RFR: 8205677: [8u] casts and type change for 8u to enable later Windows compilers

Kevin Walls kevin.walls at oracle.com
Thu Jul 5 08:46:09 UTC 2018


I'd like to get a review of:

8205677: [8u] casts and type change for 8u to enable later Windows compilers

This is a collection of new small changes aiming to permit 8u to build 
with later Windows compilers (and also with the current VS2010).

The changes are:

8u webrev: http://cr.openjdk.java.net/~kevinw/8205677/webrev.00/


hotspot\src\share\vm\classfile\altHashing.cpp(227): warning C4838: 
conversion from 'unsigned int' to 'const jint' requires a narrowing 

(jint) casts are present in the later JDK 
test/hotspot/gtest/classfile/test_AltHashing.cpp and look like they were 
in JDK9 from the start.

warning C4312: 'type cast': conversion from 'unsigned int' to 'Monitor 
*' of greater size

-  _monitor = (Monitor*) 0xDEAD000F;
+  _monitor = (Monitor*) (uintptr_t) 0xDEAD000F;

..\hotspot\src\share\vm\oops/typeArrayOop.hpp(132): error C2440: '=': 
cannot convert from 'jlong' to 'jlong *'
..\hotspot\src\share\vm\oops/typeArrayOop.hpp(132): note: Conversion 
from integral type to pointer type requires reinterpret_cast, C-style 
cast or function-style cast

-    *long_at_addr(which) = (long)contents;
+    *long_at_addr(which) = (jlong)contents;

warning C4334: '<<': result of 32-bit shift implicitly converted to 64 
bits (was 64-bit shift intended?)

Like in 8197864 where we cast a 1 to an intptr_t before the shift.

    assert(mr.end() == (HeapWord*)round_to((intptr_t)mr.end(),
-                        (1 << (_shifter+LogHeapWordSize))),
+                        ((intptr_t) 1 << (_shifter+LogHeapWordSize))),

hotspot\src\share\vm\runtime\memprofiler.cpp(129): warning C4477: 
'fprintf' : format string '%6ld' requires an argument of type 'long', 
but variadic argument 3 has type '::size_t'

OopMapCache::memory_size() is only used in one place, and only when 
NOTPRODUCT.  Here in 8u, we can make it return a size_t and compile 
without error.

In jdk10 onwards, after 8186042, this line in memprofiler.cpp hard-codes 
a 0L instead of OopMapCache::memory_size(), as the tracking of 
_total_memory_size was removed, but the print was kept to the same 
format.  I don't think we would remove that statistic in an update


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