Summary: Inject destructor calls to destroy a temporary when its lifetime ends.
Reviewed By: mbouaziz
Differential Revision: D15674209
fbshipit-source-id: 0f783a906
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:
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:
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:
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:
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:
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:
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:
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:
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:
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:
Now that we got rid of dummy nodes used non-dummily (biabduction state, reporting), `pname` don't need to be an option anymore.
Let's save a boxing on all nodes.
Reviewed By: jeremydubreil
Differential Revision: D9654152
fbshipit-source-id: 83b00f239
Summary: No dummy node key, as a consequence the option `--skip-duplicated-types` will have no effect on issues with no node key, i.e. issues reported by non-biabduction non-eradicate checkers.
Reviewed By: martinoluca
Differential Revision: D9633564
fbshipit-source-id: 9ff8abf21
Summary:
- abstracted the type for a node key
- moved it to its own module with an ugly `compute` to avoid cyclic dependencies...
- renamed `node_id` to `node_id_key` where needed
- moved key computation from `State` to `Procdesc.Node`
Reviewed By: jvillard
Differential Revision: D9332803
fbshipit-source-id: fe1ae8c1c
Summary: C++17 introduce guaranteed copy elision which omits constructor calls. In ownership analysis, we depended on these constructor calls to acquire ownership. In particular, when a method returns struct, previously, a constructor was used to acquire ownership. In this diff, we acquire ownership of the returned structs directly.
Reviewed By: mbouaziz
Differential Revision: D9244302
fbshipit-source-id: ae8261b99
Summary: Added variant type for statement node to make it cleaner to match a particular statement node.
Reviewed By: mbouaziz
Differential Revision: D8997124
fbshipit-source-id: e19f6eacd
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
Jules Villard
Ezgi Çiçek
Josh Berdine
Radu Grigore
Nikos Gorogiannis
Jeremy Dubreil
Mehdi Bouaziz
Daiva Naudziuniene
Martin Trojer
Dulma Churchill