archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-28 07:14:30 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8287244: Add bound check in indexed memory access var handle

Browse source 
Reviewed-by: psandoz, jvernee
This commit is contained in:
Maurizio Cimadamore 2022-05-26 08:34:49 +00:00
parent f710393e35
commit f58c9a659b
4 changed files with 87 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

18
src/java.base/share/classes/java/lang/foreign/ValueLayout.java
View file

@ -137,7 +137,7 @@ public sealed class ValueLayout extends AbstractLayout implements MemoryLayout {
* Can be used to access a multi-dimensional array whose layout is as follows:
*
* {@snippet lang=java :
* MemoryLayout arrayLayout = MemoryLayout.sequenceLayout(-1,
* SequenceLayout arrayLayout = MemoryLayout.sequenceLayout(-1,
* MemoryLayout.sequenceLayout(10,
* MemoryLayout.sequenceLayout(20, ValueLayout.JAVA_INT)));
* }
@ -151,6 +151,22 @@ public sealed class ValueLayout extends AbstractLayout implements MemoryLayout {
* offset = (10 * 20 * 4 * x) + (20 * 4 * y) + (4 * z)
* }</pre></blockquote>
*
* Additionally, the values of {@code x}, {@code y} and {@code z} are constrained as follows:
* <ul>
* <li>{@code 0 <= x < arrayLayout.elementCount() }</li>
* <li>{@code 0 <= y < 10 }</li>
* <li>{@code 0 <= z < 20 }</li>
* </ul>
* <p>
* Consider the following access expressions:
* {@snippet lang=java :
* int value1 = arrayHandle.get(10, 2, 4); // ok, accessed offset = 8176
* int value2 = arrayHandle.get(0, 0, 30); // out of bounds value for z
* }
* In the first case, access is well-formed, as the values for {@code x}, {@code y} and {@code z} conform to
* the bounds specified above. In the second case, access fails with {@link IndexOutOfBoundsException},
* as the value for {@code z} is outside its specified bounds.
*
* @param shape the size of each nested array dimension.
* @return a var handle which can be used to dereference a multi-dimensional array, featuring {@code shape.length + 1}
* {@code long} coordinates.