4 This directory contains a few sets of files that are used for
5 configuration in diverse ways:
7 *.conf Target platform configurations, please read
8 'Configurations of OpenSSL target platforms' for more
10 *.tmpl Build file templates, please read 'Build-file
11 programming with the "unified" build system' as well
12 as 'Build info files' for more information.
13 *.pm Helper scripts / modules for the main `Configure`
14 script. See 'Configure helper scripts for more
18 Configurations of OpenSSL target platforms
19 ==========================================
21 Configuration targets are a collection of facts that we know about
22 different platforms and their capabilities. We organise them in a
23 hash table, where each entry represent a specific target.
25 Note that configuration target names must be unique across all config
26 files. The Configure script does check that a config file doesn't
27 have config targets that shadow config targets from other files.
29 In each table entry, the following keys are significant:
31 inherit_from => Other targets to inherit values from.
32 Explained further below. [1]
33 template => Set to 1 if this isn't really a platform
34 target. Instead, this target is a template
35 upon which other targets can be built.
36 Explained further below. [1]
38 sys_id => System identity for systems where that
39 is difficult to determine automatically.
41 enable => Enable specific configuration features.
42 This MUST be an array of words.
43 disable => Disable specific configuration features.
44 This MUST be an array of words.
45 Note: if the same feature is both enabled
46 and disabled, disable wins.
48 as => The assembler command. This is not always
49 used (for example on Unix, where the C
50 compiler is used instead).
51 asflags => Default assembler command flags [4].
52 cpp => The C preprocessor command, normally not
53 given, as the build file defaults are
55 cppflags => Default C preprocessor flags [4].
56 defines => As an alternative, macro definitions may be
57 given here instead of in `cppflags' [4].
58 If given here, they MUST be as an array of
59 the string such as "MACRO=value", or just
60 "MACRO" for definitions without value.
61 includes => As an alternative, inclusion directories
62 may be given here instead of in `cppflags'
63 [4]. If given here, the MUST be an array
64 of strings, one directory specification
66 cc => The C compiler command, usually one of "cc",
67 "gcc" or "clang". This command is normally
68 also used to link object files and
69 libraries into the final program.
70 cxx => The C++ compiler command, usually one of
71 "c++", "g++" or "clang++". This command is
72 also used when linking a program where at
73 least one of the object file is made from
75 cflags => Defaults C compiler flags [4].
76 cxxflags => Default C++ compiler flags [4]. If unset,
77 it gets the same value as cflags.
79 (linking is a complex thing, see [3] below)
80 ld => Linker command, usually not defined
81 (meaning the compiler command is used
83 (NOTE: this is here for future use, it's
85 lflags => Default flags used when linking apps,
86 shared libraries or DSOs [4].
87 ex_libs => Extra libraries that are needed when
88 linking shared libraries, DSOs or programs.
89 The value is also assigned to Libs.private
90 in $(libdir)/pkgconfig/libcrypto.pc.
92 shared_cppflags => Extra C preprocessor flags used when
93 processing C files for shared libraries.
94 shared_cflag => Extra C compiler flags used when compiling
95 for shared libraries, typically something
97 shared_ldflag => Extra linking flags used when linking
101 module_ldflags => Has the same function as the corresponding
102 `shared_' attributes, but for building DSOs.
103 When unset, they get the same values as the
104 corresponding `shared_' attributes.
106 ar => The library archive command, the default is
108 (NOTE: this is here for future use, it's
110 arflags => Flags to be used with the library archive
111 command. On Unix, this includes the
112 command letter, 'r' by default.
114 ranlib => The library archive indexing command, the
115 default is 'ranlib' it it exists.
117 unistd => An alternative header to the typical
118 '<unistd.h>'. This is very rarely needed.
120 shared_extension => File name extension used for shared
122 obj_extension => File name extension used for object files.
