Changeset 225668 in webkit

Timestamp:

Dec 7, 2017 7:03:19 PM (6 years ago)

Author:

commit-queue@webkit.org

Message:

[Win] [64-bit] Resolve Microsoft warning C4319 on BitVector.cpp
​https://bugs.webkit.org/show_bug.cgi?id=180490

Patch by Basuke Suzuki <Basuke Suzuki> on 2017-12-07
Reviewed by Alex Christensen.

bitsInPointer() returns unsigned which is smaller than size_t.
"~"(negate) operator is applied before extending its size which result filled with zero.
This may be potentially a bug if numBits is greater than max value of unsigned long
(which is not practical).

• wtf/BitVector.cpp:

(WTF::BitVector::OutOfLineBits::create):

Location:

trunk/Source/WTF

Files:

• ChangeLog (modified) (1 diff)
• wtf/BitVector.cpp (modified) (1 diff)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2017-12-07  Basuke Suzuki  <Basuke.Suzuki@sony.com>
+
+        [Win] [64-bit] Resolve Microsoft warning C4319 on BitVector.cpp
+        https://bugs.webkit.org/show_bug.cgi?id=180490
+
+        Reviewed by Alex Christensen.
+
+        bitsInPointer() returns unsigned which is smaller than size_t.
+        "~"(negate) operator is applied before extending its size which result filled with zero.
+        This may be potentially a bug if numBits is greater than max value of unsigned long
+        (which is not practical).
+
+        * wtf/BitVector.cpp:
+        (WTF::BitVector::OutOfLineBits::create):
+
 2017-12-07  Yusuke Suzuki  <utatane.tea@gmail.com>
 

trunk/Source/WTF/wtf/BitVector.cpp

@@ -75 +75 @@
 BitVector::OutOfLineBits* BitVector::OutOfLineBits::create(size_t numBits)
 {
-    numBits = (numBits + bitsInPointer() - 1) & ~(bitsInPointer() - 1);
+    numBits = (numBits + bitsInPointer() - 1) & ~(static_cast<size_t>(bitsInPointer()) - 1);
     size_t size = sizeof(OutOfLineBits) + sizeof(uintptr_t) * (numBits / bitsInPointer());
     OutOfLineBits* result = new (NotNull, fastMalloc(size)) OutOfLineBits(numBits);