Commit Graph

2078 Commits

Author SHA1 Message Date
Anna Zaks e0ad10404d [analyzer] Fixup for r185609: actually do suppress warnings coming out of std::list.
list is the name of a class, not a namespace. Change the test as well - the previous
version did not test properly.

Fixes radar://14317928.

llvm-svn: 185898
2013-07-09 01:55:00 +00:00
Rafael Espindola 18627115f4 Use llvm::sys::fs::createUniqueFile.
Include a test that clang now produces output files with permissions matching
the umask.

llvm-svn: 185727
2013-07-05 21:13:58 +00:00
Rafael Espindola a36e78ef5d Use llvm::sys::fs::createTemporaryFile.
llvm-svn: 185717
2013-07-05 20:00:06 +00:00
Rafael Espindola e4ffbdf349 Fix PR16547.
We should not be asking unique_file to prepend the system temporary directory
when creating the html report. Unfortunately I don't think we can test this
with the current infrastructure since unique_file ignores MakeAbsolute if the
directory is already absolute and the paths provided by lit are.

I will take a quick look at making this api a bit less error prone.

llvm-svn: 185707
2013-07-05 15:05:40 +00:00
Craig Topper 2341c0d3b2 Use SmallVectorImpl instead of SmallVector for iterators and references to avoid specifying the vector size unnecessarily.
llvm-svn: 185610
2013-07-04 03:08:24 +00:00
Anna Zaks a42fb525e4 [analyzer] Suppress reports reported in std::list
The motivation is to suppresses false use-after-free reports that occur when calling
std::list::pop_front() or std::list::pop_back() twice. The analyzer does not
reason about the internal invariants of the list implementation, so just do not report
any of warnings in std::list.

Fixes radar://14317928.

llvm-svn: 185609
2013-07-04 02:38:10 +00:00
Anna Zaks 5673b6567a [analyzer] Make sure that inlined defensive checks work on div by zero.
This suppresses a false positive in std::hash_map.
Fixes  radar://14255587.

llvm-svn: 185608
2013-07-04 02:38:06 +00:00
Pavel Labath f77e736844 [analyzer] Improve handling of noreturn destructors
Summary:
The analyzer incorrectly handled noreturn destructors which were hidden inside
function calls. This happened because NoReturnFunctionChecker only listened for
PostStmt events, which are not executed for destructor calls. I've changed it to
listen to PostCall events, which should catch both cases.

Reviewers: jordan_rose

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1056

llvm-svn: 185522
2013-07-03 08:23:49 +00:00
Jordan Rose 00deddb6d8 [analyzer] Pointers-to-members are (currently) Locs, not NonLocs.
While we don't model pointers-to-members besides "null" and "non-null",
we were using Loc symbols for valid pointers and NonLoc integers for the
null case. This hit the assert committed in r185401.

Fixed by using a true (Loc) null for null member pointers.

llvm-svn: 185444
2013-07-02 16:50:24 +00:00
Pavel Labath 868bebf844 Teach static analyzer about AttributedStmts
Summary:
Static analyzer used to abort when encountering AttributedStmts, because it
asserted that the statements should not appear in the CFG. This is however not
the case, since at least the clang::fallthrough annotation makes it through.

This commit simply makes the analyzer ignore the statement attributes.

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1030

llvm-svn: 185417
2013-07-02 09:38:48 +00:00
Jordan Rose 686df32216 [analyzer] Explicitly disallow mixed Loc-NonLoc comparisons.
The one bit of code that was using this is gone, and neither C nor C++
actually allows this. Add an assertion and remove dead code.

Found by Matthew Dempsky!

llvm-svn: 185401
2013-07-02 01:37:40 +00:00
Rafael Espindola 32e3e7cefc We only create one file, no need to delete a directory.
llvm-svn: 184949
2013-06-26 14:33:23 +00:00
Rafael Espindola a9b6429ec8 Remove unused include.
llvm-svn: 184922
2013-06-26 06:15:57 +00:00
Rafael Espindola 4168ee73a4 Remove more uses of llvm::sys::Path.
llvm-svn: 184921
2013-06-26 06:13:06 +00:00
Jordan Rose b8e286548c [analyzer] Handle zeroing CXXConstructExprs.
Re-apply r184511, reverted in r184561, with the trivial default constructor
fast path removed -- it turned out not to be necessary here.

Certain expressions can cause a constructor invocation to zero-initialize
its object even if the constructor itself does no initialization. The
analyzer now handles that before evaluating the call to the constructor,
using the same "default binding" mechanism that calloc() uses, rather
than simply ignoring the zero-initialization flag.

<rdar://problem/14212563>

llvm-svn: 184815
2013-06-25 01:56:08 +00:00
Jordan Rose b3b976f061 [analyzer] Don't initialize virtual base classes more than once.
In order to make sure virtual base classes are always initialized once,
the AST contains initializers for the base class in /all/ of its
descendents, not just the immediate descendents. However, at runtime,
the most-derived object is responsible for initializing all the virtual
base classes; all the other initializers will be ignored.

The analyzer now checks to see if it's being called from another base
constructor, and if so does not perform virtual base initialization.

<rdar://problem/14236851>

llvm-svn: 184814
2013-06-25 01:55:59 +00:00
Eli Friedman 57d1f1c8a5 Use getAs<> where appropriate on QualTypes instead of using dyn_cast.
llvm-svn: 184775
2013-06-24 18:47:11 +00:00
Anna Zaks 7925e3db63 [analyzer] Add a debug checker that prints Exploded Graph
Add a debug checker that is useful to understand how the ExplodedGraph is
built; it can be triggered using the following command:

 clang -cc1 -analyze -analyzer-checker=debug.ViewExplodedGraph my_program.c

A patch by Béatrice Creusillet!

llvm-svn: 184768
2013-06-24 18:12:12 +00:00
Reid Kleckner 7f62b95480 Check the canonical parameter type with getAs<>() in a static checker
This will prevent breakage when I introduce the DecayedType sugar node.

llvm-svn: 184755
2013-06-24 16:56:16 +00:00
Anna Zaks 27982c70fc [analyzer] Use output form collections’ count to decide if ObjC for loop should be entered
This fixes false positives by allowing us to know that a loop is always entered if
the collection count method returns a positive value and vice versa.

Addresses radar://14169391.

llvm-svn: 184618
2013-06-22 00:23:26 +00:00
Jordan Rose e83cb0922b Revert "[analyzer] Handle zeroing CXXConstructExprs."
Per review from Anna, this really should have been two commits, and besides
it's causing problems on our internal buildbot. Reverting until these have
been worked out.

