This is a "quick fix".
The underlining issue is that when a const pointer to a struct is passed
into a function, we do not invalidate the pointer fields. This results
in false positives that are common in C++ (since copy constructors are
prevalent). (Silences two llvm false positives.)
llvm-svn: 174468
This is a more natural order of evaluation, and it is very important
for visualization in the static analyzer. Within Xcode, the arrows
will not jump from right to left, which looks very visually jarring.
It also provides a more natural location for dataflow-based diagnostics.
Along the way, we found a case in the analyzer diagnostics where we
needed to indicate that a variable was "captured" by a block.
-fsyntax-only timings on sqlite3.c show no visible performance change,
although this is just one test case.
Fixes <rdar://problem/13016513>
llvm-svn: 174447
...again. The problem has not been fixed and our internal buildbot is still
getting hangs.
This reverts r174212, originally applied in r173951, then reverted in r174069.
Will not re-apply until the entire project analyzes successfully on my
local machine.
llvm-svn: 174265
Inlining these functions is essential for correctness. We often have
cases where we do not inline calls. For example, the shallow mode and
when reanalyzing previously inlined ObjC methods as top level.
llvm-svn: 174245
This allows us to keep from chaining LazyCompoundVals in cases like this:
CGRect r = CGRectMake(0, 0, 640, 480);
CGRect r2 = r;
CGRect r3 = r2;
Previously we only made this optimization if the struct did not begin with
an aggregate member, to make sure that we weren't picking up an LCV for
the first field of the struct. But since LazyCompoundVals are typed, we can
make that inference directly by comparing types.
This is a pure optimization; the test changes are to guard against possible
future regressions.
llvm-svn: 174211
It's causing hangs on our internal analyzer buildbot. Will restore after
investigating.
This reverts r173951 / baa7ca1142990e1ad6d4e9d2c73adb749ff50789.
llvm-svn: 174069
This is a hack to work around the fact that we don't track extents for our
default bindings:
CGPoint p;
p.x = 0.0;
p.y = 0.0;
rectParam.origin = p;
use(rectParam.size); // warning: uninitialized value in rectParam.size.width
In this case, the default binding for 'p' gets copied into 'rectParam',
because the 'origin' field is at offset 0 within CGRect. From then on,
rectParam's old default binding (in this case a symbol) is lost.
This patch silences the warning by pretending that lazy bindings are never
made from uninitialized memory, but not only is that not true, the original
default binding is still getting overwritten (see FIXME test cases).
The long-term solution is tracked in <rdar://problem/12701038>
PR14765 and <rdar://problem/12875012>
llvm-svn: 174031
positives.
The includeSuffix was only set on the first iteration through the
function, resulting in invalid regions being produced by getLazyBinding
(ex: zoomRegion.y).
llvm-svn: 174016
Redefine the shallow mode to inline all functions for which we have a
definite definition (ipa=inlining). However, only inline functions that
are up to 4 basic blocks large and cut the max exploded nodes generated
per top level function in half.
This makes shallow faster and allows us to keep inlining small
functions. For example, we would keep inlining wrapper functions and
constructors/destructors.
With the new shallow, it takes 104s to analyze sqlite3, whereas
the deep mode is 658s and previous shallow is 209s.
llvm-svn: 173958
This is faster for the analyzer to process than inlining the constructor
and performing a member-wise copy, and it also solves the problem of
warning when a partially-initialized POD struct is copied.
Before:
CGPoint p;
p.x = 0;
CGPoint p2 = p; <-- assigned value is garbage or undefined
After:
CGPoint p;
p.x = 0;
CGPoint p2 = p; // no-warning
This matches our behavior in C, where we don't see a field-by-field copy.
<rdar://problem/12305288>
llvm-svn: 173951
When the analyzer sees an initializer, it checks if the initializer
contains a CXXConstructExpr. If so, it trusts that the CXXConstructExpr
does the necessary work to initialize the object, and performs no further
initialization.
This patch looks through any implicit wrapping expressions like
ExprWithCleanups to find the CXXConstructExpr inside.
Fixes PR15070.
llvm-svn: 173557
The idea is to introduce a higher level "user mode" option for
different use scenarios. For example, if one wants to run the analyzer
for a small project each time the code is built, they would use
the "shallow" mode.
The user mode option will influence the default settings for the
lower-level analyzer options. For now, this just influences the ipa
modes, but we plan to find more optimal settings for them.
llvm-svn: 173386
The idea is to eventually place all analyzer options under
"analyzer-config". In addition, this lays the ground for introduction of
a high-level analyzer mode option, which will influence the
default setting for IPAMode.
llvm-svn: 173385
Before:
Calling implicit default constructor for 'Foo' (where Foo is constructed)
Entered call from 'test' (at "=default" or 'Foo' declaration)
Calling default constructor for 'Bar' (at "=default" or 'Foo' declaration)
After:
Calling implicit default constructor for 'Foo' (where Foo is constructed)
Calling default constructor for 'Bar' (at "=default" or 'Foo' declaration)
This only affects the plist diagnostics; this note is never shown in the
other diagnostics.
llvm-svn: 172915
Suppress the warning by just not emitting the report. The sink node
would get generated, which is fine since we did reach a bad state.
Motivation
Due to the way code is structured in some of these macros, we do not
reason correctly about it and report false positives. Specifically, the
following loop reports a use-after-free. Because of the way the code is
structured inside of the macro, the analyzer assumes that the list can
have cycles, so you end up with use-after-free in the loop, that is
safely deleting elements of the list. (The user does not have a way to
teach the analyzer about shape of data structures.)
SLIST_FOREACH_SAFE(item, &ctx->example_list, example_le, tmpitem) {
if (item->index == 3) { // if you remove each time, no complaints
assert((&ctx->example_list)->slh_first == item);
SLIST_REMOVE(&ctx->example_list, item, example_s, example_le);
free(item);
}
}
llvm-svn: 172883
The issue here is that if we have 2 leaks reported at the same line for
which we cannot print the corresponding region info, they will get
treated as the same by issue_hash+description. We need to AUGMENT the
issue_hash with the allocation info to differentiate the two issues.
Add the "hash" (offset from the beginning of a function) representing
allocation site to solve the issue.
We might want to generalize solution in the future when we decide to
track more than just the 2 locations from the diagnostics.
llvm-svn: 171825
Instead of using several callbacks to identify the pointer escape event,
checkers now can register for the checkPointerEscape.
Converted the Malloc checker to use the new callback.
SimpleStreamChecker will be converted next.
llvm-svn: 170625
performance heuristic
After inlining a function with more than 13 basic blocks 32 times, we
are not going to inline it anymore. The idea is that inlining large
functions leads to drastic performance implications. Since the function
has already been inlined, we know that we've analyzed it in many
contexts.
The following metrics are used:
- Large function is a function with more than 13 basic blocks (we
should switch to another metric, like cyclomatic complexity)
- We consider that we've inlined a function many times if it's been
inlined 32 times. This number is configurable with -analyzer-config
max-times-inline-large=xx
This heuristic addresses a performance regression introduced with
inlining on one benchmark. The analyzer on this benchmark became 60
times slower with inlining turned on. The heuristic allows us to analyze
it in 24% of the time. The performance improvements on the other
benchmarks I've tested with are much lower - under 10%, which is
expected.
llvm-svn: 170361
We don't handle array destructors correctly yet, but we now apply the same
hack (explicitly destroy the first element, implicitly invalidate the rest)
for multidimensional arrays that we already use for linear arrays.
<rdar://problem/12858542>
llvm-svn: 170000
Anna Zaks