Fix 9953: false positive: uninitvar (#3548)

Author: pfultz2

lib/valueflow.cpp

@@ -1317,42 +1317,6 @@ static void valueFlowPointerAlias(TokenList *tokenlist)
     }
 }
 
-static void valueFlowUninitPointerAliasDeref(TokenList *tokenlist)
-{
-    for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
-        if (!tok->isUnaryOp("*"))
-            continue;
-        if (!astIsPointer(tok->astOperand1()))
-            continue;
-
-        const Token* lifeTok = nullptr;
-        ErrorPath errorPath;
-        for (const ValueFlow::Value& v:tok->astOperand1()->values()) {
-            if (!v.isLocalLifetimeValue())
-                continue;
-            lifeTok = v.tokvalue;
-            errorPath = v.errorPath;
-        }
-        if (!lifeTok)
-            continue;
-        if (lifeTok->varId() == 0)
-            continue;
-        const Variable * var = lifeTok->variable();
-        if (!var)
-            continue;
-        if (!var->isConst() && isVariableChanged(lifeTok->next(), tok, lifeTok->varId(), !var->isLocal(), tokenlist->getSettings(), tokenlist->isCPP()))
-            continue;
-        for (const ValueFlow::Value& v:lifeTok->values()) {
-            // Forward uninit values since not all values can be forwarded directly
-            if (!v.isUninitValue())
-                continue;
-            ValueFlow::Value value = v;
-            value.errorPath.insert(value.errorPath.begin(), errorPath.begin(), errorPath.end());
-            setTokenValue(tok, value, tokenlist->getSettings());
-        }
-    }
-}
-
 static void valueFlowBitAnd(TokenList *tokenlist)
 {
     for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
@@ -7698,7 +7662,6 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
         valueFlowLifetime(tokenlist, symboldatabase, errorLogger, settings);
         valueFlowFunctionDefaultParameter(tokenlist, symboldatabase, settings);
         valueFlowUninit(tokenlist, symboldatabase, settings);
-        valueFlowUninitPointerAliasDeref(tokenlist);
         if (tokenlist->isCPP()) {
             valueFlowAfterMove(tokenlist, symboldatabase, settings);
             valueFlowSmartPointer(tokenlist, errorLogger, settings);

test/testuninitvar.cpp

@@ -5358,6 +5358,14 @@ class TestUninitVar : public TestFixture {
                         "}");
         ASSERT_EQUALS("[test.cpp:7] -> [test.cpp:2]: (error) Uninitialized variable: *buflen\n", errout.str());
 
+        // # 9953
+        valueFlowUninit("uint32_t f(uint8_t *mem) {\n"
+                        "    uint32_t u32;\n"
+                        "    uint8_t *buf = (uint8_t *)(&u32);\n"
+                        "    buf[0] = mem[0];\n"
+                        "    return(*(uint32_t *)buf);\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void valueFlowUninitStructMembers()
@@ -5427,7 +5435,7 @@ class TestUninitVar : public TestFixture {
                         "    x = *(&ab);\n"
                         "}\n",
                         "test.c");
-        ASSERT_EQUALS("[test.c:5] -> [test.c:5]: (error) Uninitialized variable: *(&ab).b\n", errout.str());
+        ASSERT_EQUALS("[test.c:5]: (error) Uninitialized variable: *(&ab).b\n", errout.str());
 
         valueFlowUninit("void f(void) {\n"
                         "    struct AB ab;\n"