From 533c01d9b1ef57b4758609de8459a137b233d3e3 Mon Sep 17 00:00:00 2001
From: Gabor Horvath <xazax.hun@gmail.com>
Date: Tue, 19 Apr 2016 13:29:05 +0000
Subject: [PATCH] [clang-tidy] readability-container-size-empty fixes

Summary: This patch fixes PR27410 and adds std::basic_string support.

Reviewers: Eugene.Zelenko, hokein

Subscribers: cfe-commits, o.gyorgy

Differential Revision: http://reviews.llvm.org/D19262

llvm-svn: 266734
---
 .../readability/ContainerSizeEmptyCheck.cpp        | 20 +++++++++++--------
 .../readability-container-size-empty.cpp           | 23 ++++++++++++++++++++++
 2 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
index f194b47..5639615 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp
@@ -16,6 +16,7 @@ using namespace clang::ast_matchers;
 
 static bool isContainerName(llvm::StringRef ClassName) {
   static const char *const ContainerNames[] = {"array",
+                                               "basic_string",
                                                "deque",
                                                "forward_list",
                                                "list",
@@ -59,14 +60,13 @@ void ContainerSizeEmptyCheck::registerMatchers(MatchFinder *Finder) {
     return;
 
   const auto WrongUse = anyOf(
-      hasParent(
-          binaryOperator(
-              anyOf(has(integerLiteral(equals(0))),
-                    allOf(anyOf(hasOperatorName("<"), hasOperatorName(">="),
-                                hasOperatorName(">"), hasOperatorName("<=")),
-                          hasEitherOperand(
-                              ignoringImpCasts(integerLiteral(equals(1)))))))
-              .bind("SizeBinaryOp")),
+      hasParent(binaryOperator(
+                    anyOf(hasOperatorName("<"), hasOperatorName(">="),
+                          hasOperatorName(">"), hasOperatorName("<="),
+                          hasOperatorName("=="), hasOperatorName("!=")),
+                    hasEitherOperand(ignoringImpCasts(anyOf(
+                        integerLiteral(equals(1)), integerLiteral(equals(0))))))
+                    .bind("SizeBinaryOp")),
       hasParent(implicitCastExpr(
           hasImplicitDestinationType(booleanType()),
           anyOf(
@@ -122,6 +122,10 @@ void ContainerSizeEmptyCheck::check(const MatchFinder::MatchResult &Result) {
     if (Value > 1)
       return;
 
+    if (Value == 1 && (OpCode == BinaryOperatorKind::BO_EQ ||
+                       OpCode == BinaryOperatorKind::BO_NE))
+      return;
+
     // Always true, no warnings for that.
     if ((OpCode == BinaryOperatorKind::BO_GE && Value == 0 && ContainerIsLHS) ||
         (OpCode == BinaryOperatorKind::BO_LE && Value == 0 && !ContainerIsLHS))
diff --git a/clang-tools-extra/test/clang-tidy/readability-container-size-empty.cpp b/clang-tools-extra/test/clang-tidy/readability-container-size-empty.cpp
index eb453fc..a3f6385 100644
--- a/clang-tools-extra/test/clang-tidy/readability-container-size-empty.cpp
+++ b/clang-tools-extra/test/clang-tidy/readability-container-size-empty.cpp
@@ -7,6 +7,15 @@ template <typename T> struct vector {
   bool empty() const;
 };
 
+template <typename T> struct basic_string {
+  basic_string();
+  unsigned long size() const;
+  bool empty() const;
+};
+
+typedef basic_string<char> string;
+typedef basic_string<wchar_t> wstring;
+
 inline namespace __v2 {
 template <typename T> struct set {
   set();
@@ -20,10 +29,24 @@ template <typename T> struct set {
 
 int main() {
   std::set<int> intSet;
+  std::string str;
+  std::wstring wstr;
+  str.size() + 0;
+  str.size() - 0;
+  0 + str.size();
+  0 - str.size();
   if (intSet.size() == 0)
     ;
   // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: the 'empty' method should be used to check for emptiness instead of 'size' [readability-container-size-empty]
   // CHECK-FIXES: {{^  }}if (intSet.empty()){{$}}
+  if (str.size() == 0)
+    ;
+  // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: the 'empty' method should be used
+  // CHECK-FIXES: {{^  }}if (str.empty()){{$}}
+  if (wstr.size() == 0)
+    ;
+  // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: the 'empty' method should be used
+  // CHECK-FIXES: {{^  }}if (wstr.empty()){{$}}
   std::vector<int> vect;
   if (vect.size() == 0)
     ;
-- 
2.7.4