"

 COPYRIGHT (c) 1993 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

Object subclass:#ObjectFileLoader

       instanceVariableNames:''

       classVariableNames:'MySymbolTable Verbose LastError LinkErrorMessage NextHandleID

			   LoadedObjects PreviouslyLoadedObjects

			   ActuallyLoadedObjects SearchedLibraries'

       poolDictionaries:''

       category:'System-Compiler'

!

ObjectFileLoader comment:'

COPYRIGHT (c) 1993 by Claus Gittinger

	     All Rights Reserved

'!

!ObjectFileLoader class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1993 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

version

"

"

!

documentation

"

    This class knowns how to dynamically load in external object-modules.

    WARNING:

      As to date, this is completely experimental and WITHOUT ANY WARRANTY.

      It is still being developed and the code below needs cleanup and more

      robustness.

    There are basically two totally different mechanisms to do this:

	a) if there exists some dynamic-link facility such as:

	   GNU-DL, dlopen (sparc, SYS5.4), rld_open (NeXT),

	   this is used

	b) if no such facility exists, the normal linker is used to

	   link the module to text/data address as previously malloced,

	   and the object file loaded into that space.

    Currently, not all mechanisms work fully satisfying.

    For example, the sun dl*-functions do an exit on link-errors (which

    is certainly not what we want here :-(; the NeXT mechanism does not

    allow for selective unloading (only all or last).

    The only really useful packages are the GNU-dl package and the SGI/Unixware

    sys5.4 libdl packages. 

    The GNU-dl package is only available for a.out file formats; 

    i.e. only (a subset of) linux people can use it at this time.

    For the above reasons, dynamic object loading is currently only

    officially released for SYS5.4 and LINUX systems.

    Once stable, the functionality contained herein will be moved into

    the VM. 

    (It is needed there, to allow reloading of objectfiles upon

     image restart; i.e. before any class is reinitialilized).

"

! !

!ObjectFileLoader primitiveDefinitions!

%{

/*

 * by default, use whatever the system provides

 */

#ifdef sunos    /* sunos (pre 5.4) dlopen interface */

# define SUN_DL

# define HAS_DL

#endif

#ifdef NeXT     /* next rld interface */

# define NEXT_DL

# define HAS_DL

#endif

#ifdef SYSV4    /* sys5.4 dlopen interface */

# define SYSV4_DL

# define HAS_DL

#endif

#ifdef DL1_6    /* dl1.6 COFF loader */

# define HAS_DL

#endif

#ifdef _AIX

# define AIX_DL

# define HAS_DL

#endif

/*

 * but GNU_DL overwrites this - its better

 */

#ifdef GNU_DL   /* dld2.3.x interface */

# define HAS_DL

# undef SYSV4_DL

# undef NEXT_DL

# undef SUN_DL

# undef DL1_6

#endif

#include <stdio.h>

/*

 * if no dynamic link facilities, try it the hard way ...

 */

#ifndef HAS_DL

# ifdef A_DOT_OUT

#  include <a.out.h>

#  ifndef N_MAGIC

#   if defined(sinix) && defined(BSD)

#    define N_MAGIC(hdr) (hdr.a_magic & 0xFFFF)

#   else

#    define N_MAGIC(hdr) (hdr.a_magic)

#   endif

#  endif

# endif /* a.out */

# ifdef COFF

#  ifdef mips

#    include <sys/exec.h>

#  else

#    include <a.out.h>

#  endif

# endif /* coff */

# ifdef ELF

#  include <elf.h>

# endif /* elf */

#endif /* not HAS_DL */

#ifdef NEXT_DL

# ifndef _RLD_H_

#  define _RLD_H_

#  ifdef NEXT3

#   include <mach-o/rld.h>

#  else

#   include <rld.h>

#  endif

# endif

#endif /* NEXT_DL */

#ifdef SYSV4_DL

# include <dlfcn.h>

# define dlcfn_h

#endif

#ifdef GNU_DL

#  ifndef dld_h

#   include "dld.h"

#   define dld_h

#  endif

#endif

#ifdef DL1_6

#  ifndef dl_h

#   include "dl.h"

#   define dl_h

#  endif

#endif

#ifdef AIX_DL

# include <nlist.h>

# include <sys/ldr.h>

# include <errno.h>

#endif

%}

! !

