Summary:
Before we were computing the size of an abstract state (`range`) using the `NonNegativeBound` domain but it wasn't able to express product of symbolic values.
This diff introduces a domain for that.
The range of an interval is still computed in `NonNegativeBound` but then the product is done in `TopLiftedPolynomial` so all costs end up being of that type.
The //symbols// of a polynomial are `NonNegativeBound` (so the polynomial only represent non-negative values, perfect for a cost), which handles substitution correctly, i.e. it gives zero instead of negative values.
Reviewed By: ddino
Differential Revision: D7397229
fbshipit-source-id: 6868bb7
Summary:
Java arrays have an internal length that can be retrieved with the internal `__get_array_length`.
Here is a model for it.
Reviewed By: jvillard
Differential Revision: D7931572
fbshipit-source-id: fd4c179
Summary:
Attempt at a better naming scheme:
- `Specs.summary` are now `Summary.t`. The `Summary` module (replacing `Specs`) contains the summary of a procedure: the results of all the analyses, etc.
- `Summary.ml` is now `SummaryPayload.ml`. This concerns how each (AI) analysis extracts its payload from the master summary.
- Accordingly, checkers now define a `Payload` module where previously they defined a `Summary` module. The type is also cleaned up to use `t` instead of `payload`, etc.
- Cleaned up some names as a result, for instance `Specs.get_summary` -> `Summary.get`, etc.
Reviewed By: ngorogiannis
Differential Revision: D7935883
fbshipit-source-id: 1766545
Summary:
This is an attempt to make things more consistent, and maybe save some work
from the `Format` module in case flambda doesn't have our backs.
Reviewed By: jberdine
Differential Revision: D7775496
fbshipit-source-id: 59a6314
Summary:
The Cost analysis uses `Bound` for non-negative values only, let's make it a separate module (and abstract type).
This also separates the abstract domain part of `Bound` which we wanted anyway.
Depends on D7844267
Depends on D7843351
Depends on D7782184
Reviewed By: ddino
Differential Revision: D7844572
fbshipit-source-id: 0e6b620
Summary: We were wrongly using the underapproximation of `min` rather than the overapproximation
Reviewed By: ddino
Differential Revision: D7844267
fbshipit-source-id: c9d9247
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:
Add warning 60 (unused module) to the list of fatal warnings. Whitelisting
modules at toplevel is tricky (see inline comments) but doable.
Reviewed By: mbouaziz
Differential Revision: D7790073
fbshipit-source-id: 6f591c4
Summary:
Now that we have the abstract state at the instruction level, we don't need to reexecute instructions during the checking phase and can just query the invariant map.
Depends on D7608526
Reviewed By: skcho
Differential Revision: D7775889
fbshipit-source-id: be17e2d
Summary:
Upgrade ocamlformat, and base which needs to be done in sync in order to build
ocamlformat, and the other deps can come for the ride.
Reviewed By: jvillard
Differential Revision: D7663537
fbshipit-source-id: 3e90970
Summary:
Now that everything can run at the same time and we have preanalyses, it can be quite hard to read debug sessions.
Here come session names!
Depends on D7607336
Reviewed By: sblackshear
Differential Revision: D7607481
fbshipit-source-id: 676af86
Summary:
So we can share stuff between analyses using the same CFG and node representation.
Depends on D7586302
Depends on D7586348
Depends on D7568701
Reviewed By: sblackshear
Differential Revision: D7586645
fbshipit-source-id: ed64b2c
Summary: This will facilitate accessing Inferbo abstract state at the instruction level from the Cost analysis
Reviewed By: ddino
Differential Revision: D7568701
fbshipit-source-id: 84ac648
Summary:
Got rid of `Itv.equal` which was ambiguous and use an abstract boolean type for abstract comparison results
Depends on D7568573
Reviewed By: jvillard
Differential Revision: D7568583
fbshipit-source-id: 0e897e9
Summary:
Convenience function for `prune_eq` with zero (needed for stacked diffs).
Renamed `prune_zero` to `prune_ne_zero` to avoid ambiguity.
Reviewed By: jvillard
Differential Revision: D7568556
fbshipit-source-id: b95ab6d
Summary:
This information is already available in the trace, and can contain absolute
paths to system includes (or infer's own clang runtime), which confuses the
diff analysis.
Reviewed By: mbouaziz
Differential Revision: D7534609
fbshipit-source-id: 5bd8f8b
Summary:
It renames `eval_locs` to `eval_arr` and we use it for getting array block values the given input expressions are pointing to. For example, when given a program variable `x` as an input, `eval_arr` returns array blocks that `x` is pointing to, on the other hand, `eval` returns an abstract location of `x`.
Depends on D7471891
Reviewed By: mbouaziz
Differential Revision: D7471915
fbshipit-source-id: b994944
Summary: In the pointer arithmetics, it returns top, if we cannot precisely follow the physical memory model, e.g., (&x + 1).
