1Intro 2===== 3 4This directory contains a few sets of files that are used for 5configuration in diverse ways: 6 7 *.conf Target platform configurations, please read 8 'Configurations of OpenSSL target platforms' for more 9 information. 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 15 information. 16 17Configurations of OpenSSL target platforms 18========================================== 19 20Configuration targets are a collection of facts that we know about 21different platforms and their capabilities. We organise them in a 22hash table, where each entry represent a specific target. 23 24Note that configuration target names must be unique across all config 25files. The Configure script does check that a config file doesn't 26have config targets that shadow config targets from other files. 27 28In each table entry, the following keys are significant: 29 30 inherit_from => Other targets to inherit values from. 31 Explained further below. [1] 32 template => Set to 1 if this isn't really a platform 33 target. Instead, this target is a template 34 upon which other targets can be built. 35 Explained further below. [1] 36 37 sys_id => System identity for systems where that 38 is difficult to determine automatically. 39 40 enable => Enable specific configuration features. 41 This MUST be an array of words. 42 disable => Disable specific configuration features. 43 This MUST be an array of words. 44 Note: if the same feature is both enabled 45 and disabled, disable wins. 46 47 as => The assembler command. This is not always 48 used (for example on Unix, where the C 49 compiler is used instead). 50 asflags => Default assembler command flags [4]. 51 cpp => The C preprocessor command, normally not 52 given, as the build file defaults are 53 usually good enough. 54 cppflags => Default C preprocessor flags [4]. 55 defines => As an alternative, macro definitions may be 56 given here instead of in 'cppflags' [4]. 57 If given here, they MUST be as an array of 58 the string such as "MACRO=value", or just 59 "MACRO" for definitions without value. 60 includes => As an alternative, inclusion directories 61 may be given here instead of in 'cppflags' 62 [4]. If given here, the MUST be an array 63 of strings, one directory specification 64 each. 65 cc => The C compiler command, usually one of "cc", 66 "gcc" or "clang". This command is normally 67 also used to link object files and 68 libraries into the final program. 69 cxx => The C++ compiler command, usually one of 70 "c++", "g++" or "clang++". This command is 71 also used when linking a program where at 72 least one of the object file is made from 73 C++ source. 74 cflags => Defaults C compiler flags [4]. 75 cxxflags => Default C++ compiler flags [4]. If unset, 76 it gets the same value as cflags. 77 78 (linking is a complex thing, see [3] below) 79 ld => Linker command, usually not defined 80 (meaning the compiler command is used 81 instead). 82 (NOTE: this is here for future use, it's 83 not implemented yet) 84 lflags => Default flags used when linking apps, 85 shared libraries or DSOs [4]. 86 ex_libs => Extra libraries that are needed when 87 linking shared libraries, DSOs or programs. 88 The value is also assigned to Libs.private 89 in $(libdir)/pkgconfig/libcrypto.pc. 90 91 shared_cppflags => Extra C preprocessor flags used when 92 processing C files for shared libraries. 93 shared_cflag => Extra C compiler flags used when compiling 94 for shared libraries, typically something 95 like "-fPIC". 96 shared_ldflag => Extra linking flags used when linking 97 shared libraries. 98 module_cppflags 99 module_cflags 100 module_ldflags => Has the same function as the corresponding 101 'shared_' attributes, but for building DSOs. 102 When unset, they get the same values as the 103 corresponding 'shared_' attributes. 104 105 ar => The library archive command, the default is 106 "ar". 107 (NOTE: this is here for future use, it's 108 not implemented yet) 109 arflags => Flags to be used with the library archive 110 command. On Unix, this includes the 111 command letter, 'r' by default. 112 113 ranlib => The library archive indexing command, the 114 default is 'ranlib' it it exists. 115 116 unistd => An alternative header to the typical 117 '<unistd.h>'. This is very rarely needed. 