!ObjectFileLoader class methodsFor:'initialization'!

initialize

    "name of object file, where initial symbol table is found"

    MySymbolTable := 'smalltalk'.

    Verbose := false.

    NextHandleID := 1.

    ObjectMemory addDependent:self.

    OperatingSystem getSystemType = 'linux' ifTrue:[

	'/usr/lib/libc.a' asFilename isReadable ifTrue:[

	    SearchedLibraries := #('/usr/lib/libc.a')

	]

    ].

    "

     ObjectFileLoader initialize

    "

!

searchedLibraries:aCollectionOfArchivePathNames

    "set the pathnames of archives which are to be searched

     when unresolved references occur while loading in an object

     file. On systems which support shared libraries (all SYS5.4 based

     systems), this is usually not required. Instead, modules which are to

     be filed in (.so files) are to be prelinked with the appropriate

     shared libraries. The dynamic loader then cares about loading those

     modules (keeping track of which modules are already loaded).

     Only systems in which the dynamic load is done 'manually' by st/x

     (i.e. currently only linux) need to set this."

    SearchedLibraries := aCollectionOfArchivePathNames

!

searchedLibraries

    "see comment in #searchedLibraries:"

    ^ SearchedLibraries

!

verbose:aBoolean

    "turn on/off debug traces"

    Verbose := aBoolean

    "ObjectFileLoader verbose:true"

!

lastError

    ^ LastError

!

linkErrorMessage

    ^ LinkErrorMessage

! !

!ObjectFileLoader class methodsFor:'change & update'!

update:something

    "sent, when image is saved or restarted"

    (something == #aboutToSnapshot) ifTrue:[

	self invalidateAndRememberAllObjectFiles

    ].

    (something == #finishedSnapshot) ifTrue:[

	self revalidateAllObjectFiles

    ].

    (something == #restarted) ifTrue:[

	self reloadAllRememberedObjectFiles

    ].

    "Modified: 5.10.1995 / 15:49:14 / claus"

! !

!ObjectFileLoader class methodsFor:'defaults'!

sharedLibraryExtension

    "return a fileName extension used for dynamic loadable objects.

     This is very machine specific."

    |os|

    os := OperatingSystem getSystemType.

    (os = 'sys5_4') ifTrue:[^ '.so'].

    (os = 'iris') ifTrue:[^ '.so'].

    (os = 'linux') ifTrue:[^ '.o'].

    (os = 'aix') ifTrue:[^ '.so'].

    (os = 'hpux') ifTrue:[^ '.sl'].

    (os = 'msdos') ifTrue:[^ '.dll'].

    (os = 'mswindows') ifTrue:[^ '.dll'].

    (os = 'os2') ifTrue:[^ '.dll'].

    "/ mhmh what is a useful default ?

    ^ '.o'

!

needSeparateIDSpaces

    "return true, if we need separate I and D spaces.

     This is only needed if no dynamic-link facilitiy exists."

    |os cpu|

    os := OperatingSystem getSystemType.

    cpu := OperatingSystem getCPUType.

    (os = 'sunos') ifTrue:[

	(cpu = 'sparc') ifTrue:[ ^ true ]

    ].

    'OBJFLOADER: dont know if we need sepId - assume no' errorPrintNL.

    ^ false

!

absLd:file text:textAddr data:dataAddr

   "this should return a string to link file.o to absolute address.

    This is only needed if no dynamic-link facilitiy exists."

    |os cpu|

    os := OperatingSystem getSystemType.

    cpu := OperatingSystem getCPUType.