Reviewed By: mbouaziz
Differential Revision: D7453510
fbshipit-source-id: db8738e
Summary:
`Bottom` is only useful for unreachable code detection, which is already handled.
Let's not check `Bottom` states.
Depends on D7289084
Reviewed By: skcho
Differential Revision: D7289153
fbshipit-source-id: 8333ce7
Summary: It adds an issue type, `BUFFER_OVERRUN_U5`, for alarms involving unknown values, i.e., when the trace set includes an unknown function call.
Reviewed By: mbouaziz
Differential Revision: D7178841
fbshipit-source-id: bfe857b
Summary: It corrects a precision bug in the interval domain, with adding some test cases.
Reviewed By: mbouaziz
Differential Revision: D7230918
fbshipit-source-id: 3ec641a
Summary:
Show some `SymAssign`s (corresponding to parameters) in the trace.
Depends on D7194448
Reviewed By: skcho
Differential Revision: D7194479
fbshipit-source-id: 0deff6c
Summary: It corrects a bug that `&(x.f[n])` was evaluated to `&(x.f[0])`.
Reviewed By: mbouaziz
Differential Revision: D7179620
fbshipit-source-id: 04cbaa7
Summary: It simply resizes the target structure instead of allocating new heap memories and copying values.
Reviewed By: mbouaziz
Differential Revision: D7179353
fbshipit-source-id: 9c20f64
Summary: It avoids that locations of array fields are evaluated to the `unknown` location incorrectly by addressing the case in the `eval_lindex` function.
Reviewed By: mbouaziz
Differential Revision: D7152736
fbshipit-source-id: 2dc825e
Summary: It collects array accesses from all sub expressions in commands.
Reviewed By: mbouaziz
Differential Revision: D7165098
fbshipit-source-id: 584dc80
Summary: It does not only malloc a new heap memory, but also copy its contents.
Reviewed By: mbouaziz
Differential Revision: D7152194
fbshipit-source-id: 58cba5e
Summary:
Because it matches calls (procnames and argument list) and because I will create a `Procname`-only one.
Depends on D7124847
Reviewed By: skcho
Differential Revision: D7124877
fbshipit-source-id: eca7c21
Summary:
At function calls, it copies a subset of heap memory that is newly
allocated by callees and is reachable from the return value.
Reviewed By: mbouaziz
Differential Revision: D7081425
fbshipit-source-id: 1ce777a
Summary:
The `may_last_field` boolean value in the `decl_sym_val` function presents that the location *may* (not *must*) be a flexible array member.
By the modular analysis nature, it is impossible to determine whether a given argument is a flexible array member or not---because of lack of calling context. For example, there are two function calls of `foo` below: (2) passes a flexible array member as an argument and (1) passes a non-flexible array, however it is hard to notice when analyzing the `foo` function.
```
struct T {
int c[1];
};
struct S {
struct T a;
struct T b;
};
void foo(struct T x) { ... }
void goo () {
struct S* x = (struct S*)malloc(sizeof(struct S) + 10 * sizeof(int));
foo(&(x->a)); // (1)
foo(&(x->b)); // (2)
}
```
We assume that any given arguments may stem from the last field of struct, i.e., flexible array member. (This is why `decl_sym_val` is called with `may_last_field:true` at the first time.) With some tests, we noticed that the assumption does not harm the analysis precision, because whether regarding a parameter as a flexible array member or not is about using a symbolic array size instead of a constant array size written in the type during the analysis of callee. Therefore still it can raise correct alarms if the actual parameter is given in its caller.
Reviewed By: mbouaziz
Differential Revision: D7081295
fbshipit-source-id: a4d57a0
Summary:
It supports flexible array member using the following heuristic:
- a memory for a class is allocated by `malloc(sizeof(C) + n * sizeof(T))` format
- the last field of the class is an array
- the static size of the last field is one, i.e., `T field_name[1]`
When allocating and initializing members of classes, it sets the size of flexible array to `n+1` if the above conditions are met.
Reviewed By: mbouaziz
Differential Revision: D7056291
fbshipit-source-id: 31c5868
Summary:
The semantics of "placement new" is defined simply as an assignment.
For example, `C* x = new (y) C();` is analyzed as if `C* x = y;`.
Reviewed By: mbouaziz
Differential Revision: D7054007
fbshipit-source-id: 1c6754f
Summary:
It abstracts the environments required in modeling functions and type
declarations as a record type.
Reviewed By: mbouaziz
Differential Revision: D7065996
fbshipit-source-id: b60cd3c
Summary:
This commit improves precision of symbol instantiations.
When a return value of a callee is `[s1 + s2, _]` and if we want to
instantiate `s1` to `c3 + max(c4, s5)`, the lower bound was
substituted to `-oo` because our domain cannot express `c3 + max(c4,
s5) + s2`.
