Fixed danmar#3878 (Sign extension with unsigned char false positive)

danmar · danmar · commit 905615e99197 · 2012-06-09T08:43:13.000+02:00
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
@@ -1794,7 +1794,7 @@ void CheckOther::checkCharVariable()
 
         else if (Token::Match(tok, "[;{}] %var% = %any% [&^|] ( * %var% ) ;")) {
             const Variable* var = symbolDatabase->getVariableFromVarId(tok->tokAt(7)->varId());
-            if (!var || !var->isPointer() || var->typeStartToken()->str() != "char")
+            if (!var || !var->isPointer() || var->typeStartToken()->str() != "char" || var->typeStartToken()->isUnsigned())
                 continue;
             // it's ok with a bitwise and where the other operand is 0xff or less..
             if (tok->strAt(4) == "&" && tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
diff --git a/test/testcharvar.cpp b/test/testcharvar.cpp
@@ -212,6 +212,14 @@ class TestCharVar : public TestFixture {
               "    return ret;\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // #3878 - false positive
+        check("int f(unsigned char *p) {\n"
+              "    int ret = a();\n"
+              "    ret |= *p;\n"
+              "    return ret;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 };
 
