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-rw-r--r--lib/Analysis/ThreadSafetyCommon.cpp794
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diff --git a/lib/Analysis/ThreadSafetyCommon.cpp b/lib/Analysis/ThreadSafetyCommon.cpp
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+//===- ThreadSafetyCommon.cpp ----------------------------------*- C++ --*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of the interfaces declared in ThreadSafetyCommon.h
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/ThreadSafetyCommon.h"
+#include "clang/AST/Attr.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/Analysis/Analyses/PostOrderCFGView.h"
+#include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
+#include "clang/Analysis/Analyses/ThreadSafetyTraverse.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Basic/OperatorKinds.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+
+#include <algorithm>
+#include <climits>
+#include <vector>
+
+
+namespace clang {
+namespace threadSafety {
+
+// From ThreadSafetyUtil.h
+std::string getSourceLiteralString(const clang::Expr *CE) {
+ switch (CE->getStmtClass()) {
+ case Stmt::IntegerLiteralClass:
+ return cast<IntegerLiteral>(CE)->getValue().toString(10, true);
+ case Stmt::StringLiteralClass: {
+ std::string ret("\"");
+ ret += cast<StringLiteral>(CE)->getString();
+ ret += "\"";
+ return ret;
+ }
+ case Stmt::CharacterLiteralClass:
+ case Stmt::CXXNullPtrLiteralExprClass:
+ case Stmt::GNUNullExprClass:
+ case Stmt::CXXBoolLiteralExprClass:
+ case Stmt::FloatingLiteralClass:
+ case Stmt::ImaginaryLiteralClass:
+ case Stmt::ObjCStringLiteralClass:
+ default:
+ return "#lit";
+ }
+}
+
+namespace til {
+
+// Return true if E is a variable that points to an incomplete Phi node.
+static bool isIncompleteVar(const SExpr *E) {
+ if (const auto *V = dyn_cast<Variable>(E)) {
+ if (const auto *Ph = dyn_cast<Phi>(V->definition()))
+ return Ph->status() == Phi::PH_Incomplete;
+ }
+ return false;
+}
+
+} // end namespace til
+
+
+typedef SExprBuilder::CallingContext CallingContext;
+
+
+til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) {
+ auto It = SMap.find(S);
+ if (It != SMap.end())
+ return It->second;
+ return nullptr;
+}
+
+
+til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
+ Walker.walk(*this);
+ return Scfg;
+}
+
+
+// Translate a clang statement or expression to a TIL expression.
+// Also performs substitution of variables; Ctx provides the context.
+// Dispatches on the type of S.
+til::SExpr *SExprBuilder::translate(const Stmt *S, CallingContext *Ctx) {
+ if (!S)
+ return nullptr;
+
+ // Check if S has already been translated and cached.
+ // This handles the lookup of SSA names for DeclRefExprs here.
+ if (til::SExpr *E = lookupStmt(S))
+ return E;
+
+ switch (S->getStmtClass()) {
+ case Stmt::DeclRefExprClass:
+ return translateDeclRefExpr(cast<DeclRefExpr>(S), Ctx);
+ case Stmt::CXXThisExprClass:
+ return translateCXXThisExpr(cast<CXXThisExpr>(S), Ctx);
+ case Stmt::MemberExprClass:
+ return translateMemberExpr(cast<MemberExpr>(S), Ctx);
+ case Stmt::CallExprClass:
+ return translateCallExpr(cast<CallExpr>(S), Ctx);
+ case Stmt::CXXMemberCallExprClass:
+ return translateCXXMemberCallExpr(cast<CXXMemberCallExpr>(S), Ctx);
+ case Stmt::CXXOperatorCallExprClass:
+ return translateCXXOperatorCallExpr(cast<CXXOperatorCallExpr>(S), Ctx);
+ case Stmt::UnaryOperatorClass:
+ return translateUnaryOperator(cast<UnaryOperator>(S), Ctx);
+ case Stmt::BinaryOperatorClass:
+ case Stmt::CompoundAssignOperatorClass:
+ return translateBinaryOperator(cast<BinaryOperator>(S), Ctx);
+
+ case Stmt::ArraySubscriptExprClass:
+ return translateArraySubscriptExpr(cast<ArraySubscriptExpr>(S), Ctx);
