Vendor import of llvm-project main 8e464dd76bef, the last commit beforevendor/llvm-project/llvmorg-12-init-17869-g8e464dd76bef

the upstream release/12.x branch was created.

1 files changed, 52 insertions, 50 deletions

diff --git a/clang/lib/Analysis/LiveVariables.cpp b/clang/lib/Analysis/LiveVariables.cpp
index d24c40b457b4..8cdc4cc5bd61 100644
--- a/clang/lib/Analysis/LiveVariables.cpp
+++ b/clang/lib/Analysis/LiveVariables.cpp
@@ -27,7 +27,7 @@ namespace {
 class LiveVariablesImpl {
 public:
   AnalysisDeclContext &analysisContext;
-  llvm::ImmutableSet<const Stmt *>::Factory SSetFact;
+  llvm::ImmutableSet<const Expr *>::Factory ESetFact;
   llvm::ImmutableSet<const VarDecl *>::Factory DSetFact;
   llvm::ImmutableSet<const BindingDecl *>::Factory BSetFact;
   llvm::DenseMap<const CFGBlock *, LiveVariables::LivenessValues> blocksEndToLiveness;
@@ -45,16 +45,15 @@ public:
              LiveVariables::Observer *obs = nullptr);
 
   void dumpBlockLiveness(const SourceManager& M);
-  void dumpStmtLiveness(const SourceManager& M);
+  void dumpExprLiveness(const SourceManager& M);
 
   LiveVariablesImpl(AnalysisDeclContext &ac, bool KillAtAssign)
-    : analysisContext(ac),
-      SSetFact(false), // Do not canonicalize ImmutableSets by default.
-      DSetFact(false), // This is a *major* performance win.
-      BSetFact(false),
-      killAtAssign(KillAtAssign) {}
+      : analysisContext(ac),
+        ESetFact(false), // Do not canonicalize ImmutableSets by default.
+        DSetFact(false), // This is a *major* performance win.
+        BSetFact(false), killAtAssign(KillAtAssign) {}
 };
-}
+} // namespace
 
 static LiveVariablesImpl &getImpl(void *x) {
   return *((LiveVariablesImpl *) x);
@@ -64,8 +63,8 @@ static LiveVariablesImpl &getImpl(void *x) {
 // Operations and queries on LivenessValues.
 //===----------------------------------------------------------------------===//
 
-bool LiveVariables::LivenessValues::isLive(const Stmt *S) const {
-  return liveStmts.contains(S);
+bool LiveVariables::LivenessValues::isLive(const Expr *E) const {
+  return liveExprs.contains(E);
 }
 
 bool LiveVariables::LivenessValues::isLive(const VarDecl *D) const {
@@ -97,10 +96,10 @@ LiveVariables::LivenessValues
 LiveVariablesImpl::merge(LiveVariables::LivenessValues valsA,
                          LiveVariables::LivenessValues valsB) {
 
-  llvm::ImmutableSetRef<const Stmt *>
-    SSetRefA(valsA.liveStmts.getRootWithoutRetain(), SSetFact.getTreeFactory()),
-    SSetRefB(valsB.liveStmts.getRootWithoutRetain(), SSetFact.getTreeFactory());
-
+  llvm::ImmutableSetRef<const Expr *> SSetRefA(
+      valsA.liveExprs.getRootWithoutRetain(), ESetFact.getTreeFactory()),
+      SSetRefB(valsB.liveExprs.getRootWithoutRetain(),
+               ESetFact.getTreeFactory());
 
   llvm::ImmutableSetRef<const VarDecl *>
     DSetRefA(valsA.liveDecls.getRootWithoutRetain(), DSetFact.getTreeFactory()),
@@ -122,7 +121,7 @@ LiveVariablesImpl::merge(LiveVariables::LivenessValues valsA,
 }
 
 bool LiveVariables::LivenessValues::equals(const LivenessValues &V) const {
-  return liveStmts == V.liveStmts && liveDecls == V.liveDecls;
+  return liveExprs == V.liveExprs && liveDecls == V.liveDecls;
 }
 
