lifetimes have been extended via reference binding. The type of the
reference and the type of the temporary are not necessarily the same,
which could cause a crash. Fixes <rdar://problem/10398199>.
llvm-svn: 144646
property references to use a new PseudoObjectExpr
expression which pairs a syntactic form of the expression
with a set of semantic expressions implementing it.
This should significantly reduce the complexity required
elsewhere in the compiler to deal with these kinds of
expressions (e.g. IR generation's special l-value kind,
the static analyzer's Message abstraction), at the lower
cost of specifically dealing with the odd AST structure
of these expressions. It should also greatly simplify
efforts to implement similar language features in the
future, most notably Managed C++'s properties and indexed
properties.
Most of the effort here is in dealing with the various
clients of the AST. I've gone ahead and simplified the
ObjC rewriter's use of properties; other clients, like
IR-gen and the static analyzer, have all the old
complexity *and* all the new complexity, at least
temporarily. Many thanks to Ted for writing and advising
on the necessary changes to the static analyzer.
I've xfailed a small diagnostics regression in the static
analyzer at Ted's request.
llvm-svn: 143867
implicitly perform an lvalue-to-rvalue conversion if used on an lvalue
expression. Also improve the documentation of Expr::Evaluate* to indicate which
of them will accept expressions with side-effects.
llvm-svn: 143263
temporary objects and local variables. When detected, these split the
block, marking the new one as having only the exit block as a successor.
This prevents a large number of false positives in warnings sensitive to
no-return constructs such as -Wreturn-type, and fixes the remainder of
PR10063 along with several variations of this bug that had not been
reported. The test cases are extended across the board to cover these
patterns.
This also checks in a stress test for these types of CFGs. The stress
test declares some 32k variables, a mixture of no-return and normal
destructors. Previously, this resulted in roughly 2500 CFG blocks, but
didn't model any of the no-return destructors. With this patch, it
results in over 33k blocks, many of them now unreachable.
The nice thing about how the analyzer is set up? This causes *no*
regression in performance of building the CFG. It actually in some cases
makes it faster, as best I can benchmark. The analysis for -Wreturn-type
(and any other that cares about no-return code paths) is technically
slower now as it has to look at many more candidate blocks, but it
computes the correct answer. I have more test cases to follow, I think
they all work now. Also I have further work that should dramatically
simplify analyses in the presence of no-return.
llvm-svn: 139586
and case statements. Use this to make the logic in the CFG builder more
robust at finding the actual statements within a compound statement,
even when there are many layers of labels obscuring it.
Also extend the test cases for a large chunk of PR10063. Still more work
to do here though.
llvm-svn: 139437
incorrectly in the CFG, and also the static analyzer. This patch regresses the analyzer a bit, but
that needs to be followed up with a better solution.
Fixes <rdar://problem/10008112>.
llvm-svn: 138372
MaterializeTemporaryExpr captures a reference binding to a temporary
value, making explicit that the temporary value (a prvalue) needs to
be materialized into memory so that its address can be used. The
intended AST invariant here is that a reference will always bind to a
glvalue, and MaterializeTemporaryExpr will be used to convert prvalues
into glvalues for that binding to happen. For example, given
const int& r = 1.0;
The initializer of "r" will be a MaterializeTemporaryExpr whose
subexpression is an implicit conversion from the double literal "1.0"
to an integer value.
IR generation benefits most from this new node, since it was
previously guessing (badly) when to materialize temporaries for the
purposes of reference binding. There are likely more refactoring and
cleanups we could perform there, but the introduction of
MaterializeTemporaryExpr fixes PR9565, a case where IR generation
would effectively bind a const reference directly to a bitfield in a
struct. Addresses <rdar://problem/9552231>.
llvm-svn: 133521
Also, have Environment stop looking through NoOp casts; it didn't match the behavior of LiveVariables. And once that's gone, the whole cast block of that switch is unnecessary.
llvm-svn: 132840
This introduces a generic base class for the expression evaluator
classes, which handles a few common expression types which were
previously handled separately in each class. Also, the expression
evaluator now uses ConstStmtVisitor.
llvm-svn: 131281
1) Change the CFG to include the DeclStmt for conditional variables, instead of using the condition itself as a faux DeclStmt.
2) Update ExprEngine (the static analyzer) to understand (1), so not to regress.
3) Update UninitializedValues.cpp to initialize all tracked variables to Uninitialized at the start of the function/method.
4) Only use the SelfReferenceChecker (SemaDecl.cpp) on global variables, leaving the dataflow analysis to handle other cases.
The combination of (1) and (3) allows the dataflow-based -Wuninitialized to find self-init problems when the initializer
contained control-flow.
llvm-svn: 128858
Change the interface to expose the new information and deal with the enormous fallout.
Introduce the new ExceptionSpecificationType value EST_DynamicNone to more easily deal with empty throw specifications.
