[analyzer] Annotate ProgramState update methods with LLVM_NODISCARD.

Because our program states are immutable, methods like "add<>", "set<>", "bind"
create a copy of the program state instead of mutating the existing state.
If the updated state is discarded, it clearly indicates a bug.
Such bugs are introduced frequently, hence the warn_unused_result annotation.

Differential Revision: https://reviews.llvm.org/D47499

llvm-svn: 333679
This commit is contained in:
Artem Dergachev 2018-05-31 18:30:41 +00:00
parent d44a6eab40
commit 38f7bb7798
1 changed files with 63 additions and 54 deletions

View File

@ -177,20 +177,20 @@ public:
///
/// This returns a new state with the added constraint on \p cond.
/// If no new state is feasible, NULL is returned.
ProgramStateRef assume(DefinedOrUnknownSVal cond, bool assumption) const;
LLVM_NODISCARD ProgramStateRef assume(DefinedOrUnknownSVal cond,
bool assumption) const;
/// Assumes both "true" and "false" for \p cond, and returns both
/// corresponding states (respectively).
///
/// This is more efficient than calling assume() twice. Note that one (but not
/// both) of the returned states may be NULL.
std::pair<ProgramStateRef, ProgramStateRef>
LLVM_NODISCARD std::pair<ProgramStateRef, ProgramStateRef>
assume(DefinedOrUnknownSVal cond) const;
ProgramStateRef assumeInBound(DefinedOrUnknownSVal idx,
DefinedOrUnknownSVal upperBound,
bool assumption,
QualType IndexType = QualType()) const;
LLVM_NODISCARD ProgramStateRef
assumeInBound(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound,
bool assumption, QualType IndexType = QualType()) const;
/// Assumes that the value of \p Val is bounded with [\p From; \p To]
/// (if \p assumption is "true") or it is fully out of this range
@ -198,7 +198,7 @@ public:
///
/// This returns a new state with the added constraint on \p cond.
/// If no new state is feasible, NULL is returned.
ProgramStateRef assumeInclusiveRange(DefinedOrUnknownSVal Val,
LLVM_NODISCARD ProgramStateRef assumeInclusiveRange(DefinedOrUnknownSVal Val,
const llvm::APSInt &From,
const llvm::APSInt &To,
bool assumption) const;
@ -208,7 +208,7 @@ public:
///
/// This is more efficient than calling assume() twice. Note that one (but not
/// both) of the returned states may be NULL.
std::pair<ProgramStateRef, ProgramStateRef>
LLVM_NODISCARD std::pair<ProgramStateRef, ProgramStateRef>
assumeInclusiveRange(DefinedOrUnknownSVal Val, const llvm::APSInt &From,
const llvm::APSInt &To) const;
@ -232,15 +232,16 @@ public:
/// Create a new state by binding the value 'V' to the statement 'S' in the
/// state's environment.
ProgramStateRef BindExpr(const Stmt *S, const LocationContext *LCtx,
SVal V, bool Invalidate = true) const;
LLVM_NODISCARD ProgramStateRef BindExpr(const Stmt *S,
const LocationContext *LCtx, SVal V,
bool Invalidate = true) const;
ProgramStateRef bindLoc(Loc location,
SVal V,
LLVM_NODISCARD ProgramStateRef bindLoc(Loc location, SVal V,
const LocationContext *LCtx,
bool notifyChanges = true) const;
ProgramStateRef bindLoc(SVal location, SVal V, const LocationContext *LCtx) const;
LLVM_NODISCARD ProgramStateRef bindLoc(SVal location, SVal V,
const LocationContext *LCtx) const;
/// Initializes the region of memory represented by \p loc with an initial
/// value. Once initialized, all values loaded from any sub-regions of that
@ -248,14 +249,15 @@ public:
/// This method should not be used on regions that are already initialized.
/// If you need to indicate that memory contents have suddenly become unknown
/// within a certain region of memory, consider invalidateRegions().
ProgramStateRef bindDefaultInitial(SVal loc, SVal V,
const LocationContext *LCtx) const;
LLVM_NODISCARD ProgramStateRef
bindDefaultInitial(SVal loc, SVal V, const LocationContext *LCtx) const;
/// Performs C++ zero-initialization procedure on the region of memory
/// represented by \p loc.
ProgramStateRef bindDefaultZero(SVal loc, const LocationContext *LCtx) const;
LLVM_NODISCARD ProgramStateRef
bindDefaultZero(SVal loc, const LocationContext *LCtx) const;
ProgramStateRef killBinding(Loc LV) const;
LLVM_NODISCARD ProgramStateRef killBinding(Loc LV) const;
/// Returns the state with bindings for the given regions
/// cleared from the store.
@ -275,14 +277,14 @@ public:
/// the call and should be considered directly invalidated.