This reverts r184511 / 98123284826bb4ce422775563ff1a01580ec5766.

llvm-svn: 184561
2013-06-21 16:30:32 +00:00
Jordan Rose 4ace1a74c0 [analyzer] Handle zeroing CXXConstructExprs.
Certain expressions can cause a constructor invocation to zero-initialize
its object even if the constructor itself does no initialization. The
analyzer now handles that before evaluating the call to the constructor,
using the same "default binding" mechanism that calloc() uses, rather
than simply ignoring the zero-initialization flag.

As a bonus, trivial default constructors are now no longer inlined; they
are instead processed explicitly by ExprEngine. This has a (positive)
effect on the generated path edges: they no longer stop at a default
constructor call unless there's a user-provided implementation.

<rdar://problem/14212563>

llvm-svn: 184511
2013-06-21 00:59:00 +00:00
Pavel Labath cb0b876b39 Fix static analyzer crash when casting from an incomplete type
Summary:
When doing a reinterpret+dynamic cast from an incomplete type, the analyzer
would crash (bug #16308). This fix makes the dynamic cast evaluator ignore
incomplete types, as they can never be used in a dynamic_cast. Also adding a
regression test.

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1006

llvm-svn: 184403
2013-06-20 07:45:01 +00:00
Pavel Labath 963f91b3a2 Fix a crash in the static analyzer (bug #16307)
Summary:
When processing a call to a function, which got passed less arguments than it
expects, the analyzer would crash.

I've also added a test for that and a analyzer warning which detects these
cases.

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D994

llvm-svn: 184288
2013-06-19 08:19:56 +00:00
Anna Zaks d60a41d941 [analyzer] Do not create a CompoundVal for lvalue InitListExprs.
These should be treated like scalars. This fixes a crash reported in radar://14164698.

llvm-svn: 184257
2013-06-18 23:16:20 +00:00
Anna Zaks 0325646705 [analyzer] Do not report uninitialized value warnings inside swap functions.
This silences warnings that could occur when one is swapping partially initialized structs. We suppress
not only the assignments of uninitialized members, but any values inside swap because swap could
potentially be used as a subroutine to swap class members.

This silences a warning from std::try::function::swap() on partially initialized objects.

llvm-svn: 184256
2013-06-18 23:16:15 +00:00
Reid Kleckner 2ab0ac5360 [AST] Don't include RecursiveASTVisitor.h in ASTContext.h
The untemplated implementation of getParents() doesn't need to be in a
header file.

RecursiveASTVisitor.h is full of repeated macro expansion.  Moving this
include to ASTContext.cpp speeds up compilation of
LambdaMangleContext.cpp, a small C++ file with few includes, from 3.7s
to 2.8s for me locally.  I haven't measured a full build, but it can't
hurt.

I had to fix a few static analyzer files that were depending on
transitive includes of C++ AST headers.

Reviewers: rsmith, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D982

llvm-svn: 184075
2013-06-17 12:56:08 +00:00
Rafael Espindola cb4bb19070 Use the sys::ExecuteAndWait that takes StringRefs.
Also don't depend on Program.h including PathV1.h.

llvm-svn: 183935
2013-06-13 20:08:52 +00:00
Rafael Espindola 0725a7d972 Update for llvm change.
llvm-svn: 183930
2013-06-13 19:25:45 +00:00
Richard Smith cc1b96d356 PR12086, PR15117
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).

This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.

llvm-svn: 183872
2013-06-12 22:31:48 +00:00
Rafael Espindola a3346d8765 Use the global functions instead of the Program methods.
llvm-svn: 183861
2013-06-12 20:44:26 +00:00
Benjamin Kramer fbf914ceb0 Port HTMLDiagnostics to PathV2. No intended functionality change.
llvm-svn: 183849
2013-06-12 18:13:05 +00:00
Pavel Labath 7e18009a7a Fix memory corruption in CStringChecker
Summary:
"register" functions for the checker were caching the checker objects in a
static variable. This caused problems when the function is called with a
different CheckerManager.

Reviewers: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D955

llvm-svn: 183823
2013-06-12 07:45:04 +00:00
Rafael Espindola be5138885d Include PathV1.h in files that use it.
This is preparation for replacing Path.h with PathV2.h.

llvm-svn: 183781
2013-06-11 19:59:07 +00:00
Anna Zaks 8ebeb643fd [analyzer] Minor fixups to r183062
Based on feedback from Jordan.

llvm-svn: 183600
2013-06-08 00:29:29 +00:00
Anna Zaks 22895473af [analyzer; alternate edges] Fix the edge locations in presence of macros.
We drew the diagnostic edges to wrong statements in cases the note was on a macro.
The fix is simple, but seems to work just fine for a whole bunch of test cases (plist-macros.cpp).

Also, removes an unnecessary edge in edges-new.mm, when function signature starts with a macro.

llvm-svn: 183599
2013-06-08 00:29:24 +00:00
Anna Zaks de2ae19cf6 [analyzer] Address Jordan’s code review for r183451
llvm-svn: 183455
2013-06-06 22:32:11 +00:00
Anna Zaks b1b95d9409 [analyzer] Ensure that pieces with invalid locations always get removed from the BugReport
The function in which we were doing it used to be conditionalized. Add a new unconditional
cleanup step.

This fixes PR16227 (radar://14073870) - a crash when generating html output for one of the test files.

llvm-svn: 183451
2013-06-06 22:02:58 +00:00
Anna Zaks 496312a364 [analyzer] fixup the comment
llvm-svn: 183450
2013-06-06 22:02:55 +00:00
Jordan Rose cf10ea8cb2 [analyzer; new edges] Simplify edges in a C++11 for-range loop.
Previously our edges were completely broken here; now, the final result
is a very simple set of edges in most cases: one up to the "for" keyword
for context, and one into the body of the loop. This matches the behavior
for ObjC for-in loops.

In the AST, however, CXXForRangeStmts are handled very differently from
ObjCForCollectionStmts. Since they are specified in terms of equivalent
statements in the C++ standard, we actually have implicit AST nodes for
all of the semantic statements. This makes evaluation very easy, but
diagnostic locations a bit trickier. Fortunately, the problem can be
generally defined away by marking all of the implicit statements as
part of the top-level for-range statement.

One of the implicit statements in a for-range statement is the declaration
of implicit iterators __begin and __end. The CFG synthesizes two
separate DeclStmts to match each of these decls, but until now these
synthetic DeclStmts weren't in the function's ParentMap. Now, the CFG
keeps track of its synthetic statements, and the AnalysisDeclContext will
make sure to add them to the ParentMap.

<rdar://problem/14038483>

llvm-svn: 183449
2013-06-06 21:53:45 +00:00
Jordan Rose d2f8a6a993 [analyzer] Improve debug output for PathDiagnosticPieces.
You can now dump a single PathDiagnosticPiece or PathDiagnosticLocation.

llvm-svn: 183367
2013-06-06 01:57:19 +00:00
Anna Zaks 148974d678 [analyzer] Fix a crash that occurs when processing an rvalue array.
When processing ArrayToPointerDecay, we expect the array to be a location, not a LazyCompoundVal.
Special case the rvalue arrays by using a location to represent them. This case is handled similarly
elsewhere in the code.

