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Diffstat (limited to 'Configurations/README-design.md')
| -rw-r--r-- | Configurations/README-design.md | 218 |
1 files changed, 107 insertions, 111 deletions
diff --git a/Configurations/README-design.md b/Configurations/README-design.md index b79d0b2e49..ef21a3ae28 100644 --- a/Configurations/README-design.md +++ b/Configurations/README-design.md @@ -4,17 +4,17 @@ Design document for the unified scheme data How are things connected? ------------------------- -The unified scheme takes all its data from the build.info files seen +The unified scheme takes all its data from the `build.info` files seen throughout the source tree. These files hold the minimum information needed to build end product files from diverse sources. See the -section on build.info files below. +section on `build.info` files below. -From the information in build.info files, Configure builds up an -information database as a hash table called %unified_info, which is +From the information in `build.info` files, `Configure` builds up an +information database as a hash table called `%unified_info`, which is stored in configdata.pm, found at the top of the build tree (which may or may not be the same as the source tree). -Configurations/common.tmpl uses the data from %unified_info to +[`Configurations/common.tmpl`](common.tmpl) uses the data from `%unified_info` to generate the rules for building end product files as well as intermediary files with the help of a few functions found in the build-file templates. See the section on build-file templates further @@ -23,36 +23,35 @@ down for more information. build.info files ---------------- -As mentioned earlier, build.info files are meant to hold the minimum +As mentioned earlier, `build.info` files are meant to hold the minimum information needed to build output files, and therefore only (with a few possible exceptions [1]) have information about end products (such as scripts, library files and programs) and source files (such as C files, C header files, assembler files, etc). Intermediate files such -as object files are rarely directly referred to in build.info files (and -when they are, it's always with the file name extension .o), they are -inferred by Configure. By the same rule of minimalism, end product -file name extensions (such as .so, .a, .exe, etc) are never mentioned -in build.info. Their file name extensions will be inferred by the +as object files are rarely directly referred to in `build.info` files (and +when they are, it's always with the file name extension `.o`), they are +inferred by `Configure`. By the same rule of minimalism, end product +file name extensions (such as `.so`, `.a`, `.exe`, etc) are never mentioned +in `build.info`. Their file name extensions will be inferred by the build-file templates, adapted for the platform they are meant for (see -sections on %unified_info and build-file templates further down). +sections on `%unified_info` and build-file templates further down). -The variables PROGRAMS, LIBS, MODULES and SCRIPTS are used to declare -end products. There are variants for them with '_NO_INST' as suffix -(PROGRAM_NO_INST etc) to specify end products that shouldn't get -installed. +The variables `PROGRAMS`, `LIBS`, `MODULES` and `SCRIPTS` are used to declare +end products. There are variants for them with `_NO_INST` as suffix +(`PROGRAM_NO_INST` etc) to specify end products that shouldn't get installed. -The variables SOURCE, DEPEND, INCLUDE and DEFINE are indexed by a +The variables `SOURCE`, `DEPEND`, `INCLUDE` and `DEFINE` are indexed by a produced file, and their values are the source used to produce that particular produced file, extra dependencies, include directories needed, or C macros to be defined. -All their values in all the build.info throughout the source tree are +All their values in all the `build.info` throughout the source tree are collected together and form a set of programs, libraries, modules and scripts to be produced, source files, dependencies, etc etc etc. Let's have a pretend example, a very limited contraption of OpenSSL, -composed of the program 'apps/openssl', the libraries 'libssl' and -'libcrypto', an module 'engines/ossltest' and their sources and +composed of the program `apps/openssl`, the libraries `libssl` and +`libcrypto`, an module `engines/ossltest` and their sources and dependencies. # build.info @@ -61,11 +60,11 @@ dependencies. INCLUDE[libssl]=include DEPEND[libssl]=libcrypto -This is the top directory build.info file, and it tells us that two -libraries are to be built, the include directory 'include/' shall be +This is the top directory `build.info` file, and it tells us that two +libraries are to be built, the include directory `include/` shall be used throughout when building anything that will end up in each -library, and that the library 'libssl' depend on the library -'libcrypto' to function properly. +library, and that the library `libssl` depend on the library +`libcrypto` to function properly. # apps/build.info PROGRAMS=openssl @@ -73,15 +72,15 @@ library, and that the library 'libssl' depend on the library INCLUDE[openssl]=.. ../include DEPEND[openssl]=../libssl -This is the build.info file in 'apps/', one may notice that all file -paths mentioned are relative to the directory the build.info file is +This is the `build.info` file in `apps/`, one may notice that all file +paths mentioned are relative to the directory the `build.info` file is located in. This one tells us that there's a program to be built -called 'apps/openssl' (the file name extension will depend on the -platform and is therefore not mentioned in the build.info file). It's -built from one source file, 'apps/openssl.c', and building it requires -the use of '.' and 'include' include directories (both are declared -from the point of view of the 'apps/' directory), and that the program -depends on the library 'libssl' to function properly. +called `apps/openss` (the file name extension will depend on the +platform and is therefore not mentioned in the `build.info` file). It's +built from one source file, `apps/openssl.c`, and building it requires +the use of `.