/// \param ITraits information about special handling for a particular
/// region/symbol.
ProgramStateRef
LLVM_NODISCARD ProgramStateRef
invalidateRegions(ArrayRef<const MemRegion *> Regions, const Expr *E,
unsigned BlockCount, const LocationContext *LCtx,
bool CausesPointerEscape, InvalidatedSymbols *IS = nullptr,
const CallEvent *Call = nullptr,
RegionAndSymbolInvalidationTraits *ITraits = nullptr) const;
ProgramStateRef
LLVM_NODISCARD ProgramStateRef
invalidateRegions(ArrayRef<SVal> Regions, const Expr *E,
unsigned BlockCount, const LocationContext *LCtx,
bool CausesPointerEscape, InvalidatedSymbols *IS = nullptr,
@ -291,8 +293,8 @@ public:
/// enterStackFrame - Returns the state for entry to the given stack frame,
/// preserving the current state.
ProgramStateRef enterStackFrame(const CallEvent &Call,
const StackFrameContext *CalleeCtx) const;
LLVM_NODISCARD ProgramStateRef enterStackFrame(
const CallEvent &Call, const StackFrameContext *CalleeCtx) const;
/// Get the lvalue for a base class object reference.
Loc getLValue(const CXXBaseSpecifier &BaseSpec, const SubRegion *Super) const;
@ -370,26 +372,28 @@ public:
const MemRegion * const *end) const;
/// Create a new state in which the statement is marked as tainted.
ProgramStateRef addTaint(const Stmt *S, const LocationContext *LCtx,
LLVM_NODISCARD ProgramStateRef
addTaint(const Stmt *S, const LocationContext *LCtx,
TaintTagType Kind = TaintTagGeneric) const;
/// Create a new state in which the value is marked as tainted.
ProgramStateRef addTaint(SVal V, TaintTagType Kind = TaintTagGeneric) const;
LLVM_NODISCARD ProgramStateRef
addTaint(SVal V, TaintTagType Kind = TaintTagGeneric) const;
/// Create a new state in which the symbol is marked as tainted.
ProgramStateRef addTaint(SymbolRef S,
LLVM_NODISCARD ProgramStateRef addTaint(SymbolRef S,
TaintTagType Kind = TaintTagGeneric) const;
/// Create a new state in which the region symbol is marked as tainted.
ProgramStateRef addTaint(const MemRegion *R,
TaintTagType Kind = TaintTagGeneric) const;
LLVM_NODISCARD ProgramStateRef
addTaint(const MemRegion *R, TaintTagType Kind = TaintTagGeneric) const;
/// Create a new state in a which a sub-region of a given symbol is tainted.
/// This might be necessary when referring to regions that can not have an
/// individual symbol, e.g. if they are represented by the default binding of
/// a LazyCompoundVal.
ProgramStateRef addPartialTaint(SymbolRef ParentSym,
const SubRegion *SubRegion,
LLVM_NODISCARD ProgramStateRef
addPartialTaint(SymbolRef ParentSym, const SubRegion *SubRegion,
TaintTagType Kind = TaintTagGeneric) const;
/// Check if the statement is tainted in the current state.
@ -406,7 +410,8 @@ public:
void *const* FindGDM(void *K) const;
template <typename T>
ProgramStateRef add(typename ProgramStateTrait<T>::key_type K) const;
LLVM_NODISCARD ProgramStateRef
add(typename ProgramStateTrait<T>::key_type K) const;
template <typename T>
typename ProgramStateTrait<T>::data_type
@ -424,25 +429,29 @@ public:
template <typename T>
typename ProgramStateTrait<T>::context_type get_context() const;
template <typename T>
LLVM_NODISCARD ProgramStateRef
remove(typename ProgramStateTrait<T>::key_type K) const;
template <typename T>
ProgramStateRef remove(typename ProgramStateTrait<T>::key_type K) const;
template<typename T>
ProgramStateRef remove(typename ProgramStateTrait<T>::key_type K,
LLVM_NODISCARD ProgramStateRef
remove(typename ProgramStateTrait<T>::key_type K,
typename ProgramStateTrait<T>::context_type C) const;
template <typename T>
ProgramStateRef remove() const;
template <typename T> LLVM_NODISCARD ProgramStateRef remove() const;
template <typename T>
ProgramStateRef set(typename ProgramStateTrait<T>::data_type D) const;
LLVM_NODISCARD ProgramStateRef
set(typename ProgramStateTrait<T>::data_type D) const;
template <typename T>
ProgramStateRef set(typename ProgramStateTrait<T>::key_type K,
LLVM_NODISCARD ProgramStateRef
set(typename ProgramStateTrait<T>::key_type K,
typename ProgramStateTrait<T>::value_type E) const;
template <typename T>
ProgramStateRef set(typename ProgramStateTrait<T>::key_type K,
LLVM_NODISCARD ProgramStateRef
set(typename ProgramStateTrait<T>::key_type K,
typename ProgramStateTrait<T>::value_type E,
typename ProgramStateTrait<T>::context_type C) const;