+ case Stmt::ConditionalOperatorClass:
+ return translateConditionalOperator(cast<ConditionalOperator>(S), Ctx);
+ case Stmt::BinaryConditionalOperatorClass:
+ return translateBinaryConditionalOperator(
+ cast<BinaryConditionalOperator>(S), Ctx);
+
+ // We treat these as no-ops
+ case Stmt::ParenExprClass:
+ return translate(cast<ParenExpr>(S)->getSubExpr(), Ctx);
+ case Stmt::ExprWithCleanupsClass:
+ return translate(cast<ExprWithCleanups>(S)->getSubExpr(), Ctx);
+ case Stmt::CXXBindTemporaryExprClass:
+ return translate(cast<CXXBindTemporaryExpr>(S)->getSubExpr(), Ctx);
+
+ // Collect all literals
+ case Stmt::CharacterLiteralClass:
+ case Stmt::CXXNullPtrLiteralExprClass:
+ case Stmt::GNUNullExprClass:
+ case Stmt::CXXBoolLiteralExprClass:
+ case Stmt::FloatingLiteralClass:
+ case Stmt::ImaginaryLiteralClass:
+ case Stmt::IntegerLiteralClass:
+ case Stmt::StringLiteralClass:
+ case Stmt::ObjCStringLiteralClass:
+ return new (Arena) til::Literal(cast<Expr>(S));
+
+ case Stmt::DeclStmtClass:
+ return translateDeclStmt(cast<DeclStmt>(S), Ctx);
+ default:
+ break;
+ }
+ if (const CastExpr *CE = dyn_cast<CastExpr>(S))
+ return translateCastExpr(CE, Ctx);
+
+ return new (Arena) til::Undefined(S);
+}
+
+
+til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
+ CallingContext *Ctx) {
+ const ValueDecl *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
+
+ // Function parameters require substitution and/or renaming.
+ if (const ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(VD)) {
+ const FunctionDecl *FD =
+ cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
+ unsigned I = PV->getFunctionScopeIndex();
+
+ if (Ctx && Ctx->FunArgs && FD == Ctx->AttrDecl->getCanonicalDecl()) {
+ // Substitute call arguments for references to function parameters
+ assert(I < Ctx->NumArgs);
+ return translate(Ctx->FunArgs[I], Ctx->Prev);
+ }
+ // Map the param back to the param of the original function declaration
+ // for consistent comparisons.
+ VD = FD->getParamDecl(I);
+ }
+
+ // For non-local variables, treat it as a referenced to a named object.
+ return new (Arena) til::LiteralPtr(VD);
+}
+
+
+til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
+ CallingContext *Ctx) {
+ // Substitute for 'this'
+ if (Ctx && Ctx->SelfArg)
+ return translate(Ctx->SelfArg, Ctx->Prev);
+ assert(SelfVar && "We have no variable for 'this'!");
+ return SelfVar;
+}
+
+
+til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
+ CallingContext *Ctx) {
+ til::SExpr *E = translate(ME->getBase(), Ctx);
+ E = new (Arena) til::SApply(E);
+ return new (Arena) til::Project(E, ME->getMemberDecl());
+}
+
+
+til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
+ CallingContext *Ctx) {
+ // TODO -- Lock returned
+ til::SExpr *E = translate(CE->getCallee(), Ctx);
+ for (const auto *Arg : CE->arguments()) {
+ til::SExpr *A = translate(Arg, Ctx);
+ E = new (Arena) til::Apply(E, A);
+ }
+ return new (Arena) til::Call(E, CE);
+}
+
+
+til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
+ const CXXMemberCallExpr *ME, CallingContext *Ctx) {
+ return translateCallExpr(cast<CallExpr>(ME), Ctx);
+}
+
+
+til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
+ const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
+ return translateCallExpr(cast<CallExpr>(OCE), Ctx);
+}
+
+
+til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
+ CallingContext *Ctx) {
+ switch (UO->getOpcode()) {
+ case UO_PostInc:
+ case UO_PostDec:
+ case UO_PreInc:
+ case UO_PreDec:
+ return new (Arena) til::Undefined(UO);
+
+ // We treat these as no-ops
+ case UO_AddrOf:
+ case UO_Deref:
+ case UO_Plus:
+ return translate(UO->getSubExpr(), Ctx);
+
+ case UO_Minus:
+ return new (Arena)
+ til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
+ case UO_Not:
+ return new (Arena)
+ til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
+ case UO_LNot:
+ return new (Arena)
+ til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
+
+ // Currently unsupported
+ case UO_Real:
+ case UO_Imag:
+ case UO_Extension:
+ return new (Arena) til::Undefined(UO);
+ }
+ return new (Arena) til::Undefined(UO);
+}
+
+
+til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
+ const BinaryOperator *BO,
+ CallingContext *Ctx, bool Reverse) {
+ til::SExpr *E0 = translate(BO->getLHS(), Ctx);
+ til::SExpr *E1 = translate(BO->getRHS(), Ctx);
+ if (Reverse)
+ return new (Arena) til::BinaryOp(Op, E1, E0);
+ else
+ return new (Arena) til::BinaryOp(Op, E0, E1);
+}
+
+
+til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
+ const BinaryOperator *BO,
+ CallingContext *Ctx,
+ bool Assign) {
+ const Expr *LHS = BO->getLHS();
+ const Expr *RHS = BO->getRHS();
+ til::SExpr *E0 = translate(LHS, Ctx);
+ til::SExpr *E1 = translate(RHS, Ctx);
+
+ const ValueDecl *VD = nullptr;
+ til::SExpr *CV = nullptr;
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LHS)) {
+ VD = DRE->getDecl();
+ CV = lookupVarDecl(VD);
+ }
+
+ if (!Assign) {
+ til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
+ E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
+ E1 = addStatement(E1, nullptr, VD);
+ }
+ if (VD && CV)
+ return updateVarDecl(VD, E1);
+ return new (Arena) til::Store(E0, E1);
+}
+
+
+til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
+ CallingContext *Ctx) {
+ switch (BO->getOpcode()) {
+ case BO_PtrMemD:
+ case BO_PtrMemI:
+ return new (Arena) til::Undefined(BO);
+
+ case BO_Mul: return translateBinOp(til::BOP_Mul, BO, Ctx);
+ case BO_Div: return translateBinOp(til::BOP_Div, BO, Ctx);
+ case BO_Rem: return translateBinOp(til::BOP_Rem, BO, Ctx);
+ case BO_Add: return translateBinOp(til::BOP_Add, BO, Ctx);
+ case BO_Sub: return translateBinOp(til::BOP_Sub, BO, Ctx);
+ case BO_Shl: return translateBinOp(til::BOP_Shl, BO, Ctx);
+ case BO_Shr: return translateBinOp(til::BOP_Shr, BO, Ctx);
+ case BO_LT: return translateBinOp(til::BOP_Lt, BO, Ctx);
+ case BO_GT: return translateBinOp(til::BOP_Lt, BO, Ctx, true);
+ case BO_LE: return translateBinOp(til::BOP_Leq, BO, Ctx);
+ case BO_GE: return translateBinOp(til::BOP_Leq, BO, Ctx, true);
+ case BO_EQ: return translateBinOp(til::BOP_Eq, BO, Ctx);
+ case BO_NE: return translateBinOp(til::BOP_Neq, BO, Ctx);
+ case BO_And: return translateBinOp(til::BOP_BitAnd, BO, Ctx);
+ case BO_Xor: return translateBinOp(til::BOP_BitXor, BO, Ctx);
+ case BO_Or: return translateBinOp(til::BOP_BitOr, BO, Ctx);
+ case BO_LAnd: return translateBinOp(til::BOP_LogicAnd, BO, Ctx);
+ case BO_LOr: return translateBinOp(til::BOP_LogicOr, BO, Ctx);
+
+ case BO_Assign: return translateBinAssign(til::BOP_Eq, BO, Ctx, true);
+ case BO_MulAssign: return translateBinAssign(til::BOP_Mul, BO, Ctx);
+ case BO_DivAssign: return translateBinAssign(til::BOP_Div, BO, Ctx);
+ case BO_RemAssign: return translateBinAssign(til::BOP_Rem, BO, Ctx);
+ case BO_AddAssign: return translateBinAssign(til::BOP_Add, BO, Ctx);
+ case BO_SubAssign: return translateBinAssign(til::BOP_Sub, BO, Ctx);
+ case BO_ShlAssign: return translateBinAssign(til::BOP_Shl, BO, Ctx);
+ case BO_ShrAssign: return translateBinAssign(til::BOP_Shr, BO, Ctx);
+ case BO_AndAssign: return translateBinAssign(til::BOP_BitAnd, BO, Ctx);
+ case BO_XorAssign: return translateBinAssign(til::BOP_BitXor, BO, Ctx);
+ case BO_OrAssign: return translateBinAssign(til::BOP_BitOr, BO, Ctx);
+
+ case BO_Comma:
+ // The clang CFG should have already processed both sides.