123 On unix, this defaults to ".o" (NOTE: this
124 is here for future use, it's not
126 exe_extension => File name extension used for executable
127 files. On unix, this defaults to "" (NOTE:
128 this is here for future use, it's not
130 shlib_variant => A "variant" identifier inserted between the base
131 shared library name and the extension. On "unixy"
132 platforms (BSD, Linux, Solaris, MacOS/X, ...) this
133 supports installation of custom OpenSSL libraries
134 that don't conflict with other builds of OpenSSL
135 installed on the system. The variant identifier
136 becomes part of the SONAME of the library and also
137 any symbol versions (symbol versions are not used or
138 needed with MacOS/X). For example, on a system
139 where a default build would normally create the SSL
140 shared library as 'libssl.so -> libssl.so.1.1' with
141 the value of the symlink as the SONAME, a target
142 definition that sets 'shlib_variant => "-abc"' will
143 create 'libssl.so -> libssl-abc.so.1.1', again with
144 an SONAME equal to the value of the symlink. The
145 symbol versions associated with the variant library
146 would then be 'OPENSSL_ABC_<version>' rather than
147 the default 'OPENSSL_<version>'. The string inserted
148 into symbol versions is obtained by mapping all
149 letters in the "variant" identifier to upper case
150 and all non-alphanumeric characters to '_'.
152 thread_scheme => The type of threads is used on the
153 configured platform. Currently known
154 values are "(unknown)", "pthreads",
155 "uithreads" (a.k.a solaris threads) and
156 "winthreads". Except for "(unknown)", the
157 actual value is currently ignored but may
158 be used in the future. See further notes
160 dso_scheme => The type of dynamic shared objects to build
161 for. This mostly comes into play with
162 modules, but can be used for other purposes
163 as well. Valid values are "DLFCN"
164 (dlopen() et al), "DLFCN_NO_H" (for systems
165 that use dlopen() et al but do not have
166 fcntl.h), "DL" (shl_load() et al), "WIN32"
168 asm_arch => The architecture to be used for compiling assembly
169 source. This acts as a selector in build.info files.
170 uplink_arch => The architecture to be used for compiling uplink
171 source. This acts as a selector in build.info files.
172 This is separate from asm_arch because it's compiled
173 even when 'no-asm' is given, even though it contains
175 perlasm_scheme => The perlasm method used to create the
176 assembler files used when compiling with
177 assembler implementations.
178 shared_target => The shared library building method used.
179 This serves multiple purposes:
180 - as index for targets found in shared_info.pl.
181 - as linker script generation selector.
182 To serve both purposes, the index for shared_info.pl
183 should end with '-shared', and this suffix will be
184 removed for use as a linker script generation
185 selector. Note that the latter is only used if
186 'shared_defflag' is defined.
187 build_scheme => The scheme used to build up a Makefile.
188 In its simplest form, the value is a string
189 with the name of the build scheme.
190 The value may also take the form of a list
191 of strings, if the build_scheme is to have
192 some options. In this case, the first
193 string in the list is the name of the build
195 Currently recognised build scheme is "unified".
196 For the "unified" build scheme, this item
197 *must* be an array with the first being the
198 word "unified" and the second being a word
199 to identify the platform family.
201 multilib => On systems that support having multiple
202 implementations of a library (typically a
203 32-bit and a 64-bit variant), this is used
204 to have the different variants in different
207 bn_ops => Building options (was just bignum options in
208 the earlier history of this option, hence the
209 name). This is a string of words that describe
210 algorithms' implementation parameters that
211 are optimal for the designated target platform,
212 such as the type of integers used to build up
213 the bignum, different ways to implement certain
214 ciphers and so on. To fully comprehend the
215 meaning, the best is to read the affected
219 THIRTY_TWO_BIT bignum limbs are 32 bits,
220 this is default if no
221 option is specified, it
222 works on any supported
223 system [unless "wider"
224 limb size is implied in
226 BN_LLONG bignum limbs are 32 bits,
227 but 64-bit 'unsigned long
228 long' is used internally
230 SIXTY_FOUR_BIT_LONG bignum limbs are 64 bits
231 and sizeof(long) is 8;
232 SIXTY_FOUR_BIT bignums limbs are 64 bits,
233 but execution environment
235 RC4_CHAR RC4 key schedule is made
236 up of 'unsigned char's;
237 RC4_INT RC4 key schedule is made
238 up of 'unsigned int's;
239 EXPORT_VAR_AS_FN for shared libraries,
244 [1] as part of the target configuration, one can have a key called
245 'inherit_from' that indicate what other configurations to inherit
246 data from. These are resolved recursively.
248 Inheritance works as a set of default values that can be overridden
249 by corresponding key values in the inheriting configuration.
251 Note 1: any configuration table can be used as a template.
252 Note 2: pure templates have the attribute 'template => 1' and
253 cannot be used as build targets.