Fixes PR16206.

llvm-svn: 183359
2013-06-06 00:19:36 +00:00
Jordan Rose 7a8bd94365 [analyzer; new edges] Don't crash if the top-level entry edge is missing.
We previously asserted that there was a top-level function entry edge, but
if the function decl's location is invalid (or within a macro) this edge
might not exist. Change the assertion to an actual check, and don't drop
the first path piece if it doesn't match.

<rdar://problem/14070304>

llvm-svn: 183358
2013-06-06 00:12:41 +00:00
Jordan Rose b67b7b201f [analyzer; new edges] Ignore self-edges, not all edges with the same location.
The edge optimizer needs to see edges for, say, implicit casts (which have
the same source location as their operand) to uniformly simplify the
entire path. However, we still don't want to produce edges from a statement
to /itself/, which could occur when two nodes in a row have the same
statement location.

This necessitated moving the check for redundant notes to after edge
optimization, since the check relies on notes being adjacent in the path.

<rdar://problem/14061675>

llvm-svn: 183357
2013-06-06 00:12:37 +00:00
Jordan Rose 5e2b3a30a0 [analyzer] Enable the new edge algorithm by default.
...but don't yet migrate over the existing plist tests. Some of these
would be trivial to migrate; others could use a bit of inspection first.
In any case, though, the new edge algorithm seems to have proven itself,
and we'd like more coverage (and more usage) of it going forwards.

llvm-svn: 183165
2013-06-03 23:00:19 +00:00
Jordan Rose 7ce598aeee [analyzer; new edges] Omit subexpression back-edges that span multiple lines.
A.1 -> A -> B
becomes
A.1 -> B

This only applies if there's an edge from a subexpression to its parent
expression, and that is immediately followed by another edge from the
parent expression to a subsequent expression. Normally this is useful for
bringing the edges back to the left side of the code, but when the
subexpression is on a different line the backedge ends up looking strange,
and may even obscure code. In these cases, it's better to just continue
to the next top-level statement.

llvm-svn: 183164
2013-06-03 23:00:09 +00:00
Jordan Rose 5f16849b34 [analyzer; new edges] Don't eliminate subexpr edge cycles if the line is long.
Specifically, if the line is over 80 characters, or if the top-level
statement spans mulitple lines, we should preserve sub-expression edges
even if they form a simple cycle as described in the last commit, because
it's harder to infer what's going on than it is for shorter lines.

llvm-svn: 183163
2013-06-03 23:00:05 +00:00
Jordan Rose 8c54b44fb3 [analyzer; new edges] Eliminate "cycle edges" for a single subexpression.
Generating context arrows can result in quite a few arrows surrounding a
relatively simple expression, often containing only a single path note.

|
1 +--2---+
v/       v
auto m = new m // 3 (the path note)
|\       |
5 +--4---+
v

Note also that 5 and 1 are two ends of the "same" arrow, i.e. they go from
event to event. 3 is not an arrow but the path note itself.

Now, if we see a pair of edges like 2 and 4---where 4 is the reverse of 2
and there is optionally a single path note between them---we will
eliminate /both/ edges. Anything more complicated will be left as is
(more edges involved, an inlined call, etc).

The next commit will refine this to preserve the arrows in a larger
expression, so that we don't lose all context.

llvm-svn: 183162
2013-06-03 23:00:00 +00:00
Jordan Rose 06e800727e [analyzer; new edges] Improve enclosing contexts for logical expressions.
The old edge builder didn't have a notion of nested statement contexts,
so there was no special treatment of a logical operator inside an if
(or inside another logical operator). The new edge builder always tries
to establish the full context up to the top-level statement, so it's
important to know how much context has been established already rather
than just checking the innermost context.

This restores some of the old behavior for the old edge generation:
the context of a logical operator's non-controlling expression is the
subexpression in the old edge algorithm, but the entire operator
expression in the new algorithm.

llvm-svn: 183160
2013-06-03 22:59:53 +00:00
Jordan Rose b1db073dac [analyzer; new edges] Include context for edges to sub-expressions.
The current edge-generation algorithm sometimes creates edges from a
top-level statement A to a sub-expression B.1 that's not at the start of B.
This creates a "swoosh" effect where the arrow is drawn on top of the
text at the start of B. In these cases, the results are clearer if we see
an edge from A to B, then another one from B to B.1.

Admittedly, this does create a /lot/ of arrows, some of which merely hop
into a subexpression and then out again for a single note. The next commit
will eliminate these if the subexpression is simple enough.

This updates and reuses some of the infrastructure from the old edge-
generation algorithm to find the "enclosing statement" context for a
given expression. One change in particular marks the context of the
LHS or RHS of a logical binary operator (&&, ||) as the entire operator
expression, rather than the subexpression itself. This matches our behavior
for ?:, and allows us to handle nested context information.

<rdar://problem/13902816>

llvm-svn: 183159
2013-06-03 22:59:48 +00:00
Jordan Rose c892bb04ca [analyzer; new edges] Include a top-level function entry edge while optimizing.
Although we don't want to show a function entry edge for a top-level path,
having it makes optimizing edges a little more uniform.

This does not affect any edges now, but will affect context edge generation
(next commit).

llvm-svn: 183158
2013-06-03 22:59:45 +00:00
Anna Zaks a4bc5e1201 [analyzer] Malloc checker should only escape the receiver when “[O init..]” is called.
Jordan has pointed out that it is valuable to warn in cases when the arguments to init escape.
For example, NSData initWithBytes id not going to free the memory.

llvm-svn: 183062
2013-05-31 23:47:32 +00:00
Anna Zaks 737926ba6c [analyzer] Fix a false positive reported on rare strange code, which happens to be in JSONKit
llvm-svn: 183055
2013-05-31 22:39:13 +00:00
Ted Kremenek 7c6b4084dd [analyzer; new edges] add simplifySimpleBranches() to reduce edges for branches.
In many cases, the edge from the "if" to the condition, followed by an edge from the branch condition to the target code, is uninteresting.

In such cases, we should fold the two edges into one from the "if" to the target.

This also applies to loops.

Implements <rdar://problem/14034763>.

llvm-svn: 183018
2013-05-31 16:56:54 +00:00
Ted Kremenek 263595f4f3 [analyzer; new edges] in splitBranchConditionEdges() do not check that predecessor edge has source in the same lexical scope as the target branch.
Fixes <rdar://problem/14031292>.

llvm-svn: 182987
2013-05-31 06:11:17 +00:00
Ted Kremenek d59fbca225 [analyzer;alternate arrows] Rename 'adjustBranchEdges' to 'splitBranchConditionEdges'.
llvm-svn: 182986
2013-05-31 06:11:11 +00:00
Jordan Rose ca0ecb61e1 Revert "[analyzer; alternate edges] don't add an edge incoming from the start of a function"
...and make this work correctly in the current codebase.

