Fix #11300 FP accessMoved with write access (inconclusive)

Author: web-flow

lib/astutils.cpp

@@ -3470,7 +3470,10 @@ static ExprUsage getFunctionUsage(const Token* tok, int indirect, const Settings
         bool hasIndirect = false;
         const bool isuninitbad = settings.library.isuninitargbad(ftok, argnr + 1, indirect, &hasIndirect);
         if (isuninitbad && (!addressOf || isnullbad))
-            return ExprUsage::Used;
+             return ExprUsage::Used;
+        const Library::ArgumentChecks::Direction dir = settings.library.getArgDirection(ftok, argnr + 1, indirect);
+        if (dir == Library::ArgumentChecks::Direction::DIR_OUT)
+            return ExprUsage::NotUsed;
     }
     return ExprUsage::Inconclusive;
 }

test/testother.cpp

@@ -304,6 +304,7 @@ class TestOther : public TestFixture {
         TEST_CASE(moveForRange);
         TEST_CASE(moveTernary);
         TEST_CASE(movePointerAlias);
+        TEST_CASE(moveOutparam);
 
         TEST_CASE(funcArgNamesDifferent);
         TEST_CASE(funcArgOrderDifferent);
@@ -12730,6 +12731,19 @@ class TestOther : public TestFixture {
         ASSERT_EQUALS("[test.cpp:5:8]: (warning) Access of moved variable '.'. [accessMoved]\n", errout_str());
     }
 
+    void moveOutparam()
+    {
+        check("void f(std::vector<std::string>& v) {\n" // #11300
+              "    std::string l;\n"
+              "    while (std::getline(std::cin, l)) {\n"
+              "        if (!l.empty()) {\n"
+              "            v.emplace_back(std::move(l));\n"
+              "        }\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void funcArgNamesDifferent() {
         check("void func1(int a, int b, int c);\n"
               "void func1(int a, int b, int c) { }\n"