[NFC] Minor refactoring to setup the stage for supporting pointers in ExprMutationAnalyzer

llvm-svn: 342353

1 files changed, 86 insertions, 43 deletions

diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
index f8ede47bda8..50d4d0b8890 100644
--- a/clang/lib/Analysis/ExprMutationAnalyzer.cpp
+++ b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
@@ -64,33 +64,83 @@ const auto isMoveOnly = [] {
                                            unless(isDeleted()))))));
 };
 
+template <class T> struct NodeID;
+template <> struct NodeID<Expr> { static const std::string value; };
+template <> struct NodeID<Decl> { static const std::string value; };
+const std::string NodeID<Expr>::value = "expr";
+const std::string NodeID<Decl>::value = "decl";
+
+template <class T, class F = const Stmt *(ExprMutationAnalyzer::*)(const T *)>
+const Stmt *tryEachMatch(ArrayRef<ast_matchers::BoundNodes> Matches,
+                         ExprMutationAnalyzer *Analyzer, F Finder) {
+  const StringRef ID = NodeID<T>::value;
+  for (const auto &Nodes : Matches) {
+    if (const Stmt *S = (Analyzer->*Finder)(Nodes.getNodeAs<T>(ID)))
+      return S;
+  }
+  return nullptr;
+}
+
 } // namespace
 
 const Stmt *ExprMutationAnalyzer::findMutation(const Expr *Exp) {
-  const auto Memoized = Results.find(Exp);
-  if (Memoized != Results.end())
+  return findMutationMemoized(Exp,
+                              {&ExprMutationAnalyzer::findDirectMutation,
+                               &ExprMutationAnalyzer::findMemberMutation,
+                               &ExprMutationAnalyzer::findArrayElementMutation,
+                               &ExprMutationAnalyzer::findCastMutation,
+                               &ExprMutationAnalyzer::findRangeLoopMutation,
+                               &ExprMutationAnalyzer::findReferenceMutation,
+                               &ExprMutationAnalyzer::findFunctionArgMutation},
+                              Results);
+}
+
+const Stmt *ExprMutationAnalyzer::findMutation(const Decl *Dec) {
+  return tryEachDeclRef(Dec, &ExprMutationAnalyzer::findMutation);
+}
+
+const Stmt *ExprMutationAnalyzer::findPointeeMutation(const Expr *Exp) {
+  return findMutationMemoized(Exp, {/*TODO*/}, PointeeResults);
+}
+
+const Stmt *ExprMutationAnalyzer::findPointeeMutation(const Decl *Dec) {
+  return tryEachDeclRef(Dec, &ExprMutationAnalyzer::findPointeeMutation);
+}
+
+const Stmt *ExprMutationAnalyzer::findMutationMemoized(
+    const Expr *Exp, llvm::ArrayRef<MutationFinder> Finders,
+    ResultMap &MemoizedResults) {
+  const auto Memoized = MemoizedResults.find(Exp);
+  if (Memoized != MemoizedResults.end())
     return Memoized->second;
 
   if (isUnevaluated(Exp))
-    return Results[Exp] = nullptr;
-
-  for (const auto &Finder : {&ExprMutationAnalyzer::findDirectMutation,
-                             &ExprMutationAnalyzer::findMemberMutation,
-                             &ExprMutationAnalyzer::findArrayElementMutation,
-                             &ExprMutationAnalyzer::findCastMutation,
-                             &ExprMutationAnalyzer::findRangeLoopMutation,
-                             &ExprMutationAnalyzer::findReferenceMutation,
-                             &ExprMutationAnalyzer::findFunctionArgMutation}) {
+    return MemoizedResults[Exp] = nullptr;
+
+  for (const auto &Finder : Finders) {
     if (const Stmt *S = (this->*Finder)(Exp))
-      return Results[Exp] = S;
+      return MemoizedResults[Exp] = S;
   }
 
-  return Results[Exp] = nullptr;
+  return MemoizedResults[Exp] = nullptr;
+}
+
+const Stmt *ExprMutationAnalyzer::tryEachDeclRef(const Decl *Dec,
+                                                 MutationFinder Finder) {
+  const auto Refs =
+      match(findAll(declRefExpr(to(equalsNode(Dec))).bind(NodeID<Expr>::value)),
+            Stm, Context);
+  for (const auto &RefNodes : Refs) {
+    const auto *E = RefNodes.getNodeAs<Expr>(NodeID<Expr>::value);
+    if ((this->*Finder)(E))
+      return E;
+  }
+  return nullptr;
 }
 
 bool ExprMutationAnalyzer::isUnevaluated(const Expr *Exp) {
   return selectFirst<Expr>(
-             "expr",
+             NodeID<Expr>::value,
              match(
                  findAll(
                      expr(equalsNode(Exp),
@@ -115,37 +165,30 @@ bool ExprMutationAnalyzer::isUnevaluated(const Expr *Exp) {
                                   genericSelectionExpr(hasControllingExpr(
                                       hasDescendant(equalsNode(Exp)))),
                                   cxxNoexceptExpr())))))
-                         .bind("expr")),
+                         .bind(NodeID<Expr>::value)),
                  Stm, Context)) != nullptr;
 }
 
 const Stmt *
 ExprMutationAnalyzer::findExprMutation(ArrayRef<BoundNodes> Matches) {
-  for (const auto &Nodes : Matches) {
-    if (const Stmt *S = findMutation(Nodes.getNodeAs<Expr>("expr")))
-      return S;
-  }
-  return nullptr;
+  return tryEachMatch<Expr>(Matches, this, &ExprMutationAnalyzer::findMutation);
 }
 
 const Stmt *
 ExprMutationAnalyzer::findDeclMutation(ArrayRef<BoundNodes> Matches) {
-  for (const auto &DeclNodes : Matches) {
-    if (const Stmt *S = findMutation(DeclNodes.getNodeAs<Decl>("decl")))
-      return S;
-  }
-  return nullptr;
+  return tryEachMatch<Decl>(Matches, this, &ExprMutationAnalyzer::findMutation);
 }
 
