Fix #9696 FP uninitdata - writing pointer to stream (#3772)

Author: chrchr-github

lib/checkuninitvar.cpp

@@ -1263,8 +1263,13 @@ const Token* CheckUninitVar::isVariableUsage(bool cpp, const Token *vartok, cons
         if (isLikelyStreamRead(cpp, vartok->previous()))
             return nullptr;
 
-        if (valueExpr->valueType() && valueExpr->valueType()->type == ValueType::Type::VOID)
-            return nullptr;
+        if (const auto* vt = valueExpr->valueType()) {
+            if (vt->type == ValueType::Type::VOID)
+                return nullptr;
+            // passing a char* to a stream will dereference it
+            if ((alloc == CTOR_CALL || alloc == ARRAY) && vt->pointer && vt->type != ValueType::Type::CHAR && vt->type != ValueType::Type::WCHAR_T)
+                return nullptr;
+        }
     }
     if (astIsRhs(derefValue) && isLikelyStreamRead(cpp, derefValue->astParent()))
         return nullptr;

test/testuninitvar.cpp

@@ -525,6 +525,24 @@ class TestUninitVar : public TestFixture {
                                "}");
                 ASSERT_EQUALS("[test.cpp:3]: (error) Memory is allocated but not initialized: p\n", errout.str());
 
+                checkUninitVar("void f() {\n" // #9696
+                               "  int *p = new int[10];\n"
+                               "  std::cout << p << 1;\n"
+                               "}");
+                ASSERT_EQUALS("", errout.str());
+
+                checkUninitVar("void f() {\n"
+                               "  int i[10];\n"
+                               "  std::cout << i;\n"
+                               "  char c[10];\n"
+                               "  std::cout << c;\n"
+                               "  wchar_t w[10];\n"
+                               "  std::cout << w;\n"
+                               "}");
+                ASSERT_EQUALS("[test.cpp:5]: (error) Uninitialized variable: c\n"
+                              "[test.cpp:7]: (error) Uninitialized variable: w\n",
+                              errout.str());
+
                 checkUninitVar("void f() {\n"
                                "  char p[10];\n"
                                "  std::cout << p << 1;\n"