diff options
Diffstat (limited to 'clang')
3 files changed, 44 insertions, 6 deletions
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h index 16c30ec1330..a9ca3451d8f 100644 --- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h +++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h @@ -113,7 +113,8 @@ private: public: RangeSet Intersect(BasicValueFactory &BV, Factory &F, llvm::APSInt Lower, llvm::APSInt Upper) const; - + RangeSet Intersect(BasicValueFactory &BV, Factory &F, + const RangeSet &Other) const; RangeSet Negate(BasicValueFactory &BV, Factory &F) const; void print(raw_ostream &os) const; diff --git a/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp b/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp index c6ebc85812d..5c3eb0d66a0 100644 --- a/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp +++ b/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp @@ -173,6 +173,22 @@ RangeSet RangeSet::Intersect(BasicValueFactory &BV, Factory &F, return newRanges; } +// Returns a set containing the values in the receiving set, intersected with +// the range set passed as parameter. +RangeSet RangeSet::Intersect(BasicValueFactory &BV, Factory &F, + const RangeSet &Other) const { + PrimRangeSet newRanges = F.getEmptySet(); + + for (iterator i = Other.begin(), e = Other.end(); i != e; ++i) { + RangeSet newPiece = Intersect(BV, F, i->From(), i->To()); + for (iterator j = newPiece.begin(), ee = newPiece.end(); j != ee; ++j) { + newRanges = F.add(newRanges, *j); + } + } + + return newRanges; +} + // Turn all [A, B] ranges to [-B, -A]. Ranges [MIN, B] are turned to range set // [MIN, MIN] U [-B, MAX], when MIN and MAX are the minimal and the maximal // signed values of the type. @@ -461,14 +477,21 @@ static RangeSet applyBitwiseConstraints( RangeSet RangeConstraintManager::getRange(ProgramStateRef State, SymbolRef Sym) { - if (ConstraintRangeTy::data_type *V = State->get<ConstraintRange>(Sym)) - return *V; - - BasicValueFactory &BV = getBasicVals(); + ConstraintRangeTy::data_type *V = State->get<ConstraintRange>(Sym); // If Sym is a difference of symbols A - B, then maybe we have range set // stored for B - A. - if (const RangeSet *R = getRangeForMinusSymbol(State, Sym)) + BasicValueFactory &BV = getBasicVals(); + const RangeSet *R = getRangeForMinusSymbol(State, Sym); + + // If we have range set stored for both A - B and B - A then calculate the + // effective range set by intersecting the range set for A - B and the + // negated range set of B - A. + if (V && R) + return V->Intersect(BV, F, R->Negate(BV, F)); + if (V) + return *V; + if (R) return R->Negate(BV, F); // Lazily generate a new RangeSet representing all possible values for the diff --git a/clang/test/Analysis/constraint_manager_negate_difference.c b/clang/test/Analysis/constraint_manager_negate_difference.c index 2236c1693b9..4412ae0e973 100644 --- a/clang/test/Analysis/constraint_manager_negate_difference.c +++ b/clang/test/Analysis/constraint_manager_negate_difference.c @@ -96,3 +96,17 @@ void negate_mixed(int m, int n) { return; clang_analyzer_eval(n - m <= 0); // expected-warning{{TRUE}} } + +void effective_range(int m, int n) { + assert(m - n >= 0); + assert(n - m >= 0); + clang_analyzer_eval(m - n == 0); // expected-warning{{TRUE}} + clang_analyzer_eval(n - m == 0); // expected-warning{{TRUE}} +} + +void effective_range_2(int m, int n) { + assert(m - n <= 0); + assert(n - m <= 0); + clang_analyzer_eval(m - n == 0); // expected-warning{{TRUE}} expected-warning{{FALSE}} + clang_analyzer_eval(n - m == 0); // expected-warning{{TRUE}} expected-warning{{FALSE}} +} |