-const Stmt *ExprMutationAnalyzer::findMutation(const Decl *Dec) {
-  const auto Refs = match(
-      findAll(declRefExpr(to(equalsNode(Dec))).bind("expr")), Stm, Context);
-  for (const auto &RefNodes : Refs) {
-    const auto *E = RefNodes.getNodeAs<Expr>("expr");
-    if (findMutation(E))
-      return E;
-  }
-  return nullptr;
+const Stmt *ExprMutationAnalyzer::findExprPointeeMutation(
+    ArrayRef<ast_matchers::BoundNodes> Matches) {
+  return tryEachMatch<Expr>(Matches, this,
+                            &ExprMutationAnalyzer::findPointeeMutation);
+}
+
+const Stmt *ExprMutationAnalyzer::findDeclPointeeMutation(
+    ArrayRef<ast_matchers::BoundNodes> Matches) {
+  return tryEachMatch<Decl>(Matches, this,
+                            &ExprMutationAnalyzer::findPointeeMutation);
 }
 
 const Stmt *ExprMutationAnalyzer::findDirectMutation(const Expr *Exp) {
@@ -237,7 +280,7 @@ const Stmt *ExprMutationAnalyzer::findMemberMutation(const Expr *Exp) {
       match(findAll(expr(anyOf(memberExpr(hasObjectExpression(equalsNode(Exp))),
                                cxxDependentScopeMemberExpr(
                                    hasObjectExpression(equalsNode(Exp)))))
-                        .bind("expr")),
+                        .bind(NodeID<Expr>::value)),
             Stm, Context);
   return findExprMutation(MemberExprs);
 }
@@ -246,7 +289,7 @@ const Stmt *ExprMutationAnalyzer::findArrayElementMutation(const Expr *Exp) {
   // Check whether any element of an array is mutated.
   const auto SubscriptExprs = match(
       findAll(arraySubscriptExpr(hasBase(ignoringImpCasts(equalsNode(Exp))))
-                  .bind("expr")),
+                  .bind(NodeID<Expr>::value)),
       Stm, Context);
   return findExprMutation(SubscriptExprs);
 }
@@ -259,7 +302,7 @@ const Stmt *ExprMutationAnalyzer::findCastMutation(const Expr *Exp) {
                                        nonConstReferenceType())),
                                    implicitCastExpr(hasImplicitDestinationType(
                                        nonConstReferenceType()))))
-                        .bind("expr")),
+                        .bind(NodeID<Expr>::value)),
             Stm, Context);
   return findExprMutation(Casts);
 }
@@ -269,8 +312,8 @@ const Stmt *ExprMutationAnalyzer::findRangeLoopMutation(const Expr *Exp) {
   // check all declRefExpr of the loop variable.
   const auto LoopVars =
       match(findAll(cxxForRangeStmt(
-                hasLoopVariable(
-                    varDecl(hasType(nonConstReferenceType())).bind("decl")),
+                hasLoopVariable(varDecl(hasType(nonConstReferenceType()))
+                                    .bind(NodeID<Decl>::value)),
                 hasRangeInit(equalsNode(Exp)))),
             Stm, Context);
   return findDeclMutation(LoopVars);
@@ -286,7 +329,7 @@ const Stmt *ExprMutationAnalyzer::findReferenceMutation(const Expr *Exp) {
                         callee(cxxMethodDecl(ofClass(isMoveOnly()),
                                              returns(nonConstReferenceType()))),
                         argumentCountIs(1), hasArgument(0, equalsNode(Exp)))
-                        .bind("expr")),
+                        .bind(NodeID<Expr>::value)),
             Stm, Context);
   if (const Stmt *S = findExprMutation(Ref))
     return S;
@@ -305,7 +348,7 @@ const Stmt *ExprMutationAnalyzer::findReferenceMutation(const Expr *Exp) {
               // that separately.
               unless(hasParent(declStmt(hasParent(
                   cxxForRangeStmt(hasRangeStmt(equalsBoundNode("stmt"))))))))
-              .bind("decl"))),
+              .bind(NodeID<Decl>::value))),
       Stm, Context);
   return findDeclMutation(Refs);
 }
@@ -320,10 +363,10 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
       findAll(expr(anyOf(callExpr(NonConstRefParam, IsInstantiated, FuncDecl),
                          cxxConstructExpr(NonConstRefParam, IsInstantiated,
                                           FuncDecl)))
-                  .bind("expr")),
+                  .bind(NodeID<Expr>::value)),
       Stm, Context);
   for (const auto &Nodes : Matches) {
-    const auto *Exp = Nodes.getNodeAs<Expr>("expr");
+    const auto *Exp = Nodes.getNodeAs<Expr>(NodeID<Expr>::value);
     const auto *Func = Nodes.getNodeAs<FunctionDecl>("func");
     if (!Func->getBody())
       return Exp;