llvm-project/clang
Jordan Rose f342adef47 [analyzer] Use a forward BFS instead of a reverse BFS to find shortest paths.
For a given bug equivalence class, we'd like to emit the report with the
shortest path. So far to do this we've been trimming the ExplodedGraph to
only contain relevant nodes, then doing a reverse BFS (starting at all the
error nodes) to find the shortest paths from the root. However, this is
fairly expensive when we are suppressing many bug reports in the same
equivalence class.

r177468-9 tried to solve this problem by breaking cycles during graph
trimming, then updating the BFS priorities after each suppressed report
instead of recomputing the whole thing. However, breaking cycles is not
a cheap operation because an analysis graph minus cycles is still a DAG,
not a tree.

This fix changes the algorithm to do a single forward BFS (starting from the
root) and to use that to choose the report with the shortest path by looking
at the error nodes with the lowest BFS priorities. This was Anna's idea, and
has the added advantage of requiring no update step: we can just pick the
error node with the next lowest priority to produce the next bug report.

<rdar://problem/13474689>

llvm-svn: 177764
2013-03-22 21:15:28 +00:00
..
INPUTS Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164766 2012-09-27 10:16:10 +00:00
bindings cindex.py: Handle NULL pointers when parsing translation units 2013-03-19 15:30:48 +00:00
docs Update docs after moving clang-format from clang-tools-extra to cfe. 2013-03-22 12:44:20 +00:00
examples Nuke SetUpBuildDumpLog. 2013-01-20 01:58:28 +00:00
include [analyzer] Fix ExprEngine::ViewGraph to handle C++ initializers. 2013-03-22 21:15:16 +00:00
lib [analyzer] Use a forward BFS instead of a reverse BFS to find shortest paths. 2013-03-22 21:15:28 +00:00
runtime Split ubsan runtime into three pieces (clang part): 2013-03-20 23:49:07 +00:00
test [analyzer] Fix test to actually test what was intended. 2013-03-22 21:15:26 +00:00
tools Add clang-format to the corresponding Makefile. 2013-03-22 11:43:51 +00:00
unittests Better fix for r177725. 2013-03-22 16:55:40 +00:00
utils Documentation parsing. Some refactoring and code 2013-03-08 23:59:23 +00:00
www Add a linebreak. Linebreaks are cool. 2013-03-18 21:57:52 +00:00
.arcconfig Add .arcconfig to the repository. Useful if someone wants to use phabricator's command line tool. 2012-12-01 12:08:08 +00:00
.gitignore Reverted unintendedly-committed file. 2013-01-31 19:05:31 +00:00
CMakeLists.txt CMake: -Wno-nested-anon-types for Clang. 2013-03-02 00:49:47 +00:00
CODE_OWNERS.TXT Duplicate some common owners between Clang and LLVM. 2012-11-27 00:48:12 +00:00
INSTALL.txt Minor tweak to install docs 2013-02-05 22:01:16 +00:00
LICENSE.TXT Update the copyright coredits -- Happy new year 2013! 2013-01-01 10:00:19 +00:00
Makefile The top-level clang Makefile is #included into other Makefiles. (sigh) So we 2012-10-03 08:39:19 +00:00
ModuleInfo.txt
NOTES.txt Remove an uninteresting note 2013-02-05 21:13:55 +00:00
README.txt

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:              http://clang.llvm.org/
Building and using Clang:          http://clang.llvm.org/get_started.html
Clang Static Analyzer:             http://clang-analyzer.llvm.org/
Information on the LLVM project:   http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/