[clang-tidy] Fix a regression of readability-container-size-empty after the AST ElaboratedType change.

[hokein]

Summary

With 15f3cd6bfc670ba6106184a903eb04be059e5977, we no longer emit a
diagnostic on a real std::vector case where the size method returns a
sugar size_type. This patch fixes it.

std::vector<int> v;
if (v.size() == 0) // => no check diagnostics
  ;

[ymandel]

Thanks! It makes me a little sad that QualType has both isIntegerType and isIntegralType. Nice spotting that difference!

clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.cpp

AST_MATCHER(Expr, usedInBooleanContext) {
   Builder->removeBindings([ExprName](const BoundNodesMap &Nodes) {
     return Nodes.getNode(ExprName).getNodeKind().isNone();
   });
   return Result;
 }
 AST_MATCHER(CXXConstructExpr, isDefaultConstruction) {
   return Node.getConstructor()->isDefaultConstructor();
 }
+AST_MATCHER(QualType, isIntegralType) {
+  return Node->isIntegralType(Finder->getASTContext());
+}
 } // namespace ast_matchers
 namespace tidy {
 namespace readability {
 
 using utils::isBinaryOrTernary;
 
 ContainerSizeEmptyCheck::ContainerSizeEmptyCheck(StringRef Name,
                                                  ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context) {}
 
 void ContainerSizeEmptyCheck::registerMatchers(MatchFinder *Finder) {
   const auto ValidContainerRecord = cxxRecordDecl(isSameOrDerivedFrom(
       namedDecl(
-          has(cxxMethodDecl(isConst(), parameterCountIs(0), isPublic(),
-                            hasName("size"),
-                            returns(qualType(isInteger(), unless(booleanType()),
-                                             unless(elaboratedType()))))
+          has(cxxMethodDecl(
+                  isConst(), parameterCountIs(0), isPublic(), hasName("size"),
+                  returns(qualType(isIntegralType(), unless(booleanType()))))
                   .bind("size")),
           has(cxxMethodDecl(isConst(), parameterCountIs(0), isPublic(),
                             hasName("empty"), returns(booleanType()))
                   .bind("empty")))
           .bind("container")));
 
   const auto ValidContainerNonTemplateType =
       qualType(hasUnqualifiedDesugaredType(

clang-tools-extra/test/clang-tidy/checkers/readability/container-size-empty.cpp

 }
 
 bool call_through_unique_ptr_deref(const std::unique_ptr<std::vector<int>> &ptr) {
   return (*ptr).size() > 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: the 'empty' method should be used
   // CHECK-MESSAGES: :9:8: note: method 'vector'::empty() defined here
   // CHECK-FIXES: {{^  }}return !(*ptr).empty();
 }
+
+struct TypedefSize {
+  typedef int size_type;
+  size_type size() const;
+  bool empty() const;
+};
+void test() {
+  TypedefSize ts;
+  if (ts.size() == 0)
+    ;
+  // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: the 'empty' method should be used
+  // CHECK-FIXES: {{^  }}if (ts.empty()){{$}}
+}