118 119 shared_extension => File name extension used for shared 120 libraries. 121 obj_extension => File name extension used for object files. 122 On unix, this defaults to ".o" (NOTE: this 123 is here for future use, it's not 124 implemented yet) 125 exe_extension => File name extension used for executable 126 files. On unix, this defaults to "" (NOTE: 127 this is here for future use, it's not 128 implemented yet) 129 shlib_variant => A "variant" identifier inserted between the base 130 shared library name and the extension. On "unixy" 131 platforms (BSD, Linux, Solaris, MacOS/X, ...) this 132 supports installation of custom OpenSSL libraries 133 that don't conflict with other builds of OpenSSL 134 installed on the system. The variant identifier 135 becomes part of the SONAME of the library and also 136 any symbol versions (symbol versions are not used or 137 needed with MacOS/X). For example, on a system 138 where a default build would normally create the SSL 139 shared library as 'libssl.so -> libssl.so.1.1' with 140 the value of the symlink as the SONAME, a target 141 definition that sets 'shlib_variant => "-abc"' will 142 create 'libssl.so -> libssl-abc.so.1.1', again with 143 an SONAME equal to the value of the symlink. The 144 symbol versions associated with the variant library 145 would then be 'OPENSSL_ABC_<version>' rather than 146 the default 'OPENSSL_<version>'. The string inserted 147 into symbol versions is obtained by mapping all 148 letters in the "variant" identifier to uppercase 149 and all non-alphanumeric characters to '_'. 150 151 thread_scheme => The type of threads is used on the 152 configured platform. Currently known 153 values are "(unknown)", "pthreads", 154 "uithreads" (a.k.a solaris threads) and 155 "winthreads". Except for "(unknown)", the 156 actual value is currently ignored but may 157 be used in the future. See further notes 158 below [2]. 159 dso_scheme => The type of dynamic shared objects to build 160 for. This mostly comes into play with 161 modules, but can be used for other purposes 162 as well. Valid values are "DLFCN" 163 (dlopen() et al), "DLFCN_NO_H" (for systems 164 that use dlopen() et al but do not have 165 fcntl.h), "DL" (shl_load() et al), "WIN32" 166 and "VMS". 167 asm_arch => The architecture to be used for compiling assembly 168 source. This acts as a selector in build.info files. 169 uplink_arch => The architecture to be used for compiling uplink 170 source. This acts as a selector in build.info files. 171 This is separate from asm_arch because it's compiled 172 even when 'no-asm' is given, even though it contains 173 assembler source. 174 perlasm_scheme => The perlasm method used to create the 175 assembler files used when compiling with 176 assembler implementations. 177 shared_target => The shared library building method used. 178 This serves multiple purposes: 179 - as index for targets found in shared_info.pl. 180 - as linker script generation selector. 181 To serve both purposes, the index for shared_info.pl 182 should end with '-shared', and this suffix will be 183 removed for use as a linker script generation 184 selector. Note that the latter is only used if 185 'shared_defflag' is defined. 186 build_scheme => The scheme used to build up a Makefile. 187 In its simplest form, the value is a string 188 with the name of the build scheme. 189 The value may also take the form of a list 190 of strings, if the build_scheme is to have 191 some options. In this case, the first 192 string in the list is the name of the build 193 scheme. 194 Currently recognised build scheme is "unified". 195 For the "unified" build scheme, this item 196 *must* be an array with the first being the 197 word "unified" and the second being a word 198 to identify the platform family. 199 200 multilib => On systems that support having multiple 201 implementations of a library (typically a 202 32-bit and a 64-bit variant), this is used 203 to have the different variants in different 204 directories. 205 206 multibin => On systems that support having multiple 207 implementations of a library and binaries 208 (typically a 32-bit and a 64-bit variant), 209 this is used to have the different variants 210 in different binary directories. This setting 211 works in conjunction with multilib. 