47 Commits

Author SHA1 Message Date
Anna Zaks
d56c8794d3 [analyzer] Malloc checker: rework realloc handling:
1) Support the case when realloc fails to reduce False Positives. (We
essentially need to restore the state of the pointer being reallocated.)

2) Realloc behaves differently under special conditions (from pointer is
null, size is 0). When detecting these cases, we should consider
under-constrained states (size might or might not be 0). The
old version handled this in a very hacky way. The code did not
differentiate between definite and possible (no consideration for
under-constrained states). Further, after processing each special case,
the realloc processing function did not return but chained to the next
special case processing. So you could end up in an execution in which
you first see the states in which size is 0 and realloc ~ free(),
followed by the states corresponding to size is not 0 followed by the
evaluation of the regular realloc behavior.

llvm-svn: 150402
2012-02-13 18:05:39 +00:00
Anna Zaks
41b84847bf [analyzer] Malloc Checker: reduce false negatives rate by assuming that
a pointer cannot escape through calls to system functions. Also, stop
after reporting the first use-after-free.

llvm-svn: 150315
2012-02-11 23:46:36 +00:00
Anna Zaks
3aa5225d5e [analyzer] Malloc Checker: Report a leak when we are returning freed
memory.
(As per one test case, the existing checker thought that this could
cause a lot of false positives - not sure if that's valid, to be
verified.)

llvm-svn: 150313
2012-02-11 21:44:39 +00:00
Anna Zaks
d3571e5ad3 [analyzer] Malloc checker: Leak bugs should be suppressed by sinks.
Resolves a common false positive, where we were reporting a leak inside
asserts

llvm-svn: 150312
2012-02-11 21:02:40 +00:00
Anna Zaks
bb1ef9011d [analyzer] MallocChecker: refactor/improve the symbol escape logic.
We use the same logic here as the RetainRelease checker.

llvm-svn: 150311
2012-02-11 21:02:35 +00:00
Anna Zaks
3188686c55 [analyzer] MallocChecker Cleanup - harden against crashes, fix an error
(use of return instead of continue), wording.

llvm-svn: 150215
2012-02-10 01:11:00 +00:00
Benjamin Kramer
541687f4be Remove unused fun.
llvm-svn: 150172
2012-02-09 12:05:18 +00:00
Anna Zaks
78edc2fb3c [analyzer] MallocChecker: address a diagnostic "fixme".
llvm-svn: 150158
2012-02-09 06:48:19 +00:00
Anna Zaks
2b5bb97986 [analyzer] Add custom path diagnostic to the Malloc Checker.
Very simple so far - we just highlight every allocation and release
site.

llvm-svn: 150156
2012-02-09 06:25:51 +00:00
Anna Zaks
12259b443d [analyzer] MallocChecker cleanup, more tests.
llvm-svn: 150155
2012-02-09 06:25:47 +00:00
Anna Zaks
a1b227b6a7 [analyzer] MallocChecker: implement pessimistic version of the checker,
which allows values to escape through unknown calls.

Assumes all calls but the malloc family are unknown.

Also, catch a use-after-free when a pointer is passed to a
function after a call to free (previously, you had to explicitly
dereference the pointer value).

llvm-svn: 150112
2012-02-08 23:16:56 +00:00
Anna Zaks
cd37bf4ec8 [analyzer] Split the MallocChecker into two versions - pessimistic and
optimistic.

TODO: actually implement the pessimistic version of the checker. Ex: it
needs to assume that any function that takes a pointer might free it.

The optimistic version relies on annotations to tell us which functions
can free the pointer.

llvm-svn: 150111
2012-02-08 23:16:52 +00:00
Anna Zaks
c68bf4c036 [analyzer] MallocChecker: convert from using evalCall to
post visit of CallExpr.

In general, we should avoid using evalCall as it leads to interference
with other checkers.

llvm-svn: 150086
2012-02-08 20:13:28 +00:00
Dylan Noblesmith
2c1dd2716a Basic: import SmallString<> into clang namespace
(I was going to fix the TODO about DenseMap too, but
that would break self-host right now. See PR11922.)

llvm-svn: 149799
2012-02-05 02:13:05 +00:00
Dylan Noblesmith
e27789991d Basic: import OwningPtr<> into clang namespace
llvm-svn: 149798
2012-02-05 02:12:40 +00:00
Benjamin Kramer
4903802fbf Move a method from IdentifierTable.h out of line and remove the SmallString include.
Fix all the transitive include users.