` and `include/` include directories (both are declared +from the point of view of the `apps/` directory), and that the program +depends on the library `libssl` to function properly. # crypto/build.info LIBS=../libcrypto @@ -92,32 +91,32 @@ depends on the library 'libssl' to function properly. DEPEND[buildinf.h]=../Makefile DEPEND[../util/mkbuildinf.pl]=../util/Foo.pm -This is the build.info file in 'crypto', and it tells us a little more -about what's needed to produce 'libcrypto'. LIBS is used again to -declare that 'libcrypto' is to be produced. This declaration is -really unnecessary as it's already mentioned in the top build.info +This is the `build.info` file in `crypto/`, and it tells us a little more +about what's needed to produce `libcrypto`. LIBS is used again to +declare that `libcrypto` is to be produced. This declaration is +really unnecessary as it's already mentioned in the top `build.info` file, but can make the info file easier to understand. This is to show that duplicate information isn't an issue. -This build.info file informs us that 'libcrypto' is built from a few -source files, 'crypto/aes.c', 'crypto/evp.c' and 'crypto/cversion.c'. +This `build.info` file informs us that `libcrypto` is built from a few +source files, `crypto/aes.c`, `crypto/evp.c` and `crypto/cversion.c`. It also shows us that building the object file inferred from -'crypto/cversion.c' depends on 'crypto/buildinf.h'. Finally, it +`crypto/cversion.c` depends on `crypto/buildinf.h`. Finally, it also shows the possibility to declare how some files are generated using some script, in this case a perl script, and how such scripts can be declared to depend on other files, in this case a perl module. Two things are worth an extra note: -'DEPEND[cversion.o]' mentions an object file. DEPEND indexes is the +`DEPEND[cversion.o]` mentions an object file. DEPEND indexes is the only location where it's valid to mention them # ssl/build.info LIBS=../libssl SOURCE[../libssl]=tls.c -This is the build.info file in 'ssl/', and it tells us that the -library 'libssl' is built from the source file 'ssl/tls.c'. +This is the build.info file in `ssl/`, and it tells us that the +library `libssl` is built from the source file `ssl/tls.c`. # engines/build.info MODULES=dasync @@ -130,17 +129,17 @@ library 'libssl' is built from the source file 'ssl/tls.c'. DEPEND[ossltest]=../libcrypto.a INCLUDE[ossltest]=../include -This is the build.info file in 'engines/', telling us that two modules -called 'engines/dasync' and 'engines/ossltest' shall be built, that -dasync's source is 'engines/e_dasync.c' and ossltest's source is -'engines/e_ossltest.c' and that the include directory 'include/' may +This is the `build.info` file in `engines/`, telling us that two modules +called `engines/dasync` and `engines/ossltest` shall be built, that +`dasync`'s source is `engines/e_dasync.c` and `ossltest`'s source is +`engines/e_ossltest.c` and that the include directory `include/` may be used when building anything that will be part of these modules. -Also, both modules depend on the library 'libcrypto' to function -properly. ossltest is explicitly linked with the static variant of -the library 'libcrypto'. Finally, only dasync is being installed, as -ossltest is only for internal testing. +Also, both modules depend on the library `libcrypto` to function +properly. `ossltest` is explicitly linked with the static variant of +the library `libcrypto`. Finally, only `dasync` is being installed, as +`ossltest` is only for internal testing. -When Configure digests these build.info files, the accumulated +When `Configure` digests these `build.info` files, the accumulated information comes down to this: LIBS=libcrypto libssl @@ -170,83 +169,81 @@ information comes down to this: DEPEND[crypto/buildinf.h]=Makefile DEPEND[util/mkbuildinf.pl]=util/Foo.pm - A few notes worth mentioning: -LIBS may be used to declare routine libraries only. +`LIBS` may be used to declare routine libraries only. -PROGRAMS may be used to declare programs only. +`PROGRAMS` may be used to declare programs only. -MODULES may be used to declare modules only. +`MODULES` may be used to declare modules only. -The indexes for SOURCE must only be end product files, such as -libraries, programs or modules. The values of SOURCE variables must +The indexes for `SOURCE` must only be end product files, such as +libraries, programs or modules. The values of `SOURCE` variables must only be source files (possibly generated). -INCLUDE and DEPEND shows a relationship between different files +`INCLUDE` and `DEPEND` shows a relationship between different files (usually produced files) or between files and directories, such as a program depending on a library, or between an object file and some extra source file. -When Configure processes the build.info files, it will take it as +When `Configure` processes the `build.info` files, it will take it as truth without question, and will therefore perform very few checks. If the build tree is separate from the source tree, it will assume that all built files and up in the build directory and that all source files are to be found in the source tree, if they can be found there. -Configure will assume that source files that can't be found in the -source tree (such as 'crypto/bildinf.h' in the example above) are +`Configure` will assume that source files that can't be found in the +source tree (such as `crypto/bildinf.h` in the example above) are generated and will be found in the build tree. +The `%unified_info` database +---------------------------- -The %unified_info database --------------------------- - -The information in all the build.info get digested by Configure and -collected into the %unified_info database, divided into the following +The information in all the `build.info` get digested by `Configure` and +collected into the `%unified_info` database, divided into the following indexes: - depends => a hash table containing 'file' => [ 'dependency' ... ] - pairs. These are directly inferred from the DEPEND - variables in build.info files. + depends => a hash table containing 'file' => [ 'dependency' ... ] + pairs. These are directly inferred from the DEPEND + variables in build.info files. - modules => a list of modules. These are directly inferred from - the MODULES variable in build.info files. + modules => a list of modules. These are directly inferred from + the MODULES variable in build.info files. - generate => a hash table containing 'file' => [ 'generator' ... ] - pairs. These are directly inferred from the GENERATE - variables in build.info files. + generate => a hash table containing 'file' => [ 'generator' ... ] + pairs. These are directly inferred from the GENERATE + variables in build.info files. - includes => a hash table containing 'file' => [ 'include' ... ] - pairs. These are directly inferred from the INCLUDE - variables in build.info files. + includes => a hash table containing 'file' => [ 'include' ... ] + pairs. These are directly inferred from the INCLUDE + variables in build.info files. - install => a hash table containing 'type' => [ 'file' ... ] pairs. - The types are 'programs', 'libraries', 'modules' and - 'scripts', and the array of files list the files of - that type that should be installed. + install => a hash table containing 'type' => [ 'file' ... ] pairs. + The types are 'programs', 'libraries', 'modules' and + 'scripts', and the array of files list the files of + that type that should be installed. - libraries => a list of libraries. These are directly inferred from - the LIBS variable in build.info files. + libraries => a list of libraries. These are directly inferred from + the LIBS variable in build.info files. - programs => a list of programs. These are directly inferred from - the PROGRAMS variable in build.info files. + programs => a list of programs. These are directly inferred from + the PROGRAMS variable in build.info files. - scripts => a list of scripts. There are directly inferred from - the SCRIPTS variable in build.info files. + scripts => a list of scripts. There are directly inferred from + the SCRIPTS variable in build.info files. - sources => a hash table containing 'file' => [ 'sourcefile' ... ] - pairs. These are indirectly inferred from the SOURCE - variables in build.info files. Object files are - mentioned in this hash table, with source files from - SOURCE variables, and AS source files for programs and - libraries. + sources => a hash table containing 'file' => [ 'sourcefile' ... ] + pairs. These are indirectly inferred from the SOURCE + variables in build.info files. Object files are + mentioned in this hash table, with source files from + SOURCE variables, and AS source files for programs and + libraries. - shared_sources => - a hash table just like 'sources', but only as source - files (object files) for building shared libraries. + shared_sources => + a hash table just like 'sources', but only as source + files (object files) for building shared libraries. -As an example, here is how the build.info files example from the -section above would be digested into a %unified_info table: +As an example, here is how the `build.info` files example from the +section above would be digested into a `%unified_info` table: our %unified_info = ( "depends" => @@ -399,20 +396,19 @@ section above would be digested into a %unified_info table: }, ); -As can be seen, everything in %unified_info is fairly simple suggest +As can be seen, everything in `%unified_info` is fairly simple suggest of information. Still, it tells us that to build all programs, we -must build 'apps/openssl', and to build the latter, we will need to -build all its sources ('apps/openssl.o' in this case) and all the -other things it depends on (such as 'libssl'). All those dependencies -need to be built as well, using the same logic, so to build 'libssl', -we need to build 'ssl/tls.o' as well as 'libcrypto', and to build the +must build `apps/openssl`, and to build the latter, we will need to +build all its sources (`apps/openssl.o` in this case) and all the +other things it depends on (such as `libssl`). All those dependencies +need to be built as well, using the same logic, so to build `libssl`, +we need to build `ssl/tls.o` as well as `libcrypto`, and to build the latter... - Build-file templates -------------------- -Build-file templates are essentially build-files (such as Makefile on +Build-file templates are essentially build-files (such as `Makefile` on Unix) with perl code fragments mixed in. Those perl code fragment will generate all the configuration dependent data, including all the rules needed to build end product files and intermediary files alike. @@ -461,7 +457,7 @@ etc. incs => [ "INCL/PATH", ... ] intent => one of "lib", "dso", "bin" ); - 'obj' has the intended object file with '.o' + 'obj' has the intended object file with `.o` extension, src2obj() is expected to change it to something more suitable for the platform. 'srcs' has the list of source files to build the @@ -557,13 +553,13 @@ etc. resulting script from. Along with the build-file templates is the driving template -Configurations/common.tmpl, which looks through all the information in -%unified_info and generates all the rulesets to build libraries, +[`Configurations/common.tmpl`](common.tmpl), which looks through all the +information in `%unified_info` and generates all the rulesets to build libraries, programs and all intermediate files, using the rule generating functions defined in the build-file template. -As an example with the smaller build.info set we've seen as an -example, producing the rules to build 'libcrypto' would result in the +As an example with the smaller `build.info` set we've seen as an +example, producing the rules to build `libcrypto` would result in the following calls: # Note: obj2shlib will only be called if shared libraries are |