+ return translate(BO->getRHS(), Ctx);
+ }
+ return new (Arena) til::Undefined(BO);
+}
+
+
+til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
+ CallingContext *Ctx) {
+ clang::CastKind K = CE->getCastKind();
+ switch (K) {
+ case CK_LValueToRValue: {
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
+ til::SExpr *E0 = lookupVarDecl(DRE->getDecl());
+ if (E0)
+ return E0;
+ }
+ til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
+ return new (Arena) til::Load(E0);
+ }
+ case CK_NoOp:
+ case CK_DerivedToBase:
+ case CK_UncheckedDerivedToBase:
+ case CK_ArrayToPointerDecay:
+ case CK_FunctionToPointerDecay: {
+ til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
+ return E0;
+ }
+ default: {
+ // FIXME: handle different kinds of casts.
+ til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
+ return new (Arena) til::Cast(til::CAST_none, E0);
+ }
+ }
+}
+
+
+til::SExpr *
+SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
+ CallingContext *Ctx) {
+ til::SExpr *E0 = translate(E->getBase(), Ctx);
+ til::SExpr *E1 = translate(E->getIdx(), Ctx);
+ return new (Arena) til::ArrayIndex(E0, E1);
+}
+
+
+til::SExpr *
+SExprBuilder::translateConditionalOperator(const ConditionalOperator *C,
+ CallingContext *Ctx) {
+ return new (Arena) til::Undefined(C);
+}
+
+
+til::SExpr *SExprBuilder::translateBinaryConditionalOperator(
+ const BinaryConditionalOperator *C, CallingContext *Ctx) {
+ return new (Arena) til::Undefined(C);
+}
+
+
+til::SExpr *
+SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
+ DeclGroupRef DGrp = S->getDeclGroup();
+ for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) {
+ if (VarDecl *VD = dyn_cast_or_null<VarDecl>(*I)) {
+ Expr *E = VD->getInit();
+ til::SExpr* SE = translate(E, Ctx);
+
+ // Add local variables with trivial type to the variable map
+ QualType T = VD->getType();
+ if (T.isTrivialType(VD->getASTContext())) {
+ return addVarDecl(VD, SE);
+ }
+ else {
+ // TODO: add alloca
+ }
+ }
+ }
+ return nullptr;
+}
+
+
+
+// If (E) is non-trivial, then add it to the current basic block, and
+// update the statement map so that S refers to E. Returns a new variable
+// that refers to E.
+// If E is trivial returns E.
+til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
+ const ValueDecl *VD) {
+ if (!E)
+ return nullptr;
+ if (til::ThreadSafetyTIL::isTrivial(E))
+ return E;
+
+ til::Variable *V = new (Arena) til::Variable(E, VD);
+ CurrentInstructions.push_back(V);
+ if (S)
+ insertStmt(S, V);
+ return V;
+}
+
+
+// Returns the current value of VD, if known, and nullptr otherwise.
+til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
+ auto It = LVarIdxMap.find(VD);
+ if (It != LVarIdxMap.end()) {
+ assert(CurrentLVarMap[It->second].first == VD);
+ return CurrentLVarMap[It->second].second;
+ }
+ return nullptr;
+}
+
+
+// if E is a til::Variable, update its clangDecl.
