Extend readability-container-size-empty to add comparisons to empty-state objects.

Patch by Josh Zimmerman.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@301185 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 0 deletions

diff --git a/clang-tidy/utils/ASTUtils.cpp b/clang-tidy/utils/ASTUtils.cpp
index cedac4f5..eff45b5b 100644
--- a/clang-tidy/utils/ASTUtils.cpp
+++ b/clang-tidy/utils/ASTUtils.cpp
@@ -23,6 +23,22 @@ const FunctionDecl *getSurroundingFunction(ASTContext &Context,
       "function", match(stmt(hasAncestor(functionDecl().bind("function"))),
                         Statement, Context));
 }
+
+bool IsBinaryOrTernary(const Expr *E) {
+  const Expr *E_base = E->IgnoreImpCasts();
+  if (clang::isa<clang::BinaryOperator>(E_base) ||
+      clang::isa<clang::ConditionalOperator>(E_base)) {
+    return true;
+  }
+
+  if (const auto *Operator =
+          clang::dyn_cast<clang::CXXOperatorCallExpr>(E_base)) {
+    return Operator->isInfixBinaryOp();
+  }
+
+  return false;
+}
+
 } // namespace utils
 } // namespace tidy
 } // namespace clang
diff --git a/clang-tidy/utils/ASTUtils.h b/clang-tidy/utils/ASTUtils.h
index 898ba9e6..7f753270 100644
--- a/clang-tidy/utils/ASTUtils.h
+++ b/clang-tidy/utils/ASTUtils.h
@@ -18,6 +18,8 @@ namespace utils {
 // Returns the (closest) Function declaration surrounding |Statement| or NULL.
 const FunctionDecl *getSurroundingFunction(ASTContext &Context,
                                            const Stmt &Statement);
+// Determine whether Expr is a Binary or Ternary expression.
+bool IsBinaryOrTernary(const Expr *E);
 } // namespace utils
 } // namespace tidy
 } // namespace clang