Index: include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h =================================================================== --- include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h +++ include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h @@ -330,6 +330,18 @@ ProgramStateRef addTaint(const MemRegion *R, TaintTagType Kind = TaintTagGeneric) const; + /// Create a new state in which the statement is marked as non-tainted. + ProgramStateRef removeTaint(const Stmt *S, const LocationContext *LCtx, + TaintTagType Kind = TaintTagGeneric) const; + + /// Create a new state in which the symbol is marked as non-tainted. + ProgramStateRef removeTaint(SymbolRef S, + TaintTagType Kind = TaintTagGeneric) const; + + /// Create a new state in which the region symbol is marked as non-tainted. + ProgramStateRef removeTaint(const MemRegion *R, + TaintTagType Kind = TaintTagGeneric) const; + /// Check if the statement is tainted in the current state. bool isTainted(const Stmt *S, const LocationContext *LCtx, TaintTagType Kind = TaintTagGeneric) const; Index: lib/StaticAnalyzer/Core/ProgramState.cpp =================================================================== --- lib/StaticAnalyzer/Core/ProgramState.cpp +++ lib/StaticAnalyzer/Core/ProgramState.cpp @@ -684,6 +684,42 @@ return NewState; } +ProgramStateRef ProgramState::removeTaint(const Stmt *S, + const LocationContext *LCtx, + TaintTagType Kind) const { + if (const Expr *E = dyn_cast_or_null(S)) + S = E->IgnoreParens(); + + SymbolRef Sym = getSVal(S, LCtx).getAsSymbol(); + if (Sym) + return removeTaint(Sym, Kind); + + const MemRegion *R = getSVal(S, LCtx).getAsRegion(); + removeTaint(R, Kind); + + // Cannot remove taint, so just return the state. + return this; +} + +ProgramStateRef ProgramState::removeTaint(const MemRegion *R, + TaintTagType Kind) const { + if (const SymbolicRegion *SR = dyn_cast_or_null(R)) + return removeTaint(SR->getSymbol(), Kind); + return this; +} + +ProgramStateRef ProgramState::removeTaint(SymbolRef Sym, + TaintTagType Kind) const { + // If this is a symbol cast, remove the cast before removing the taint. Taint + // is cast agnostic. + while (const SymbolCast *SC = dyn_cast(Sym)) + Sym = SC->getOperand(); + + ProgramStateRef NewState = remove(Sym); + assert(NewState); + return NewState; +} + bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx, TaintTagType Kind) const { if (const Expr *E = dyn_cast_or_null(S))