By: jeremydubreil, mbouaziz, jberdine
Differential Revision: D8071249
fbshipit-source-id: 97ca23a
Summary:
Previously, the type of `trans_result` contained a list of SIL expressions.
However, most of the time we expect to get exactly one, and getting a different
number is a soft(!) error, usually returning `-1`.
This splits `trans_result` into `control`, which contains the information
needed for temporary computation (hence when we don't necessarily know the
return value yet), and a new version of `trans_result` that includes `control`,
the previous `exps` list but replaced by a single `return` expression instead,
and a couple other values that made sense to move out of `control`. This allows
some flexibility in the frontend compared to enforcing exactly one return
expression always: if they are not known yet we stick to `control` instead (see
eg `compute_controls_to_parent`).
This creates more garbage temporary identifiers, however they do not show up in
the final cfg. Instead, we see that temporary IDs are now often not
consecutive...
The most painful complication is in the treatment of `DeclRefExpr`, which was
actually returning *two* expressions: the method name and the `this` object.
Now the method name is a separate (optional) field in `trans_result`.
Reviewed By: mbouaziz
Differential Revision: D7881088
fbshipit-source-id: 41ad3b5
Summary:
This simplifies the frontends and backends in most cases. Before this diff,
returning `void` could be modelled either with a `None` return, or a dummy
return variable with type `Tvoid`. Now it's always the latter.
Reviewed By: sblackshear, dulmarod
Differential Revision: D7832938
fbshipit-source-id: 0a403d1
Summary:
When looking at large CFGs, at least in `xdot`, it's often difficult to find
the procedure you're looking for. Sorting the proc names puts them in
alphabetical order, which makes searching one procedure easier.
Reviewed By: mbouaziz
Differential Revision: D7758521
fbshipit-source-id: 8e9997f
Summary:
Not sure what an "iCFG" is but the dotty is only about CFGs anyway.
Diff obtained by mass-`sed`.
Reviewed By: sblackshear
Differential Revision: D6324280
fbshipit-source-id: b7603bb
Summary:
The previous domain for SIOF was duplicating some work with the generic Trace
domain, and basically was a bit confused and confusing. A sink was a set of
global accesses, and a state contains a set of sinks. Then the checker has to
needlessly jump through hoops to normalize this set of sets of accesses into a
set of accesses.
The new domain has one sink = one access, as suggested by sblackshear. This simplifies
a few things, and makes the dedup logic much easier: just grab the first report
of the list of reports for a function.
We only report on the fake procedures generated to initialise a global, and the
filtering means that we keep only one report per global.
Reviewed By: sblackshear
Differential Revision: D5932138
fbshipit-source-id: acb7285
Summary:
With this change and the previous facebook-clang-plugins change, infer no
longer exhausts the biniou buffer when reading the serialized C++ AST.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D5891081
fbshipit-source-id: cf48eac
Summary: `__attribute__((annotate("")))` is better way of passing information to the frontend
Reviewed By: jberdine
Differential Revision: D4818805
fbshipit-source-id: 6e8add2
Jules Villard
David Lively
Mehdi Bouaziz
Dulma Churchill
Andrzej Kotulski