However, we can have instantiations that are preciser than `-oo`:
(1) `c3 + c4 + s2`
(2) or `c3 + s5 + s2`
because they are smaller than the ideal instantiation, `c3 + max(c4,
s5) + s2` and it is on the lower bound position.
For now, the implementation instantiates to (1) between the two ones,
because constant values introduced by `assert` or `assume`(`if`)
command are often used as safety conditions, e.g., `assert(index >=
0);` can place before array accesses. (We can change the stratege
later if we find that it doesn't work on some other cases.)
Reviewed By: mbouaziz
Differential Revision: D7020063
fbshipit-source-id: 62fb390
Summary:
It prunes abstract memories on `assert` commands.
Problem: Since the assert command is sometimes translated to two
sequential `if` statments, it was not able to prune the memory
precisely at `assert` commands in Inferbo---the pruned memory at the
first branch was joined before the second branch.
Solution: To avoid losing the pruning information at the first branch,
now, it records which locations are pruned at the first branch and
applies the same pruning at the next branch if they have
semantically the same condition.
Reviewed By: mbouaziz
Differential Revision: D6895919
fbshipit-source-id: 15ac1cb
Summary: The heuristics to determine the end of a block/procedure was too brittle, the new one ignores non significant instructions.
Reviewed By: jvillard
Differential Revision: D6845380
fbshipit-source-id: feab557
Summary:
- `NonZeroInt` for added guarantees on the invariants of `SymLinear` coefficients
- some simplifications
- some optimizations
Reviewed By: jvillard
Differential Revision: D6833968
fbshipit-source-id: 39e28a0
Summary:
`&::.*-->` allows to match any path end.
Used for models of `std::array` to force unmodelled functions (and types) to have a Skip summary
Depends on D6408415
Reviewed By: jvillard
Differential Revision: D6611203
fbshipit-source-id: 6663b2c
Summary:
Found the dead code with the script in the next commit, iteratively until no
warnings remained.
Methodology:
1. I kept pretty-printers for values, which can be useful to use from infer's REPL (or
when printf-debugging infer in general)
2. I kept functions that formed some consistent API (but not often, so YMMV), for instance if it looked like `Set.S`, or if it provides utility functions for stuff in development (mostly the procname dispatcher functions)
3. I tried not to lose comments associated with values no longer exported: if the value is commented in the .mli and not the .ml, I moved the comment
4. Some comments needed updating (not claiming I caught all of those)
5. Sometimes I rewrote the comments a bit when I noticed mis-attached comments
Reviewed By: mbouaziz
Differential Revision: D6723482
fbshipit-source-id: eabaafd
Summary:
Upgrade ocamlformat to 0.3, and (necessarily) base to v0.10.0.
- Fix accumulated mis-formatting
- Update opam.lock to unbreak clean build
- Update to base v0.10.0
- Update opam.lock for base
- Update offline opam repo
- Everyone should already have removed their ocamlformat pin
- ocamlformat 0.3 supports output to stdout natively
- bump version of ocamlformat
Reviewed By: jeremydubreil
Differential Revision: D6636741
fbshipit-source-id: 41a56a8
Summary:
Model for `folly::split` that handles the representation in the cpp model.
Depends on D6544992
Reviewed By: jvillard
Differential Revision: D6545006
fbshipit-source-id: 2b7a139
Summary:
Allows:
- matching function arguments with or without capturing,
- capturing part of an argument, e.g. expression only,
- optional arguments, wrapped into an OCaml option if captured.
Reviewed By: jvillard
Differential Revision: D6544992
fbshipit-source-id: a64ba45
Summary: There was a back and forth conversion between `string` and `IssueType.t` which was not necessary.
Reviewed By: sblackshear
Differential Revision: D6562747
fbshipit-source-id: 70b57a2
Summary:
It seems that the abstraction instructions were not previously added the the CFG.
This is a functional changes to make sure that the abstraction state is always added. We can simplify the code later and just run this step before storing the CFG instead of after loading them.
Reviewed By: sblackshear, jvillard
Differential Revision: D6383672
fbshipit-source-id: cedcb8a
Summary:
justmovingthingsaround
Models need these functions, they have to be somewhere else.
The split might seem weird for now but will (hopefully) look more obvious in the following diff.
Reviewed By: skcho
Differential Revision: D6408322
fbshipit-source-id: c7e430f
Summary:
Extends `ProcnameDispatcher` to allow matching typenames only.
There isn't much new here, mainly moving stuff so that we only have to open one module to use the operators.
Reviewed By: skcho
Differential Revision: D6408245
fbshipit-source-id: afc6533
Summary:
- Plug model checkers
- Add alloc size safety condition on alloc of negative, zero or big size
Reviewed By: sblackshear
Differential Revision: D6375144
fbshipit-source-id: bbea6f3
Mehdi Bouaziz
Jules Villard
Josh Berdine
Sungkeun Cho
Dino Distefano
Jeremy Dubreil
Sam Blackshear