This change was a lot bigger than I originally anticipated; among
other things it requires us storing more information in the CFG to
record what block-level expressions need to be evaluated as lvalues.

The big change is that CFGBlocks no longer contain Stmt*'s by
CFGElements.  Currently CFGElements just wrap Stmt*, but they also
store a bit indicating whether the block-level expression should be
evalauted as an lvalue.  DeclStmts involving the initialization of a
reference require us treating the initialization expression as an
lvalue, even though that information isn't recorded in the AST.
Conceptually this change isn't that complicated, but it required
bubbling up the data through the CFGBuilder, to GRCoreEngine, and
eventually to GRExprEngine.

The addition of CFGElement is also useful for when we want to handle
more control-flow constructs or other data we want to keep in the CFG
that isn't represented well with just a block of statements.

In GRExprEngine, this patch introduces logic for evaluating the
lvalues of references, which currently retrieves the internal "pointer
value" that the reference represents.  EvalLoad does a two stage load
to catch null dereferences involving an invalid reference (although
this could possibly be caught earlier during the initialization of a
reference).

Symbols are currently symbolicated using the reference type, instead
of a pointer type, and special handling is required creating
ElementRegions that layer on SymbolicRegions (see the changes to
RegionStoreManager).

Along the way, the DeadStoresChecker also silences warnings involving
dead stores to references.  This was the original change I introduced
(which I wrote test cases for) that I realized caused GRExprEngine to
crash.

llvm-svn: 91501

now, don't construct CFGs that contain C++ try/catch statements, and
have GRExprEngine abort a path if it encounters a C++ construct it
doesn't understand (which is mostly everything at this point).

llvm-svn: 91389

llvm-svn: 90583

llvm-svn: 90137

llvm-svn: 90028

llvm-svn: 89830

llvm-svn: 84697

llvm-svn: 84695

Use a BumpPtrAllocator to allocate all aspects of CFG, including CFGBlocks, successor and predecessor vectors, etc.

Speedup: when doing 'clang-cc -analyze -dump-cfg' (without actual printing, just
CFG building) on the amalgamated SQLite source (all of SQLite in one source
file), runtime reduced by 9%.

This fixes: <rdar://problem/7250745>

llvm-svn: 83899

have the iterators and operator[] handle the traversal of statements, as they
are stored in reverse order. Tests show this has no real performance impact, but
it does simply the CFG construction logic and will make it slightly easier to
change the allocation strategy for CFGBlocks (as we have fewer copies).

llvm-svn: 82702

llvm-svn: 81346

of its subexpressions resulted in a "bad CFG".

llvm-svn: 80298

llvm-svn: 79941

llvm-svn: 79854

Although this does not make the CFG more correct, it makes the CFG more 
beautiful without multiple roots.

llvm-svn: 79509

Otherwise we get a wrong CFG.

llvm-svn: 79507

calls to noreturn function pointers when CFG building.

llvm-svn: 77089

llvm-svn: 76955

TryEvaluateBool instead of using a raw 'int'.  This avoids any
confusion of how 'int' converts to bool, and makes the resultant code
easier to read.

Condense a bunch of 'addSuccessor()' calls in 'if ... else' to use the
ternary operator instead.

llvm-svn: 76947

llvm-svn: 76911

llvm-svn: 76814

llvm-svn: 76795

llvm-svn: 76531

llvm-svn: 76530

llvm-svn: 76529

llvm-svn: 76522

llvm-svn: 76500

Fix some fallout from CFGBuilder restructuring: all expressions that we explicitly handle have the possibility to be block-level expressions.

llvm-svn: 76277

llvm-svn: 76261

is an algorithm that is much easier to understand and slightly more efficient.
Thanks to Mike Stump for our discussions on the CFGBuilder and his comments that
helped prompt this long needed cleanup.

llvm-svn: 76250

llvm-svn: 76205

llvm-svn: 76202

llvm-svn: 76196

llvm-svn: 76180

code with the new method.

llvm-svn: 76164

conventions.  Also reflowed comments and removed spaces at end of
lines and fixed up 80 col violations.

llvm-svn: 76140

llvm-svn: 76133

llvm-svn: 76092

block would get hooked up in some cases when processing empty compound
statements.

llvm-svn: 74743

This is simple enough, but then I thought it would be nice to make PrintingPolicy
get a LangOptions so that various things can key off "bool" and "C++" independently.
This spiraled out of control.  There are many fixme's, but I think things are slightly
better than they were before.

One thing that can be improved: CFG should probably have an ASTContext pointer in it,
which would simplify its clients.

llvm-svn: 74493