+inline void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
+ if (!E)
+ return;
+ if (til::Variable *V = dyn_cast<til::Variable>(E)) {
+ if (!V->clangDecl())
+ V->setClangDecl(VD);
+ }
+}
+
+// Adds a new variable declaration.
+til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
+ maybeUpdateVD(E, VD);
+ LVarIdxMap.insert(std::make_pair(VD, CurrentLVarMap.size()));
+ CurrentLVarMap.makeWritable();
+ CurrentLVarMap.push_back(std::make_pair(VD, E));
+ return E;
+}
+
+
+// Updates a current variable declaration. (E.g. by assignment)
+til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
+ maybeUpdateVD(E, VD);
+ auto It = LVarIdxMap.find(VD);
+ if (It == LVarIdxMap.end()) {
+ til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
+ til::SExpr *St = new (Arena) til::Store(Ptr, E);
+ return St;
+ }
+ CurrentLVarMap.makeWritable();
+ CurrentLVarMap.elem(It->second).second = E;
+ return E;
+}
+
+
+// Make a Phi node in the current block for the i^th variable in CurrentVarMap.
+// If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
+// If E == null, this is a backedge and will be set later.
+void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
+ unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
+ assert(ArgIndex > 0 && ArgIndex < NPreds);
+
+ til::Variable *V = dyn_cast<til::Variable>(CurrentLVarMap[i].second);
+ if (V && V->getBlockID() == CurrentBB->blockID()) {
+ // We already have a Phi node in the current block,
+ // so just add the new variable to the Phi node.
+ til::Phi *Ph = dyn_cast<til::Phi>(V->definition());
+ assert(Ph && "Expecting Phi node.");
+ if (E)
+ Ph->values()[ArgIndex] = E;
+ return;
+ }
+
+ // Make a new phi node: phi(..., E)
+ // All phi args up to the current index are set to the current value.
+ til::SExpr *CurrE = CurrentLVarMap[i].second;
+ til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
+ Ph->values().setValues(NPreds, nullptr);
+ for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
+ Ph->values()[PIdx] = CurrE;
+ if (E)
+ Ph->values()[ArgIndex] = E;
+ // If E is from a back-edge, or either E or CurrE are incomplete, then
+ // mark this node as incomplete; we may need to remove it later.
+ if (!E || isIncompleteVar(E) || isIncompleteVar(CurrE)) {
+ Ph->setStatus(til::Phi::PH_Incomplete);
+ }
+
+ // Add Phi node to current block, and update CurrentLVarMap[i]
+ auto *Var = new (Arena) til::Variable(Ph, CurrentLVarMap[i].first);
+ CurrentArguments.push_back(Var);
+ if (Ph->status() == til::Phi::PH_Incomplete)
+ IncompleteArgs.push_back(Var);
+
+ CurrentLVarMap.makeWritable();
+ CurrentLVarMap.elem(i).second = Var;
+}
+
+
+// Merge values from Map into the current variable map.
+// This will construct Phi nodes in the current basic block as necessary.
+void SExprBuilder::mergeEntryMap(LVarDefinitionMap Map) {
+ assert(CurrentBlockInfo && "Not processing a block!");
+
+ if (!CurrentLVarMap.valid()) {
+ // Steal Map, using copy-on-write.
+ CurrentLVarMap = std::move(Map);
+ return;
+ }
+ if (CurrentLVarMap.sameAs(Map))
+ return; // Easy merge: maps from different predecessors are unchanged.
+
+ unsigned NPreds = CurrentBB->numPredecessors();
+ unsigned ESz = CurrentLVarMap.size();
+ unsigned MSz = Map.size();
+ unsigned Sz = std::min(ESz, MSz);
+
+ for (unsigned i=0; i<Sz; ++i) {
+ if (CurrentLVarMap[i].first != Map[i].first) {
+ // We've reached the end of variables in common.
+ CurrentLVarMap.makeWritable();
+ CurrentLVarMap.downsize(i);
+ break;
+ }
+ if (CurrentLVarMap[i].second != Map[i].second)
+ makePhiNodeVar(i, NPreds, Map[i].second);
+ }
+ if (ESz > MSz) {
+ CurrentLVarMap.makeWritable();
+ CurrentLVarMap.downsize(Map.size());
+ }
+}
+
+
+// Merge a back edge into the current variable map.
