src/share/vm/utilities/utf8.cpp

rev 6283 : redundant memcpy

*** 327,353 ****
    return result;
  }
  
  char* UNICODE::as_utf8(jchar* base, int length) {
    int utf8_len = utf8_length(base, length);
!   u_char* result = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);
!   u_char* p = result;
!   for (int index = 0; index < length; index++) {
!     p = utf8_write(p, base[index]);
!   }
!   *p = '\0';
!   assert(p == &result[utf8_len], "length prediction must be correct");
!   return (char*) result;
  }
  
  char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {
    u_char* p = (u_char*)buf;
-   u_char* end = (u_char*)buf + buflen;
    for (int index = 0; index < length; index++) {
      jchar c = base[index];
!     if (p + utf8_size(c) >= end) break;      // string is truncated
!     p = utf8_write(p, base[index]);
    }
    *p = '\0';
    return buf;
  }
  
--- 327,349 ----
    return result;
  }
  
  char* UNICODE::as_utf8(jchar* base, int length) {
    int utf8_len = utf8_length(base, length);
!   u_char* buf = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);
!   char* result = as_utf8(base, length, (char*) buf, utf8_len + 1);
!   assert((int) strlen(result) == utf8_len, "length prediction must be correct");
!   return result;
  }
  
  char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {
    u_char* p = (u_char*)buf;
    for (int index = 0; index < length; index++) {
      jchar c = base[index];
!     buflen -= utf8_size(c);
!     if (buflen <= 0) break; // string is truncated
!     p = utf8_write(p, c);
    }
    *p = '\0';
    return buf;
  }
  
*** 387,391 ****
--- 383,413 ----
        p += 6;
      }
    }
    *p = '\0';
  }
+ 
+ #ifndef PRODUCT
+ void TestAsUtf8() {
+   char res[60];
+   jchar str[20];
+ 
+   for (int i = 0; i < 20; i++) {
+     str[i] = 0x0800; // char that is 2B in UTF-16 but 3B in UTF-8
+   }
+   str[19] = (jchar)'\0';
+ 
+   // The resulting string in UTF-8 is 3*19 bytes long, but should be truncated
+   UNICODE::as_utf8(str, 19, res, 10);
+   assert(strlen(res) == 9, "string should be truncated here");
+ 
+   UNICODE::as_utf8(str, 19, res, 18);
+   assert(strlen(res) == 15, "string should be truncated here");
+ 
+   UNICODE::as_utf8(str, 19, res, 20);
+   assert(strlen(res) == 18, "string should be truncated here");
+ 
+   // Test with an "unbounded" buffer
+   UNICODE::as_utf8(str, 19, res, INT_MAX);
+   assert(strlen(res) == 3*19, "string should end here");
+ }
+ #endif
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