255 If several configurations are given in the 'inherit_from' array,
256 the values of same attribute are concatenated with space
257 separation. With this, it's possible to have several smaller
258 templates for different configuration aspects that can be combined
259 into a complete configuration.
261 instead of a scalar value or an array, a value can be a code block
262 of the form 'sub { /* your code here */ }'. This code block will
263 be called with the list of inherited values for that key as
264 arguments. In fact, the concatenation of strings is really done
265 by using 'sub { join(" ",@_) }' on the list of inherited values.
273 ignored => "This should not appear in the end result",
282 inherit_from => [ "foo", "bar" ],
283 hehe => sub { join(" ",(@_,"!!!")) },
287 The entry for "laughter" will become as follows after processing:
296 [2] OpenSSL is built with threading capabilities unless the user
297 specifies 'no-threads'. The value of the key 'thread_scheme' may
298 be "(unknown)", in which case the user MUST give some compilation
301 [3] OpenSSL has three types of things to link from object files or
304 - shared libraries; that would be libcrypto and libssl.
305 - shared objects (sometimes called dynamic libraries); that would
307 - applications; those are apps/openssl and all the test apps.
309 Very roughly speaking, linking is done like this (words in braces
310 represent the configuration settings documented at the beginning
314 {ld} $(CFLAGS) {lflags} {shared_ldflag} -o libfoo.so \
315 foo/something.o foo/somethingelse.o {ex_libs}
318 {ld} $(CFLAGS) {lflags} {module_ldflags} -o libeng.so \
319 blah1.o blah2.o -lcrypto {ex_libs}
322 {ld} $(CFLAGS) {lflags} -o app \
323 app1.o utils.o -lssl -lcrypto {ex_libs}
325 [4] There are variants of these attribute, prefixed with `lib_',
326 `dso_' or `bin_'. Those variants replace the unprefixed attribute
327 when building library, DSO or program modules specifically.
329 Historically, the target configurations came in form of a string with
330 values separated by colons. This use is deprecated. The string form
333 "target" => "{cc}:{cflags}:{unistd}:{thread_cflag}:{sys_id}:{lflags}:{bn_ops}:{cpuid_obj}:{bn_obj}:{ec_obj}:{des_obj}:{aes_obj}:{bf_obj}:{md5_obj}:{sha1_obj}:{cast_obj}:{rc4_obj}:{rmd160_obj}:{rc5_obj}:{wp_obj}:{cmll_obj}:{modes_obj}:{padlock_obj}:{perlasm_scheme}:{dso_scheme}:{shared_target}:{shared_cflag}:{shared_ldflag}:{shared_extension}:{ranlib}:{arflags}:{multilib}"
339 The build.info files that are spread over the source tree contain the
340 minimum information needed to build and distribute OpenSSL. It uses a
341 simple and yet fairly powerful language to determine what needs to be
342 built, from what sources, and other relationships between files.
344 For every build.info file, all file references are relative to the
345 directory of the build.info file for source files, and the
346 corresponding build directory for built files if the build tree
347 differs from the source tree.
349 When processed, every line is processed with the perl module
350 Text::Template, using the delimiters "{-" and "-}". The hashes
351 %config and %target are passed to the perl fragments, along with
352 $sourcedir and $builddir, which are the locations of the source
353 directory for the current build.info file and the corresponding build
354 directory, all relative to the top of the build tree.
356 'Configure' only knows inherently about the top build.info file. For
357 any other directory that has one, further directories to look into
358 must be indicated like this:
360 SUBDIRS=something someelse
362 On to things to be built; they are declared by setting specific
370 Note that the files mentioned for PROGRAMS, LIBS and MODULES *must* be
371 without extensions. The build file templates will figure them out.
