Assign values to pointers with C++11 init (cppcheck-opensource#5055)

* Assign values to pointers with C++11 init

* Handle assigning empty init list

Author: chrchr-github

lib/valueflow.cpp

@@ -1343,6 +1343,11 @@ static Token * valueFlowSetConstantValue(Token *tok, const Settings *settings, b
         if (!tok->isTemplateArg())
             value.setKnown();
         setTokenValue(tok->next(), std::move(value), settings, isInitList);
+    } else if (Token::Match(tok, "%name% = { }") && tok->variable() &&
+               (tok->variable()->isPointer() || (tok->variable()->valueType() && tok->variable()->valueType()->isIntegral()))) {
+        ValueFlow::Value value(0);
+        value.setKnown();
+        setTokenValue(tok->tokAt(2), std::move(value), settings, isInitList);
     }
     return tok->next();
 }
@@ -5814,7 +5819,7 @@ static void valueFlowAfterAssign(TokenList *tokenlist,
             if (tok->str() != "=" && !(isInit = isVariableInit(tok)))
                 continue;
 
-            if (tok->astParent() && !(tok->astParent()->str() == ";" && astIsLHS(tok)))
+            if (tok->astParent() && !((tok->astParent()->str() == ";" && astIsLHS(tok)) || tok->astParent()->str() == "*"))
                 continue;
 
             // Lhs should be a variable

test/testvalueflow.cpp

@@ -5054,6 +5054,46 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(true, value.isKnown());
         ASSERT_EQUALS(1, value.intvalue);
 
+        code = "bool f() {\n"
+               "  int* p{};\n"
+               "  return p == nullptr;\n" // <- known value
+               "}";
+        value = valueOfTok(code, "==");
+        ASSERT_EQUALS(true, value.isKnown());
+        ASSERT_EQUALS(1, value.intvalue);
+
+        code = "bool f() {\n"
+               "  int* p{ nullptr };\n"
+               "  return p == nullptr;\n" // <- known value
+               "}";
+        value = valueOfTok(code, "==");
+        ASSERT_EQUALS(true, value.isKnown());
+        ASSERT_EQUALS(1, value.intvalue);
+
+        code = "bool f() {\n"
+               "  int* p{ 0 };\n"
+               "  return p == nullptr;\n" // <- known value
+               "}";
+        value = valueOfTok(code, "==");
+        ASSERT_EQUALS(true, value.isKnown());
+        ASSERT_EQUALS(1, value.intvalue);
+
+        code = "bool f() {\n"
+               "  int* p = {};\n"
+               "  return p == nullptr;\n" // <- known value
+               "}";
+        value = valueOfTok(code, "==");
+        ASSERT_EQUALS(true, value.isKnown());
+        ASSERT_EQUALS(1, value.intvalue);
+
+        code = "bool f() {\n"
+               "  int i = {};\n"
+               "  return i == 0;\n" // <- known value
+               "}";
+        value = valueOfTok(code, "==");
+        ASSERT_EQUALS(true, value.isKnown());
+        ASSERT_EQUALS(1, value.intvalue);
+
         // calculation with known result
         code = "int f(int x) { a = x & 0; }"; // <- & is 0
         value = valueOfTok(code, "&");