In earlier patches regarding AnalyzerOptions, a lot of effort went into
gathering all config options, and changing the interface so that potential
misuse can be eliminited.
Up until this point, AnalyzerOptions only evaluated an option when it was
querried. For example, if we had a "-no-false-positives" flag, AnalyzerOptions
would store an Optional field for it that would be None up until somewhere in
the code until the flag's getter function is called.
However, now that we're confident that we've gathered all configs, we can
evaluate off of them before analysis, so we can emit a error on invalid input
even if that prticular flag will not matter in that particular run of the
analyzer. Another very big benefit of this is that debug.ConfigDumper will now
show the value of all configs every single time.
Also, almost all options related class have a similar interface, so uniformity
is also a benefit.
The implementation for errors on invalid input will be commited shorty.
Differential Revision: https://reviews.llvm.org/D53692
llvm-svn: 348031
During the review of D41938 a condition check with an early exit accidentally
slipped into a branch, leaving the other branch unprotected. This may result in
an assertion later on. This hotfix moves this contition check outside of the
branch.
Differential Revision: https://reviews.llvm.org/D55051
llvm-svn: 347981
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
By making sure the returned value from getKnownSVal is consistent with
the value used inside expression engine.
PR38427
Differential Revision: https://reviews.llvm.org/D51252
llvm-svn: 340965
This fix is similar to r337769 and addresses a regression caused by r337167.
When an operation between a nonloc::LocAsInteger and a non-pointer symbol
is performed, the LocAsInteger-specific part of information is lost.
When the non-pointer symbol is collapsing into a constant, we cannot easily
re-evaluate the result, because we need to recover the missing
LocAsInteger-specific information (eg., integer type, or the very fact that
this pointer was at some point converted to an integer).
Add one more defensive check to prevent crashes on trying to simplify a
SymSymExpr with different Loc-ness of operands.
Differential Revision:
llvm-svn: 338420
Patch https://reviews.llvm.org/rC329780 not only rearranges comparisons but
also binary expressions. This latter behavior is not protected by the analyzer
option. Hower, since no complexity threshold is enforced to the symbols this
may result in exponential execution time if the expressions are too complex:
https://bugs.llvm.org/show_bug.cgi?id=38208. For a quick fix we extended the
analyzer option to also cover the additive cases.
This is only a temporary fix, the final solution should be enforcing the
complexity threshold to the symbols.
Differential Revision: https://reviews.llvm.org/D49536
llvm-svn: 337678
The canonical representation of pointer &SymRegion{$x} casted to boolean is
"$x != 0", not "$x". Assertion added in r337227 catches that.
Differential Revision: https://reviews.llvm.org/D48232
llvm-svn: 337228
In the current SVal hierarchy there are multiple ways of representing certain
values but few are actually used and expected to be seen by the code.
In particular, a value of a symbolic pointer is always represented by a
loc::MemRegionVal that wraps a SymbolicRegion that wraps the pointer symbol
and never by a nonloc::SymbolVal that wraps that symbol directly.
Assert the aforementioned fact. Fix one minor violation of it.
Differential Revision: https://reviews.llvm.org/D48205
llvm-svn: 337227
Memoize simplification so that we didn't need to simplify the same symbolic
expression twice within the same program state.
Gives ~25% performance boost on the artificial test in test/Analysis/hangs.c.
Differential Revision: https://reviews.llvm.org/D47402
llvm-svn: 333671
When neither LHS nor RHS of a binary operator expression can be simplified,
return the original expression instead of re-evaluating the binary operator.
Such re-evaluation was causing recusrive re-simplification which caused
the algorithmic complexity to explode.
Differential Revision: https://reviews.llvm.org/D47155
llvm-svn: 333670
Expression rearrangement in SValBuilder (see rL329780) crashes with an assert if the type of the integer is different from the type of the symbol. This fix adds a check that prevents rearrangement in such cases.
