dlltool(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COPYRIGHT | COLOPHON

DLLTOOL(1)                GNU Development Tools               DLLTOOL(1)

NAME         top

       dlltool - create files needed to build and use DLLs

SYNOPSIS         top

       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]
               [-y|--output-delaylib 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] [--add-stdcall-underscore]
               [-k|--kill-at] [-A|--add-stdcall-alias]
               [-p|--ext-prefix-alias prefix]
               [-x|--no-idata4] [-c|--no-idata5]
               [--use-nul-prefixed-import-tables]
               [-I|--identify library-file-name] [--identify-strict]
               [-i|--interwork]
               [-n|--nodelete] [-t|--temp-prefix prefix]
               [-v|--verbose]
               [-h|--help] [-V|--version]
               [--no-leading-underscore] [--leading-underscore]
               [object-file ...]

DESCRIPTION         top

       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 (an `import library').  This file can be created by giving
       the -l option to dlltool when it is creating or reading in a .def
       file.

       If the -y option is specified, dlltool generates a delay-import
       library that can be used instead of the normal import library to
       allow a program to link to the dll only as soon as an imported
       function is called for the first time. The resulting executable
       will need to be linked to the static delayimp library containing
       __delayLoadHelper2(), which in turn will import LoadLibraryA and
       GetProcAddress from kernel32.

       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

       dlltool may also be used to query an existing import library to
       determine the name of the DLL to which it is associated.  See the
       description of the -I or --identify option.

OPTIONS         top

       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.

       -y filename
       --output-delaylib filename
           Specifies the name of the delay-import 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 all exported
           symbols.

       --no-leading-underscore
       --leading-underscore
           Specifies whether standard symbol should be forced to be
           prefixed, or not.

       --add-stdcall-underscore
           Specifies that when dlltool is creating the exports file it
           should prepend an underscore to the names of exported stdcall
           functions. Variable names and non-stdcall function names are
           not modified.  This option is useful when creating GNU-
           compatible import libs for third party DLLs that were built
           with MS-Windows tools.

       -k
       --kill-at
           Specifies that @<number> suffixes should be omitted from the
           names of stdcall functions that will be imported from the
           DLL.  This is useful when creating an import library for a
           DLL which exports stdcall functions but without the usual
           @<number> symbol name suffix.

           This does not change the naming of symbols provided by the
           import library to programs linked against it, but only the
           entries in the import table (ie the .idata section).

       -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.

       --use-nul-prefixed-import-tables
           Specifies that when dlltool is creating the exports and
           library files it should prefix the ".idata4" and ".idata5" by
           zero an element. This emulates old gnu import library
           generation of "dlltool". By default this option is turned
           off.

       -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 filename
       --identify filename
           Specifies that dlltool should inspect the import library
           indicated by filename and report, on "stdout", the name(s) of
           the associated DLL(s).  This can be performed in addition to
           any other operations indicated by the other options and
           arguments.  dlltool fails if the import library does not
           exist or is not actually an import library. See also
           --identify-strict.

       --identify-strict
           Modifies the behavior of the --identify option, such that an
           error is reported if filename is associated with more than
           one DLL.

       -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.

       @file
           Read command-line options from file.  The options read are
           inserted in place of the original @file option.  If file does
           not exist, or cannot be read, then the option will be treated
           literally, and not removed.

           Options in file are separated by whitespace.  A whitespace
           character may be included in an option by surrounding the
           entire option in either single or double quotes.  Any
           character (including a backslash) may be included by
           prefixing the character to be included with a backslash.  The
           file may itself contain additional @file options; any such
           options will be processed recursively.

SEE ALSO         top

       The Info pages for binutils.

COPYRIGHT         top

       Copyright (c) 1991-2021 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 1.3 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".

COLOPHON         top

       This page is part of the binutils (a collection of tools for
       working with executable binaries) project.  Information about the
       project can be found at ⟨http://www.gnu.org/software/binutils/⟩.
       If you have a bug report for this manual page, see
       ⟨http://sourceware.org/bugzilla/enter_bug.cgi?product=binutils⟩.
       This page was obtained from the tarball binutils-2.36.1.tar.gz
       fetched from ⟨https://ftp.gnu.org/gnu/binutils/⟩ on 2021-06-20.
       If you discover any rendering problems in this HTML version of
       the page, or you believe there is a better or more up-to-date
       source for the page, or you have corrections or improvements to
       the information in this COLOPHON (which is not part of the
       original manual page), send a mail to man-pages@man7.org

binutils-2.36.1                2021-02-06                     DLLTOOL(1)