llvm-svn: 149783
2012-02-04 13:45:25 +00:00
Benjamin Kramer
3307c508c9 Move various diagnostic operator<< overloads out of line and remove includes of Diagnostic.h.
Fix all the files that depended on transitive includes of Diagnostic.h.
With this patch in place changing a diagnostic no longer requires a full rebuild of the StaticAnalyzer.

llvm-svn: 149781
2012-02-04 12:31:12 +00:00
Ted Kremenek
49b1e38e4b Change references to 'const ProgramState *' to typedef 'ProgramStateRef'.
At this point this is largely cosmetic, but it opens the door to replace
ProgramStateRef with a smart pointer that more eagerly acts in the role
of reclaiming unused ProgramState objects.

llvm-svn: 149081
2012-01-26 21:29:00 +00:00
David Blaikie
f47fa304a4 Remove unnecessary default cases in switches over enums.
This allows -Wswitch-enum to find switches that need updating when these enums are modified.

llvm-svn: 148281
2012-01-17 02:30:50 +00:00
Ted Kremenek
632e3b7ee2 [analyzer] Make the entries in 'Environment' context-sensitive by making entries map from
(Stmt*,LocationContext*) pairs to SVals instead of Stmt* to SVals.

This is needed to support basic IPA via inlining.  Without this, we cannot tell
if a Stmt* binding is part of the current analysis scope (StackFrameContext) or
part of a parent context.

This change introduces an uglification of the use of getSVal(), and thus takes
two steps forward and one step back.  There are also potential performance implications
of enlarging the Environment.  Both can be addressed going forward by refactoring the
APIs and optimizing the internal representation of Environment.  This patch
mainly introduces the functionality upon when we want to build upon (and clean up).

llvm-svn: 147688
2012-01-06 22:09:28 +00:00
Anna Zaks
8158ef0dec [analyzer] Be less pessimistic about invalidation of global variables
as a result of a call.

Problem:
Global variables, which come in from system libraries should not be
invalidated by all calls. Also, non-system globals should not be
invalidated by system calls.

Solution:
The following solution to invalidation of globals seems flexible enough
for taint (does not invalidate stdin) and should not lead to too
many false positives. We split globals into 3 classes:

* immutable - values are preserved by calls (unless the specific
global is passed in as a parameter):
     A :  Most system globals and const scalars

* invalidated by functions defined in system headers:
     B: errno

* invalidated by all other functions (note, these functions may in
turn contain system calls):
     B: errno
     C: all other globals (which are not in A nor B)

llvm-svn: 147569
2012-01-04 23:54:01 +00:00
Ted Kremenek
778d2bb8d4 Fix 80 col violations.
llvm-svn: 147566
2012-01-04 23:48:37 +00:00
Anna Zaks
c6aa531a8f [analyzer] Refactor checkers to use helper function for getting callee Decl and name.
We are getting name of the called function or it's declaration in a few checkers. Refactor them to use the helper function in the CheckerContext. 

llvm-svn: 145576
2011-12-01 05:57:37 +00:00
Anna Zaks
da4c8d6811 [analyzer] Rename generateNode -> addTransition in CheckerContext
Also document addTransition methods.

llvm-svn: 143059
2011-10-26 21:06:34 +00:00
Anna Zaks
b473816b4a [analyzer] Simplify CheckerContext
Remove dead members/parameters: ProgramState, respondsToCallback, autoTransition.
Remove addTransition method since it's the same as generateNode. Maybe we should
rename generateNode to genTransition (since a transition is always automatically
generated)?

llvm-svn: 142946
2011-10-25 19:57:06 +00:00
Anna Zaks
3eae33412d [analyze] Convert EndOfPath callback to use CheckerContext
Get rid of the EndOfPathBuilder completely.
Use the generic NodeBuilder to generate nodes.
Enqueue the end of path frontier explicitly.

llvm-svn: 142943
2011-10-25 19:56:48 +00:00
Benjamin Kramer
b89514a9b8 Change operator<< for raw_ostream and NamedDecl to take a reference instead of a pointer.
Passing a pointer was a bad idea as it collides with the overload for void*.

llvm-svn: 141971
2011-10-14 18:45:37 +00:00
Anna Zaks
3e0f415d0d [analyzer] Remove the dependency on CheckerContext::getStmt() as well as the method itself.
llvm-svn: 141262
2011-10-06 00:43:15 +00:00
Anna Zaks
23d7ba3579 [analyzer] Removing references to CheckerContext::getNodeBuilder(): checkers can obtain block count directly from the Context.
llvm-svn: 141112
2011-10-04 20:43:05 +00:00
Zhongxing Xu
bfb8e2fe6e If size was equal to 0, either NULL or a pointer suitable to be passed to
free() is returned by realloc(). Most code expect NULL.

