diff options
Diffstat (limited to 'src/net/java/games/gluegen/StructLayout.java')
-rw-r--r-- | src/net/java/games/gluegen/StructLayout.java | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/net/java/games/gluegen/StructLayout.java b/src/net/java/games/gluegen/StructLayout.java new file mode 100644 index 000000000..2a500ceae --- /dev/null +++ b/src/net/java/games/gluegen/StructLayout.java @@ -0,0 +1,138 @@ +/* + * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * - Redistribution of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistribution in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * Neither the name of Sun Microsystems, Inc. or the names of + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * This software is provided "AS IS," without a warranty of any kind. ALL + * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, + * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A + * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN + * MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR + * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR + * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR + * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR + * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE + * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, + * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF + * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. + * + * You acknowledge that this software is not designed or intended for use + * in the design, construction, operation or maintenance of any nuclear + * facility. + * + * Sun gratefully acknowledges that this software was originally authored + * and developed by Kenneth Bradley Russell and Christopher John Kline. + */ + +package net.java.games.gluegen; + +import net.java.games.gluegen.cgram.types.*; + +public class StructLayout { + private int baseOffset; + private int structAlignment; + + protected StructLayout(int baseOffset, + int structAlignment) { + this.baseOffset = baseOffset; + this.structAlignment = structAlignment; + } + + public void layout(CompoundType t) { + int n = t.getNumFields(); + int curOffset = baseOffset; + int maxSize = 0; + for (int i = 0; i < n; i++) { + Field f = t.getField(i); + Type ft = f.getType(); + if (ft.isInt() || ft.isFloat() || ft.isDouble() || ft.isPointer()) { + int sz = ft.getSize(); + if ((curOffset % sz) != 0) { + curOffset += sz - (curOffset % sz); + } + f.setOffset(curOffset); + if (t.isUnion()) { + maxSize = Math.max(maxSize, sz); + } else { + curOffset += sz; + } + } else if (ft.isCompound()) { + new StructLayout(0, structAlignment).layout(ft.asCompound()); + if ((curOffset % structAlignment) != 0) { + curOffset += structAlignment - (curOffset % structAlignment); + } + f.setOffset(curOffset); + if (t.isUnion()) { + maxSize = Math.max(maxSize, ft.getSize()); + } else { + curOffset += ft.getSize(); + } + } else if (ft.isArray()) { + ArrayType arrayType = ft.asArray(); + CompoundType compoundElementType = arrayType.getBaseElementType().asCompound(); + if (compoundElementType != null) { + new StructLayout(0, structAlignment).layout(compoundElementType); + arrayType.recomputeSize(); + } + // Note: not sure how this rounding is done + if ((curOffset % structAlignment) != 0) { + curOffset += structAlignment - (curOffset % structAlignment); + } + f.setOffset(curOffset); + curOffset += ft.getSize(); + } else { + // FIXME + String name = t.getName(); + if (name == null) { + name = t.toString(); + } + throw new RuntimeException("Complicated field types (" + ft + + " " + f.getName() + + " in type " + name + + ") not implemented yet"); + } + } + // FIXME: I think the below is wrong; better check with some examples + // if ((curOffset % structAlignment) != 0) { + // curOffset += structAlignment - (curOffset % structAlignment); + // } + if (t.isUnion()) { + t.setSize(maxSize); + } else { + t.setSize(curOffset); + } + } + + + + public static StructLayout createForCurrentPlatform() { + String os = System.getProperty("os.name").toLowerCase(); + String cpu = System.getProperty("os.arch").toLowerCase(); + if ((os.startsWith("windows") && cpu.equals("x86")) || + (os.startsWith("linux") && cpu.equals("i386")) || + (os.startsWith("sunos") && cpu.equals("sparc")) || + (os.startsWith("sunos") && cpu.equals("i386"))|| + (os.startsWith("mac os") && cpu.equals("ppc")) + ) { + // FIXME: make struct alignment configurable? May need to change + // packing rules on a per-type basis? + return new StructLayout(0, 8); + } else { + // FIXME: add more ports + throw new RuntimeException("Please port StructLayout to your OS (" + os + ") and CPU (" + cpu + ")"); + } + } +} |