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[Analyzer] Mark `SymbolData` parts of iterator position as live in program state maps 

Marking a symbolic expression as live is non-recursive. In our checkers we
either use conjured symbols or conjured symbols plus/minus integers to
represent abstract position of iterators, so in this latter case we also
must mark the `SymbolData` part of these symbolic expressions as live to
prevent them from getting reaped.

Differential Revision: https://reviews.llvm.org/D48764

llvm-svn: 337151
This commit is contained in:
Adam Balogh 2018-07-16 09:27:27 +00:00
parent 0a75de4bfe
commit 0a7592b5e2
1 changed files with 31 additions and 19 deletions
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50
clang/lib/StaticAnalyzer/Checkers/IteratorChecker.cpp
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@ -488,14 +488,18 @@ void IteratorChecker::checkLiveSymbols(ProgramStateRef State,
// alive
auto RegionMap = State->get<IteratorRegionMap>();
for (const auto Reg : RegionMap) {
const auto Pos = Reg.second;
SR.markLive(Pos.getOffset());
const auto Offset = Reg.second.getOffset();
for (auto i = Offset->symbol_begin(); i != Offset->symbol_end(); ++i)
if (isa<SymbolData>(*i))
SR.markLive(*i);
}
auto SymbolMap = State->get<IteratorSymbolMap>();
for (const auto Sym : SymbolMap) {
const auto Pos = Sym.second;
SR.markLive(Pos.getOffset());
const auto Offset = Sym.second.getOffset();
for (auto i = Offset->symbol_begin(); i != Offset->symbol_end(); ++i)
if (isa<SymbolData>(*i))
SR.markLive(*i);
}
auto ContMap = State->get<ContainerMap>();
@ -1157,21 +1161,31 @@ ProgramStateRef relateIteratorPositions(ProgramStateRef State,
const IteratorPosition &Pos2,
bool Equal) {
auto &SVB = State->getStateManager().getSValBuilder();
// FIXME: This code should be reworked as follows:
// 1. Subtract the operands using evalBinOp().
// 2. Assume that the result doesn't overflow.
// 3. Compare the result to 0.
// 4. Assume the result of the comparison.
const auto comparison =
SVB.evalBinOp(State, BO_EQ, nonloc::SymbolVal(Pos1.getOffset()),
nonloc::SymbolVal(Pos2.getOffset()), SVB.getConditionType())
.getAs<DefinedSVal>();
nonloc::SymbolVal(Pos2.getOffset()),
SVB.getConditionType());
if (comparison) {
auto NewState = State->assume(*comparison, Equal);
if (const auto CompSym = comparison->getAsSymbol()) {
return assumeNoOverflow(NewState, cast<SymIntExpr>(CompSym)->getLHS(), 2);
}
assert(comparison.getAs<DefinedSVal>() &&
"Symbol comparison must be a `DefinedSVal`");
return NewState;
auto NewState = State->assume(comparison.castAs<DefinedSVal>(), Equal);
if (const auto CompSym = comparison.getAsSymbol()) {
assert(isa<SymIntExpr>(CompSym) &&
"Symbol comparison must be a `SymIntExpr`");
assert(BinaryOperator::isComparisonOp(
cast<SymIntExpr>(CompSym)->getOpcode()) &&
"Symbol comparison must be a comparison");
return assumeNoOverflow(NewState, cast<SymIntExpr>(CompSym)->getLHS(), 2);
}
return State;
return NewState;
}
bool isZero(ProgramStateRef State, const NonLoc &Val) {
@ -1225,14 +1239,12 @@ bool compare(ProgramStateRef State, NonLoc NL1, NonLoc NL2,
auto &SVB = State->getStateManager().getSValBuilder();
const auto comparison =
SVB.evalBinOp(State, Opc, NL1, NL2, SVB.getConditionType())
.getAs<DefinedSVal>();
SVB.evalBinOp(State, Opc, NL1, NL2, SVB.getConditionType());
if (comparison) {
return !State->assume(*comparison, false);
}
assert(comparison.getAs<DefinedSVal>() &&
"Symbol comparison must be a `DefinedSVal`");
return false;
return !State->assume(comparison.castAs<DefinedSVal>(), false);
}
} // namespace