 //===----------------------------------------------------------------------===//
@@ -141,8 +140,8 @@ bool LiveVariables::isLive(const Stmt *S, const VarDecl *D) {
   return isAlwaysAlive(D) || getImpl(impl).stmtsToLiveness[S].isLive(D);
 }
 
-bool LiveVariables::isLive(const Stmt *Loc, const Stmt *S) {
-  return getImpl(impl).stmtsToLiveness[Loc].isLive(S);
+bool LiveVariables::isLive(const Stmt *Loc, const Expr *Val) {
+  return getImpl(impl).stmtsToLiveness[Loc].isLive(Val);
 }
 
 //===----------------------------------------------------------------------===//
@@ -186,27 +185,27 @@ static const VariableArrayType *FindVA(QualType Ty) {
   return nullptr;
 }
 
-static const Stmt *LookThroughStmt(const Stmt *S) {
-  while (S) {
-    if (const Expr *Ex = dyn_cast<Expr>(S))
-      S = Ex->IgnoreParens();
-    if (const FullExpr *FE = dyn_cast<FullExpr>(S)) {
-      S = FE->getSubExpr();
+static const Expr *LookThroughExpr(const Expr *E) {
+  while (E) {
+    if (const Expr *Ex = dyn_cast<Expr>(E))
+      E = Ex->IgnoreParens();
+    if (const FullExpr *FE = dyn_cast<FullExpr>(E)) {
+      E = FE->getSubExpr();
       continue;
     }
-    if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(S)) {
-      S = OVE->getSourceExpr();
+    if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
+      E = OVE->getSourceExpr();
       continue;
     }
     break;
   }
-  return S;
+  return E;
 }
 
-static void AddLiveStmt(llvm::ImmutableSet<const Stmt *> &Set,
-                        llvm::ImmutableSet<const Stmt *>::Factory &F,
-                        const Stmt *S) {
-  Set = F.add(Set, LookThroughStmt(S));
+static void AddLiveExpr(llvm::ImmutableSet<const Expr *> &Set,
+                        llvm::ImmutableSet<const Expr *>::Factory &F,
+                        const Expr *E) {
+  Set = F.add(Set, LookThroughExpr(E));
 }
 
 void TransferFunctions::Visit(Stmt *S) {
@@ -215,8 +214,8 @@ void TransferFunctions::Visit(Stmt *S) {
 
   StmtVisitor<TransferFunctions>::Visit(S);
 
-  if (isa<Expr>(S)) {
-    val.liveStmts = LV.SSetFact.remove(val.liveStmts, S);
+  if (const auto *E = dyn_cast<Expr>(S)) {
+    val.liveExprs = LV.ESetFact.remove(val.liveExprs, E);
   }
 
   // Mark all children expressions live.
@@ -233,7 +232,7 @@ void TransferFunctions::Visit(Stmt *S) {
       // Include the implicit "this" pointer as being live.
       CXXMemberCallExpr *CE = cast<CXXMemberCallExpr>(S);
       if (Expr *ImplicitObj = CE->getImplicitObjectArgument()) {
-        AddLiveStmt(val.liveStmts, LV.SSetFact, ImplicitObj);
+        AddLiveExpr(val.liveExprs, LV.ESetFact, ImplicitObj);
       }
       break;
     }
@@ -250,7 +249,7 @@ void TransferFunctions::Visit(Stmt *S) {
       if (const VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl())) {
         for (const VariableArrayType* VA = FindVA(VD->getType());
              VA != nullptr; VA = FindVA(VA->getElementType())) {
-          AddLiveStmt(val.liveStmts, LV.SSetFact, VA->getSizeExpr());
+          AddLiveExpr(val.liveExprs, LV.ESetFact, VA->getSizeExpr());
         }
       }
       break;
@@ -263,7 +262,7 @@ void TransferFunctions::Visit(Stmt *S) {
       if (OpaqueValueExpr *OV = dyn_cast<OpaqueValueExpr>(child))
         child = OV->getSourceExpr();
       child = child->IgnoreParens();
-      val.liveStmts = LV.SSetFact.add(val.liveStmts, child);
+      val.liveExprs = LV.ESetFact.add(val.liveExprs, child);
       return;
     }
 
