From 004d7d5333ce3041b52dfaea20aec6e4a771c4cf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 27 Apr 2019 17:17:51 +0200
Subject: [PATCH] Fixed #8580 (False positive: unused function (lambda))

---
 lib/checkunusedfunctions.cpp | 11 +++++++++--
 test/testunusedfunctions.cpp | 11 +++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/lib/checkunusedfunctions.cpp b/lib/checkunusedfunctions.cpp
index e4add4ca8..fda9e6fc3 100644
--- a/lib/checkunusedfunctions.cpp
+++ b/lib/checkunusedfunctions.cpp
@@ -20,6 +20,7 @@
 //---------------------------------------------------------------------------
 #include "checkunusedfunctions.h"
 
+#include "astutils.h"
 #include "errorlogger.h"
 #include "library.h"
 #include "settings.h"
@@ -91,8 +92,14 @@ void CheckUnusedFunctions::parseTokens(const Tokenizer &tokenizer, const char Fi
     }
 
     // Function usage..
+    const Token *lambdaEndToken = nullptr;
     for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next()) {
 
+        if (tok == lambdaEndToken)
+            lambdaEndToken = nullptr;
+        else if (!lambdaEndToken && tok->str() == "[")
+            lambdaEndToken = findLambdaEndToken(tok);
+
         // parsing of library code to find called functions
         if (settings->library.isexecutableblock(FileName, tok->str())) {
             const Token * markupVarToken = tok->tokAt(settings->library.blockstartoffset(FileName));
@@ -192,9 +199,9 @@ void CheckUnusedFunctions::parseTokens(const Tokenizer &tokenizer, const char Fi
 
         const Token *funcname = nullptr;
 
-        if (tok->scope()->isExecutable() && Token::Match(tok, "%name% (")) {
+        if ((lambdaEndToken || tok->scope()->isExecutable()) && Token::Match(tok, "%name% (")) {
             funcname = tok;
-        } else if (tok->scope()->isExecutable() && Token::Match(tok, "%name% <") && Token::simpleMatch(tok->linkAt(1), "> (")) {
+        } else if ((lambdaEndToken || tok->scope()->isExecutable()) && Token::Match(tok, "%name% <") && Token::simpleMatch(tok->linkAt(1), "> (")) {
             funcname = tok;
         } else if (Token::Match(tok, "[;{}.,()[=+-/|!?:]")) {
             funcname = tok->next();
diff --git a/test/testunusedfunctions.cpp b/test/testunusedfunctions.cpp
index e7fde3202..66c299aed 100644
--- a/test/testunusedfunctions.cpp
+++ b/test/testunusedfunctions.cpp
@@ -337,6 +337,17 @@ private:
               "int m_i;\n"
               "};");
         ASSERT_EQUALS("", errout.str());
+
+        // #8580
+        check("int foo() { return 12345; }\n"
+              "int bar(std::function<int()> func) { return func(); }\n"
+              "\n"
+              "class A {\n"
+              "public:\n"
+              "  A() : a(bar([] { return foo(); })) {}\n"
+              "  const int a;\n"
+              "};");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void member_function_ternary() {