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[PATCH] Java: array alignment patch.
- To: gcc-patches at gcc dot gnu dot org, java-patches at gcc dot gnu dot org
- Subject: [PATCH] Java: array alignment patch.
- From: Alexandre Petit-Bianco <apbianco at cygnus dot com>
- Date: Tue, 6 Feb 2001 17:36:00 -0800
- Reply-to: apbianco at cygnus dot com
This patch fixes a problem with the alignment of the data member of
the array objects:
http://gcc.gnu.org/ml/java/2001-02/threads.html#00099
It's been tested on x86/PPC/Alpha Linux. I'm checking this in. Let me
know if it breaks something.
Special thanks to Jeff Sturm for investigating this and for his
extensive testing support on alpha!
./A
2001-02-05 Jeff Sturm <jeff.sturm@commerceone.com>
Alexandre Petit-Bianco <apbianco@cygnus.com>
* typeck.c (build_prim_array_type): Added leading comment.
(build_java_array_type): Moved locals out of
block. Always create the `data' field, fixed alignment to match
C++.
Index: typeck.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/typeck.c,v
retrieving revision 1.36
diff -u -p -r1.36 typeck.c
--- typeck.c 2001/02/04 22:44:06 1.36
+++ typeck.c 2001/02/07 01:26:16
@@ -359,6 +359,11 @@ java_array_type_length (array_type)
return -1;
}
+/* An array of unknown length will be ultimately given an length of
+ -2, so that we can still have `length' producing a negative value
+ even if found. This was part of an optimization amaing at removing
+ `length' from static arrays. We could restore it, FIXME. */
+
tree
build_prim_array_type (element_type, length)
tree element_type;
@@ -378,7 +383,7 @@ build_java_array_type (element_type, len
tree element_type;
HOST_WIDE_INT length;
{
- tree sig, t, fld;
+ tree sig, t, fld, atype, arfld;
char buf[12];
tree elsig = build_java_signature (element_type);
tree el_name = element_type;
@@ -416,39 +421,11 @@ build_java_array_type (element_type, len
FIELD_PUBLIC (fld) = 1;
FIELD_FINAL (fld) = 1;
- if (length >= 0)
- {
- tree atype = build_prim_array_type (element_type, length);
- tree arfld = build_decl (FIELD_DECL, get_identifier ("data"), atype);
-
- DECL_CONTEXT (arfld) = t;
- TREE_CHAIN (fld) = arfld;
-
- /* We need to force the data field to begin at an alignment at
- least equal to the biggest alignment in an object type node
- in order to be compatible with the way that JArray is defined
- in CNI. However, we can't exceed BIGGEST_FIELD_ALIGNMENT. */
- {
- unsigned desired_align = TYPE_ALIGN (object_type_node);
- desired_align = MAX (desired_align, TYPE_ALIGN (element_type));
-#ifdef BIGGEST_FIELD_ALIGNMENT
- desired_align = MIN (desired_align,
- (unsigned) BIGGEST_FIELD_ALIGNMENT);
-#endif
-#ifdef ADJUST_FIELD_ALIGN
- desired_align = ADJUST_FIELD_ALIGN (fld, desired_align);
-#endif
- DECL_ALIGN (arfld) = desired_align;
- }
- }
- else
- {
- unsigned desired_align = TYPE_ALIGN (element_type);
-#ifdef BIGGEST_FIELD_ALIGNMENT
- desired_align = MIN (desired_align, (unsigned) BIGGEST_FIELD_ALIGNMENT);
-#endif
- TYPE_ALIGN (t) = desired_align;
- }
+ atype = build_prim_array_type (element_type, length);
+ arfld = build_decl (FIELD_DECL, get_identifier ("data"), atype);
+ DECL_CONTEXT (arfld) = t;
+ TREE_CHAIN (fld) = arfld;
+ DECL_ALIGN (arfld) = TYPE_ALIGN (element_type);
/* We could layout_class, but that loads java.lang.Object prematurely.
* This is called by the parser, and it is a bad idea to do load_class