Review Request JDK-8136930 Examine implications for custom launchers, equivalent of java -X options in particular

[harold seigel]

Hi David,

On 6/5/2016 8:50 PM, David Holmes wrote:
> There seem to be far too many string literals for the various 
> jdk.module.* forms and lots of hard-coded string lengths. It would be 
> nice if that could be cleaned up using #defines, or string constant 
> variables, so that all the potential property names can be located in 
> one place.

Would you prefer an implementation that looks like this?  (The isdigit() 
issue will be addressed separately.)

    #define MODULE_PROPERTY_PREFIX "jdk.module"
    #define ADDEXPORTS "addexports"
    #define ADDREADS "addreads"
    #define PATCH "patch"
    #define ADDMODS "addmods"
    #define LIMITMODS "limitmods"

    // Return true if the option is one of the module-related java
    properties
    // that can only be set using the proper module-related option and
    cannot
    // be read by jvmti.
    // It's expected that the caller removed the leading "-D" from 'option'.
    bool Arguments::is_internal_module_property(const char* option) {
       assert((strncmp(option, "-D", 2) != 0), "Unexpected leading -D");
       if (strncmp(option, MODULE_PROPERTY_PREFIX ".",
    strlen(MODULE_PROPERTY_PREFIX) + 1) == 0) {
         const char* prop_end = option + 11; // 11 is strlen("jdk.module.")
         // For the repeating properties such as (-Djdk.module.patch.0
         // -Djdk.module.patch.1, etc) return true for
    "-D<property_name>.<digit>...".
         if (((strncmp(prop_end, ADDEXPORTS ".", strlen(ADDEXPORTS) + 1)
    == 0) && isdigit(prop_end[11])) ||
             ((strncmp(prop_end, ADDREADS ".", strlen(ADDREADS) + 1) ==
    0) && isdigit(prop_end[9])) ||
             ((strncmp(prop_end, PATCH ".", strlen(PATCH) + 1) == 0) &&
    isdigit(prop_end[6]))) {
           return true;
         }
         return Arguments::is_matching_property(prop_end, ADDMODS,
    strlen(ADDMODS)) ||
                Arguments::is_matching_property(prop_end, LIMITMODS,
    strlen(LIMITMODS));
       }
       return false;
    }
                   ...

Thanks, Harold