And we only need to transfer one final ProgramState.

llvm-svn: 138937
2011-09-01 04:53:59 +00:00
Anna Zaks
3a6bdf8f82 Remove EnhancedBugReport and RangedBugReport - pull all the extra functionality they provided into their parent BugReport. The only functional changes are: made getRanges() non const - it adds default range to Ranges if none are supplied, made getStmt() private, which was another FIXME.
llvm-svn: 137894
2011-08-17 23:00:25 +00:00
Ted Kremenek
001fd5b498 Rename GRState to ProgramState, and cleanup some code formatting along the way.
llvm-svn: 137665
2011-08-15 22:09:50 +00:00
Ted Kremenek
5ef32dbf2a Cleanup various declarations of 'Stmt*' to be 'Stmt *', etc. in libAnalyzer and libStaticAnalyzer[*]. It was highly inconsistent, and very ugly to look at.
llvm-svn: 137537
2011-08-12 23:37:29 +00:00
Ted Kremenek
e227f49302 [analyzer] fix bug in malloc checker where the tracked symbol would not properly be removed from the state.
llvm-svn: 136418
2011-07-28 23:07:51 +00:00
Chris Lattner
0e62c1cc0b remove unneeded llvm:: namespace qualifiers on some core types now that LLVM.h imports
them into the clang namespace.

llvm-svn: 135852
2011-07-23 10:55:15 +00:00
Lenny Maiorani
005b5c1aee More accurately model realloc() when the size argument is 0. realloc() with a size of 0 is equivalent to free(). The memory region should be marked as free and not used again.
Unit tests f2_realloc_0(), f6_realloc(), and f7_realloc() contributed by Marshall Clow <mclow.lists@gmail.com>. Thanks! 

llvm-svn: 130303
2011-04-27 14:49:29 +00:00
Zhongxing Xu
af2371e368 Remove a redundant method. We have a const version.
llvm-svn: 128762
2011-04-02 03:20:45 +00:00
Argyrios Kyrtzidis
6a5674ffa6 [analyzer] Rename CheckerV2 -> Checker.
llvm-svn: 126726
2011-03-01 01:16:21 +00:00
Argyrios Kyrtzidis
183f0fb4cf [analyzer] Migrate MallocChecker to CheckerV2.
llvm-svn: 126606
2011-02-28 01:26:35 +00:00
Argyrios Kyrtzidis
f1b5d1f01b [analyzer] Refactor EndOfFunctionNodeBuilder.
-Introduce EndOfFunctionNodeBuilder::withCheckerTag to allow it be "specialized" with a
 checker tag and not require the checkers to pass a tag.
-For EndOfFunctionNodeBuilder::generateNode, reverse the order of tag/P parameters since
 there are actual calls that assume the second parameter is ExplodedNode.

llvm-svn: 126332
2011-02-23 21:04:49 +00:00
Chris Lattner
5a9b1ec94c simplify a bit.
llvm-svn: 125724
2011-02-17 05:38:27 +00:00
Ted Kremenek
f8cbac4b91 Split 'include/clang/StaticAnalyzer' into 'include/clang/StaticAnalyzer/Core' and 'include/clang/StaticAnalyzer/Checkers'.
This layout matches lib/StaticAnalyzer, which corresponds to two StaticAnalyzer libraries.

llvm-svn: 125251
2011-02-10 01:03:03 +00:00
Argyrios Kyrtzidis
f410a6299f [analyzer] lib/StaticAnalyzer/Checkers/ExprEngineExperimentalChecks.h -> lib/StaticAnalyzer/Checkers/ExperimentalChecks.h
llvm-svn: 125122
2011-02-08 22:30:11 +00:00
Ted Kremenek
b86ec25256 Remove unnecessary save-and-restore of the
node builder's 'HasGeneratedNode' field.

llvm-svn: 123362
2011-01-13 04:36:40 +00:00
Argyrios Kyrtzidis
1790c975e7 [analyzer] Add 'isLoad' parameter in Checker::visitLocation() to conveniently distinguish between loads/stores.
llvm-svn: 123261
2011-01-11 19:45:13 +00:00
Ted Kremenek
926c96211e Rename misc. methods in GRSubEngine to start
with a lower-case letter.  No functionality change.

llvm-svn: 123211
2011-01-11 02:34:45 +00:00
Ted Kremenek
d99bd55a5e Chris Lattner has strong opinions about directory
layout.  :)

Rename the 'EntoSA' directories to 'StaticAnalyzer'.

Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).

llvm-svn: 122514
2010-12-23 19:38:26 +00:00