From 8a7992c6aca9e95ede7108061737e2bd5aef4524 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Thu, 3 Mar 2022 09:41:26 +0100
Subject: [PATCH] Suppress operatorEqVarError for known non-copyable types
 (#3869)

* Fix FP operatorEqVarError with class hierarchy

* Suppress operatorEqVarError for std::mutex

* Add test, non-copyable Qt types

* Update cppcheck-cfg.rng
---
 cfg/cppcheck-cfg.rng      | 12 ++++++++++++
 cfg/qt.cfg                |  6 ++++++
 cfg/std.cfg               |  4 ++++
 lib/checkclass.cpp        |  2 +-
 test/testconstructors.cpp | 11 +++++++++++
 5 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/cfg/cppcheck-cfg.rng b/cfg/cppcheck-cfg.rng
index 84ac7040d..432c84fee 100644
--- a/cfg/cppcheck-cfg.rng
+++ b/cfg/cppcheck-cfg.rng
@@ -534,6 +534,18 @@
               </choice>
             </zeroOrMore>
           </element>
+          <element name="operatorEqVarError">
+            <zeroOrMore>
+              <choice>
+                <element name="check">
+                  <ref name="DATA-EXTNAME"/>
+                </element>
+                <element name="suppress">
+                  <ref name="DATA-EXTNAME"/>
+                </element>
+              </choice>
+            </zeroOrMore>
+          </element>          
         </optional>
       </element>
 
diff --git a/cfg/qt.cfg b/cfg/qt.cfg
index 2362b7f3b..f944411a1 100644
--- a/cfg/qt.cfg
+++ b/cfg/qt.cfg
@@ -5109,6 +5109,12 @@
       <suppress>QApplication</suppress>
       <suppress>QMutexLocker</suppress>      
     </unusedvar>
+    <operatorEqVarError>
+      <suppress>QMutex</suppress>      
+      <suppress>QRecursiveMutex</suppress>      
+      <suppress>QSemaphore</suppress>      
+      <suppress>QReadWriteLock</suppress>      
+    </operatorEqVarError>
   </type-checks>
   <!-- Treat QStringList as QList<QString> since we can't remove the template parameter when we inherit. -->
   <define name="QStringList" value="QList&lt;QString&gt;"/>
diff --git a/cfg/std.cfg b/cfg/std.cfg
index c1d2471d5..9f800dba1 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -8390,6 +8390,10 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
       <suppress>std::basic_ofstream</suppress>      
       <check>std::pair</check>
     </unusedvar>
+    <operatorEqVarError>
+      <suppress>std::mutex</suppress>
+      <suppress>std::recursive_mutex</suppress>    
+    </operatorEqVarError>
   </type-checks>
   <podtype name="char8_t,std::char8_t" sign="u" size="1"/>
   <podtype name="char16_t,std::char16_t" sign="u" size="2"/>
diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index e72b80b1e..ff4f87252 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -275,7 +275,7 @@ void CheckClass::constructors()
                         }
                     }
 
-                    if (classNameUsed)
+                    if (classNameUsed && mSettings->library.getTypeCheck("operatorEqVarError", var.getTypeName()) != Library::TypeCheck::suppress)
                         operatorEqVarError(func.token, scope->className, var.name(), missingCopy);
                 } else if (func.access != AccessControl::Private || mSettings->standards.cpp >= Standards::CPP11) {
                     // If constructor is not in scope then we maybe using a constructor from a different template specialization
diff --git a/test/testconstructors.cpp b/test/testconstructors.cpp
index 7104bdbc6..0dcf7b4d0 100644
--- a/test/testconstructors.cpp
+++ b/test/testconstructors.cpp
@@ -1854,6 +1854,17 @@ private:
               "void Fred::operator=(const Fred &f)\n"
               "{ }", true);
         ASSERT_EQUALS("[test.cpp:13]: (warning, inconclusive) Member variable 'Fred::ints' is not assigned a value in 'Fred::operator='.\n", errout.str());
+
+        Settings s;
+        s.certainty.setEnabled(Certainty::inconclusive, true);
+        s.severity.enable(Severity::style);
+        s.severity.enable(Severity::warning);
+        LOAD_LIB_2(s.library, "std.cfg");
+        check("struct S {\n"
+              "    S& operator=(const S& s) { return *this; }\n"
+              "    std::mutex m;\n"
+              "};\n", s);
+        ASSERT_EQUALS("", errout.str());
     }
 
     void uninitVar1() {