Summary:
Using the `caml_alloc_some` and `ptr_to_option` functions that
allocate OCaml `option` values enables simplifications in many
cases. These simplifications also result in avoiding unnecessary
double initialization in many cases, so yield a minor optimization as
well.
Also, change to avoid using the old unprefixed functions such as
`alloc_small` and instead use the current `caml_alloc_small`.
A few of the changed functions were slightly rewritten in the
early-return style.
Upstream Differential Revision: https://reviews.llvm.org/D99473
Reviewed By: ngorogiannis
Differential Revision: D27564884
fbshipit-source-id: 17883785c
Summary:
In several functions an OCaml block is allocated and no further OCaml
allocation functions (or other functions that might trigger allocation
or collection) are performed before the block is fully initialized. In
these cases, it is safe and slightly more efficient to allocate an
uninitialized block.
Also, the code does not become more complex after the non-initializing
allocation, since in the case that a non-small allocation is made, the
initial values stored are definitely not pointers to OCaml young
blocks, and so initializing via direct assignment is still safe. That
is, in general if `caml_alloc_small` is called, initializing it with
direct assignments is safe, but if `caml_alloc_shr` is
called (e.g. for a block larger than `Max_young_wosize`), then
`caml_initialize` should be called to inform the GC of a potential
major to minor pointer. But if the initial value is definitely not a
young OCaml block, direct assignment is safe.
Upstream Differential Revision: https://reviews.llvm.org/D99472
Reviewed By: ngorogiannis
Differential Revision: D27564878
fbshipit-source-id: 20cd69e92
Summary:
Using `Store_field` to initialize fields of blocks allocated with
`caml_alloc_small` is unsafe. The fields of blocks allocated by
`caml_alloc_small` are not initialized, and `Store_field` calls the
OCaml GC write barrier. If the uninitialized value of a field happens
to point into the OCaml heap, then it will e.g. be added to a conflict
set or followed and have what the GC thinks are color bits
changed. This leads to crashes or memory corruption.
This diff fixes a few (I think all) instances of this problem. Some of
these are creating option values. OCaml 4.12 has a dedicated
`caml_alloc_some` function for this, so this diff adds a compatible
function with a version check to avoid conflict. With that, macros for
accessing option values are also added.
Upstream Differential Revision: https://reviews.llvm.org/D99471
Reviewed By: ngorogiannis
Differential Revision: D27564868
fbshipit-source-id: 1dfdd0530
Summary:
This diff pulls in upstream changes to the LLVM OCaml
bindings. Includes upstream commits:
> Add (get/set)_module_identifer functions
> Fix documentation for verify_function and const_of_int64
> DebugInfo support for OCaml bindings
> llvmbuildectomy - compatibility with ocaml bindings
> Remove ConstantPropagation
> Remove and move tests to SCCP.
Also includes updates to llvm-dune to adapt the build to the added
header file.
Reviewed By: ngorogiannis
Differential Revision: D27564717
fbshipit-source-id: af63e2aba
Summary: We have been referring to the arguments of a function call as "params". This has been bothering me. Let's fix it!
Reviewed By: ngorogiannis
Differential Revision: D27649158
fbshipit-source-id: 10e0b28cb
Summary:
To avoid too big abstract states due to instantiated templates in C++,
this diff loosens the compare functions of field names and ungated
callees.
Reviewed By: ezgicicek
Differential Revision: D27625775
fbshipit-source-id: e33e9d34c
Summary:
Nullsafe/biabduction tests were sensitive to Java version: they were recorded for Java 8 but if the machine that is used to run the tests had Java 11, tests would fail. This diff aims to resolve this issue by
- making our tests produce java8-compatible bytecode so that tests don't fail on Java 11 machines
- removing nullsafe tests that exercise obscure Java 8 behavior that cannot be alleviated with backward compatible bytecode on Java 11
- changing lambda argument printing to be Java 11 compatible
Reviewed By: martintrojer
Differential Revision: D27500731
fbshipit-source-id: 77fe302ea
Summary:
Reporting all ungated (un configed?) function calls causes many FPs. Instead, we rely on complexity analysis to determine whether a function is cheap/expensive: if the callee's complexity is not symbolic (e.g. constant), we consider it as cheap and don't keep track of it.
Note that we don't take the instantiated/modeled cost into account yet. So, if we have `foo(int n)` with complexity `O(n)`, and call it as `foo(3)`, we would still keep track of it. Similarly, if `foo` is a modeled function with constant time complexity, we would have no summary for it hence would keep track of it.
These will be improved later.
Reviewed By: skcho
Differential Revision: D27430485
fbshipit-source-id: d5f66320d
Summary:
This diff removes additional inferbo options `--bufferoverrun` from cost tests, since printing
inferbo issues is not that useful to understand cost results.