After living on this for a while, it turns out to look very strange for
inlined functions that have only a single statement, and somewhat strange
for inlined functions in general (since they are still conceptually in the
middle of the path, and there is a function-entry path note).

It's worth noting that this only affects inlined functions; in the new
arrow generation algorithm, the top-level function still starts at the
first real statement in the function body, not the enclosing CompoundStmt.

This reverts r182078 / dbfa950abe0e55b173286a306ee620eff5f72ea.

llvm-svn: 182963
2013-05-30 21:30:17 +00:00
Jordan Rose 278d9de314 [analyzer] Don't crash if a block's signature just has the return type.
It is okay to declare a block without an argument list: ^ {} or ^void {}.
In these cases, the BlockDecl's signature-as-written will just contain
the return type, rather than the entire function type. It is unclear if
this is intentional, but the analyzer shouldn't crash because of it.

<rdar://problem/14018351>

llvm-svn: 182948
2013-05-30 18:14:27 +00:00
Jordan Rose 543bdd1237 [analyzer; new edges] In for(;;), use the ForStmt itself for loop notes.
Most loop notes (like "entering loop body") are attached to the condition
expression guarding a loop or its equivalent. For loops may not have a
condition expression, though. Rather than crashing, just use the entire
ForStmt as the location. This is probably the best we can do.

<rdar://problem/14016063>

llvm-svn: 182904
2013-05-30 01:05:58 +00:00
Jordan Rose 1bd1927a14 [analyzer] Accept references to variables declared "extern void" (C only).
In C, 'void' is treated like any other incomplete type, and though it is
never completed, you can cast the address of a void-typed variable to do
something useful. (In C++ it's illegal to declare a variable with void type.)

Previously we asserted on this code; now we just treat it like any other
incomplete type.

And speaking of incomplete types, we don't know their extent. Actually
check that in TypedValueRegion::getExtent, though that's not being used
by any checkers that are on by default.

llvm-svn: 182880
2013-05-29 20:50:34 +00:00
Anna Zaks 5416ab0156 [analyzer] Use the expression’s type instead of region’s type in ArrayToPointer decay evaluation
This gives slightly better precision, specifically, in cases where a non-typed region represents the array
or when the type is a non-array type, which can happen when an array is a result of a reinterpret_cast.

llvm-svn: 182810
2013-05-28 23:24:01 +00:00
Anna Zaks 6477e97af7 [analyzer] Re-enable reasoning about CK_LValueBitCast
It’s important for us to reason about the cast as it is used in std::addressof. The reason we did not
handle the cast previously was a crash on a test case (see commit r157478). The crash was in
processing array to pointer decay when the region type was not an array. Address the issue, by
just returning an unknown in that case.

llvm-svn: 182808
2013-05-28 22:32:08 +00:00
Anna Zaks bac964e14f [analyzer] Use a more generic MemRegion.getAsOffset to evaluate bin operators on MemRegions
In addition to enabling more code reuse, this suppresses some false positives by allowing us to
compare an element region to its base. See the ptr-arith.cpp test cases for an example.

llvm-svn: 182780
2013-05-28 17:31:43 +00:00
Duncan Sands f3dcb68d76 Fix comment type pointed out by Kim Gräsman.
llvm-svn: 182702
2013-05-25 02:22:10 +00:00
Jordan Rose 56138268b0 [analyzer] Treat analyzer-synthesized function bodies like implicit bodies.
When generating path notes, implicit function bodies are shown at the call
site, so that, say, copying a POD type in C++ doesn't jump you to a header
file. This is especially important when the synthesized function itself
calls another function (or block), in which case we should try to jump the
user around as little as possible.

By checking whether a called function has a body in the AST, we can tell
if the analyzer synthesized the body, and if we should therefore collapse
the call down to the call site like a true implicitly-defined function.

<rdar://problem/13978414>

llvm-svn: 182677
2013-05-24 21:43:11 +00:00
Jordan Rose 7291666cd9 [analyzer; new edges] Properly set location after exiting an inlined call.
The new edge algorithm would keep track of the previous location in each
location context, so that it could draw arrows coming in and out of each
inlined call. However, it tried to access the location of the call before
it was actually set (at the CallEnter node). This only affected
unterminated calls at the end of a path; calls with visible exit nodes
already had a valid location.

This patch ditches the location context map, since we're processing the
nodes in order anyway, and just unconditionally updates the PrevLoc
variable after popping out of an inlined call.

<rdar://problem/13983470>

llvm-svn: 182676
2013-05-24 21:43:05 +00:00
Duncan Sands 7d1e660b03 Fix comment typo pointed out by maslen on IRC.
llvm-svn: 182642
2013-05-24 13:41:43 +00:00
Benjamin Kramer bf8d2540a3 Make helper functions static.
llvm-svn: 182589
2013-05-23 15:53:44 +00:00
Ted Kremenek a76dd19507 [analyzer;alternate edges] fix type that was causing the wrong path piece to get removed.
llvm-svn: 182562
2013-05-23 06:41:58 +00:00
Pete Cooper f2ec16eb8b Insert explicit casts to try appease overload resolution in the buildbots
llvm-svn: 182514
2013-05-22 21:02:38 +00:00
Ted Kremenek f63269fdc5 Use scope-resolution operator to hopefully unbreak Windows builds.
llvm-svn: 182509
2013-05-22 20:01:35 +00:00
Ted Kremenek 561060b7f5 Simplifiy code using return value of erase().
llvm-svn: 182506
2013-05-22 19:25:03 +00:00
Ted Kremenek 0962e56f00 [analyzer; alternate edges] remove redundant adjacent "events" with the same text.
Fixes <rdar://problem/13949982>

llvm-svn: 182505
2013-05-22 19:10:41 +00:00
Ted Kremenek 55efcadc1c [analyzer;alternate edges] remove puny edges on the same line that span less than 3 columns.
These are legitimate control-flow edges, but visually they add
no value.

Implements <rdar://problem/13941325>.

llvm-svn: 182502
2013-05-22 18:52:35 +00:00
Ted Kremenek d2d2a9f17b Remove unnecessary assignment.
llvm-svn: 182501
2013-05-22 18:52:32 +00:00
Jordan Rose 1bfe9c787f [analyzer] Don't crash if a block doesn't have a type signature.
Currently, blocks instantiated in templates lose their "signature as
written"; it's not clear if this is intentional. Change the analyzer's
use of BlockDecl::getSignatureAsWritten to check whether or not the
signature is actually there.

