xnu-7195.101.1.tar.gz

[apple/xnu.git] / EXTERNAL_HEADERS / mach-o / nlist.h

diff --git a/EXTERNAL_HEADERS/mach-o/nlist.h b/EXTERNAL_HEADERS/mach-o/nlist.h
index a9cd4bd8a41c50f63f7c7fac271037311ca69f41..133e36b49872ef3e7201f82d6361547f83fd736d 100644 (file)
--- a/EXTERNAL_HEADERS/mach-o/nlist.h
+++ b/EXTERNAL_HEADERS/mach-o/nlist.h
@@ -1,31 +1,24 @@
 /*
 /*

- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
+ * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.

  * 
  * 

- * This file contains Original Code and/or Modifications of Original Code 
- * as defined in and that are subject to the Apple Public Source License 
- * Version 2.0 (the 'License'). You may not use this file except in 
- * compliance with the License.  The rights granted to you under the 
- * License may not be used to create, or enable the creation or 
- * redistribution of, unlawful or unlicensed copies of an Apple operating 
- * system, or to circumvent, violate, or enable the circumvention or 
- * violation of, any terms of an Apple operating system software license 
- * agreement.
- *
- * Please obtain a copy of the License at 
- * http://www.opensource.apple.com/apsl/ and read it before using this 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this

  * file.
  * file.

- *
- * The Original Code and all software distributed under the License are 
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
- * Please see the License for the specific language governing rights and 
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and

  * limitations under the License.
  * limitations under the License.

- *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
+ * 
+ * @APPLE_LICENSE_HEADER_END@

  */
 #ifndef _MACHO_NLIST_H_
 #define _MACHO_NLIST_H_
  */
 #ifndef _MACHO_NLIST_H_
 #define _MACHO_NLIST_H_


@@ -70,39 +63,42 @@
  *
  *     @(#)nlist.h     8.2 (Berkeley) 1/21/94
  */
  *
  *     @(#)nlist.h     8.2 (Berkeley) 1/21/94
  */

+#include <stdint.h>

 
 /*
 
 /*

- * Format of a symbol table entry of a Mach-O file.  Modified from the BSD
- * format.  The modifications from the original format were changing n_other
- * (an unused field) to n_sect and the addition of the N_SECT type.  These
- * modifications are required to support symbols in an arbitrary number of
- * sections not just the three sections (text, data and bss) in a BSD file.
+ * Format of a symbol table entry of a Mach-O file for 32-bit architectures.
+ * Modified from the BSD format.  The modifications from the original format
+ * were changing n_other (an unused field) to n_sect and the addition of the
+ * N_SECT type.  These modifications are required to support symbols in a larger
+ * number of sections not just the three sections (text, data and bss) in a BSD
+ * file.

  */
 struct nlist {
        union {
  */
 struct nlist {
        union {

+#ifndef __LP64__

                char *n_name;   /* for use when in-core */
                char *n_name;   /* for use when in-core */

-               long  n_strx;   /* index into the string table */
+#endif
+               uint32_t n_strx;        /* index into the string table */

        } n_un;
        } n_un;

-       unsigned char n_type;   /* type flag, see below */
-       unsigned char n_sect;   /* section number or NO_SECT */
-       short         n_desc;   /* see <mach-o/stab.h> */
-       unsigned long n_value;  /* value of this symbol (or stab offset) */
+       uint8_t n_type;         /* type flag, see below */
+       uint8_t n_sect;         /* section number or NO_SECT */
+       int16_t n_desc;         /* see <mach-o/stab.h> */
+       uint32_t n_value;       /* value of this symbol (or stab offset) */

 };
 
 /*
  * This is the symbol table entry structure for 64-bit architectures.
  */
 struct nlist_64 {
 };
 
 /*
  * This is the symbol table entry structure for 64-bit architectures.
  */
 struct nlist_64 {

