review request for 6718830

[Xiaobin Lu]

Webrev: http://javaweb.sfbay/~xl116366/webrev/6718830/

6718830: Hotspot fails to build with gcc 4.3

Details:

Two of the incompatibility changes introduced in gcc 4.3 will affect the 
success build of hotspot. The first change is the meaning of 
"-Wconversion" flag. This flag will now emit warnings about every 
implicit downcast such as from int to char or short, from double to 
float, or int etc. While it would be nice to fix this everywhere in our 
code base, I think it would be safe not to do so mainly because it will 
affect a lot of type declaration of the fields in our classes. For 
example, class symbolOopDesc, the "_length" field is declared as 
"unsigned short", however, the methods of setting the length accepts 
"int". Such cases widely spread across our code base. My fix is to 
disable "-Wconversion" flag for build using GCC 4.3, the old meaning of 
"-Wconversion" is regressed to "-Wtraditional-conversion" which is 
available only for C and object C code.

The second change is the removal of Pre-ISO C++ headers such as 
"iostream.h", instead the GCC 4.3 porting notes suggests to migrate to 
include "iostream" and specify "using namespace std". This will affect 
two places in our adlc code which uses "iostream" class in C++.

Verified by:
PRT
Successful build and test on OpenSuSE 11 (gcc 4.3.1)

Reviewed by:

Thanks,
-Xiaobin