212 213 bn_ops => Building options (was just bignum options in 214 the earlier history of this option, hence the 215 name). This is a string of words that describe 216 algorithms' implementation parameters that 217 are optimal for the designated target platform, 218 such as the type of integers used to build up 219 the bignum, different ways to implement certain 220 ciphers and so on. To fully comprehend the 221 meaning, the best is to read the affected 222 source. 223 The valid words are: 224 225 THIRTY_TWO_BIT bignum limbs are 32 bits, 226 this is default if no 227 option is specified, it 228 works on any supported 229 system [unless "wider" 230 limb size is implied in 231 assembly code]; 232 BN_LLONG bignum limbs are 32 bits, 233 but 64-bit 'unsigned long 234 long' is used internally 235 in calculations; 236 SIXTY_FOUR_BIT_LONG bignum limbs are 64 bits 237 and sizeof(long) is 8; 238 SIXTY_FOUR_BIT bignums limbs are 64 bits, 239 but execution environment 240 is ILP32; 241 RC4_CHAR RC4 key schedule is made 242 up of 'unsigned char's; 243 Note: should not be used 244 for new configuration 245 targets 246 RC4_INT RC4 key schedule is made 247 up of 'unsigned int's; 248 Note: should not be used 249 for new configuration 250 targets 251 252[1] as part of the target configuration, one can have a key called 253 `inherit_from` that indicates what other configurations to inherit 254 data from. These are resolved recursively. 255 256 Inheritance works as a set of default values that can be overridden 257 by corresponding key values in the inheriting configuration. 258 259 Note 1: any configuration table can be used as a template. 260 Note 2: pure templates have the attribute `template => 1` and 261 cannot be used as build targets. 262 263 If several configurations are given in the `inherit_from` array, 264 the values of same attribute are concatenated with space 265 separation. With this, it's possible to have several smaller 266 templates for different configuration aspects that can be combined 267 into a complete configuration. 268 269 Instead of a scalar value or an array, a value can be a code block 270 of the form `sub { /* your code here */ }`. This code block will 271 be called with the list of inherited values for that key as 272 arguments. In fact, the concatenation of strings is really done 273 by using `sub { join(" ",@_) }` on the list of inherited values. 274 275 An example: 276 277 "foo" => { 278 template => 1, 279 haha => "ha ha", 280 hoho => "ho", 281 ignored => "This should not appear in the end result", 282 }, 283 "bar" => { 284 template => 1, 285 haha => "ah", 286 hoho => "haho", 287 hehe => "hehe" 288 }, 289 "laughter" => { 290 inherit_from => [ "foo", "bar" ], 291 hehe => sub { join(" ",(@_,"!!!")) }, 292 ignored => "", 293 } 294 295 The entry for "laughter" will become as follows after processing: 296 297 "laughter" => { 298 haha => "ha ha ah", 299 hoho => "ho haho", 300 hehe => "hehe !!!", 301 ignored => "" 302 } 303 304[2] OpenSSL is built with threading capabilities unless the user 305 specifies `no-threads`. The value of the key `thread_scheme` may 306 be `(unknown)`, in which case the user MUST give some compilation 307 flags to `Configure`. 308 309[3] OpenSSL has three types of things to link from object files or 310 static libraries: 311 312 - shared libraries; that would be libcrypto and libssl. 313 - shared objects (sometimes called dynamic libraries); that would 314 be the modules. 315 - applications; those are apps/openssl and all the test apps. 316 317 Very roughly speaking, linking is done like this (words in braces 318 represent the configuration settings documented at the beginning 319 of this file): 320 321 shared libraries: 322 {ld} $(CFLAGS) {lflags} {shared_ldflag} -o libfoo.so \ 323 foo/something.o foo/somethingelse.o {ex_libs} 324 325 shared objects: 326 {ld} $(CFLAGS) {lflags} {module_ldflags} -o libeng.so \ 327 blah1.o blah2.o -lcrypto {ex_libs} 328 329 applications: 330 {ld} $(CFLAGS) {lflags} -o app \ 331 app1.o utils.o -lssl -lcrypto {ex_libs} 332 333[4] There are variants of these attribute, prefixed with `lib_`, 334 `dso_` or `bin_`. Those variants replace the unprefixed attribute 335 when building library, DSO or program modules specifically. 