-       union {
-               uint32_t n_strx;        /* index into the string table */
-       } n_un;
-       uint8_t n_type;         /* type flag, see below */
-       uint8_t n_sect;         /* section number or NO_SECT */
-       uint16_t n_desc;        /* see <mach-o/stab.h> */
-       uint64_t n_value;       /* value of this symbol (or stab offset) */
+    union {
+        uint32_t  n_strx; /* index into the string table */
+    } n_un;
+    uint8_t n_type;        /* type flag, see below */
+    uint8_t n_sect;        /* section number or NO_SECT */
+    uint16_t n_desc;       /* see <mach-o/stab.h> */
+    uint64_t n_value;      /* value of this symbol (or stab offset) */

 };
 
 };
 

-

 /*
  * Symbols with a index into the string table of zero (n_un.n_strx == 0) are
  * defined to have a null, "", name.  Therefore all string indexes to non null
 /*
  * Symbols with a index into the string table of zero (n_un.n_strx == 0) are
  * defined to have a null, "", name.  Therefore all string indexes to non null


@@ -111,7 +107,7 @@ struct nlist_64 {
  */
 
 /*
  */
 
 /*

- * The n_type field really contains three fields:
+ * The n_type field really contains four fields:

  *     unsigned char N_STAB:3,
  *                   N_PEXT:1,
  *                   N_TYPE:3,
  *     unsigned char N_STAB:3,
  *                   N_PEXT:1,
  *                   N_TYPE:3,


@@ -165,8 +161,14 @@ struct nlist_64 {
  * Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
  * who's values (n_value) are non-zero.  In which case the value of the n_value
  * field is the size (in bytes) of the common symbol.  The n_sect field is set
  * Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
  * who's values (n_value) are non-zero.  In which case the value of the n_value
  * field is the size (in bytes) of the common symbol.  The n_sect field is set

- * to NO_SECT.
+ * to NO_SECT.  The alignment of a common symbol may be set as a power of 2
+ * between 2^1 and 2^15 as part of the n_desc field using the macros below. If
+ * the alignment is not set (a value of zero) then natural alignment based on
+ * the size is used.

  */
  */

+#define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)
+#define SET_COMM_ALIGN(n_desc,align) \
+    (n_desc) = (((n_desc) & 0xf0ff) | (((align) & 0x0f) << 8))

 
 /*
  * To support the lazy binding of undefined symbols in the dynamic link-editor,
 
 /*
  * To support the lazy binding of undefined symbols in the dynamic link-editor,


@@ -188,7 +190,7 @@ struct nlist_64 {
  * REFERENCE_FLAG_DEFINED, is also used.
  */
 /* Reference type bits of the n_desc field of undefined symbols */
  * REFERENCE_FLAG_DEFINED, is also used.
  */
 /* Reference type bits of the n_desc field of undefined symbols */

-#define REFERENCE_TYPE                         0xf
+#define REFERENCE_TYPE                         0x7

 /* types of references */
 #define REFERENCE_FLAG_UNDEFINED_NON_LAZY              0
 #define REFERENCE_FLAG_UNDEFINED_LAZY                  1
 /* types of references */
 #define REFERENCE_FLAG_UNDEFINED_NON_LAZY              0
 #define REFERENCE_FLAG_UNDEFINED_LAZY                  1


