From 26ba29c303c19ca957047312f281642f29019177 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Sat, 21 Oct 2023 12:41:39 +0200
Subject: [PATCH] Fix #12086 FN passedByValue with index operator and
 namespaced function call (#5574)

---
 lib/astutils.cpp   |  2 +-
 lib/astutils.h     |  2 +-
 lib/checkother.cpp | 20 ++------------------
 lib/valueflow.cpp  |  2 +-
 test/testother.cpp |  8 ++++++++
 5 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 949d79b70..e735a078f 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -3052,7 +3052,7 @@ const Token* getIteratorExpression(const Token* tok)
     return nullptr;
 }
 
-bool isIteratorPair(std::vector<const Token*> args)
+bool isIteratorPair(const std::vector<const Token*>& args)
 {
     if (args.size() != 2)
         return false;
diff --git a/lib/astutils.h b/lib/astutils.h
index dd56b4cb5..c5fe9e095 100644
--- a/lib/astutils.h
+++ b/lib/astutils.h
@@ -393,7 +393,7 @@ const Token* getIteratorExpression(const Token* tok);
 /**
  * Are the arguments a pair of iterators/pointers?
  */
-bool isIteratorPair(std::vector<const Token*> args);
+bool isIteratorPair(const std::vector<const Token*>& args);
 
 CPPCHECKLIB const Token *findLambdaStartToken(const Token *last);
 
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index a8120b59c..d937e625b 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1281,27 +1281,11 @@ static bool canBeConst(const Variable *var, const Settings* settings)
             if (parent->str() == ">>" && parent->astOperand2() == tok2)
                 return false;
         } else if (parent->str() == "," || parent->str() == "(") { // function argument
-            const Token* tok3 = tok2->previous();
-            int argNr = 0;
-            while (tok3 && tok3->str() != "(") {
-                if (tok3->link() && Token::Match(tok3, ")|]|}|>"))
-                    tok3 = tok3->link();
-                else if (tok3->link())
-                    break;
-                else if (tok3->str() == ";")
-                    break;
-                else if (tok3->str() == ",")
-                    argNr++;
-                tok3 = tok3->previous();
-            }
-            if (!tok3 || tok3->str() != "(")
-                return false;
-            const Token* functionTok = tok3->astOperand1();
+            int argNr = -1;
+            const Token* functionTok = getTokenArgumentFunction(tok2, argNr);
             if (!functionTok)
                 return false;
             const Function* tokFunction = functionTok->function();
-            if (!tokFunction && functionTok->str() == "." && (functionTok = functionTok->astOperand2()))
-                tokFunction = functionTok->function();
             if (tokFunction) {
                 const Variable* argVar = tokFunction->getArgumentVar(argNr);
                 if (!argVar || (!argVar->isConst() && argVar->isReference()))
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index eebe52fd2..ff8279d99 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -4280,7 +4280,7 @@ static bool hasBorrowingVariables(const std::list<Variable>& vars, const std::ve
 static void valueFlowLifetimeUserConstructor(Token* tok,
                                              const Function* constructor,
                                              const std::string& name,
-                                             std::vector<const Token*> args,
+                                             const std::vector<const Token*>& args,
                                              TokenList& tokenlist,
                                              ErrorLogger* errorLogger,
                                              const Settings* settings)
diff --git a/test/testother.cpp b/test/testother.cpp
index 2912b1d59..b3d0fc0d2 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -2159,6 +2159,14 @@ private:
               "T::T(std::string s) noexcept(true) : m(std::move(s)) {}\n");
         ASSERT_EQUALS("", errout.str());
 
+        check("namespace N {\n" // #12086
+              "    void g(int);\n"
+              "}\n"
+              "void f(std::vector<int> v) {\n"
+              "    N::g(v[0]);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:4]: (performance) Function parameter 'v' should be passed by const reference.\n", errout.str());
+
         Settings settings1 = settingsBuilder().platform(Platform::Type::Win64).build();
         check("using ui64 = unsigned __int64;\n"
               "ui64 Test(ui64 one, ui64 two) { return one + two; }\n",