From 95dc05b21d3e3fe8bf56dfed69e36e84593f7835 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Thu, 13 Jan 2022 08:05:05 +0100
Subject: [PATCH] Fix #7732 false negative: (style) Unused variable: std::pair
 (#3695)

---
 cfg/qt.cfg             |  6 ++++++
 cfg/std.cfg            |  6 ++++++
 lib/checkunusedvar.cpp |  6 ++++--
 test/testunusedvar.cpp | 13 ++++++++++++-
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/cfg/qt.cfg b/cfg/qt.cfg
index 27c3f5882..2362b7f3b 100644
--- a/cfg/qt.cfg
+++ b/cfg/qt.cfg
@@ -5104,6 +5104,12 @@
       <function name="crend" yields="end-iterator"/>
     </access>
   </container>
+  <type-checks>
+    <unusedvar>
+      <suppress>QApplication</suppress>
+      <suppress>QMutexLocker</suppress>      
+    </unusedvar>
+  </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;"/>
   <define name="Q_ARG(type, data)" value="QArgument&lt;type &gt;(#type, data)"/>
diff --git a/cfg/std.cfg b/cfg/std.cfg
index 79c5257a9..080c409dc 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -8342,6 +8342,12 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
       <suppress>std::lock_guard</suppress>
       <suppress>std::unique_lock</suppress>
       <suppress>std::shared_lock</suppress>
+      <suppress>std::fstream</suppress>
+      <suppress>std::wfstream</suppress>      
+      <suppress>std::ofstream</suppress>
+      <suppress>std::wofstream</suppress>
+      <suppress>std::basic_fstream</suppress>
+      <suppress>std::basic_ofstream</suppress>      
       <check>std::pair</check>
     </unusedvar>
   </type-checks>
diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 7ee724df4..b88578b78 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -1192,7 +1192,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 continue;
 
             if (tok->isName()) {
-                if (isRaiiClass(tok->valueType(), mTokenizer->isCPP(), true))
+                if (isRaiiClass(tok->valueType(), mTokenizer->isCPP(), false))
                     continue;
                 tok = tok->next();
             }
@@ -1223,6 +1223,8 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 op1tok = op1tok->astOperand1();
 
             const Variable *op1Var = op1tok ? op1tok->variable() : nullptr;
+            if (!op1Var && Token::Match(tok, "(|{") && tok->previous() && tok->previous()->variable())
+                op1Var = tok->previous()->variable();
             std::string bailoutTypeName;
             if (op1Var) {
                 if (op1Var->isReference() && op1Var->nameToken() != tok->astOperand1())
@@ -1278,8 +1280,8 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                                     Severity::information,
                                     "checkLibraryCheckType",
                                     "--check-library: Provide <type-checks><unusedvar> configuration for " + bailoutTypeName);
-                        continue;
                     }
+                    continue;
                 }
 
                 // warn
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 0000d7892..923e1c7ca 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -5431,6 +5431,17 @@ private:
                               "    std::unique_lock<std::mutex> lock(m);\n" // #4624
                               "}");
         ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f() {\n" // #7732
+                              "    const std::pair<std::string, std::string> p(\"a\", \"b\");\n"
+                              "    std::pair<std::string, std::string> q{\"a\", \"b\" };\n"
+                              "    auto r = std::pair<std::string, std::string>(\"a\", \"b\");\n"
+                              "    auto s = std::pair<std::string, std::string>{ \"a\", \"b\" };\n"
+                              "}\n");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'p' is assigned a value that is never used.\n"
+                      "[test.cpp:3]: (style) Variable 'q' is assigned a value that is never used.\n"
+                      "[test.cpp:4]: (style) Variable 'r' is assigned a value that is never used.\n"
+                      "[test.cpp:5]: (style) Variable 's' is assigned a value that is never used.\n", errout.str());
     }
 
     void localVarClass() {
@@ -5610,7 +5621,7 @@ private:
                               "    int buf[6];\n"
                               "    Data data(buf);\n"
                               "}");
-        ASSERT_EQUALS("", errout.str());
+        ASSERT_EQUALS("[test.cpp:3]: (information) --check-library: Provide <type-checks><unusedvar> configuration for Data\n", errout.str());
     }
 
     void localvarCpp11Initialization() {