Add a new metadata symbol type for checkers to use. Metadata symbols must be associated with a region and will be collected if the region dies or its checker fails to mark it as in use.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111076 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/SymbolManager.cpp b/lib/Checker/SymbolManager.cpp
index 6095fe5..f94e32c 100644
--- a/lib/Checker/SymbolManager.cpp
+++ b/lib/Checker/SymbolManager.cpp
@@ -78,6 +78,11 @@
os << "extent_$" << getSymbolID() << '{' << getRegion() << '}';
}
+void SymbolMetadata::dumpToStream(llvm::raw_ostream& os) const {
+ os << "meta_$" << getSymbolID() << '{'
+ << getRegion() << ',' << T.getAsString() << '}';
+}
+
void SymbolRegionValue::dumpToStream(llvm::raw_ostream& os) const {
os << "reg_$" << getSymbolID() << "<" << R << ">";
}
@@ -150,6 +155,24 @@
return cast<SymbolExtent>(SD);
}
+const SymbolMetadata*
+SymbolManager::getMetadataSymbol(const MemRegion* R, const Stmt* S, QualType T,
+ unsigned Count, const void* SymbolTag) {
+
+ llvm::FoldingSetNodeID profile;
+ SymbolMetadata::Profile(profile, R, S, T, Count, SymbolTag);
+ void* InsertPos;
+ SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
+ if (!SD) {
+ SD = (SymExpr*) BPAlloc.Allocate<SymbolMetadata>();
+ new (SD) SymbolMetadata(SymbolCounter, R, S, T, Count, SymbolTag);
+ DataSet.InsertNode(SD, InsertPos);
+ ++SymbolCounter;
+ }
+
+ return cast<SymbolMetadata>(SD);
+}
+
const SymIntExpr *SymbolManager::getSymIntExpr(const SymExpr *lhs,
BinaryOperator::Opcode op,
const llvm::APSInt& v,
@@ -198,6 +221,10 @@
return Ctx.getSizeType();
}
+QualType SymbolMetadata::getType(ASTContext&) const {
+ return T;
+}
+
QualType SymbolRegionValue::getType(ASTContext& C) const {
return R->getValueType();
}
@@ -222,6 +249,11 @@
TheDead.erase(sym);
}
+void SymbolReaper::markInUse(SymbolRef sym) {
+ if (isa<SymbolMetadata>(sym))
+ MetadataInUse.insert(sym);
+}
+
bool SymbolReaper::maybeDead(SymbolRef sym) {
if (isLive(sym))
return false;
@@ -230,6 +262,31 @@
return true;
}
+static bool IsLiveRegion(SymbolReaper &Reaper, const MemRegion *MR) {
+ MR = MR->getBaseRegion();
+
+ if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
+ return Reaper.isLive(SR->getSymbol());
+
+ if (const VarRegion *VR = dyn_cast<VarRegion>(MR))
+ return Reaper.isLive(VR);
+
+ // FIXME: This is a gross over-approximation. What we really need is a way to
+ // tell if anything still refers to this region. Unlike SymbolicRegions,
+ // AllocaRegions don't have associated symbols, though, so we don't actually
+ // have a way to track their liveness.
+ if (isa<AllocaRegion>(MR))
+ return true;
+
+ if (isa<CXXThisRegion>(MR))
+ return true;
+
+ if (isa<MemSpaceRegion>(MR))
+ return true;
+
+ return false;
+}
+
bool SymbolReaper::isLive(SymbolRef sym) {
if (TheLiving.count(sym))
return true;
@@ -243,11 +300,21 @@
}
if (const SymbolExtent *extent = dyn_cast<SymbolExtent>(sym)) {
- const MemRegion *Base = extent->getRegion()->getBaseRegion();
- if (const VarRegion *VR = dyn_cast<VarRegion>(Base))
- return isLive(VR);
- if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Base))
- return isLive(SR->getSymbol());
+ if (IsLiveRegion(*this, extent->getRegion())) {
+ markLive(sym);
+ return true;
+ }
+ return false;
+ }
+
+ if (const SymbolMetadata *metadata = dyn_cast<SymbolMetadata>(sym)) {
+ if (MetadataInUse.count(sym)) {
+ if (IsLiveRegion(*this, metadata->getRegion())) {
+ markLive(sym);
+ MetadataInUse.erase(sym);
+ return true;
+ }
+ }
return false;
}
@@ -261,12 +328,13 @@
}
bool SymbolReaper::isLive(const VarRegion *VR) const {
- const StackFrameContext *SFC = VR->getStackFrame();
+ const StackFrameContext *VarContext = VR->getStackFrame();
+ const StackFrameContext *CurrentContext = LCtx->getCurrentStackFrame();
- if (SFC == LCtx->getCurrentStackFrame())
+ if (VarContext == CurrentContext)
return LCtx->getLiveVariables()->isLive(Loc, VR->getDecl());
- else
- return SFC->isParentOf(LCtx->getCurrentStackFrame());
+
+ return VarContext->isParentOf(CurrentContext);
}
SymbolVisitor::~SymbolVisitor() {}