Commit Graph

12 Commits

Author SHA1 Message Date
Jordan Rose 2de3daa0a2 [analyzer] Enable destructor inlining by default (c++-inlining=destructors).
This turns on not only destructor inlining, but inlining of constructors
for types with non-trivial destructors. Per r178516, we will still not
inline the constructor or destructor of anything that looks like a
container unless the analyzer-config option 'c++-container-inlining' is
set to 'true'.

In addition to the more precise path-sensitive model, this allows us to
catch simple smart pointer issues:

  #include <memory>

  void test() {
    std::auto_ptr<int> releaser(new int[4]);
  } // memory allocated with 'new[]' should not be deleted with 'delete'

<rdar://problem/12295363>

llvm-svn: 178805
2013-04-04 23:10:29 +00:00
Jordan Rose e189b869c5 [analyzer] For now, don't inline [cd]tors of C++ containers.
This is a heuristic to make up for the fact that the analyzer doesn't
model C++ containers very well. One example is modeling that
'std::distance(I, E) == 0' implies 'I == E'. In the future, it would be
nice to model this explicitly, but for now it just results in a lot of
false positives.

The actual heuristic checks if the base type has a member named 'begin' or
'iterator'. If so, we treat the constructors and destructors of that type
as opaque, rather than inlining them.

This is intended to drastically reduce the number of false positives
reported with experimental destructor support turned on. We can tweak the
heuristic in the future, but we'd rather err on the side of false negatives
for now.

<rdar://problem/13497258>

llvm-svn: 178516
2013-04-02 00:26:35 +00:00
Ted Kremenek 338c3aa8d1 Add static analyzer support for conditionally executing static initializers.
llvm-svn: 178318
2013-03-29 00:09:28 +00:00
Jordan Rose 4587b28758 [analyzer] Turn on C++ constructor inlining by default.
This enables constructor inlining for types with non-trivial destructors.
The plan is to enable destructor inlining within the next month, but that
needs further verification.

<rdar://problem/12295329>

llvm-svn: 176200
2013-02-27 18:49:43 +00:00
Anna Zaks c84d151892 [analyzer] Make shallow mode more shallow.
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
2013-01-30 19:12:39 +00:00
Anna Zaks 66b9f1660e [analyzer] Use analyzer config for max-inlinable-size option.
llvm-svn: 173957
2013-01-30 19:12:36 +00:00
Anna Zaks 36d988f023 [analyzer] Add "-analyzer-config mode=[deep|shallow] ".
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
2013-01-24 23:15:34 +00:00
Anna Zaks 6bab4ef4e8 [analyzer] Replace "-analyzer-ipa" with "-analyzer-config ipa".
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
2013-01-24 23:15:30 +00:00
Anna Zaks d53182b0df [analyzer] Implement "do not inline large functions many times"
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
2012-12-17 20:08:51 +00:00
Jordan Rose 746c06d0bc [analyzer] Replace -analyzer-no-eagerly-trim-egraph with graph-trim-interval.
After every 1000 CFGElements processed, the ExplodedGraph trims out nodes
that satisfy a number of criteria for being "boring" (single predecessor,
single successor, and more). Rather than controlling this with a cc1 option,
which can only disable this behavior, we now have an analyzer-config option,
'graph-trim-interval', which can change this interval from 1000 to something
else. Setting the value to 0 disables reclamation.

The next commit relies on this behavior to actually test anything.

llvm-svn: 166528
2012-10-23 23:59:05 +00:00
Ted Kremenek 3c6932922e Tweak AnalyzerOptions::getOptionAsInteger() to populate the string
table, making it printable with the ConfigDump checker.  Along the
way, fix a really serious bug where the value was getting parsed
from the string in code that was in an assert() call.  This means
in a Release-Asserts build this code wouldn't work as expected.

llvm-svn: 165041
2012-10-02 20:31:56 +00:00
Ted Kremenek 5faa5e04a3 Change AnalyzerOptions::mayInlineCXXMemberFunction to default populate
the config string table.  Also setup a test for dumping the analyzer
configuration for C++.

llvm-svn: 165040
2012-10-02 20:31:52 +00:00