    (os = 'sunos') ifTrue:[

	(cpu = 'sparc') ifTrue:[

" "

	    ^ ('ld -A ' , MySymbolTable , ' -x -Bstatic' ,

	       ' -Ttext ' , (textAddr printStringRadix:16) , 

	       ' -Tdata ' , (dataAddr printStringRadix:16) , ' ' , file)

" "

"

	    ^ ('ld -A ' , MySymbolTable , ' -T ',

			  (textAddr printStringRadix:16),

			  ' -N -x ' , file)

"

	]

    ].

"

    (os = 'ultrix') ifTrue:[

	(cpu = 'mips') ifTrue:[

	    ^ ('ld -A ' , MySymbolTable , ' -x -N -T ' , (textAddr printStringRadix:16) , ' ' , file)

	]

    ].

"

    self error:'do not know how to link absolute'

!

absLd:file text:textAddr

   "this should return a string to link file.o to absolute address.

    This is only needed if no dynamic-link facilitiy exists."

    |os cpu|

    os := OperatingSystem getSystemType.

    cpu := OperatingSystem getCPUType.

    (os = 'sunos') ifTrue:[

	(cpu = 'sparc') ifTrue:[

	    ^ ('ld -A ' , MySymbolTable , ' -T ',

			  (textAddr printStringRadix:16),

			  ' -N -x ' , file)

	]

    ].

    self error:'do not know how to link absolute'

!

nm:file

   "this should return a string to list the namelist of file"

    |os|

    os := OperatingSystem getSystemType.

    (os = 'iris') ifTrue:[

	^ 'nm -B ' , file

    ].

    ^ 'nm ' , file

! !

!ObjectFileLoader class methodsFor:'loading objects'!

loadFile:oFile with:librariesString

    "load in an object files code, linking in libraries.

     This is only needed if no dynamic link facility exists."

    |tmpOfile errStream errors errText handle pid cmd|

    pid := OperatingSystem getProcessId printString.

    tmpOfile := '/tmp/stc_ld' ,  pid.

    cmd := 'ld -o ', tmpOfile, ' -r ' , oFile , ' ' , librariesString , '>/tmp/out 2>/tmp/err'.

    Verbose ifTrue:[

	('executing: ld -o ', cmd) infoPrintNL

    ].

    (OperatingSystem executeCommand:cmd) ifFalse:[

	errStream := FileStream oldFileNamed:'/tmp/err'.

	errStream isNil ifTrue:[

	    self notify:'errors during link.'

	] ifFalse:[

	    errors := errStream contents.

	    errText := errors asStringCollection.

	    (errText size > 20) ifTrue:[

		errText grow:20.

		errText add:'... '.

		errors := errText

	    ].

	    OperatingSystem executeCommand:'rm /tmp/err /tmp/out'.

	    self notify:('link errors:\\' , errors asString) withCRs

	].

	^ false

    ].

    handle := self loadFile:tmpOfile.

    OperatingSystem executeCommand:('rm ' , tmpOfile).

    ^ handle

!

loadFile:oFile

    "load in an object file - return a handle or nil.

     This is only needed if no dynamic link facility exists.

     It allocates some memory for text and data, calls for the linker

     to relocate the oFile to that address and loads the sections."

    |unixCommand errStream errors errText

     text data textSize dataSize dataAddr textAddr newTextSize newDataSize|

    "find out, how much memory we need"

    textSize := self textSizeOf:oFile.

    textSize isNil ifTrue:[

	'bad text-size in object file' errorPrintNL.

	^ nil

    ].

    Verbose ifTrue:[

	('text-size: ' , (textSize printStringRadix:16)) infoPrintNL

    ].

    dataSize := self dataSizeOf:oFile.

    dataSize isNil ifTrue:[

	'bad data-size in object file' errorPrintNL.

	^ nil

    ].

    Verbose ifTrue:[

	('data-size: ' , (dataSize printStringRadix:16)) infoPrintNL

    ].

    "allocate some memory for text and some for data;

     then call linker to link the file to those addresses"

    self needSeparateIDSpaces ifTrue:[

	text := ExternalBytes newForText:textSize.

	text isNil ifTrue:[

	    'cannot allocate memory for text' errorPrintNL.

	    ^ nil