<rdar://problem/13954714>

llvm-svn: 182497
2013-05-22 18:09:44 +00:00
Anna Zaks 2f74ff1b3c [analyzer] Do not assert on reports ending in calls within macros.
The crash is triggered by the newly added option (-analyzer-config report-in-main-source-file=true) introduced in r182058.

Note, ideally, we’d like to report the issue within the main source file here as well.
For now, just do not crash.

llvm-svn: 182445
2013-05-22 01:54:34 +00:00
Ted Kremenek 9f0629f669 [analyzer;alternate edges] prune out extra edges to a subexpression where we dive-in and out of a subexpression.
Fixes <rdar://problem/13941891>.

llvm-svn: 182426
2013-05-21 21:38:05 +00:00
Ted Kremenek 6d5bbec32e [analyzer; alternated edges] look through expressions just like Environment does.
llvm-svn: 182425
2013-05-21 21:38:02 +00:00
Ted Kremenek d4167a66e1 [analyzer; alternate edges] optimize edges for ObjC fast enumeration loops.
Fixes <rdar://problem/13942300>.

llvm-svn: 182342
2013-05-21 00:34:40 +00:00
Jordan Rose 933e5ba722 [analyzer] New edges: include an edge to the end-of-path location.
llvm-svn: 182188
2013-05-18 02:27:13 +00:00
Jordan Rose 7c40d078b5 [analyzer] Add a debug dump for PathPieces, a list of PathDiagnosticPieces.
Originally implemented by Ted, extended by me.

llvm-svn: 182186
2013-05-18 02:26:59 +00:00
Jordan Rose 433b0f5455 Revert "[analyzer; alternate edges] improve support for edges with PseudoObjectExprs."
Ted and I spent a long time discussing this today and found out that neither
the existing code nor the new code was doing what either of us thought it
was, which is never good. The good news is we found a much simpler way to
fix the motivating test case (an ObjCSubscriptExpr).

This reverts r182083, but pieces of it will come back in subsequent commits.

llvm-svn: 182185
2013-05-18 02:26:50 +00:00
Anna Zaks 6334579623 [analyzer] Address Jordan's review comments for r182058
llvm-svn: 182156
2013-05-17 20:51:16 +00:00
Ted Kremenek 35de14540f [analyzer; alternate edges] improve support for edges with PseudoObjectExprs.
This optimizes some spurious edges resulting from PseudoObjectExprs.
This required far more changes than I anticipated.  The current
ParentMap does not record any hierarchy information between
a PseudoObjectExpr and its *semantic* expressions that may be
wrapped in OpaqueValueExprs, which are the expressions actually
laid out in the CFG.  This means the arrow pruning logic could
not map from an expression to its containing PseudoObjectExprs.

To solve this, this patch adds a variant of ParentMap that
returns the "semantic" parentage of expressions (essentially
as they are viewed by the CFG).  This alternate ParentMap is then
used by the arrow reducing logic to identify edges into pseudo
object expressions, and then eliminate them.

llvm-svn: 182083
2013-05-17 09:41:40 +00:00
Ted Kremenek fd8f4b0171 [analyzer; alternate edges] treat 'if' statements the same way we do as 'for' or 'while'.
This means adding an extra edge from the 'if' to the condition,
which aesthetically looks more pleasing.

llvm-svn: 182079
2013-05-17 06:48:27 +00:00
Ted Kremenek 504eb552a8 [analyzer; alternate edges] don't add an edge incoming from the start of a function
for a nested call.  This matches what we do with the first stack frame.

llvm-svn: 182078
2013-05-17 06:48:22 +00:00
Jordan Rose fbe4d85035 [analyzer] Don't inline ~shared_ptr.
The analyzer can't see the reference count for shared_ptr, so it doesn't
know whether a given destruction is going to delete the referenced object.
This leads to spurious leak and use-after-free warnings.

For now, just ban destructors named '~shared_ptr', which catches
std::shared_ptr, std::tr1::shared_ptr, and boost::shared_ptr.

PR15987

llvm-svn: 182071
2013-05-17 02:16:49 +00:00
Anna Zaks c5e2eca042 [analyzer] Add an option to use the last location in the main source file as the report location.
Previously, we’ve used the last location of the analyzer issue path as the location of the
report. This might not provide the best user experience, when one analyzer a source
file and the issue appears in the header. Introduce an option to use the last location
of the path that is in the main source file as the report location.

New option can be enabled with -analyzer-config report-in-main-source-file=true.

llvm-svn: 182058
2013-05-16 22:30:45 +00:00
Jordan Rose a7f94ce8a3 Remove unused, awkward CFGStmtVisitor and subclasses.
This class is a StmtVisitor that distinguishes between block-level and
non-block-level statements in a CFG. However, it does so using a hard-coded
idea of which statements might be block-level, which probably isn't accurate
anymore. The only implementer of the CFGStmtVisitor hierarchy was the
analyzer's DeadStoresChecker, and the analyzer creates a linearized CFG
anyway (every non-trivial statement is a block-level statement).

This also allows us to remove the block-expr map ("BlkExprMap"), which
mapped statements to positions in the CFG. Apart from having a helper type
that really should have just been Optional<unsigned>, it was only being
used to ask /if/ a particular expression was block-level, for traversal
purposes in CFGStmtVisitor.

llvm-svn: 181945
2013-05-15 23:22:55 +00:00
David Blaikie d4da8728ba Provide operator<< for stream output of DeclarationNames
ASTDumper was already trying to do this & instead got an implicit bool
conversion by surprise (thus printing out 0 or 1 instead of the name of
the declaration). To avoid that issue & simplify call sites, simply make
it the normal/expected operator<<(raw_ostream&, ...) overload & simplify
all the existing call sites. (bonus: this function doesn't need to be a
member or friend, it's just using public API in DeclarationName)

llvm-svn: 181832
2013-05-14 21:04:00 +00:00
Anna Zaks 6afa8f1609 [analyzer] Refactor: address Jordan’s code review of r181738.
(Modifying the checker to record that the values are no longer nil will be done separately.)

llvm-svn: 181744
2013-05-13 23:49:51 +00:00
Anna Zaks bb2a2c865f [analyzer] Warn about nil elements/keys/values in array and dictionary literals.
llvm-svn: 181738
2013-05-13 21:48:20 +00:00
Rafael Espindola 3ae00052cd Cleanup handling of UniqueExternalLinkage.
This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.

Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.

Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.

llvm-svn: 181677
2013-05-13 00:12:11 +00:00
Anna Zaks 4063fa1cdc [analyzer] Assume [NSNull null] does not return nil.
llvm-svn: 181616
2013-05-10 18:04:46 +00:00
Anna Zaks 3feb2cd5bb [analyzer] Do not check if sys/queue.h file is a system header.
In most cases it is, by just looking at the name. Also, this check prevents the heuristic from working in strange user settings.
radar://13839692

llvm-svn: 181615
2013-05-10 18:04:43 +00:00
Jordan Rose 757fbb0b14 [analyzer] Indirect invalidation counts as an escape for leak checkers.
Consider this example:

  char *p = malloc(sizeof(char));
  systemFunction(&p);
  free(p);

In this case, when we call systemFunction, we know (because it's a system
function) that it won't free 'p'. However, we /don't/ know whether or not
it will /change/ 'p', so the analyzer is forced to invalidate 'p', wiping
out any bindings it contains. But now the malloc'd region looks like a
leak, since there are no more bindings pointing to it, and we'll get a
spurious leak warning.

The fix for this is to notice when something is becoming inaccessible due
to invalidation (i.e. an imperfect model, as opposed to being explicitly
overwritten) and stop tracking it at that point. Currently, the best way
to determine this for a call is the "indirect escape" pointer-escape kind.

In practice, all the patch does is take the "system functions don't free
memory" special case and limit it to direct parameters, i.e. just the
arguments to a call and not other regions accessible to them. This is a
conservative change that should only cause us to escape regions more
eagerly, which means fewer leak warnings.

This isn't perfect for several reasons, the main one being that this
example is treated the same as the one above:

  char **p = malloc(sizeof(char *));
  systemFunction(p + 1);
  // leak

Currently, "addresses accessible by offsets of the starting region" and
"addresses accessible through bindings of the starting region" are both
considered "indirect" regions, hence this uniform treatment.

Another issue is our longstanding problem of not distinguishing const and
non-const bindings; if in the first example systemFunction's parameter were
a char * const *, we should know that the function will not overwrite 'p',
and thus we can safely report the leak.

<rdar://problem/13758386>

llvm-svn: 181607
2013-05-10 17:07:16 +00:00
Ted Kremenek 399980acf5 [analyzer; alternate arrows] for "loop back" edges add back the extra edge to the closing '}'
llvm-svn: 181505
2013-05-09 06:55:41 +00:00
Ted Kremenek b5999f6321 [analyzer;alternate arrows] adapt 'for' loop aesthetic cleanup to 'while' loops.
llvm-svn: 181504
2013-05-09 06:55:35 +00:00
Ted Kremenek cba4a0c593 [analyzer; alternate edges] insert an extra edge for 'for' statements to conditions.
llvm-svn: 181385
2013-05-08 01:15:24 +00:00
Ted Kremenek 0e84ac83eb [analyzer;alternate edges] edges from subexpressions of "?:" are important to retain
llvm-svn: 181384
2013-05-08 01:15:20 +00:00
Ted Kremenek 68a60451b3 [analyzer;alternate arrows] Fix inconsistencies in recorded location context when handling interprocedural paths.
llvm-svn: 181362
2013-05-07 21:12:06 +00:00
Ted Kremenek 1c382b2936 [analyzer; alternate arrows] add back recording whether we visited the first edge.
llvm-svn: 181361
2013-05-07 21:12:03 +00:00
Ted Kremenek abf617c27e [analyzer; alternate arrows] remove pruning of loop diagnostics.
llvm-svn: 181360
2013-05-07 21:12:00 +00:00
Ted Kremenek b48f5d9d56 [analyzer; alternate arrows] include logical '||' and '&&' as anchors for edges.
llvm-svn: 181359
2013-05-07 21:11:57 +00:00
Ted Kremenek 3a865221c7 [analyzer; alternate arrows] include an edge from the "break" or "continue"
llvm-svn: 181358
2013-05-07 21:11:54 +00:00
Ted Kremenek f3510071f3 [analyzer; alternate arrows] the extra edge to the closing '}' in a loop adds no value.
llvm-svn: 181357
2013-05-07 21:11:52 +00:00
Ted Kremenek 2f2a3042e1 [analyzer; alternate arrows] the initializer of a ForStmt isn't interesting either.
llvm-svn: 181356
2013-05-07 21:11:49 +00:00
Anna Zaks e5e416c6de [analyzer] Fix a crash triggered by printing a note on a default argument
Instead, use the location of the call to print the note.

llvm-svn: 181337
2013-05-07 17:42:42 +00:00
Ted Kremenek ae7c38ddc7 [analyzer; alternate arrows] The ForStmt increment is not a critical anchor for arrows.
llvm-svn: 181333
2013-05-07 17:02:41 +00:00
Ted Kremenek 75b8cdee19 [analyzer; alternate edges] simplify optimization rules to look at control-flow conditions to prune edges.
llvm-svn: 181292
2013-05-07 07:30:07 +00:00
Ted Kremenek 868b55336e [analyzer; alternate arrows] use the terminator condition as the location for 'entering loop body'
llvm-svn: 181291
2013-05-07 07:30:00 +00:00
Ted Kremenek fe516f8924 [analyzer; alternate arrows] provide a diagnostic for entering a loop for the first time.
llvm-svn: 181282
2013-05-07 01:18:10 +00:00
Ted Kremenek 9af6baaaa3 [analyzer; alternate arrows] don't increment the path iterator when we just deleted the next iterator.
This is an optimization.  It is possible that by deleting the next
edge we will pattern match again at the current spot.

llvm-svn: 181256
2013-05-06 21:59:37 +00:00
Jordan Rose 50e5db8a6b [analyzer] Remove now-unused bindCompoundLiteral helper function.
The one user has been changed to use getLValue on the compound literal
expression and then use the normal bindLoc to assign a value. No need
to special case this in the StoreManager.

llvm-svn: 181214
2013-05-06 16:48:26 +00:00
Jordan Rose 5d2abefb62 [analyzer] Handle CXXTemporaryObjectExprs in compound literals.
This occurs because in C++11 the compound literal syntax can trigger a
constructor call via list-initialization. That is, "Point{x, y}" and
"(Point){x, y}" end up being equivalent. If this occurs, the inner
CXXConstructExpr will have already handled the object construction; the
CompoundLiteralExpr just needs to propagate that value forwards.

<rdar://problem/13804098>

llvm-svn: 181213
2013-05-06 16:48:20 +00:00
Ted Kremenek 7b9b5a2c48 [analyzer;alternate edges] start experimenting with control flow "barriers" to prevent an edge being optimized away.
llvm-svn: 181088
2013-05-04 01:13:22 +00:00
Ted Kremenek 992b3112ce [analyzer;alternate edges] ignore parentheses when determining edge levels.
llvm-svn: 181087
2013-05-04 01:13:12 +00:00
Ted Kremenek bcd6b0d891 [analyzer; alternate edges] - eliminate unnecessary edges where between parents and subexpressions.
llvm-svn: 181086
2013-05-04 01:13:08 +00:00
Ted Kremenek ccb6d1ea0c [analyzer; alternate edges] - merge control edges where we descend to a subexpression and pop back out.
llvm-svn: 181085
2013-05-04 01:13:05 +00:00
Ted Kremenek 6cf3c97c55 [analyzer; alternate edges] prune edges whose end/begin locations have the same statement parents.
This change required some minor changes to LocationContextMap to have it map
from PathPieces to LocationContexts instead of PathDiagnosticCallPieces to
LocationContexts.  These changes are in the other diagnostic
generation logic as well, but are functionally equivalent.