@@ -284,36 +283,39 @@ void TransferFunctions::Visit(Stmt *S) {
       // If one of the branches is an expression rather than a compound
       // statement, it will be bad if we mark it as live at the terminator
       // of the if-statement (i.e., immediately after the condition expression).
-      AddLiveStmt(val.liveStmts, LV.SSetFact, cast<IfStmt>(S)->getCond());
+      AddLiveExpr(val.liveExprs, LV.ESetFact, cast<IfStmt>(S)->getCond());
       return;
     }
     case Stmt::WhileStmtClass: {
       // If the loop body is an expression rather than a compound statement,
       // it will be bad if we mark it as live at the terminator of the loop
       // (i.e., immediately after the condition expression).
-      AddLiveStmt(val.liveStmts, LV.SSetFact, cast<WhileStmt>(S)->getCond());
+      AddLiveExpr(val.liveExprs, LV.ESetFact, cast<WhileStmt>(S)->getCond());
       return;
     }
     case Stmt::DoStmtClass: {
       // If the loop body is an expression rather than a compound statement,
       // it will be bad if we mark it as live at the terminator of the loop
       // (i.e., immediately after the condition expression).
-      AddLiveStmt(val.liveStmts, LV.SSetFact, cast<DoStmt>(S)->getCond());
+      AddLiveExpr(val.liveExprs, LV.ESetFact, cast<DoStmt>(S)->getCond());
       return;
     }
     case Stmt::ForStmtClass: {
       // If the loop body is an expression rather than a compound statement,
       // it will be bad if we mark it as live at the terminator of the loop
       // (i.e., immediately after the condition expression).
-      AddLiveStmt(val.liveStmts, LV.SSetFact, cast<ForStmt>(S)->getCond());
+      AddLiveExpr(val.liveExprs, LV.ESetFact, cast<ForStmt>(S)->getCond());
       return;
     }
 
   }
 
+  // HACK + FIXME: What is this? One could only guess that this is an attempt to
+  // fish for live values, for example, arguments from a call expression.
+  // Maybe we could take inspiration from UninitializedVariable analysis?
   for (Stmt *Child : S->children()) {
-    if (Child)
-      AddLiveStmt(val.liveStmts, LV.SSetFact, Child);
+    if (const auto *E = dyn_cast_or_null<Expr>(Child))
+      AddLiveExpr(val.liveExprs, LV.ESetFact, E);
   }
 }
 
@@ -416,7 +418,7 @@ VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *UE)
   const Expr *subEx = UE->getArgumentExpr();
   if (subEx->getType()->isVariableArrayType()) {
     assert(subEx->isLValue());
-    val.liveStmts = LV.SSetFact.add(val.liveStmts, subEx->IgnoreParens());
+    val.liveExprs = LV.ESetFact.add(val.liveExprs, subEx->IgnoreParens());
   }
 }
 
@@ -613,19 +615,19 @@ void LiveVariablesImpl::dumpBlockLiveness(const SourceManager &M) {
   llvm::errs() << "\n";
 }
 
-void LiveVariables::dumpStmtLiveness(const SourceManager &M) {
-  getImpl(impl).dumpStmtLiveness(M);
+void LiveVariables::dumpExprLiveness(const SourceManager &M) {
+  getImpl(impl).dumpExprLiveness(M);
 }
 
-void LiveVariablesImpl::dumpStmtLiveness(const SourceManager &M) {
+void LiveVariablesImpl::dumpExprLiveness(const SourceManager &M) {
   // Don't iterate over blockEndsToLiveness directly because it's not sorted.
-  for (auto I : *analysisContext.getCFG()) {
+  for (const CFGBlock *B : *analysisContext.getCFG()) {
 
-    llvm::errs() << "\n[ B" << I->getBlockID()
-                 << " (live statements at block exit) ]\n";
-    for (auto S : blocksEndToLiveness[I].liveStmts) {
+    llvm::errs() << "\n[ B" << B->getBlockID()
+                 << " (live expressions at block exit) ]\n";
+    for (const Expr *E : blocksEndToLiveness[B].liveExprs) {
       llvm::errs() << "\n";
-      S->dump();
+      E->dump();
     }
     llvm::errs() << "\n";
   }