336 337Historically, the target configurations came in form of a string with 338values separated by colons. This use is deprecated. The string form 339looked like this: 340 341 "target" => "{cc}:{cflags}:{unistd}:{thread_cflag}:{sys_id}:{lflags}: 342 {bn_ops}:{cpuid_obj}:{bn_obj}:{ec_obj}:{des_obj}:{aes_obj}: 343 {bf_obj}:{md5_obj}:{sha1_obj}:{cast_obj}:{rc4_obj}: 344 {rmd160_obj}:{rc5_obj}:{wp_obj}:{cmll_obj}:{modes_obj}: 345 {padlock_obj}:{perlasm_scheme}:{dso_scheme}:{shared_target}: 346 {shared_cflag}:{shared_ldflag}:{shared_extension}:{ranlib}: 347 {arflags}:{multilib}" 348 349Build info files 350================ 351 352The `build.info` files that are spread over the source tree contain the 353minimum information needed to build and distribute OpenSSL. It uses a 354simple and yet fairly powerful language to determine what needs to be 355built, from what sources, and other relationships between files. 356 357For every `build.info` file, all file references are relative to the 358directory of the `build.info` file for source files, and the 359corresponding build directory for built files if the build tree 360differs from the source tree. 361 362When processed, every line is processed with the perl module 363Text::Template, using the delimiters `{-` and `-}`. The hashes 364`%config` and `%target` are passed to the perl fragments, along with 365$sourcedir and $builddir, which are the locations of the source 366directory for the current `build.info` file and the corresponding build 367directory, all relative to the top of the build tree. 368 369`Configure` only knows inherently about the top `build.info` file. For 370any other directory that has one, further directories to look into 371must be indicated like this: 372 373 SUBDIRS=something someelse 374 375On to things to be built; they are declared by setting specific 376variables: 377 378 PROGRAMS=foo bar 379 LIBS=libsomething 380 MODULES=libeng 381 SCRIPTS=myhack 382 383Note that the files mentioned for PROGRAMS, LIBS and MODULES *must* be 384without extensions. The build file templates will figure them out. 385 386For each thing to be built, it is then possible to say what sources 387they are built from: 388 389 PROGRAMS=foo bar 390 SOURCE[foo]=foo.c common.c 391 SOURCE[bar]=bar.c extra.c common.c 392 393It's also possible to tell some other dependencies: 394 395 DEPEND[foo]=libsomething 396 DEPEND[libbar]=libsomethingelse 397 398(it could be argued that 'libsomething' and 'libsomethingelse' are 399source as well. However, the files given through SOURCE are expected 400to be located in the source tree while files given through DEPEND are 401expected to be located in the build tree) 402 403It's also possible to depend on static libraries explicitly: 404 405 DEPEND[foo]=libsomething.a 406 DEPEND[libbar]=libsomethingelse.a 407 408This should be rarely used, and care should be taken to make sure it's 409only used when supported. For example, native Windows build doesn't 410support building static libraries and DLLs at the same time, so using 411static libraries on Windows can only be done when configured 412`no-shared`. 413 414In some cases, it's desirable to include some source files in the 415shared form of a library only: 416 417 SHARED_SOURCE[libfoo]=dllmain.c 418 419For any file to be built, it's also possible to tell what extra 420include paths the build of their source files should use: 421 422 INCLUDE[foo]=include 423 424It's also possible to specify C macros that should be defined: 425 426 DEFINE[foo]=FOO BAR=1 427 428In some cases, one might want to generate some source files from 429others, that's done as follows: 430 431 GENERATE[foo.s]=asm/something.pl $(CFLAGS) 432 GENERATE[bar.s]=asm/bar.S 433 434The value of each GENERATE line is a command line or part of it. 435Configure places no rules on the command line, except that the first 436item must be the generator file. It is, however, entirely up to the 437build file template to define exactly how those command lines should 438be handled, how the output is captured and so on. 439 440Sometimes, the generator file itself depends on other files, for 441example if it is a perl script that depends on other perl modules. 442This can be expressed using DEPEND like this: 443 444 DEPEND[asm/something.pl]=../perlasm/Foo.pm 445 446There may also be cases where the exact file isn't easily specified, 447but an inclusion directory still needs to be specified. INCLUDE can 448be used in that case: 449 450 INCLUDE[asm/something.pl]=../perlasm 451 452NOTE: GENERATE lines are limited to one command only per GENERATE. 