of visiting all block-level statements in a CFG.

Tightened implementation of UninitializedValues.

llvm-svn: 42106

variable instead of a temporary.

llvm-svn: 42102

with CFG *edges* instead of blocks.  This will fascilitate dataflow
analyses that are sensitive to block terminators, and also simplifies
some reasoning.

Updated UninitializedValues to comply to this new interface.

llvm-svn: 42099

too "conservative").

Several revisions to UninitializedValues checker after testing.  We
now appear to be working correctly (probably some bugs still, but main
functionality appears to be there).  Implemented careful emitting of
warnings so that we wouldn't get a cascade of warnings for simply not
defining a single variable and using it everywhere.  This way the
warnings point closer to the root cause rather than "symptoms" from
using values derived from uninitialized variables.

llvm-svn: 42067

llvm-svn: 42056

globals and function parameters.

llvm-svn: 42055

for reporting errors and running the checker.

llvm-svn: 42046

llvm-svn: 42041

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