From e1a4d10fc073997cf9d6abc835d295e50e92f770 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 23 Jul 2003 09:53:53 +0000 Subject: [PATCH] boehm.cc (_Jv_BuildGCDescr): Wrote. * boehm.cc (_Jv_BuildGCDescr): Wrote. Include limits.h. From-SVN: r69700 --- libjava/ChangeLog | 5 +++++ libjava/boehm.cc | 46 ++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 47 insertions(+), 4 deletions(-) diff --git a/libjava/ChangeLog b/libjava/ChangeLog index cad0018014f..cf97e58d824 100644 --- a/libjava/ChangeLog +++ b/libjava/ChangeLog @@ -1,3 +1,8 @@ +2003-07-22 Tom Tromey + + * boehm.cc (_Jv_BuildGCDescr): Wrote. + Include limits.h. + 2003-07-22 Tom Tromey * java/awt/Window.java (getWarningString): Just return the diff --git a/libjava/boehm.cc b/libjava/boehm.cc index 5006059dabd..8e621594bf2 100644 --- a/libjava/boehm.cc +++ b/libjava/boehm.cc @@ -1,6 +1,6 @@ // boehm.cc - interface between libjava and Boehm GC. -/* Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation +/* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation This file is part of libgcj. @@ -11,6 +11,7 @@ details. */ #include #include +#include #include #include @@ -325,11 +326,48 @@ _Jv_MarkArray (void *addr, void *msp, void *msl, void * /*env*/) // since another one could be registered first. But the compiler also // knows this, so in that case everything else will break, too. #define GCJ_DEFAULT_DESCR GC_MAKE_PROC(GC_GCJ_RESERVED_MARK_PROC_INDEX,0) + void * -_Jv_BuildGCDescr(jclass) +_Jv_BuildGCDescr(jclass self) { - /* FIXME: We should really look at the class and build the descriptor. */ - return (void *)(GCJ_DEFAULT_DESCR); + jlong desc = 0; + + // Note: for now we only consider a bitmap mark descriptor. We + // could also handle the case where the first N fields of a type are + // references. However, this is not very likely to be used by many + // classes, and it is easier to compute things this way. + + for (jclass klass = self; klass != NULL; klass = klass->getSuperclass()) + { + jfieldID field = JvGetFirstInstanceField(klass); + int count = JvNumInstanceFields(klass); + + for (int i = 0; i < count; ++i) + { + if (field->isRef()) + { + unsigned int off = field->getOffset(); + // If we run into a weird situation, we bail. + if (off % sizeof (void *) != 0) + return (void *) (GCJ_DEFAULT_DESCR); + off /= sizeof (void *); + // Bottom 2 bits are reserved. + off += 2; + // If we find a field outside the range of our bitmap, + // fall back to procedure marker. + if (off > CHAR_BIT * sizeof (void *)) + return (void *) (GCJ_DEFAULT_DESCR); + desc |= 1 << off; + } + + field = field->getNextField(); + } + } + + // For bitmap mark type, bottom bits are 01. + desc |= 1; + // Bogus warning avoidance (on many platforms). + return (void *) (unsigned long) desc; } // Allocate some space that is known to be pointer-free. -- 2.30.2