Summary:
It's better (=possibly more efficient) to take the opportunity to
normalize linear terms when we can instead of possibly having to apply
the same normalization over and over on individual terms until the next
round of proper normalization.
Reviewed By: skcho
Differential Revision: D27464885
fbshipit-source-id: 0dc01a089
Summary:
When we don't know the value being shifted it may help to translate
bit-shifting into multiplication by a constant as it might surface
linear terms, eg `x<<1` is `2*x`.
Reviewed By: skcho
Differential Revision: D27464847
fbshipit-source-id: 9b3b5f0d0
Summary:
The simplifications done by `simplify_shallow` are all taken care of by
`eval_const_shallow` as well, they just also happen to help when not
*all* of the term is a constant. However, they might be less
precise/efficient than in the constant case, in particular in the next
diff that translates `x << c` into `x * 2^c` when `c` is constant.
Reviewed By: skcho
Differential Revision: D27464805
fbshipit-source-id: 452bc6ab1
Summary:
On some pathological examples of crypto primitives like libsodium, later
diffs make pulse grind to a halt due to an explosion in the size of
literals. This is at least partly due to the fact the arithmetic doesn't
operate modulo 2^64.
Due to the fact the arithmetic is confused in any case when we reach
such large numbers, cap them, currently at 2^128. This removes pathological
cases for now, even now on libsodium Pulse is ~5 times faster than before!
Take this opportunity to put the modified Q/Z modules in the own files.
Reviewed By: jberdine
Differential Revision: D27463933
fbshipit-source-id: 342d941e2
Summary: Just some scaffolding to save a bit of churn from the next diff.
Reviewed By: skcho
Differential Revision: D27328348
fbshipit-source-id: 4f5bfcc65
Summary:
This was added in C++14. Was investigating how SIOF dealt with this but
it turns out it already does the right thing as the translation unit of
global variable templates shows up as the place they are instantiated
(not the one where they are declared), which works well for SIOF
checking.
Reviewed By: da319
Differential Revision: D27500998
fbshipit-source-id: b8b9b9c48
Summary:
This is better suited than the generic "cGeneral_utils", and saves
exporting one of them too.
Reviewed By: da319
Differential Revision: D27500933
fbshipit-source-id: f4224f63b
Summary: One source of non-deterministic diff result is when there are multiple overloaded methods the cardinals of unchecked callees of which are the same. This diff tries to select one of them in a more deterministic manner.
Reviewed By: ezgicicek, ngorogiannis
Differential Revision: D27430757
fbshipit-source-id: 38ba5d8dc
Summary: Error message was accidentally changed to a specific nullptr error message (D26887140 (cba144b779)) for any invalidation (use after delete, etc). This diff reverts back the error message for a general case and keeps the special case for nullptr dereference. Also fixed spacing for nullptr dereference error message.
Reviewed By: jvillard
Differential Revision: D27407628
fbshipit-source-id: 2649f3032
Summary:
The title
Also notice that there is a duplication of an error.
Reviewed By: skcho
Differential Revision: D27426933
fbshipit-source-id: dbd2f861a
Summary: Autogenerated methods sometimes lead to false positives. Also, clean up a little the models file.
Reviewed By: da319
Differential Revision: D27393933
fbshipit-source-id: f79b1a6eb
Summary: To support objc nil messaging for unknown function calls we prune `self` to be positive in the `normal` specification and add additional specification to handle nil case.
Reviewed By: skcho
Differential Revision: D27360757
fbshipit-source-id: 119999b30
Summary:
This addresses a test difference between java versions. Infer's java tests are recorded with Java8 where string concat with a constant string uses `toString`. However, if tests are run on a machine where Java 11 is used, string concat is done via `makeConcatWithConstants` which causes tests to fail.
As a workaround, we replace the test so that Java version dependent string concat is not used.
Reviewed By: ngorogiannis
Differential Revision: D27394621
fbshipit-source-id: dfe1af2ac
Summary:
Fixing `IsInstanceOf` term simplification for null case. Before, this
was only being done if value was known to be null at the moment of the
call to `instanceof`. Otherwise, the `IsInstanceOf` term would remain in
the formula unnecessarily.