Differential Revision: https://reviews.llvm.org/D45557
llvm-svn: 330064
Since the range-based constraint manager (default) is weak in handling comparisons where symbols are on both sides it is wise to rearrange them to have symbols only on the left side. Thus e.g. A + n >= B + m becomes A - B >= m - n which enables the constraint manager to store a range m - n .. MAX_VALUE for the symbolic expression A - B. This can be used later to check whether e.g. A + k == B + l can be true, which is also rearranged to A - B == l - k so the constraint manager can check whether l - k is in the range (thus greater than or equal to m - n).
The restriction in this version is the the rearrangement happens only if both the symbols and the concrete integers are within the range [min/4 .. max/4] where min and max are the minimal and maximal values of their type.
The rearrangement is not enabled by default. It has to be enabled by using -analyzer-config aggressive-relational-comparison-simplification=true.
Co-author of this patch is Artem Dergachev (NoQ).
Differential Revision: https://reviews.llvm.org/D41938
llvm-svn: 329780
Represent the symbolic value for results of pointer arithmetic on void pointers
in a different way: instead of making void-typed element regions, make
char-typed element regions.
Add an assertion that ensures that no void-typed regions are ever constructed.
This is a refactoring of internals that should not immediately affect
the analyzer's (default) behavior.
Differential Revision: https://reviews.llvm.org/D40939
llvm-svn: 322775
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.
All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.
llvm-svn: 320707
This patch fixes analyzer's crash on the newly added test case
(see also https://bugs.llvm.org/show_bug.cgi?id=34374).
Pointers subtraction appears to be modeled incorrectly
in the following example:
char* p;
auto n = p - reinterpret_cast<char*>((unsigned long)1);
In this case the analyzer (built without this patch)
tries to create a symbolic value for the difference
treating reinterpret_cast<char*>((unsigned long)1)
as an integer, that is not correct.
Differential revision: https://reviews.llvm.org/D38214
Test plan: make check-all
llvm-svn: 314141
This diff fixes modeling of arithmetic
expressions where pointers are treated as integers
(i.e. via C-style / reinterpret casts).
For now we return UnknownVal unless the operation is a comparison.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D37120
llvm-svn: 311935
This diff fixes a crash (triggered assert) on the newly added test case.
In the method Simplifier::VisitSymbolData we check the type of S and return
Loc/NonLoc accordingly.
Differential revision: https://reviews.llvm.org/D36564
llvm-svn: 310887
This is a follow up for one of
the previous diffs https://reviews.llvm.org/D32328.
getTypeSize and with getIntWidth are not equivalent for bool
(see https://clang.llvm.org/doxygen/ASTContext_8cpp_source.html#l08444),
this causes a number of issues
(for instance, if APint X representing a bool is created
with the wrong bit width then X is not comparable against Min/Max
(because of the different bit width), that results in crashes
(triggered asserts) inside assume* methods),
for examples see the newly added test cases.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D35041
llvm-svn: 307604
We now check the type of the super-region pointer for most SubRegion classes
in compile time; some checks are run-time though.
This is an API-breaking change (we now require explicit casts to specific region
sub-classes), but in practice very few checkers are affected.
Differential Revision: https://reviews.llvm.org/D26838
llvm-svn: 300189
SValBuilder tries to constant-fold symbols in the left-hand side of the symbolic
expression whenever it fails to evaluate the expression directly. However, it
only constant-folds them when they are atomic expressions, not when they are
complicated expressions themselves. This patch adds recursive constant-folding
to the left-hand side subexpression (there's a lack of symmetry because we're
trying to have symbols on the left and constants on the right). As an example,
we'd now be able to handle operations similar to "$x + 1 < $y", when $x is
constrained to a constant.
rdar://problem/31354676
Differential Revision: https://reviews.llvm.org/D31886
llvm-svn: 300178
If the value is known, but we cannot increment it, conjure a symbol to
represent the result of the operation based on the operator expression,
not on the sub-expression.
In particular, no longer crash on comparing a result of a LocAsInteger increment
to a constant integer.
rdar://problem/31067356
Differential Revision: https://reviews.llvm.org/D31289
llvm-svn: 298927
Add a new type of NonLoc SVal for C++ pointer-to-member operations. This SVal
supports both pointers to member functions and pointers to member data.
