Create ConstantExpr class

A ConstantExpr class represents a full expression that's in a context where a
constant expression is required. This class reflects the path the evaluator
took to reach the expression rather than the syntactic context in which the
expression occurs.

In the future, the class will be expanded to cache the result of the evaluated
expression so that it's not needlessly re-evaluated

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D53475

llvm-svn: 345692

4 files changed, 11 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
index 8899fa67a3c..8ace8768154 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -1265,7 +1265,7 @@ static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) {
     if (!S)
       break;
 
-    if (isa<ExprWithCleanups>(S) ||
+    if (isa<FullExpr>(S) ||
         isa<CXXBindTemporaryExpr>(S) ||
         isa<SubstNonTypeTemplateParmExpr>(S))
       continue;
diff --git a/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp b/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
index 344c88099c5..99069d8be05 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -136,8 +136,8 @@ const Expr *bugreporter::getDerefExpr(const Stmt *S) {
       E = AE->getBase();
     } else if (const auto *PE = dyn_cast<ParenExpr>(E)) {
       E = PE->getSubExpr();
-    } else if (const auto *EWC = dyn_cast<ExprWithCleanups>(E)) {
-      E = EWC->getSubExpr();
+    } else if (const auto *FE = dyn_cast<FullExpr>(E)) {
+      E = FE->getSubExpr();
     } else {
       // Other arbitrary stuff.
       break;
@@ -1494,8 +1494,8 @@ static const MemRegion *getLocationRegionIfReference(const Expr *E,
 static const Expr *peelOffOuterExpr(const Expr *Ex,
                                     const ExplodedNode *N) {
   Ex = Ex->IgnoreParenCasts();
-  if (const auto *EWC = dyn_cast<ExprWithCleanups>(Ex))
-    return peelOffOuterExpr(EWC->getSubExpr(), N);
+  if (const auto *FE = dyn_cast<FullExpr>(Ex))
+    return peelOffOuterExpr(FE->getSubExpr(), N);
   if (const auto *OVE = dyn_cast<OpaqueValueExpr>(Ex))
     return peelOffOuterExpr(OVE->getSourceExpr(), N);
   if (const auto *POE = dyn_cast<PseudoObjectExpr>(Ex)) {
diff --git a/clang/lib/StaticAnalyzer/Core/Environment.cpp b/clang/lib/StaticAnalyzer/Core/Environment.cpp
index 96b59310363..da99dbc7acb 100644
--- a/clang/lib/StaticAnalyzer/Core/Environment.cpp
+++ b/clang/lib/StaticAnalyzer/Core/Environment.cpp
@@ -44,6 +44,9 @@ static const Expr *ignoreTransparentExprs(const Expr *E) {
   case Stmt::ExprWithCleanupsClass:
     E = cast<ExprWithCleanups>(E)->getSubExpr();
     break;
+  case Stmt::ConstantExprClass:
+    E = cast<ConstantExpr>(E)->getSubExpr();
+    break;
   case Stmt::CXXBindTemporaryExprClass:
     E = cast<CXXBindTemporaryExpr>(E)->getSubExpr();
     break;
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index f30cf5a2162..2b48cd0f72d 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -1267,6 +1267,9 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::ObjCPropertyRefExprClass:
       llvm_unreachable("These are handled by PseudoObjectExpr");
 
+    case Expr::ConstantExprClass:
+      return Visit(cast<ConstantExpr>(S)->getSubExpr(), Pred, DstTop);
+
     case Stmt::GNUNullExprClass: {
       // GNU __null is a pointer-width integer, not an actual pointer.
       ProgramStateRef state = Pred->getState();