Fix 10574: ValueFlow: conditional values in constructor initializer list (#3556)

Author: pfultz2

lib/reverseanalyzer.cpp

@@ -127,6 +127,11 @@ struct ReverseTraversal {
             i = tok->index();
             if (tok == start || (tok->str() == "{" && (tok->scope()->type == Scope::ScopeType::eFunction ||
                                                        tok->scope()->type == Scope::ScopeType::eLambda))) {
+                const Function* f = tok->scope()->function;
+                if (f && f->isConstructor()) {
+                    if (const Token* initList = f->constructorMemberInitialization())
+                        traverse(tok->previous(), tok->tokAt(initList->index() - tok->index()));
+                }
                 break;
             }
             if (Token::Match(tok, "return|break|continue"))

test/testvalueflow.cpp

@@ -81,6 +81,7 @@ class TestValueFlow : public TestFixture {
         TEST_CASE(valueFlowBeforeConditionSwitch);
         TEST_CASE(valueFlowBeforeConditionTernaryOp);
         TEST_CASE(valueFlowBeforeConditionForward);
+        TEST_CASE(valueFlowBeforeConditionConstructor);
 
         TEST_CASE(valueFlowAfterAssign);
         TEST_CASE(valueFlowAfterSwap);
@@ -1753,6 +1754,30 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(true, testValueOfX(code, 4U, 123));
     }
 
+    void valueFlowBeforeConditionConstructor()
+    {
+        const char* code;
+
+        code = "struct Fred {\n"
+               "    Fred(int *x)\n"
+               "      : i(*x) {\n"    // <- dereference x
+               "        if (!x) {}\n" // <- check x
+               "    }\n"
+               "    int i;\n"
+               "};\n";
+        ASSERT_EQUALS(true, testValueOfX(code, 3U, 0));
+
+        code = "struct Fred {\n"
+               "    Fred(int *x)\n"
+               "      : i(*x), j(0) {\n" // <- dereference x
+               "        if (!x) {}\n"    // <- check x
+               "    }\n"
+               "    int i;\n"
+               "    int j;\n"
+               "};\n";
+        ASSERT_EQUALS(true, testValueOfX(code, 3U, 0));
+    }
+
     void valueFlowAfterAssign() {
         const char *code;