Update the tests for noexcept and fix the various bugs uncovered, such as lack of tentative parsing support.
llvm-svn: 127537
Instead, create a small set of Stmt* -> CFGBlock* mappings during CFG construction for only the statements we care about
relating to the diagnostics we want to check for reachability.
llvm-svn: 127396
Moreover, change AnalysisContext to use an OwningPtr for created analysis objects instead
of directly managing them.
Finally, add a 'forcedBlkExprs' entry to CFG::BuildOptions that will be used by the
CFGBuilder to force specific expressions to be block-level expressions.
llvm-svn: 127385
This fixes a crash reported in PR9287, and also fixes a false positive involving the value of such ternary
expressions not properly getting propagated.
llvm-svn: 126362
class and to bind the shared value using OpaqueValueExpr. This fixes an
unnoticed problem with deserialization of these expressions where the
deserialized form would lose the vital pointer-equality trait; or rather,
it fixes it because this patch also does the right thing for deserializing
OVEs.
Change OVEs to not be a "temporary object" in the sense that copy elision is
permitted.
This new representation is not totally unawkward to work with, but I think
that's really part and parcel with the semantics we're modelling here. In
particular, it's much easier to fix things like the copy elision bug and to
make the CFG look right.
I've tried to update the analyzer to deal with this in at least some
obvious cases, and I think we get a much better CFG out, but the printing
of OpaqueValueExprs probably needs some work.
llvm-svn: 125744
LabelDecl and LabelStmt. There is a 1-1 correspondence between the
two, but this simplifies a bunch of code by itself. This is because
labels are the only place where we previously had references to random
other statements, causing grief for AST serialization and other stuff.
This does cause one regression (attr(unused) doesn't silence unused
label warnings) which I'll address next.
This does fix some minor bugs:
1. "The only valid attribute " diagnostic was capitalized.
2. Various diagnostics printed as ''labelname'' instead of 'labelname'
3. This reduces duplication of label checking between functions and blocks.
Review appreciated, particularly for the cindex and template bits.
llvm-svn: 125733
implicit lvalue-to-rvalue casts that John McCall
recently introduced. This causes a whole bunch
of logic in the analyzer for handling lvalues
to vanish. It does, however, raise a few issues
in the analyzer w.r.t to modeling various constructs
(e.g., field accesses to compound literals).
The .c/.m analysis test cases that fail are
due to a missing lvalue-to-rvalue cast that
will get introduced into the AST. The .cpp
failures were more than I could investigate in
one go, and the patch was already getting huge.
I have XFAILED some of these tests, and they
should obviously be further investigated.
Some highlights of this patch include:
- CFG no longer requires an lvalue bit for
CFGElements
- StackFrameContext doesn't need an 'asLValue'
flag
- The "VisitLValue" path from GRExprEngine has
been eliminated.
Besides the test case failures (XFAILed), there
are surely other bugs that are fallout from
this change.
llvm-svn: 121960
struct X {
X() : au_i1(123) {}
union {
int au_i1;
float au_f1;
};
};
clang will now deal with au_i1 explicitly as an IndirectFieldDecl.
llvm-svn: 120900
not actually frequently used, because ImpCastExprToType only creates a node
if the types differ. So explicitly create an ICE in the lvalue-to-rvalue
conversion code in DefaultFunctionArrayLvalueConversion() as well as several
other new places, and consistently deal with the consequences throughout the
compiler.
In addition, introduce a new cast kind for loading an ObjCProperty l-value,
and make sure we emit those nodes whenever an ObjCProperty l-value appears
that's not on the LHS of an assignment operator.
This breaks a couple of rewriter tests, which I've x-failed until future
development occurs on the rewriter.
Ted Kremenek kindly contributed the analyzer workarounds in this patch.
llvm-svn: 120890
1. "no 'else' after 'return'" -- this is for conformance with the
coding standards.
2. move 'else' to the line of the previous '}' -- this is for consistency.
Reviewed by kremenek.
llvm-svn: 119983
it is possible for the confluence block to only have a single predecessor due to calls to 'noreturn'
functions. Fixes assertion failure reported in PR 8619.
llvm-svn: 119284
Elidable CXXConstructExpr should inhibit calling destructor for temporary
that is copied, not the one created. This is because eliding copy constructor
means that the object that was to be copied will be constructed directly in
memory the copy would be constructed in.
llvm-svn: 119044
1. For statement: const C& c = C(0) ?: C(1) destructors generated for condition will not differ from those generated for case without prolonged lifetime of temporary,
2. There will be no destructor for constant reference member bound to temporary at the exit from constructor.
llvm-svn: 118158
containing a DoStmt, and the LHS doesn't create a new block, then we should
return RBlock. Otherwise we'll incorrectly return NULL.
Also relax an assertion in VisitWhileStmt(). Reset 'Block' when it is finished.
llvm-svn: 117436
Ted Kremenek