Index: lib/Analysis/CFLSteensAliasAnalysis.cpp =================================================================== --- lib/Analysis/CFLSteensAliasAnalysis.cpp +++ lib/Analysis/CFLSteensAliasAnalysis.cpp @@ -118,8 +118,6 @@ CFLGraph &Graph; SmallVectorImpl &ReturnValues; - SmallPtrSetImpl &Externals; - SmallPtrSetImpl &Escapes; SmallVectorImpl &InstantiatedRelations; SmallVectorImpl &InstantiatedAttrs; @@ -131,12 +129,16 @@ } void addNode(Value *Val) { + assert(Val != nullptr); if (!Graph.addNode(Val)) return; - if (isa(Val)) - Externals.insert(Val); - else if (auto CExpr = dyn_cast(Val)) + if (isa(Val)) { + Graph.addAttr(Val, getGlobalOrArgAttrFromValue(*Val)); + // Currently we do not attempt to be smart on globals + InstantiatedAttrs.push_back( + InstantiatedAttr{InstantiatedValue{Val, 1}, getAttrUnknown()}); + } else if (auto CExpr = dyn_cast(Val)) if (hasUsefulEdges(CExpr)) visitConstantExpr(CExpr); } @@ -147,6 +149,7 @@ } void addEdge(Value *From, Value *To, EdgeType Type) { + assert(From != nullptr && To != nullptr); if (!From->getType()->isPointerTy() || !To->getType()->isPointerTy()) return; addNode(From); @@ -158,12 +161,9 @@ public: GetEdgesVisitor(CFLSteensAAResult &AA, const TargetLibraryInfo &TLI, CFLGraph &Graph, SmallVectorImpl &ReturnValues, - SmallPtrSetImpl &Externals, - SmallPtrSetImpl &Escapes, SmallVectorImpl &InstantiatedRelations, SmallVectorImpl &InstantiatedAttrs) : AA(AA), TLI(TLI), Graph(Graph), ReturnValues(ReturnValues), - Externals(Externals), Escapes(Escapes), InstantiatedRelations(InstantiatedRelations), InstantiatedAttrs(InstantiatedAttrs) {} @@ -334,13 +334,22 @@ // anything, too (unless the result is marked noalias). if (!CS.onlyReadsMemory()) for (Value *V : CS.args()) { - if (V->getType()->isPointerTy()) - Escapes.insert(V); + if (V->getType()->isPointerTy()) { + // The argument itself escapes. + addNodeWithAttr(V, getAttrEscaped()); + // The fate of argument memory is unknown. Note that since AliasAttrs + // is transitive with respect to dereference, we only need to specify + // it for the first-level memory. + InstantiatedAttrs.push_back( + InstantiatedAttr{InstantiatedValue{V, 1}, getAttrUnknown()}); + } } if (Inst->getType()->isPointerTy()) { auto *Fn = CS.getCalledFunction(); if (Fn == nullptr || !Fn->doesNotAlias(0)) + // No need to call addNodeWithAttr() since we've added Inst at the + // beginning of this function and we know it is not a global. Graph.addAttr(Inst, getAttrUnknown()); } } @@ -412,8 +421,6 @@ SmallVector ReturnedValues; // Auxiliary structures used by the builder - SmallPtrSet ExternalValues; - SmallPtrSet EscapedValues; SmallVector InstantiatedRelations; SmallVector InstantiatedAttrs; @@ -432,7 +439,10 @@ void addArgumentToGraph(Argument &Arg) { if (Arg.getType()->isPointerTy()) { Graph.addNode(&Arg); - ExternalValues.insert(&Arg); + Graph.addAttr(&Arg, getGlobalOrArgAttrFromValue(Arg)); + // Pointees of a formal parameter is known to the caller + InstantiatedAttrs.push_back( + InstantiatedAttr{InstantiatedValue{&Arg, 1}, getAttrCaller()}); } } @@ -446,8 +456,8 @@ if (!hasUsefulEdges(&Inst)) return; - GetEdgesVisitor(Analysis, TLI, Graph, ReturnedValues, ExternalValues, - EscapedValues, InstantiatedRelations, InstantiatedAttrs) + GetEdgesVisitor(Analysis, TLI, Graph, ReturnedValues, InstantiatedRelations, + InstantiatedAttrs) .visit(Inst); } @@ -473,12 +483,6 @@ const SmallVector &getReturnValues() const { return ReturnedValues; } - const SmallPtrSet &getExternalValues() const { - return ExternalValues; - } - const SmallPtrSet &getEscapedValues() const { - return EscapedValues; - } const SmallVector &getInstantiatedRelations() const { return InstantiatedRelations; } @@ -666,19 +670,6 @@ } } - // Special handling for globals and arguments - for (auto *External : GraphBuilder.getExternalValues()) { - SetBuilder.add(External); - auto Attr = getGlobalOrArgAttrFromValue(*External); - if (Attr.any()) { - SetBuilder.noteAttributes(External, Attr); - if (isa(External)) - SetBuilder.addAttributesBelow(External, 1, getAttrUnknown()); - else - SetBuilder.addAttributesBelow(External, 1, getAttrCaller()); - } - } - // Special handling for interprocedural aliases for (auto &Edge : GraphBuilder.getInstantiatedRelations()) { auto FromVal = Edge.From.Val; @@ -696,13 +687,6 @@ SetBuilder.addAttributesBelow(Val, IPAttr.IValue.DerefLevel, IPAttr.Attr); } - // Special handling for opaque external functions - for (auto *Escape : GraphBuilder.getEscapedValues()) { - SetBuilder.add(Escape); - SetBuilder.noteAttributes(Escape, getAttrEscaped()); - SetBuilder.addAttributesBelow(Escape, 1, getAttrUnknown()); - } - return FunctionInfo(*Fn, GraphBuilder.getReturnValues(), SetBuilder.build()); }