NAME
dlltool - Create files needed to build and use DLLs.
SYNOPSIS
dlltool [-d│--input-def def-file-name]
[-b│--base-file base-file-name]
[-e│--output-exp exports-file-name]
[-z│--output-def def-file-name]
[-l│--output-lib library-file-name]
[--export-all-symbols] [--no-export-all-symbols]
[--exclude-symbols list]
[--no-default-excludes]
[-S│--as path-to-assembler] [-f│--as-flags options]
[-D│--dllname name] [-m│--machine machine]
[-a│--add-indirect] [-U│--add-underscore] [-k│--kill-at]
[-A│--add-stdcall-alias]
[-p│--ext-prefix-alias prefix]
[-x│--no-idata4] [-c│--no-idata5] [-i│--interwork]
[-n│--nodelete] [-t│--temp-prefix prefix]
[-v│--verbose]
[-h│--help] [-V│--version]
[object-file ...]
DESCRIPTION
dlltool reads its inputs, which can come from the -d and -b options as
well as object files specified on the command line. It then processes
these inputs and if the -e option has been specified it creates a
exports file. If the -l option has been specified it creates a library
file and if the -z option has been specified it creates a def file.
Any or all of the -e, -l and -z options can be present in one
invocation of dlltool.
When creating a DLL, along with the source for the DLL, it is necessary
to have three other files. dlltool can help with the creation of these
files.
The first file is a .def file which specifies which functions are
exported from the DLL, which functions the DLL imports, and so on.
This is a text file and can be created by hand, or dlltool can be used
to create it using the -z option. In this case dlltool will scan the
object files specified on its command line looking for those functions
which have been specially marked as being exported and put entries for
them in the .def file it creates.
In order to mark a function as being exported from a DLL, it needs to
have an -export:<name_of_function> entry in the .drectve section of the
object file. This can be done in C by using the asm() operator:
asm (".section .drectve");
asm (".ascii \"-export:my_func\"");
int my_func (void) { ... }
The second file needed for DLL creation is an exports file. This file
is linked with the object files that make up the body of the DLL and it
handles the interface between the DLL and the outside world. This is a
binary file and it can be created by giving the -e option to dlltool
when it is creating or reading in a .def file.
The third file needed for DLL creation is the library file that
programs will link with in order to access the functions in the DLL.
This file can be created by giving the -l option to dlltool when it is
creating or reading in a .def file.
dlltool builds the library file by hand, but it builds the exports file
by creating temporary files containing assembler statements and then
assembling these. The -S command line option can be used to specify
the path to the assembler that dlltool will use, and the -f option can
be used to pass specific flags to that assembler. The -n can be used
to prevent dlltool from deleting these temporary assembler files when
it is done, and if -n is specified twice then this will prevent dlltool
from deleting the temporary object files it used to build the library.
Here is an example of creating a DLL from a source file dll.c and also
creating a program (from an object file called program.o) that uses
that DLL:
gcc -c dll.c
dlltool -e exports.o -l dll.lib dll.o
gcc dll.o exports.o -o dll.dll
gcc program.o dll.lib -o program
OPTIONS
The command line options have the following meanings:
-d filename
--input-def filename
Specifies the name of a .def file to be read in and processed.
-b filename
--base-file filename
Specifies the name of a base file to be read in and processed. The
contents of this file will be added to the relocation section in
the exports file generated by dlltool.
-e filename
--output-exp filename
Specifies the name of the export file to be created by dlltool.
-z filename
--output-def filename
Specifies the name of the .def file to be created by dlltool.
-l filename
--output-lib filename
Specifies the name of the library file to be created by dlltool.
--export-all-symbols
Treat all global and weak defined symbols found in the input object
files as symbols to be exported. There is a small list of symbols
which are not exported by default; see the --no-default-excludes
option. You may add to the list of symbols to not export by using
the --exclude-symbols option.
--no-export-all-symbols
Only export symbols explicitly listed in an input .def file or in
.drectve sections in the input object files. This is the default
behaviour. The .drectve sections are created by dllexport
attributes in the source code.
--exclude-symbols list
Do not export the symbols in list. This is a list of symbol names
separated by comma or colon characters. The symbol names should
not contain a leading underscore. This is only meaningful when
--export-all-symbols is used.
--no-default-excludes
When --export-all-symbols is used, it will by default avoid
exporting certain special symbols. The current list of symbols to
avoid exporting is DllMain@12, DllEntryPoint@0, impure_ptr. You
may use the --no-default-excludes option to go ahead and export
these special symbols. This is only meaningful when
--export-all-symbols is used.
-S path
--as path
Specifies the path, including the filename, of the assembler to be
used to create the exports file.
-f options
--as-flags options
Specifies any specific command line options to be passed to the
assembler when building the exports file. This option will work
even if the -S option is not used. This option only takes one
argument, and if it occurs more than once on the command line, then
later occurrences will override earlier occurrences. So if it is
necessary to pass multiple options to the assembler they should be
enclosed in double quotes.
-D name
--dll-name name
Specifies the name to be stored in the .def file as the name of the
DLL when the -e option is used. If this option is not present,
then the filename given to the -e option will be used as the name
of the DLL.
-m machine
-machine machine
Specifies the type of machine for which the library file should be
built. dlltool has a built in default type, depending upon how it
was created, but this option can be used to override that. This is
normally only useful when creating DLLs for an ARM processor, when
the contents of the DLL are actually encode using Thumb
instructions.
-a
--add-indirect
Specifies that when dlltool is creating the exports file it should
add a section which allows the exported functions to be referenced
without using the import library. Whatever the hell that means!
-U
--add-underscore
Specifies that when dlltool is creating the exports file it should
prepend an underscore to the names of the exported functions.
-k
--kill-at
Specifies that when dlltool is creating the exports file it should
not append the string @ <number>. These numbers are called ordinal
numbers and they represent another way of accessing the function in
a DLL, other than by name.
-A
--add-stdcall-alias
Specifies that when dlltool is creating the exports file it should
add aliases for stdcall symbols without @ <number> in addition to
the symbols with @ <number>.
-p
--ext-prefix-alias prefix
Causes dlltool to create external aliases for all DLL imports with
the specified prefix. The aliases are created for both external
and import symbols with no leading underscore.
-x
--no-idata4
Specifies that when dlltool is creating the exports and library
files it should omit the ".idata4" section. This is for
compatibility with certain operating systems.
-c
--no-idata5
Specifies that when dlltool is creating the exports and library
files it should omit the ".idata5" section. This is for
compatibility with certain operating systems.
-i
--interwork
Specifies that dlltool should mark the objects in the library file
and exports file that it produces as supporting interworking
between ARM and Thumb code.
-n
--nodelete
Makes dlltool preserve the temporary assembler files it used to
create the exports file. If this option is repeated then dlltool
will also preserve the temporary object files it uses to create the
library file.
-t prefix
--temp-prefix prefix
Makes dlltool use prefix when constructing the names of temporary
assembler and object files. By default, the temp file prefix is
generated from the pid.
-v
--verbose
Make dlltool describe what it is doing.
-h
--help
Displays a list of command line options and then exits.
-V
--version
Displays dlltool’s version number and then exits.
SEE ALSO
The Info pages for binutils.
COPYRIGHT
Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
Texts. A copy of the license is included in the section entitled ‘‘GNU
Free Documentation License’’.