Interestingly, this optimize requires delaying "cleanUpLocation()" until
later; possibly after all edges have been optimized.  This is because
we need PathDiagnosticLocations to refer to the semantic entity (e.g. a statement)
as long as possible.  Raw source locations tell us nothing about
the semantic relationship between two locations in a path.

llvm-svn: 181084
2013-05-04 01:13:01 +00:00
Ted Kremenek 74c0d388e8 [analyzer;alternate edges] - add in events (loop iterations, etc)
These were being dropped due a transcription mistake from the original
algorithm.

llvm-svn: 181083
2013-05-04 01:12:55 +00:00
Ted Kremenek acf99a1a51 [analyzer] Start hacking up alternate control-flow edge generation. WIP. Not guaranteed to do anything useful yet.
llvm-svn: 181040
2013-05-03 18:25:33 +00:00
Jordan Rose 320fbf057c [analyzer] Check the stack frame when looking for a var's initialization.
FindLastStoreBRVisitor is responsible for finding where a particular region
gets its value; if the region is a VarRegion, it's possible that value was
assigned at initialization, i.e. at its DeclStmt. However, if a function is
called recursively, the same DeclStmt may be evaluated multiple times in
multiple stack frames. FindLastStoreBRVisitor was not taking this into
account and just picking the first one it saw.

<rdar://problem/13787723>

llvm-svn: 180997
2013-05-03 05:47:31 +00:00
Jordan Rose cea47b78fc [analyzer] Fix trackNullOrUndef when tracking args that have nil receivers.
There were actually two bugs here:
- if we decided to look for an interesting lvalue or call expression, we
  wouldn't go find its node if we also knew we were at a (different) call.
- if we looked through one message send with a  nil receiver, we thought we
  were still looking at an argument to the original call.

Put together, this kept us from being able to track the right values, which
means sub-par diagnostics and worse false-positive suppression.

Noticed by inspection.

llvm-svn: 180996
2013-05-03 05:47:24 +00:00
Ted Kremenek 57f745ec96 Make cleanUpLocation() a self-contained function.
llvm-svn: 180986
2013-05-03 01:16:26 +00:00
Ted Kremenek f12d9d93fe Re-apply 180974 with the build error fixed. This was the result
of a weird merge error with git.

llvm-svn: 180981
2013-05-03 00:32:44 +00:00
Rafael Espindola c73756b178 Revert "Change LocationContextMap to be a temporary instead of shared variable in BugReporter."
This reverts commit 180974. It broke the build.

llvm-svn: 180979
2013-05-03 00:22:49 +00:00
Ted Kremenek 48bd5fddf3 Change LocationContextMap to be a temporary instead of shared variable in BugReporter.
BugReporter is used to process ALL bug reports.  By using a shared map,
we are having mappings from different PathDiagnosticPieces to LocationContexts
well beyond the point where we are processing a given report.  This
state is inherently error prone, and is analogous to using a global
variable.  Instead, just create a temporary map, one per report,
and when we are done with it we throw it away.  No extra state.

llvm-svn: 180974
2013-05-02 23:56:33 +00:00
Jordan Rose c76d7e3d96 [analyzer] Don't try to evaluate MaterializeTemporaryExpr as a constant.
...and don't consider '0' to be a null pointer constant if it's the
initializer for a float!

Apparently null pointer constant evaluation looks through both
MaterializeTemporaryExpr and ImplicitCastExpr, so we have to be more
careful about types in the callers. For RegionStore this just means giving
up a little more; for ExprEngine this means handling the
MaterializeTemporaryExpr case explicitly.

Follow-up to r180894.

llvm-svn: 180944
2013-05-02 19:51:20 +00:00
Jordan Rose b147918252 [analyzer] RetainCountChecker: don't track through xpc_connection_set_context.
It is unfortunate that we have to mark these exceptions in multiple places.
This was already in CallEvent. I suppose it does let us be more precise
about saying /which/ arguments have their retain counts invalidated -- the
connection's is still valid even though the context object's isn't -- but
we're not tracking the retain count of XPC objects anyway.

<rdar://problem/13783514>

llvm-svn: 180904
2013-05-02 01:51:40 +00:00
Jordan Rose 89bbd1fb64 [analyzer] Consolidate constant evaluation logic in SValBuilder.
Previously, this was scattered across Environment (literal expressions),
ExprEngine (default arguments), and RegionStore (global constants). The
former special-cased several kinds of simple constant expressions, while
the latter two deferred to the AST's constant evaluator.

Now, these are all unified as SValBuilder::getConstantVal(). To keep
Environment fast, the special cases for simple constant expressions have
been left in, but the main benefits are that (a) unusual constants like
ObjCStringLiterals now work as default arguments and global constant
initializers, and (b) we're not duplicating code between ExprEngine and
RegionStore.

This actually caught a bug in our test suite, which is awesome: we stop
tracking allocated memory if it's passed as an argument along with some
kind of callback, but not if the callback is 0. We were testing this in
a case where the callback parameter had a default value, but that value
was 0. After this change, the analyzer now (correctly) flags that as a
leak!

<rdar://problem/13773117>

llvm-svn: 180894
2013-05-01 23:10:44 +00:00
Jordan Rose 7023a90378 [analyzer] Don't inline the [cd]tors of C++ iterators.
This goes with r178516, which instructed the analyzer not to inline the
constructors and destructors of C++ container classes. This goes a step
further and does the same thing for iterators, so that the analyzer won't
falsely decide we're trying to construct an iterator pointing to a
nonexistent element.

The heuristic for determining whether something is an iterator is the
presence of an 'iterator_category' member. This is controlled under the
same -analyzer-config option as container constructor/destructor inlining:
'c++-container-inlining'.

<rdar://problem/13770187>

llvm-svn: 180890
2013-05-01 22:39:31 +00:00
Jordan Rose dc16628c93 Re-apply "[analyzer] Model casts to bool differently from other numbers."
This doesn't appear to be the cause of the slowdown. I'll have to try a
manual bisect to see if there's really anything there, or if it's just
the bot itself taking on additional load. Meanwhile, this change helps
with correctness.

This changes an assertion and adds a test case, then re-applies r180638,
which was reverted in r180714.

