mechanism can be implemented simply by affixing the Observer to an
analysis meta data, so it doesn't need to be a required type.  This
also permits analyses not to implement an Observer if it doesn't make
sense.

Changed "DataflowValues::MetaDataTy" to
"DataflowValues::AnalysisDataTy" to reflect that the type
enscapsulated the data associated with analyzing a given CFG.

Changed CFGStmtVisitor::BlockStmt_VisitImplicitControlFlowStmt(Stmt*)
to ...VisitImplicitControlFlowExpr(Expr*).  The type narrowing is more
precise and more useful to clients.

Added CFGStmtVisitor::BlockStmt_VisitExpr to reflect the visitation of
expressions at the block statement level.  This captures all implicit
control-flow statements as well as other expressions that are hoisted
to the block level (such as conditions for terminators and function
calls).  This is especially useful for dataflow analysis.

llvm-svn: 42034

this eliminates their dependence on the preprocessor and eliminates some
duplicated code.

llvm-svn: 41993

llvm-svn: 41988

Preliminary implementation of UninitializedValues, which is based on
new solver (doesn't work yet, but compiles).

llvm-svn: 41970

Move Decl::NextDeclarator (w/ setters/getters) down to ScopedDecl/FieldDecl.

Decl is now svelte:-)

llvm-svn: 41935

llvm-svn: 41906

Removed extraneous call to Observer->ObserveStmt when handling DeclRefExprs.

llvm-svn: 41890

llvm-svn: 41888

is much simpler now.

llvm-svn: 41885

if the assigned value is a constant expression, e.g.:

int x = 0;

We then check to see if "x" is ever reassigned later.  If so, we don't
emit a warning.  This is because programmers frequently use defensive
programming to make sure a variable has a defined value.

llvm-svn: 41853

llvm-svn: 41848

warnings that some compilers diagnose

llvm-svn: 41847

that refer to direct function calls.

Modified interface of LiveVariables to only track liveness of VarDecls.
This cleans up a bunch of edge cases, and removed the bug just mentioned.

llvm-svn: 41797

"Audit" to "Observer" and "Observe"

llvm-svn: 41794

but never used.

Fix a bug in LiveVariables where uses on the LHS of self-assign
operators (e.g +=, *=, etc) would not be properly recorded in the
liveness state of the variable.

llvm-svn: 41757

that contained no declarations, or when a variable is declared but never used.

llvm-svn: 41756

llvm-svn: 41755

to variables that are no longer live.  This analysis is built on top
of CFGs and the LiveVariables analysis.

changes to driver:
 added driver option "-check-dead-stores" to run the analysis

llvm-svn: 41754

 - Finished 99% of analysis logic.  Probably a few bugs.
 - Added querying functions to query liveness.
 - Added better pretty printing of liveness.
 - Added better bookkeeping of per-variable liveness information.
 - Added LiveVariablesAuditor interface, which allows "lazy" querying
   of intra-basic block liveness information.

Driver:
 - Minor cleanups involved in dumping liveness information.

llvm-svn: 41753

source-level CFGs.  This code may change significantly in the near
future as we explore different means to implement dataflow analyses.

Added a driver option, -dump-live-variables, to view the output of
live variable analysis.  This output is very ALPHA; it will be improved shortly.

llvm-svn: 41737