373 For each thing to be built, it is then possible to say what sources
377 SOURCE[foo]=foo.c common.c
378 SOURCE[bar]=bar.c extra.c common.c
380 It's also possible to tell some other dependencies:
382 DEPEND[foo]=libsomething
383 DEPEND[libbar]=libsomethingelse
385 (it could be argued that 'libsomething' and 'libsomethingelse' are
386 source as well. However, the files given through SOURCE are expected
387 to be located in the source tree while files given through DEPEND are
388 expected to be located in the build tree)
390 It's also possible to depend on static libraries explicitly:
392 DEPEND[foo]=libsomething.a
393 DEPEND[libbar]=libsomethingelse.a
395 This should be rarely used, and care should be taken to make sure it's
396 only used when supported. For example, native Windows build doesn't
397 support building static libraries and DLLs at the same time, so using
398 static libraries on Windows can only be done when configured
401 In some cases, it's desirable to include some source files in the
402 shared form of a library only:
404 SHARED_SOURCE[libfoo]=dllmain.c
406 For any file to be built, it's also possible to tell what extra
407 include paths the build of their source files should use:
411 It's also possible to specify C macros that should be defined:
413 DEFINE[foo]=FOO BAR=1
415 In some cases, one might want to generate some source files from
416 others, that's done as follows:
418 GENERATE[foo.s]=asm/something.pl $(CFLAGS)
419 GENERATE[bar.s]=asm/bar.S
421 The value of each GENERATE line is a command line or part of it.
422 Configure places no rules on the command line, except that the first
423 item must be the generator file. It is, however, entirely up to the
424 build file template to define exactly how those command lines should
425 be handled, how the output is captured and so on.
427 Sometimes, the generator file itself depends on other files, for
428 example if it is a perl script that depends on other perl modules.
429 This can be expressed using DEPEND like this:
431 DEPEND[asm/something.pl]=../perlasm/Foo.pm
433 There may also be cases where the exact file isn't easily specified,
434 but an inclusion directory still needs to be specified. INCLUDE can
435 be used in that case:
437 INCLUDE[asm/something.pl]=../perlasm
439 NOTE: GENERATE lines are limited to one command only per GENERATE.
441 Finally, you can have some simple conditional use of the build.info
442 information, looking like this:
452 The expression in square brackets is interpreted as a string in perl,
453 and will be seen as true if perl thinks it is, otherwise false. For
454 example, the above would have "something" used, since 1 is true.
456 Together with the use of Text::Template, this can be used as
457 conditions based on something in the passed variables, for example:
459 IF[{- $disabled{shared} -}]
461 SOURCE[libcrypto]=...
468 Build-file programming with the "unified" build system
469 ======================================================
471 "Build files" are called "Makefile" on Unix-like operating systems,
472 "descrip.mms" for MMS on VMS, "makefile" for nmake on Windows, etc.
474 To use the "unified" build system, the target configuration needs to
475 set the three items 'build_scheme', 'build_file' and 'build_command'.
476 In the rest of this section, we will assume that 'build_scheme' is set
477 to "unified" (see the configurations documentation above for the
480 For any name given by 'build_file', the "unified" system expects a
481 template file in Configurations/ named like the build file, with
482 ".tmpl" appended, or in case of possible ambiguity, a combination of
483 the second 'build_scheme' list item and the 'build_file' name. For
484 example, if 'build_file' is set to "Makefile", the template could be
485 Configurations/Makefile.tmpl or Configurations/unix-Makefile.tmpl.
486 In case both Configurations/unix-Makefile.tmpl and
487 Configurations/Makefile.tmpl are present, the former takes
490 The build-file template is processed with the perl module
491 Text::Template, using "{-" and "-}" as delimiters that enclose the
492 perl code fragments that generate configuration-dependent content.
493 Those perl fragments have access to all the hash variables from
496 The build-file template is expected to define at least the following
497 perl functions in a perl code fragment enclosed with "{-" and "-}".
498 They are all expected to return a string with the lines they produce.
500 generatesrc - function that produces build file lines to generate
501 a source file from some input.
503 It's called like this:
505 generatesrc(src => "PATH/TO/tobegenerated",
506 generator => [ "generatingfile", ... ]
507 generator_incs => [ "INCL/PATH", ... ]
508 generator_deps => [ "dep1", ... ]
509 generator => [ "generatingfile", ... ]
510 incs => [ "INCL/PATH", ... ],
511 deps => [ "dep1", ... ],
512 intent => one of "libs", "dso", "bin" );
514 'src' has the name of the file to be generated.
515 'generator' is the command or part of command to
516 generate the file, of which the first item is
517 expected to be the file to generate from.
518 generatesrc() is expected to analyse and figure out
519 exactly how to apply that file and how to capture
520 the result. 'generator_incs' and 'generator_deps'
521 are include directories and files that the generator
522 file itself depends on. 'incs' and 'deps' are
523 include directories and files that are used if $(CC)
524 is used as an intermediary step when generating the
525 end product (the file indicated by 'src'). 'intent'
526 indicates what the generated file is going to be
529 src2obj - function that produces build file lines to build an
530 object file from source files and associated data.