Reviewed By: jvillard
Differential Revision: D27361025
fbshipit-source-id: 2d958a757
Summary:
Models for Java Map interface.
This consists of `Map.init()`, `Map.put(key, value)`, `Map.get(key)`,
`Map.containsKey(key)` and
`Map.isEmpty()`. With the exception of `Map.get(key)` and `Map.containsKey(key)`, these functions were modelled using the respective similar ones provided by the Java Collection interface.
Reviewed By: jvillard
Differential Revision: D27326716
fbshipit-source-id: e07f0c952
Summary:
This diff add semantics for collecting all object fields that may have config values. The collected information is used to instantiate conditional unchecked callees introduced in the previous diff.
How it works:
* The summary is extended to have `config_fields:Fields.t`. It has all fields that may have config values intra-procedurally.
* Before reporting to `config-impact-report.json`, it unions all `config_fields` from all specs.
* Using `all_config_fields`, it instantiates each summaries and writes results to `config-impact-report.json`.
Reviewed By: ezgicicek
Differential Revision: D27326306
fbshipit-source-id: 42f16ca45
Summary:
This diff extends domain and semantics to understand object fields that may have config values.
Now, `Summary.t` has one more field `unchecked_callees_conditional`, which is a map from a set of object fields to a set of callees. The meaning is that the callees are called depending of the fields, ie
* if one of field of the fields is known to be an actual config value, the callees are safely gated,
* otherwise, the callees are ungated.
For example,
```
void foo() {
if (mField1) {
if (mField2) {
callee1();
}
callee2();
}
}
```
`foo` will have `unchecked_callees_conditional` value of
```
{ {mField1,mField2} -> {callee1},
{mField1} -> {callee2} }
```
Later, if we know that `mField2` has a config value, we can say `callee1` is gated, or if we know that `mField1` has a config value, we can say `callee1` and `callee2` are gated.
The following diff will add an analysis that collects object fields that may have config values.
Reviewed By: ezgicicek
Differential Revision: D27325522
fbshipit-source-id: d4aff58cb
Summary:
Copied the documentation from a document created by rgrig
(thanks!!).
Reviewed By: rgrig
Differential Revision: D27325829
fbshipit-source-id: 118e1a2be
Summary:
The explicit marker for nondeterministic states was used to speed up the
shallow implementations of Topl, which ar enow removed.
Reviewed By: jvillard
Differential Revision: D27297019
fbshipit-source-id: 0fce93817
Summary:
refactoring Java Integer model so that it uses the new
API designed for manipulating fields in Java.
Reviewed By: jvillard
Differential Revision: D27231810
fbshipit-source-id: 0d9e3c951
Summary:
## Issue:
On `master`, it seems that there is a missing newline when Infer prints the `tenv` for a structure type:
```bash
avj@platypus /tmp/infer_bug$ cat test.c
typedef struct {
int a;
} st1;
typedef struct {
int b;
} st2;
avj@platypus /tmp/infer_bug$ infer --version
Infer version v1.0.0-55871dd28
Copyright 2009 - present Facebook. All Rights Reserved.
avj@platypus /tmp/infer_bug$ rm -rf infer-out && infer --debug run -P -- gcc -c test.c
Logs in /tmp/infer_bug/infer-out/logs
Capturing in make/cc mode...
Found 1 source file to analyze in /tmp/infer_bug/infer-out
No issues found
avj@platypus /tmp/infer_bug$ grep -A1 "dummy" infer-out/captured/*/*.tenv.debug
dummy: falsestruct st1
fields: {
--
dummy: falsestruct st2
fields: {
--
dummy: falsestruct objc_class
fields: {}
```
(notice that `dummy: false` and `struct objc_class` are on the same line, with no spacing)
## Resolution
Their PR adds an explicit newline at the end of pretty-printing a structured value, such that it is formatted correctly in the `tenv`:
```bash
avj@platypus /tmp/infer_bug$ infer --version
Infer version v1.1.0-bb5a33506
Copyright 2009 - present Facebook. All Rights Reserved.
avj@platypus /tmp/infer_bug$ rm -rf infer-out && infer --debug run -P -- gcc -c test.c
Logs in /tmp/infer_bug/infer-out/logs
Capturing in make/cc mode...