A patch by Kirill Romanenkov!
Differential Revision: https://reviews.llvm.org/D25475
llvm-svn: 289873
Unlike global/static variables, calloc etc. functions that allocate ObjC
objects behave differently in terms of memory barriers, and hacks that make
dispatch_once as fast as it possibly could be start failing.
Differential Revision: https://reviews.llvm.org/D25909
llvm-svn: 285605
The purpose of these changes is to simplify introduction of definition files
for the three hierarchies.
1. For every sub-class C of these classes, its kind in the relevant enumeration
is changed to "CKind" (or C##Kind in preprocessor-ish terms), eg:
MemRegionKind -> MemRegionValKind
RegionValueKind -> SymbolRegionValueKind
CastSymbolKind -> SymbolCastKind
SymIntKind -> SymIntExprKind
2. MemSpaceRegion used to be inconsistently used as both an abstract base and
a particular region. This region class is now an abstract base and no longer
occupies GenericMemSpaceRegionKind. Instead, a new class, CodeSpaceRegion,
is introduced for handling the unique use case for MemSpaceRegion as
"the generic memory space" (when it represents a memory space that holds all
executable code).
3. BEG_ prefixes in memory region kind ranges are renamed to BEGIN_ for
consisitency with symbol kind ranges.
4. FunctionTextRegion and BlockTextRegion are renamed to FunctionCodeRegion and
BlockCodeRegion, respectively. The term 'code' is less jargony than 'text' and
we already refer to BlockTextRegion as a 'code region' in BlockDataRegion.
Differential Revision: http://reviews.llvm.org/D16062
llvm-svn: 257598
Summary: It breaks the build for the ASTMatchers
Subscribers: klimek, cfe-commits
Differential Revision: http://reviews.llvm.org/D13893
llvm-svn: 250827
When casting the address of a FunctionTextRegion to bool, or when adding
constraints to such an address, use a stand-in symbol to represent the
presence or absence of the function if the function is weakly linked.
This is groundwork for possible simple availability testing checks, and
can already catch mistakes involving inverted null checks for
weakly-linked functions.
Currently, the implementation reuses the "extent" symbols, originally created
for tracking the size of a malloc region. Since FunctionTextRegions cannot
be dereferenced, the extent symbol will never be used for anything else.
Still, this probably deserves a refactoring in the future.
This patch does not attempt to support testing the presence of weak
/variables/ (global variables), which would likely require much more of
a change and a generalization of "region structure metadata", like the
current "extents", vs. "region contents metadata", like CStringChecker's
"string length".
Patch by Richard <tarka.t.otter@googlemail.com>!
llvm-svn: 189492
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
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
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
Previously, the analyzer used isIntegerType() everywhere, which uses the C
definition of "integer". The C++ predicate with the same behavior is
isIntegerOrUnscopedEnumerationType().
However, the analyzer is /really/ using this to ask if it's some sort of
"integrally representable" type, i.e. it should include C++11 scoped
enumerations as well. hasIntegerRepresentation() sounds like the right
predicate, but that includes vectors, which the analyzer represents by its
elements.
This commit audits all uses of isIntegerType() and replaces them with the
general isIntegerOrEnumerationType(), except in some specific cases where
it makes sense to exclude scoped enumerations, or any enumerations. These
cases now use isIntegerOrUnscopedEnumerationType() and getAs<BuiltinType>()
plus BuiltinType::isInteger().
isIntegerType() is hereby banned in the analyzer - lib/StaticAnalysis and
include/clang/StaticAnalysis. :-)
Fixes real assertion failures. PR15703 / <rdar://problem/12350701>
llvm-svn: 179081
For two concrete locations, we were producing another concrete location and
then casting it to an integer. We should just create a nonloc::ConcreteInt
to begin with.
No functionality change.
llvm-svn: 177805
We just treat this as opaque symbols, but even that allows us to handle
simple cases where the same condition is tested twice. This is very common
in the STL, which means that any project using the STL gets spurious errors.
Part of <rdar://problem/13239003>.
llvm-svn: 177800
Kristof Umann