532 It's called like this:
534 src2obj(obj => "PATH/TO/objectfile",
535 srcs => [ "PATH/TO/sourcefile", ... ],
536 deps => [ "dep1", ... ],
537 incs => [ "INCL/PATH", ... ]
538 intent => one of "lib", "dso", "bin" );
540 'obj' has the intended object file with '.o'
541 extension, src2obj() is expected to change it to
542 something more suitable for the platform.
543 'srcs' has the list of source files to build the
544 object file, with the first item being the source
545 file that directly corresponds to the object file.
546 'deps' is a list of explicit dependencies. 'incs'
547 is a list of include file directories. Finally,
548 'intent' indicates what this object file is going
551 obj2lib - function that produces build file lines to build a
552 static library file ("libfoo.a" in Unix terms) from
557 obj2lib(lib => "PATH/TO/libfile",
558 objs => [ "PATH/TO/objectfile", ... ]);
560 'lib' has the intended library file name *without*
561 extension, obj2lib is expected to add that. 'objs'
562 has the list of object files to build this library.
564 libobj2shlib - backward compatibility function that's used the
565 same way as obj2shlib (described next), and was
566 expected to build the shared library from the
567 corresponding static library when that was suitable.
568 NOTE: building a shared library from a static
569 library is now DEPRECATED, as they no longer share
570 object files. Attempting to do this will fail.
572 obj2shlib - function that produces build file lines to build a
573 shareable object library file ("libfoo.so" in Unix
574 terms) from the corresponding object files.
578 obj2shlib(shlib => "PATH/TO/shlibfile",
579 lib => "PATH/TO/libfile",
580 objs => [ "PATH/TO/objectfile", ... ],
581 deps => [ "PATH/TO/otherlibfile", ... ]);
583 'lib' has the base (static) library ffile name
584 *without* extension. This is useful in case
585 supporting files are needed (such as import
586 libraries on Windows).
587 'shlib' has the corresponding shared library name
588 *without* extension. 'deps' has the list of other
589 libraries (also *without* extension) this library
590 needs to be linked with. 'objs' has the list of
591 object files to build this library.
593 obj2dso - function that produces build file lines to build a
594 dynamic shared object file from object files.
598 obj2dso(lib => "PATH/TO/libfile",
599 objs => [ "PATH/TO/objectfile", ... ],
600 deps => [ "PATH/TO/otherlibfile",
603 This is almost the same as obj2shlib, but the
604 intent is to build a shareable library that can be
605 loaded in runtime (a "plugin"...).
607 obj2bin - function that produces build file lines to build an
608 executable file from object files.
612 obj2bin(bin => "PATH/TO/binfile",
613 objs => [ "PATH/TO/objectfile", ... ],
614 deps => [ "PATH/TO/libfile", ... ]);
616 'bin' has the intended executable file name
617 *without* extension, obj2bin is expected to add
618 that. 'objs' has the list of object files to build
619 this library. 'deps' has the list of library files
620 (also *without* extension) that the programs needs
623 in2script - function that produces build file lines to build a
624 script file from some input.
628 in2script(script => "PATH/TO/scriptfile",
629 sources => [ "PATH/TO/infile", ... ]);
631 'script' has the intended script file name.
632 'sources' has the list of source files to build the
633 resulting script from.
635 In all cases, file file paths are relative to the build tree top, and
636 the build file actions run with the build tree top as current working
639 Make sure to end the section with these functions with a string that
640 you thing is appropriate for the resulting build file. If nothing
641 else, end it like this:
643 ""; # Make sure no lingering values end up in the Makefile
647 Configure helper scripts
648 ========================
650 Configure uses helper scripts in this directory:
655 These scripts are per platform family, to check the integrity of the
656 tools used for configuration and building. The checker script used is
657 either {build_platform}-{build_file}-checker.pm or
658 {build_platform}-checker.pm, where {build_platform} is the second
659 'build_scheme' list element from the configuration target data, and
660 {build_file} is 'build_file' from the same target data.
662 If the check succeeds, the script is expected to end with a non-zero
663 expression. If the check fails, the script can end with a zero, or