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  1. JDK
  2. JDK-8214776

Avoid GCC 8.X strncpy() errors in JFR code

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    • jfr

      Gcc 8 has strict (and sometimes buggy) tests for strncpy() misuse.

      A common pattern in the JDK is:

         const size_t not_impl_len = strlen(not_impl);
         *str = NEW_C_HEAP_ARRAY(char, not_impl_len+1, mtTracing);
         strncpy(*str, not_impl, not_impl_len);
         (*str)[not_impl_len] = '\0';

      More efficient code that does not cause GCC warnings would use strncpy() to add the trailing null, resulting in shorter code:

         strncpy(*str, not_impl, not_impl_len);
         (*str)[not_impl_len] = '\0';

      becomes:

         strncpy(*str, not_impl, not_impl_len+1);

      (found by compiling with GCC 8.1)

            stooke Simon Tooke
            sgehwolf Severin Gehwolf
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