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:
Instead of storing the type environment in infer-out/captured/foo.c/foo.c.tenv,
store it in the `source_files` table of the SQLite db. This limits the number
of files we create on disk.
The "file local" type environemnts are specific to the clang integration. For
Java, there is a "global tenv" file. Instead of matching on string names, this
diff also makes the API of `Tenv` reflect this situation.
The global tenv is serialized as a separate file in "infer-out/.global.tenv"
instead of "infer-out/captured/global.tenv", because "infer-out/captured/" will
soon be removed as it now only contains the global tenv (except in debug mode,
where it will still be created).
In the DB, we either store the local tenv for the file, or "global" to indicate
that the global tenv should be consulted.
This diff also moves `Cfg.store` to `SourceFiles.add` because that function
deals with more than just `Cfg.t`.
Reviewed By: jeremydubreil
Differential Revision: D6937945
fbshipit-source-id: 001c10a
Summary:
A list of free variables was computed and passed around, but never used. The
reason OCaml wasn't complaining is that the list is eventually passed to a
recursive function, which passes it to its recursive call, so it looks like
it's used there.
Reviewed By: mbouaziz
Differential Revision: D7098556
fbshipit-source-id: b22a591
Summary:
Switch to the current stable branch for clang.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D7067890
fbshipit-source-id: aedff90
Summary:
You can capture a variable by reference in a lambda, assign to it, and then invoke the lambda.
This looks like a dead store from the perspective of the current analysis.
This diff mitigates the problem by computing an additional analysis that tracks variables captured by ref at each program point.
It refuses to report a dead store on a variable that has already been captured by reference.
Later, we might want to incorporate the results of this analysis directly into the liveness analysis instead of just using it to gate reporting.
Reviewed By: jeremydubreil
Differential Revision: D7090291
fbshipit-source-id: 25eeffa
Summary:
We frequently want to treat such vars differently than true program variables.
Used in only one place now, but will be used in a successor.
Reviewed By: mbouaziz, jvillard
Differential Revision: D7067882
fbshipit-source-id: 90e0348
Summary:
As far as I can tell nothing uses it and it is ignored by the matching engine:
the "parameters" arguments are collected from config options but never actually
used for matching.
Reviewed By: sblackshear
Differential Revision: D6976273
fbshipit-source-id: 6fed5ff
Summary:
Ran into this issue on Debian Testing, in which assert.h is probably different
due to a more recent toolchain. Without this change I get the following CFG
for `assert(e)`:
```
start
|-> prune (e) -> join
|-> prune (!e) -> __infer_fail("ASSERTION_FAILURE") -> exit
```
Notice that the first branch does not get to the exit, so infer must think that
the assertion is *always* violated, and reports `error: ASSERTION_FAILURE`.
This is broken.
Reviewed By: dulmarod
Differential Revision: D7067822
fbshipit-source-id: a2bf5ac
Summary:
- EventLogger no longer depends on ProcAttributes
- This allows for other backend classes which are used by ProcAttributes to log in the future without creating a cyclic dependency structure
Reviewed By: dulmarod
Differential Revision: D7082444
fbshipit-source-id: f32a6e2
Summary: - When a CallTrace result is CR_skip, then a reason for skipping the call will be included in the record
Reviewed By: dulmarod
Differential Revision: D7082572
fbshipit-source-id: 20ed191
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:
The struct fields in Cil have been sorted for long time, however the
checkers do not seem to depend on the sortedness.
Reviewed By: sblackshear
Differential Revision: D7027858
fbshipit-source-id: 9e7ab96
Summary:
- During the symbolic execution stage of the backend, Infer will log detailed stats about procedure calls
- Logging is accomplished directly within symExec/Tabulation
- call_result type is moved to tabulation.ml
CallStats was a broken module that allocated a lot of useless memory. Now, Specs.CallStats and InferPrint.CallsCsv as well as the Calls report kind in InferPrint no longer exist.
Reviewed By: dulmarod
Differential Revision: D7016439
fbshipit-source-id: 40911ee
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:
- StatsLogs is now its own functional module in InferPrint
- No longer stores events to be logged in a list to be later logged, just immediately logs them
Reviewed By: dulmarod
Differential Revision: D7010559
fbshipit-source-id: 1837ca9
Summary: Just some minor renaming to be more consistent with other modules. I was about to use these modules and was too lazy to type `Ident.IdentSet`.
Reviewed By: da319, avarun42
Differential Revision: D6999808
fbshipit-source-id: c24edef
Summary:
- change a use of clang_method_kind to match directly on the type rather than a brittle check for equality
- make the clang_method_kind field in AnalysisStats an option
- if procedure lang is not clang, then clang_method_kind field gets skipped while logging
Reviewed By: dulmarod
Differential Revision: D7010060
fbshipit-source-id: 077094d
Summary:
- JsonBuilder now has an add_string_opt function that takes a string option instead of a string
- Further alphabetized EventLogger
Reviewed By: dulmarod
Differential Revision: D7011763
fbshipit-source-id: 73f1a4b
Summary:
A simple intraprocedural analysis that tracks when a storage location is read or deleted.
For now, this works only with local variable storage locations; field and array accesses are ignored.
In order to test this, I added a new "use-after-lifetime" warning. It complains when a variable is read or deleted after it has already been deleted.
Reviewed By: jeremydubreil
Differential Revision: D6961314
fbshipit-source-id: 75e95a2
Jérémie Marguerie
Varun Arora
Dino Distefano
Sungkeun Cho
Jules Villard
Sam Blackshear
Dulma Churchill
Josh Berdine
Jeremy Dubreil
Nikos Gorogiannis
Ilya Sergey