Found 1 source file to analyze in /tmp/infer_bug/infer-out
No issues found
avj@platypus /tmp/infer_bug$ grep -A1 "dummy" infer-out/captured/*/*.tenv.debug
dummy: false
struct st1
--
dummy: false
struct st2
--
dummy: false
struct objc_class
--
dummy: false
```
(*edit*: I forgot to build after committing; now with updated hash)
Signed-off-by: Andrew V. Jones <andrewvaughanj@gmail.com>
Pull Request resolved: https://github.com/facebook/infer/pull/1416
Reviewed By: skcho
Differential Revision: D27264518
Pulled By: jvillard
fbshipit-source-id: 3b86b4c22
Summary:
Before this diff, TOPL had 3 implementations:
1. a post-processing of biabduction summaries
2. a post-processing of pulse summaries
3. a deep embedding in pulse
1 and 2 additionally require instrumenting SIL to generate monitors for
the TOPL properties. 3 is faster than both 1 and 2, by a good lot, and
doesn't require instrumenting the SIL code. Thus, delete 1 and 2!
Also harmonise the CLI so that TOPL is activated by --topl, which
actives it as a checker, like other analyses.
Reviewed By: rgrig
Differential Revision: D27270178
fbshipit-source-id: e86cf972b
Summary:
Changing model for Java `Collection` interface. Every collection has now two internal fields, initially set to `null`. We also keep an extra field to compute emptiness. This model was implemented based on the [preexisting model for HashMap](https://github.com/facebook/infer/blob/master/infer/models/java/src/java/util/HashMap.java).
Existing models (`add`, `remove`, `set` and `is_empty`) have been updated accordingly and new models are provided: `init` and `clear`.
This model is not yet compatible with the `Map` interface but this change will happen very soon.
Reviewed By: ezgicicek
Differential Revision: D27126815
fbshipit-source-id: 79a5fe306
Summary: This diff ignores java.lang.Math method calls since they are all cheap.
Reviewed By: ezgicicek
Differential Revision: D27267282
fbshipit-source-id: ad0a4ef4f
Summary:
There could still be divisions by zero, eg in the "mod" case: consider
"x mod (1/2)" (doesn't matter what x is). Then we'd check "1/2 =? 0" and
since it's false conclude that it's safe to take the modulo... oops!
To make things safer, harden `Z` to not throw anymore.
Also add a layer of defense in depth by wrapping the functions that do
Z/Q operations in another layer of exception catching because we really
don't want to crash the entire analysis due to that.
Reviewed By: martintrojer
Differential Revision: D27262569
fbshipit-source-id: e22187ca0
Summary:
Previously we would only simplify when the term is exactly IsInstanceOf,
and skip sub-terms. Most of the time this is the case but in the future
this could change.
Reviewed By: skcho
Differential Revision: D27156519
fbshipit-source-id: bd10574e0
Summary:
- some editing of the text
- the documentation of NULLPTR_DEREFERENCE was duplicated in
NULL_DEREFERENCE. Make the latter point to the former instead.
Reviewed By: skcho
Differential Revision: D27162785
fbshipit-source-id: 442d6efb9
Summary:
In Pulse, it usually havoc the actual parameters to unknown functions. However, it did not do that when the lengths of actuals and formals mismatch, which may happen when the frontend doesn't have enough information about procedures.
This diff havoc the actual parameters, also when there is mismatch between lengths of actuals and formals.
Reviewed By: ezgicicek
Differential Revision: D27163143
fbshipit-source-id: 1c5e0853a
Summary:
Two methods with identical method names but different number/type of args will have the same hash: e.g. `foo(int x)` and `foo(int x, int y)`. For Config Impact analysis, we assumed this type of hash collusion would never happen when we are comparing config-impact reports, but that assumption is wrong as demonstrated by the modified tests.
To deal with these, in cost analysis, we pick the highest degree among the potential collisions. We follow a similar idea here, picking the highest number of unchecked callees.