<rdar://problem/13296133> and PR15863

llvm-svn: 180864
2013-05-01 18:19:59 +00:00
Ted Kremenek eba09facff Revert "[analyzer] Change PathPieces to be a wrapper around an ilist of (through indirection) PathDiagnosticPieces."
Jordan rightly pointed out that we can do the same with std::list.

llvm-svn: 180746
2013-04-29 23:12:59 +00:00
Ted Kremenek 03ae57b5af [analyzer] Change PathPieces to be a wrapper around an ilist of (through indirection) PathDiagnosticPieces.
Much of this patch outside of PathDiagnostics.h are just minor
syntactic changes due to the return type for operator* and the like
changing for the iterator, so the real focus should be on
PathPieces itself.

This change is motivated so that we can do efficient insertion
and removal of individual pieces from within a PathPiece, just like
this was a kind of "IR" for static analyzer diagnostics.  We
currently implement path transformations by iterating over an
entire PathPiece and making a copy.  This isn't very natural for
some algorithms.

We use an ilist here instead of std::list because we want operations
to rip out/insert nodes in place, just like IR manipulation.  This
isn't being used yet, but opens the door for more powerful
transformation algorithms on diagnostic paths.

llvm-svn: 180741
2013-04-29 22:38:26 +00:00
Ted Kremenek 518e781256 [analyzer] Remove comparePath's dependency on subscript operator.
llvm-svn: 180740
2013-04-29 22:38:22 +00:00
Jordan Rose 49f888bbab Revert "[analyzer] Model casts to bool differently from other numbers."
This seems to be causing quite a slowdown on our internal analyzer bot,
and I'm not sure why. Needs further investigation.

This reverts r180638 / 9e161ea981f22ae017b6af09d660bfc3ddf16a09.

llvm-svn: 180714
2013-04-29 17:23:03 +00:00
Jordan Rose 9de821ebfd [analyzer] An ObjC for-in loop runs 0 times if the collection is nil.
In an Objective-C for-in loop "for (id element in collection) {}", the loop
will run 0 times if the collection is nil. This is because the for-in loop
is implemented using a protocol method that returns 0 when there are no
elements to iterate, and messages to nil will result in a 0 return value.

At some point we may want to actually model this message send, but for now
we may as well get the nil case correct, and avoid the false positives that
would come with this case.

<rdar://problem/13744632>

llvm-svn: 180639
2013-04-26 21:43:01 +00:00
Jordan Rose 9661c1d18a [analyzer] Model casts to bool differently from other numbers.
Casts to bool (and _Bool) are equivalent to checks against zero,
not truncations to 1 bit or 8 bits.

This improved reasoning does cause a change in the behavior of the alpha
BoolAssignment checker. Previously, this checker complained about statements
like "bool x = y" if 'y' was known not to be 0 or 1. Now it does not, since
that conversion is well-defined. It's hard to say what the "best" behavior
here is: this conversion is safe, but might be better written as an explicit
comparison against zero.

More usefully, besides improving our model of booleans, this fixes spurious
warnings when returning the address of a local variable cast to bool.

<rdar://problem/13296133>

llvm-svn: 180638
2013-04-26 21:42:55 +00:00
Anna Zaks 144579e299 [analyzer] Teach DeadStoreChecker to look though BO_Comma and disregard the LHS.
llvm-svn: 180579
2013-04-25 21:52:35 +00:00
Anna Zaks 99394bbd02 [analyzer] Fix a crash in RetainCountChecker - we should not rely on CallEnter::getCallExpr to return non-NULL
We get a CallEnter with a null expression, when processing a destructor. All other users of
CallEnter::getCallExpr work fine with null as return value.

(Addresses PR15832, Thanks to Jordan for reducing the test case!)

llvm-svn: 180234
2013-04-25 00:41:32 +00:00
Anton Yartsev 67f1ab0de8 [analyzer] Refactoring + explanatory comment.
llvm-svn: 180181
2013-04-24 10:24:38 +00:00
Anna Zaks 7712f38978 [analyzer] IvarInvalidation: correctly handle cases where only partial invalidators exist
- If only partial invalidators exist and there are no full invalidators in @implementation, report every ivar that has
not been invalidated. (Previously, we reported the first Ivar in the list, which could actually have been invalidated
by a partial invalidator. The code assumed you cannot have only partial invalidators.)

- Do not report missing invalidation method declaration if a partial invalidation method declaration exists.

llvm-svn: 180170
2013-04-24 02:49:16 +00:00
Anna Zaks 404028798f [analyzer] Set the allocation site to be the uniqueing location for retain count checker leaks.
The uniqueing location is the location which is part of the hash used to determine if two reports are
the same. This is used by the CmpRuns.py script to compare two analyzer runs and determine which
warnings are new.

llvm-svn: 180166
2013-04-23 23:57:50 +00:00
Anna Zaks 4e16b29c13 [analyzer] Refactor BugReport::getLocation and PathDiagnosticLocation::createEndOfPath for greater code reuse
The 2 functions were computing the same location using different logic (each one had edge case bugs that the other
one did not). Refactor them to rely on the same logic.

The location of the warning reported in text/command line output format will now match that of the plist file.

There is one change in the plist output as well. When reporting an error on a BinaryOperator, we use the location of the
operator instead of the beginning of the BinaryOperator expression. This matches our output on command line and
looks better in most cases.

llvm-svn: 180165
2013-04-23 23:57:43 +00:00
Jordan Rose 7467f06533 [analyzer] RetainCountChecker: Clean up path notes for autorelease.
No functionality change.

<rdar://problem/13710586>

llvm-svn: 180075
2013-04-23 01:42:25 +00:00
Jordan Rose 6e3cf2ba85 [analyzer] Model strsep(), particularly that it returns its input.
This handles the false positive leak warning in PR15374, and also serves
as a basic model for the strsep() function.

llvm-svn: 180069
2013-04-22 23:18:42 +00:00
Jordan Rose b957113b3f [analyzer] Treat reinterpret_cast like a base cast in certain cases.
The analyzer represents all pointer-to-pointer bitcasts the same way, but
this can be problematic if an implicit base cast gets layered on top of a
manual base cast (performed with reinterpret_cast instead of static_cast).
Fix this (and avoid a valid assertion) by looking through cast regions.

Using reinterpret_cast this way is only valid if the base class is at the
same offset as the derived class; this is checked by -Wreinterpret-base-class.
In the interest of performance, the analyzer doesn't repeat this check
anywhere; it will just silently do the wrong thing (use the wrong offsets
for fields of the base class) if the user code is wrong.

PR15394

llvm-svn: 180052
2013-04-22 21:36:49 +00:00
Jordan Rose 3437669ca9 [analyzer] Type information from C++ new expressions is perfect.
This improves our handling of dynamic_cast and devirtualization for
objects allocated by 'new'.

llvm-svn: 180051
2013-04-22 21:36:44 +00:00