RFR: 8080775: Better argument formatting for assert() and friends

David Lindholm david.lindholm at oracle.com
Tue Sep 22 11:38:52 UTC 2015


Please review the following patch which removes the need to use 
err_msg() or err_msg_res() to format strings that are sent to assert(), 
guarantee(), fatal() and vm_exit_out_of_memory(). These are now variadic 
macros. So,

guarantee(_saved_index == _index, err_msg("saved index: %d index: %d", 
_saved_index, _index));

is replaced by

guarantee(_saved_index == _index, "saved index: %d index: %d", 
_saved_index, _index);

This change also eliminates the need to choose if the buffer for the 
formatted string should be allocated on the stack (with err_msg()) or in 
the resource area (with err_msg_res()). There is no longer any need to 
allocate this extra buffer, since the va_list is sent all the way down 
to the functions writing the error to screen or file.

To accommodate for this, VMError is now AllStatic. All patterns of 
usages of this class was to create a VMError and immediately call 
report_and_die() on it.

Now, instead of having multiple constructors, there are multiple static 

I have also removed all usages of err_msg() and err_msg_res() in 
assert(), guarantee(), fatal() and vm_exit_out_of_memory() in this 
patch. err_msg_res() is completely removed, err_msg() is still used by 
other functions.

Since we have about 1000 asserts with "" as detailed message, I had to 
disable the gcc-only warning for empty format strings.

(As a side note, there is also a JBS bug that describes a name change 
from assert to vmassert in our code. This changeset does not include 
such a name change, since we have over 19000 asserts in our code. We 
still have a "#define assert vmassert" just like before).

Bug: https://bugs.openjdk.java.net/browse/JDK-8080775
Webrev: http://cr.openjdk.java.net/~david/JDK-8080775/webrev.00/

Testing: Passed JPRT


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