453 454Finally, you can have some simple conditional use of the `build.info` 455information, looking like this: 456 457 IF[1] 458 something 459 ELSIF[2] 460 something other 461 ELSE 462 something else 463 ENDIF 464 465The expression in square brackets is interpreted as a string in perl, 466and will be seen as true if perl thinks it is, otherwise false. For 467example, the above would have "something" used, since 1 is true. 468 469Together with the use of Text::Template, this can be used as 470conditions based on something in the passed variables, for example: 471 472 IF[{- $disabled{shared} -}] 473 LIBS=libcrypto 474 SOURCE[libcrypto]=... 475 ELSE 476 LIBS=libfoo 477 SOURCE[libfoo]=... 478 ENDIF 479 480Build-file programming with the "unified" build system 481====================================================== 482 483"Build files" are called `Makefile` on Unix-like operating systems, 484`descrip.mms` for MMS on VMS, `makefile` for `nmake` on Windows, etc. 485 486To use the "unified" build system, the target configuration needs to 487set the three items `build_scheme`, `build_file` and `build_command`. 488In the rest of this section, we will assume that `build_scheme` is set 489to "unified" (see the configurations documentation above for the 490details). 491 492For any name given by `build_file`, the "unified" system expects a 493template file in `Configurations/` named like the build file, with 494`.tmpl` appended, or in case of possible ambiguity, a combination of 495the second `build_scheme` list item and the `build_file` name. For 496example, if `build_file` is set to `Makefile`, the template could be 497`Configurations/Makefile.tmpl` or `Configurations/unix-Makefile.tmpl`. 498In case both `Configurations/unix-Makefile.tmpl` and 499`Configurations/Makefile.tmpl` are present, the former takes precedence. 500 501The build-file template is processed with the perl module 502Text::Template, using `{-` and `-}` as delimiters that enclose the 503perl code fragments that generate configuration-dependent content. 504Those perl fragments have access to all the hash variables from 505configdata.pem. 506 507The build-file template is expected to define at least the following 508perl functions in a perl code fragment enclosed with `{-` and `-}`. 509They are all expected to return a string with the lines they produce. 510 511 generatesrc - function that produces build file lines to generate 512 a source file from some input. 513 514 It's called like this: 515 516 generatesrc(src => "PATH/TO/tobegenerated", 517 generator => [ "generatingfile", ... ] 518 generator_incs => [ "INCL/PATH", ... ] 519 generator_deps => [ "dep1", ... ] 520 generator => [ "generatingfile", ... ] 521 incs => [ "INCL/PATH", ... ], 522 deps => [ "dep1", ... ], 523 intent => one of "libs", "dso", "bin" ); 524 525 'src' has the name of the file to be generated. 526 'generator' is the command or part of command to 527 generate the file, of which the first item is 528 expected to be the file to generate from. 529 generatesrc() is expected to analyse and figure out 530 exactly how to apply that file and how to capture 531 the result. 'generator_incs' and 'generator_deps' 532 are include directories and files that the generator 533 file itself depends on. 'incs' and 'deps' are 534 include directories and files that are used if $(CC) 535 is used as an intermediary step when generating the 536 end product (the file indicated by 'src'). 'intent' 537 indicates what the generated file is going to be 538 used for. 539 540 src2obj - function that produces build file lines to build an 541 object file from source files and associated data. 542 543 It's called like this: 544 545 src2obj(obj => "PATH/TO/objectfile", 546 srcs => [ "PATH/TO/sourcefile", ... ], 547 deps => [ "dep1", ... ], 548 incs => [ "INCL/PATH", ... ] 549 intent => one of "lib", "dso", "bin" ); 550 551 'obj' has the intended object file with '.o' 552 extension, src2obj() is expected to change it to 553 something more suitable for the platform. 554 'srcs' has the list of source files to build the 555 object file, with the first item being the source 556 file that directly corresponds to the object file. 557 'deps' is a list of explicit dependencies. 