@@ -206,10 +208,111 @@ struct nlist_64 {
 #define REFERENCED_DYNAMICALLY 0x0010
 
 /*
 #define REFERENCED_DYNAMICALLY 0x0010
 
 /*

- * The non-reference type bits of the n_desc field for global symbols are
- * reserved for the dynamic link editor.  All of these bits must start out
- * zero in the object file.
+ * For images created by the static link editor with the -twolevel_namespace
+ * option in effect the flags field of the mach header is marked with
+ * MH_TWOLEVEL.  And the binding of the undefined references of the image are
+ * determined by the static link editor.  Which library an undefined symbol is
+ * bound to is recorded by the static linker in the high 8 bits of the n_desc
+ * field using the SET_LIBRARY_ORDINAL macro below.  The ordinal recorded
+ * references the libraries listed in the Mach-O's LC_LOAD_DYLIB,
+ * LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_LOAD_UPWARD_DYLIB, and
+ * LC_LAZY_LOAD_DYLIB, etc. load commands in the order they appear in the
+ * headers.   The library ordinals start from 1.
+ * For a dynamic library that is built as a two-level namespace image the
+ * undefined references from module defined in another use the same nlist struct
+ * an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal.  For
+ * defined symbols in all images they also must have the library ordinal set to
+ * SELF_LIBRARY_ORDINAL.  The EXECUTABLE_ORDINAL refers to the executable
+ * image for references from plugins that refer to the executable that loads
+ * them.
+ * 
+ * The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace
+ * image that are looked up by the dynamic linker with flat namespace semantics.
+ * This ordinal was added as a feature in Mac OS X 10.3 by reducing the
+ * value of MAX_LIBRARY_ORDINAL by one.  So it is legal for existing binaries
+ * or binaries built with older tools to have 0xfe (254) dynamic libraries.  In
+ * this case the ordinal value 0xfe (254) must be treated as a library ordinal
+ * for compatibility. 
+ */
+#define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)
+#define SET_LIBRARY_ORDINAL(n_desc,ordinal) \
+       (n_desc) = (((n_desc) & 0x00ff) | (((ordinal) & 0xff) << 8))
+#define SELF_LIBRARY_ORDINAL 0x0
+#define MAX_LIBRARY_ORDINAL 0xfd
+#define DYNAMIC_LOOKUP_ORDINAL 0xfe
+#define EXECUTABLE_ORDINAL 0xff
+
+/*
+ * The bit 0x0020 of the n_desc field is used for two non-overlapping purposes
+ * and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.

  */
  */

-#define N_DESC_DISCARDED 0x8000        /* symbol is discarded */

 
 

-#endif
+/*
+ * The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a 
+ * relocatable .o file (MH_OBJECT filetype). And is used to indicate to the
+ * static link editor it is never to dead strip the symbol.
+ */
+#define N_NO_DEAD_STRIP 0x0020 /* symbol is not to be dead stripped */
+
+/*
+ * The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.
+ * But is used in very rare cases by the dynamic link editor to mark an in
+ * memory symbol as discared and longer used for linking.
+ */
+#define N_DESC_DISCARDED 0x0020        /* symbol is discarded */
+
+/*
+ * The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that
+ * the undefined symbol is allowed to be missing and is to have the address of
+ * zero when missing.
+ */
+#define N_WEAK_REF     0x0040 /* symbol is weak referenced */
+
+/*
+ * The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic
+ * linkers that the symbol definition is weak, allowing a non-weak symbol to
+ * also be used which causes the weak definition to be discared.  Currently this
+ * is only supported for symbols in coalesed sections.
+ */
+#define N_WEAK_DEF     0x0080 /* coalesed symbol is a weak definition */
+
+/*
+ * The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker
+ * that the undefined symbol should be resolved using flat namespace searching.
+ */
+#define        N_REF_TO_WEAK   0x0080 /* reference to a weak symbol */
+
+/*
+ * The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is
+ * a defintion of a Thumb function.
+ */
+#define N_ARM_THUMB_DEF        0x0008 /* symbol is a Thumb function (ARM) */
+
+/*
+ * The N_SYMBOL_RESOLVER bit of the n_desc field indicates that the
+ * that the function is actually a resolver function and should
+ * be called to get the address of the real function to use.
+ * This bit is only available in .o files (MH_OBJECT filetype)
+ */
+#define N_SYMBOL_RESOLVER  0x0100 
+
+/*
+ * The N_ALT_ENTRY bit of the n_desc field indicates that the
+ * symbol is pinned to the previous content.
+ */
+#define N_ALT_ENTRY 0x0200
+
+#ifndef __STRICT_BSD__
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+/*
+ * The function nlist(3) from the C library.
+ */
+extern int nlist (const char *filename, struct nlist *list);
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* __STRICT_BSD__ */
+
+#endif /* _MACHO_LIST_H_ */