From 1670805a8df4e44bcc15a65134f0c5581f1bc661 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Mon, 10 Jan 2022 07:43:02 +0100
Subject: [PATCH] Fix #10490 FP unreadVariable with std::shared_lock (#3672)

---
 cfg/std.cfg            |  3 +++
 test/testunusedvar.cpp | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/cfg/std.cfg b/cfg/std.cfg
index 530abcad6..79c5257a9 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -8339,6 +8339,9 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
   <type-checks>
     <unusedvar>
       <suppress>std::insert_iterator</suppress>
+      <suppress>std::lock_guard</suppress>
+      <suppress>std::unique_lock</suppress>
+      <suppress>std::shared_lock</suppress>
       <check>std::pair</check>
     </unusedvar>
   </type-checks>
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 5b2ad0751..9a93f9b0a 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -3051,6 +3051,16 @@ private:
                               "    std::shared_lock<std::shared_timed_mutex> lock( m );\n"
                               "}");
         ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f() {\n" // #10490
+                              "    std::shared_lock lock = GetLock();\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f() {\n"
+                              "    auto&& g = std::lock_guard<std::mutex> { mutex };\n"
+                              "}\n");
+        TODO_ASSERT_EQUALS("", "[test.cpp:2]: (style) Variable 'g' is assigned a value that is never used.\n", errout.str());
     }
 
     void localvar47() { // #6603