+// This will create phi nodes for all variables in the variable map.
+void SExprBuilder::mergeEntryMapBackEdge() {
+ // We don't have definitions for variables on the backedge, because we
+ // haven't gotten that far in the CFG. Thus, when encountering a back edge,
+ // we conservatively create Phi nodes for all variables. Unnecessary Phi
+ // nodes will be marked as incomplete, and stripped out at the end.
+ //
+ // An Phi node is unnecessary if it only refers to itself and one other
+ // variable, e.g. x = Phi(y, y, x) can be reduced to x = y.
+
+ assert(CurrentBlockInfo && "Not processing a block!");
+
+ if (CurrentBlockInfo->HasBackEdges)
+ return;
+ CurrentBlockInfo->HasBackEdges = true;
+
+ CurrentLVarMap.makeWritable();
+ unsigned Sz = CurrentLVarMap.size();
+ unsigned NPreds = CurrentBB->numPredecessors();
+
+ for (unsigned i=0; i < Sz; ++i) {
+ makePhiNodeVar(i, NPreds, nullptr);
+ }
+}
+
+
+// Update the phi nodes that were initially created for a back edge
+// once the variable definitions have been computed.
+// I.e., merge the current variable map into the phi nodes for Blk.
+void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
+ til::BasicBlock *BB = lookupBlock(Blk);
+ unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
+ assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
+
+ for (til::Variable *V : BB->arguments()) {
+ til::Phi *Ph = dyn_cast_or_null<til::Phi>(V->definition());
+ assert(Ph && "Expecting Phi Node.");
+ assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
+ assert(V->clangDecl() && "No local variable for Phi node.");
+
+ til::SExpr *E = lookupVarDecl(V->clangDecl());
+ assert(E && "Couldn't find local variable for Phi node.");
+
+ Ph->values()[ArgIndex] = E;
+ }
+}
+
+void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
+ const CFGBlock *First) {
+ // Perform initial setup operations.
+ unsigned NBlocks = Cfg->getNumBlockIDs();
+ Scfg = new (Arena) til::SCFG(Arena, NBlocks);
+
+ // allocate all basic blocks immediately, to handle forward references.
+ BBInfo.resize(NBlocks);
+ BlockMap.resize(NBlocks, nullptr);
+ // create map from clang blockID to til::BasicBlocks
+ for (auto *B : *Cfg) {
+ auto *BB = new (Arena) til::BasicBlock(Arena);
+ BB->reserveInstructions(B->size());
+ BlockMap[B->getBlockID()] = BB;
+ }
+ CallCtx.reset(new SExprBuilder::CallingContext(D));
+
+ CurrentBB = lookupBlock(&Cfg->getEntry());
+ auto Parms = isa<ObjCMethodDecl>(D) ? cast<ObjCMethodDecl>(D)->parameters()
+ : cast<FunctionDecl>(D)->parameters();
+ for (auto *Pm : Parms) {
+ QualType T = Pm->getType();
+ if (!T.isTrivialType(Pm->getASTContext()))
+ continue;
+
+ // Add parameters to local variable map.
+ // FIXME: right now we emulate params with loads; that should be fixed.
+ til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
+ til::SExpr *Ld = new (Arena) til::Load(Lp);
+ til::SExpr *V = addStatement(Ld, nullptr, Pm);
+ addVarDecl(Pm, V);
+ }
+}
+
+
+void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
+ // Intialize TIL basic block and add it to the CFG.
+ CurrentBB = lookupBlock(B);
+ CurrentBB->reservePredecessors(B->pred_size());
+ Scfg->add(CurrentBB);
+
+ CurrentBlockInfo = &BBInfo[B->getBlockID()];
+
+ // CurrentLVarMap is moved to ExitMap on block exit.
+ // FIXME: the entry block will hold function parameters.
+ // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
+}
+
+
+void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
+ // Compute CurrentLVarMap on entry from ExitMaps of predecessors
+
+ CurrentBB->addPredecessor(BlockMap[Pred->getBlockID()]);
+ BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
+ assert(PredInfo->UnprocessedSuccessors > 0);
+
+ if (--PredInfo->UnprocessedSuccessors == 0)
+ mergeEntryMap(std::move(PredInfo->ExitMap));
+ else
+ mergeEntryMap(PredInfo->ExitMap.clone());
+
+ ++CurrentBlockInfo->ProcessedPredecessors;
+}
+
+
+void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
+ mergeEntryMapBackEdge();
+}
+
+
+void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
+ // The merge*() methods have created arguments.
+ // Push those arguments onto the basic block.
+ CurrentBB->arguments().reserve(
+ static_cast<unsigned>(CurrentArguments.size()), Arena);
+ for (auto *V : CurrentArguments)
+ CurrentBB->addArgument(V);
+}
+
+
+void SExprBuilder::handleStatement(const Stmt *S) {
+ til::SExpr *E = translate(S, CallCtx.get());
+ addStatement(E, S);
+}
+
+
+void SExprBuilder::handleDestructorCall(const VarDecl *VD,
+ const CXXDestructorDecl *DD) {
+ til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
+ til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
+ til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
+ til::SExpr *E = new (Arena) til::Call(Ap);
+ addStatement(E, nullptr);
+}
+
+
+
+void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
+ CurrentBB->instructions().reserve(
+ static_cast<unsigned>(CurrentInstructions.size()), Arena);
+ for (auto *V : CurrentInstructions)
+ CurrentBB->addInstruction(V);
+
+ // Create an appropriate terminator
+ unsigned N = B->succ_size();
+ auto It = B->succ_begin();
+ if (N == 1) {
+ til::BasicBlock *BB = *It ? lookupBlock(*It) : nullptr;
+ // TODO: set index
+ unsigned Idx = BB ? BB->findPredecessorIndex(CurrentBB) : 0;
+ til::SExpr *Tm = new (Arena) til::Goto(BB, Idx);
+ CurrentBB->setTerminator(Tm);
+ }
+ else if (N == 2) {
+ til::SExpr *C = translate(B->getTerminatorCondition(true), CallCtx.get());
+ til::BasicBlock *BB1 = *It ? lookupBlock(*It) : nullptr;
+ ++It;
+ til::BasicBlock *BB2 = *It ? lookupBlock(*It) : nullptr;
+ unsigned Idx1 = BB1 ? BB1->findPredecessorIndex(CurrentBB) : 0;
+ unsigned Idx2 = BB2 ? BB2->findPredecessorIndex(CurrentBB) : 0;
+ til::SExpr *Tm = new (Arena) til::Branch(C, BB1, BB2, Idx1, Idx2);
+ CurrentBB->setTerminator(Tm);
+ }
+}
+
+
+void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
+ ++CurrentBlockInfo->UnprocessedSuccessors;
+}
+
+
+void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
+ mergePhiNodesBackEdge(Succ);
+ ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
+}
+
+
+void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
+ CurrentArguments.clear();
+ CurrentInstructions.clear();
+ CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
+ CurrentBB = nullptr;
+ CurrentBlockInfo = nullptr;
+}
+
+
+void SExprBuilder::exitCFG(const CFGBlock *Last) {
+ for (auto *V : IncompleteArgs) {
+ til::Phi *Ph = dyn_cast<til::Phi>(V->definition());
+ if (Ph && Ph->status() == til::Phi::PH_Incomplete)
+ simplifyIncompleteArg(V, Ph);
+ }
+
+ CurrentArguments.clear();
+ CurrentInstructions.clear();
+ IncompleteArgs.clear();
+}
+
+
+
+class TILPrinter : public til::PrettyPrinter<TILPrinter, llvm::raw_ostream> {};
+
+
+void printSCFG(CFGWalker &Walker) {
+ llvm::BumpPtrAllocator Bpa;
+ til::MemRegionRef Arena(&Bpa);
+ SExprBuilder builder(Arena);
+ til::SCFG *Cfg = builder.buildCFG(Walker);
+ TILPrinter::print(Cfg, llvm::errs());
+}
+
+
+
+} // end namespace threadSafety
+
+} // end namespace clang
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-12 11:02:32 +0000