Fix #12287 FP uninitvar when passing address to function (#5899)

Author: chrchr-github

lib/checkuninitvar.cpp

@@ -1653,11 +1653,14 @@ void CheckUninitVar::valueFlowUninit()
                     continue;
                 if (!v->subexpressions.empty() && usage == ExprUsage::PassedByReference)
                     continue;
+                bool inconclusive = false;
+                if (usage == ExprUsage::Used && v->tokvalue && tok->variable() && tok->variable()->isArgument() &&
+                    (!isVariableChangedByFunctionCall(v->tokvalue, v->indirect, mSettings, &inconclusive) || inconclusive))
+                    continue;
                 if (usage != ExprUsage::Used) {
                     if (!(Token::Match(tok->astParent(), ". %name% (") && uninitderef) &&
                         isVariableChanged(tok, v->indirect, mSettings, mTokenizer->isCPP()))
                         continue;
-                    bool inconclusive = false;
                     if (isVariableChangedByFunctionCall(tok, v->indirect, mSettings, &inconclusive) || inconclusive)
                         continue;
                 }

test/testuninitvar.cpp

@@ -6110,7 +6110,7 @@ class TestUninitVar : public TestFixture {
                         "    increment(n);\n"
                         "    return n;\n"
                         "}\n");
-        ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:1]: (warning) Uninitialized variable: i\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
 
         // #11412
         valueFlowUninit("void f(int n) {\n"
@@ -6396,6 +6396,16 @@ class TestUninitVar : public TestFixture {
                         "    return x[0];\n"
                         "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        valueFlowUninit("void f(bool* p) {\n" // #12287
+                        "    if (p)\n"
+                        "        *p = true; \n"
+                        "}\n"
+                        "void g() {\n"
+                        "    bool b;\n"
+                        "    f(&b);\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void valueFlowUninitBreak() { // Do not show duplicate warnings about the same uninitialized value
@@ -7714,6 +7724,14 @@ class TestUninitVar : public TestFixture {
             "    lookupStem(h, &stem);\n"
             "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        ctu("void increment(int& i) { ++i; }\n" // #6475
+            "int f() {\n"
+            "    int n;\n"
+            "    increment(n);\n"
+            "    return n;\n"
+            "}\n");
+        ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:1]: (error) Using argument i that points at uninitialized variable n\n", errout.str());
     }
 };