Reviewed By: ngorogiannis
Differential Revision: D27592496
fbshipit-source-id: 6ab3e6528
Summary:
Whenever an equality "t = v" (t an arbitrary term, v a variable) is
added (or "v = t"), remember the "t -> v" mapping after canonicalising t
and v. Use this to detect when two variables are equal to the same term:
`t = v` and `t = v'` now yields `v = v'` to be added to the equality
relation of variables. This increases the precision of the arithmetic
engine.
Interestingly, the impact on most code I've tried is:
1. mostly same perfs as before, if a bit slower (could be within noise)
2. slightly more (latent) bugs reported in absolute numbers
I would have expected it to be more expensive and yield fewer bugs (as
fewer false positives), but there could be second-order effects at play
here where we get more coverage. We definitely get more latent issues
due to dereferencing pointers after testing nullness, as can be seen in
the unit tests as well, which may alone explain (2).
There's some complexity when adding term equalities where the term
is linear, as we also need to add it to `linear_eqs` but `term_eqs` and
`linear_eqs` are interested in slightly different normal forms.
Reviewed By: skcho
Differential Revision: D27331336
fbshipit-source-id: 7314e127a
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:
There are not too many cases where the function name is not enough to
disambiguate a trace message, but it is still perhaps more
approachable to include the module names as well.
Reviewed By: jvillard
Differential Revision: D27396914
fbshipit-source-id: ea4c8b44f
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:
OCaml 4.12 added
```
val __FUNCTION__ : string
__FUNCTION__ returns the name of the current function or method,
including any enclosing modules or classes.
```
This diff simplifies ppx_trace using `__FUNCTION__` to obtain the name
of the function containing each call to a `Trace` function. Before
this diff this is done by maintaining a stack of function names
obtained by parsing value binding patterns during preprocessing. This
technique is not entirely robust and does not deal with some cases (if
calls to `Trace` functions appear in some places, preprocessing fails
with an exception).
Reviewed By: jvillard
Differential Revision: D27396915
fbshipit-source-id: da7aa2945
Summary:
This diff renames and moves the opam package definition files to
`<package>.opam` in an `opam` directory at the root of the
repository. This enables opam pinning the different packages contained
in the repo. It is necessary for these files to be either at the root
of the repo or in a directory named `opam` at the root of the repo, or
else opam cannot find them.
Reviewed By: skcho
Differential Revision: D27326495
fbshipit-source-id: 4c95c6955
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:
The implementation of `llvm_struct_name` before this diff calls
`caml_copy_string`, which allocates, while the `result` local variable
points to a block allocated by `caml_alloc_small` that has not yet
been initialized. If the allocation in `caml_copy_string` triggers a
garbage collection, then the GC root `result` contains a pointer to
uninitialized data, which may crash the GC or lead to a memory
corruption.
This diff fixes this by allocating and initializing the string first
and then allocating and initializing the option, thereby leaving no
dangling pointers when allocations are made.
The conversion from a C string to an OCaml string option is refactored
into a function, `cstr_to_string_option`. This function is also used
to simplify the definitions of `llvm_get_mdstring` and
`llvm_string_of_const`.
Upstream Differential Revision: https://reviews.llvm.org/D99393
Reviewed By: ngorogiannis
Differential Revision: D27360848
fbshipit-source-id: f2daa7561
Summary:
There are a number of compilation warnings regarding disregarding
const qualifiers, and casting between pointers to integer types with
different sign.
The incompatible sign warnings are due to treating the result of
`LLVMGetModuleIdentifier` as `const unsigned char *`, but it is
declared as `const char *`.
The dropped const qualifiers are due to the code pattern
`memcpy(String_val(_),_,_)` which ought to be (following the
implementation of the OCaml runtime)
`memcpy((char *)String_val(_),_,_)`. The issue is that `String_val` is
usually used to get the value of an immutable string. But in the
context of the `memcpy` calls, the string is in the process of being
initialized, so is not yet constant.
Upstream Differential Revision: https://reviews.llvm.org/D99392
Reviewed By: ngorogiannis
Differential Revision: D27360846
fbshipit-source-id: d045ad7c0
Summary:
This diff uses ptr_to_option to convert a nullable C pointer to an
OCaml option instead of the redundant implementation in
llvm_global_initializer.
Upstream Differential Revision: https://reviews.llvm.org/D99391
Reviewed By: ngorogiannis
Differential Revision: D27360847
fbshipit-source-id: b5bfcadf7
Summary: A little bit of sed to adjust links (see previous commit for effect).
Reviewed By: skcho
Differential Revision: D27360106
fbshipit-source-id: 2fa32f05f
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
Josh Berdine
Nikos Gorogiannis
Sungkeun Cho
Ezgi Çiçek
Loc Le
Jules Villard
Matthew Jin
Artem Pianykh
Daiva Naudziuniene
Gabriela Cunha Sampaio