Add --posix CLI option.

Part of ticket #2949 (new check: (style) finding non-reentrant functions)

cli/cmdlineparser.cpp

@@ -460,6 +460,13 @@ bool CmdLineParser::ParseFromArgs(int argc, const char* const argv[])
             }
         }
 
+        // Posix compliant code checks
+        else if (strcmp(argv[i], "--posix") == 0)
+        {
+            _settings->_posix = true;
+        }
+
+
         // deprecated: auto deallocated classes..
         else if (strcmp(argv[i], "--auto-dealloc") == 0)
         {
@@ -682,6 +689,7 @@ void CmdLineParser::PrintHelp()
               "                         more comments, like: // cppcheck-suppress warningId\n"
               "                         on the lines before the warning to suppress.\n"
               "    -j <jobs>            Start [jobs] threads to do the checking simultaneously.\n"
+              "    --posix              Enable checks applicable only to Posix compliant code.\n"
               "    -q, --quiet          Only print error messages.\n"
               "    --report-progress    Report progress messages while checking a file.\n"
 #ifdef HAVE_RULES

test/testcmdlineparser.cpp

@@ -100,6 +100,7 @@ private:
         TEST_CASE(ignorefilepaths1)
         TEST_CASE(ignorefilepaths2)
         TEST_CASE(checkconfig)
+        TEST_CASE(posix);
         TEST_CASE(unknownParam);
     }
 
@@ -812,6 +813,16 @@ private:
         ASSERT_EQUALS(true, settings.checkConfiguration);
     }
 
+    void posix()
+    {
+        REDIRECT;
+        const char *argv[] = {"cppcheck", "--posix", "file.cpp"};
+        Settings settings;
+        CmdLineParser parser(&settings);
+        ASSERT(parser.ParseFromArgs(3, argv));
+        ASSERT_EQUALS(true, settings._posix);
+    }
+
     void unknownParam()
     {
         REDIRECT;