'incs' 558 is a list of include file directories. Finally, 559 'intent' indicates what this object file is going 560 to be used for. 561 562 obj2lib - function that produces build file lines to build a 563 static library file ("libfoo.a" in Unix terms) from 564 object files. 565 566 called like this: 567 568 obj2lib(lib => "PATH/TO/libfile", 569 objs => [ "PATH/TO/objectfile", ... ]); 570 571 'lib' has the intended library filename *without* 572 extension, obj2lib is expected to add that. 'objs' 573 has the list of object files to build this library. 574 575 libobj2shlib - backward compatibility function that's used the 576 same way as obj2shlib (described next), and was 577 expected to build the shared library from the 578 corresponding static library when that was suitable. 579 NOTE: building a shared library from a static 580 library is now DEPRECATED, as they no longer share 581 object files. Attempting to do this will fail. 582 583 obj2shlib - function that produces build file lines to build a 584 shareable object library file ("libfoo.so" in Unix 585 terms) from the corresponding object files. 586 587 called like this: 588 589 obj2shlib(shlib => "PATH/TO/shlibfile", 590 lib => "PATH/TO/libfile", 591 objs => [ "PATH/TO/objectfile", ... ], 592 deps => [ "PATH/TO/otherlibfile", ... ]); 593 594 'lib' has the base (static) library filename 595 *without* extension. This is useful in case 596 supporting files are needed (such as import 597 libraries on Windows). 598 'shlib' has the corresponding shared library name 599 *without* extension. 'deps' has the list of other 600 libraries (also *without* extension) this library 601 needs to be linked with. 'objs' has the list of 602 object files to build this library. 603 604 obj2dso - function that produces build file lines to build a 605 dynamic shared object file from object files. 606 607 called like this: 608 609 obj2dso(lib => "PATH/TO/libfile", 610 objs => [ "PATH/TO/objectfile", ... ], 611 deps => [ "PATH/TO/otherlibfile", 612 ... ]); 613 614 This is almost the same as obj2shlib, but the 615 intent is to build a shareable library that can be 616 loaded in runtime (a "plugin"...). 617 618 obj2bin - function that produces build file lines to build an 619 executable file from object files. 620 621 called like this: 622 623 obj2bin(bin => "PATH/TO/binfile", 624 objs => [ "PATH/TO/objectfile", ... ], 625 deps => [ "PATH/TO/libfile", ... ]); 626 627 'bin' has the intended executable filename 628 *without* extension, obj2bin is expected to add 629 that. 'objs' has the list of object files to build 630 this library. 'deps' has the list of library files 631 (also *without* extension) that the programs needs 632 to be linked with. 633 634 in2script - function that produces build file lines to build a 635 script file from some input. 636 637 called like this: 638 639 in2script(script => "PATH/TO/scriptfile", 640 sources => [ "PATH/TO/infile", ... ]); 641 642 'script' has the intended script filename. 643 'sources' has the list of source files to build the 644 resulting script from. 645 646In all cases, file file paths are relative to the build tree top, and 647the build file actions run with the build tree top as current working 648directory. 649 650Make sure to end the section with these functions with a string that 651you thing is appropriate for the resulting build file. If nothing 652else, end it like this: 653 654 ""; # Make sure no lingering values end up in the Makefile 655 -} 656 657Configure helper scripts 658======================== 659 660Configure uses helper scripts in this directory: 661 662Checker scripts 663--------------- 664 665These scripts are per platform family, to check the integrity of the 666tools used for configuration and building. The checker script used is 667either `{build_platform}-{build_file}-checker.pm` or 668`{build_platform}-checker.pm`, where `{build_platform}` is the second 669`build_scheme` list element from the configuration target data, and 670`{build_file}` is `build_file` from the same target data. 671 672If the check succeeds, the script is expected to end with a non-zero 673expression. If the check fails, the script can end with a zero, or 674with a `die`. 675