That has its own disadvantages:
E.g. giving an example from cost, if we had `foo(int x)` with O(1) before, and after the change, we have also added a linear `foo(int x, int y)`, I think we would introduce a complexity increase.
Still, it is better than picking only the first/last.
Reviewed By: skcho
Differential Revision: D27156722
fbshipit-source-id: c37388f1c
Summary:
10 seems better at no visible CPU cost. Not very scientific as this is
only one data point, but neither was choosing 5 in the first place.
Measurements on OpenSSL using Pulse.ISL:
```
$ time infer --pulse-only --scheduler callgraph -j 2 --pulse-report-latent-issues --pulse-isl
| fuel | user time (s) | under-normalisation | latent issues |
|------+---------------+---------------------+---------------|
| 5 | 163 | 3074 | 160 |
| 10 | 158 | 85 | 160 |
| 15 | 174 | 32 | 160 |
| 20 | 186 | 20 | 160 |
```
Reviewed By: skcho
Differential Revision: D27156497
fbshipit-source-id: 1114b8677
Summary:
This is a refactoring for a later change. This change alters behaviour
slightly to make it less chaotic: instead of normalization doing:
"""
do normalize(phi) until phi doesn't change anymore
normalize(phi):
do normalize_linear_part(phi) until this doesn't change phi anymore
do other normalizations
"""
we now do
"""
do normalize(phi) until phi doesn't change anymore
normalize(phi):
normalize_linear_part(phi)
do other normalizations if linear didn't change
"""
In particular we no longer spend potentially-quadratic amouns of fuel
during normalization.
Reviewed By: skcho
Differential Revision: D26450391
fbshipit-source-id: 9f63e1a04
Summary:
- add a pp_new_eq function to help people who want to printf-debug stuff
- fix one case where new_eqs were reset to `[]` instead of propagated
- do not add to `new_eqs` when nothing changes during normalisation.
This avoids duplicated new_eqs that arise from regenerating the linear
equality relation multiple times during normalisation.
Reviewed By: da319
Differential Revision: D27156042
fbshipit-source-id: 59b093ec8
Summary: To implement nil summaries for unknown calls I would like to reuse functionality from PulseObjectiveCSummary which already depends on PulseOperations causing circular dependencies.
Reviewed By: jvillard
Differential Revision: D27155092
fbshipit-source-id: 1c300ead0
Summary:
See updated tests and code comments: this changes many arithmetic
operations to detect when a contradiction "p|->- * p=0" is about to be
detected, and generate a latent issue instead. It's hacky but it does
what we want. Many APIs change because of this so there's some code
churn but the overall end result is not much worse thanks to monadic
operators.
Reviewed By: skcho
Differential Revision: D26918553
fbshipit-source-id: da2abc652
Summary:
This first commit introduces test cases and the new summary type, in
particular how it is propagated during function calls. We don't yet
actually generate these summary types, this is for the next diff.
The goal is to catch this pattern:
```
foo(p) {
if(p) {}
*p = 42;
}
goo() { foo(NULL); }
```
We went foo(p) to be a latent error when p=0. Right now we detect a
contradiction p|->- * p=0 |- false. The next diff will fix it.
Reviewed By: skcho
Differential Revision: D26918552
fbshipit-source-id: 6614db17b
Summary: Mostly refactoring, get rid of some minor TODOs in the process.
Reviewed By: skcho
Differential Revision: D26916013
fbshipit-source-id: 53c34af05
Summary:
This is to avoid a circular dependency issue in the future when creating
summaries might cause new reports: PulseReport depends on
PulseExecuationDomain so the latter cannot emit reports. Move summary
creation functions to PulseSummary instead, which sits above both of
these modules.
Also limit the responsabilities of PulseLatentIssues to just latent
issues in preparation for another change.
Reviewed By: skcho
Differential Revision: D26915799
fbshipit-source-id: 3275cd514
Jules Villard
Artem Pianykh
Nikos Gorogiannis
Sungkeun Cho
Daiva Naudziuniene
Ezgi Çiçek
Gabriela Cunha Sampaio
Radu Grigore
Loc Le
Andrew V. Jones