Summary:
This diff adds trace of closure in autoreleasepool checker. We introduce a symbolic trace value for closure variable.
* It is added to the trace when closure variable is called
* and is substituted to concrete one when actual closure is given later.
Reviewed By: ezgicicek
Differential Revision: D25025883
fbshipit-source-id: a6e246be7
Summary:
Existing closure substitution only supported direct block calls to formals.
The following didn't work since the domain was only keeping track of loads/calls from formals, but didn't support stores.
```
void foo(dispatch_block_t block1){
dispatch_block_t local_block = block1;
local_block(); // we don't substitute the call here
}
```
This diff adds support for assigning a block to a local variable so that we can specialize the above example.
We now have a pair domain
- existing mapping from ids to block vars
- a new mapping from mangled to block specializations
the latter allows us to update the mapping in local block assignment (via store).
Reviewed By: skcho
Differential Revision: D25030234
fbshipit-source-id: 3f172341c
Summary:
Specialized closure substitution was broken for conditionals:
```
void foo(dispatch_block_t block1){
if (x){
block1(); // not replaced with specialized implementation
}
}
```
The problem was that when substituting function calls, it only used memory state at the exit node, rather than at each program point.
We could solve this by
- reverting the domain change in D24418560 (c47911359a), i.e. collecting all possible mappings conservatively (e.g. switch the domain back to `Map`)
- pass the `invariant_map` for substitutions at each program point.
We go with the second option here.
The closure substitution is still somewhat broken as exemplified by the following example:
```
void foo(dispatch_block_t block1){
dispatch_block_t local_block = block1;
local_block(); // we don't substitute the call here
}
```
Reviewed By: skcho
Differential Revision: D24993962
fbshipit-source-id: ebadddb58
Summary:
This was left as a TODO before: where to place calls to destructors for
C++ temporaries that are only conditionally creating when evaluating an
expression. This can happen inside the branches of a conditional
operation `b?e:f` or in potentially-short-circuited conditions on the
righ-hand side of `&&` and `||` operators.
Following the compilation scheme of clang (observed by looking at the
generated LLVM bitcode), we instrument the program with "marker"
variables, so that for instance `X x = true?X():y;` becomes (following
the execution on the true branch):
```
marker1 = 0; // initialize all markers to 0
PRUNE(true) // entering true branch
X::X(&temporary); // create temporary...
marker1 = 1; // ...triggers setting its marker to 1
X::X(&x, &temporary); // finish expression
if (marker1) {
X::~X(&temporary); // conditionally destroy the temporary
}
```
In this diff, you'll find code for:
- associating markers to temporaries that need them
- code to initialize markers to 0 before full-expressions
- code to conditionally destroy temporaries based on the values of the
markers once the full-expression has finished evaluating
Reviewed By: da319
Differential Revision: D24954070
fbshipit-source-id: cf15df7f7
Summary:
This diff adds a new experimental checker for detecting size of objects in autorelease pool in ObjC. The basic mechanism is almost the same with the previous cost calculation:
* Autorelease pool size is increased at explicit `autorelease` call
* Autorelease pool size is set as zero by the `autoreleasepool` block.
While it only supports the explicit calls as of now, we will extend the checker to handle more cases in the following diffs.
Reviewed By: ezgicicek
Differential Revision: D23473145
fbshipit-source-id: 416488176
Sungkeun Cho
Ezgi Çiçek
Jules Villard