mirror of
https://github.com/openssl/openssl.git
synced 2024-11-27 05:21:51 +08:00
ae4c745075
In some cases, one might want to generate some source files from
others, that's done as follows:
GENERATE[foo.s]=asm/something.pl $(CFLAGS)
GENERATE[bar.s]=asm/bar.S
The value of each GENERATE line is a command line or part of it.
Configure places no rules on the command line, except the the first
item muct be the generator file. It is, however, entirely up to the
build file template to define exactly how those command lines should
be handled, how the output is captured and so on.
Reviewed-by: Rich Salz <rsalz@openssl.org>
530 lines
21 KiB
Plaintext
530 lines
21 KiB
Plaintext
Design document for the unified scheme data
|
|
===========================================
|
|
|
|
How are things connected?
|
|
-------------------------
|
|
|
|
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.
|
|
|
|
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
|
|
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
|
|
down for more information.
|
|
|
|
build.info files
|
|
----------------
|
|
|
|
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
|
|
build-file templates, adapted for the platform they are meant for (see
|
|
sections on %unified_info and build-file templates further down).
|
|
|
|
The variables PROGRAMS, LIBS, ENGINES and SCRIPTS are used to declare
|
|
end products.
|
|
|
|
The variables SOURCE, DEPEND, INCLUDE and ORDINALS are indexed by a
|
|
produced file, and their values are the source used to produce that
|
|
particular produced file, extra dependencies, include directories
|
|
needed, and ordinal files (explained further below.
|
|
|
|
All their values in all the build.info throughout the source tree are
|
|
collected together and form a set of programs, libraries, engines 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 engine 'engines/ossltest' and their sources and
|
|
dependencies.
|
|
|
|
# build.info
|
|
LIBS=libcrypto libssl
|
|
ORDINALS[libcrypto]=crypto
|
|
ORDINALS[libssl]=ssl
|
|
INCLUDE[libcrypto]=include
|
|
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, there are some ordinals to be used to
|
|
declare what symbols in those libraries are seen as public, 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.
|
|
|
|
# apps/build.info
|
|
PROGRAMS=openssl
|
|
SOURCE[openssl]=openssl.c
|
|
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
|
|
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.
|
|
|
|
# crypto/build.info
|
|
LIBS=../libcrypto
|
|
SOURCE[../libcrypto]=aes.c evp.c cversion.c
|
|
DEPEND[cversion.o]=buildinf.h
|
|
|
|
GENERATE[buildinf.h]=../util/mkbuildinf.pl "$(CC) $(CFLAGS)" "$(PLATFORM)"
|
|
DEPEND[buildinf.h]=../Makefile
|
|
|
|
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'.
|
|
It also shows us that building the object file inferred from
|
|
'crypto/cversion.c' depends on 'crypto/buildinf.h'. Finally, it
|
|
also shows the possibility to include raw build-file statements in a
|
|
build.info file, in this case showing how 'buildinf.h' is built on
|
|
Unix-like operating systems.
|
|
|
|
Two things are worth an extra note:
|
|
|
|
'DEPEND[cversion.o]' mentions an object file. DEPEND indexes is the
|
|
only location where it's valid to mention them
|
|
|
|
Lines in 'BEGINRAW'..'ENDRAW' sections must always mention files as
|
|
seen from the top directory, no exception.
|
|
|
|
# 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'.
|
|
|
|
# engines/build.info
|
|
ENGINES=libossltest
|
|
SOURCE[libossltest]=e_ossltest.c
|
|
DEPEND[libossltest]=../libcrypto
|
|
INCLUDE[libossltest]=../include
|
|
|
|
This is the build.info file in 'engines/', telling us that an engine
|
|
called 'engines/libossltest' shall be built, that it's source is
|
|
'engines/e_ossltest.c' and that the include directory 'include/' may
|
|
be used when building anything that will be part of this engine.
|
|
Finally, the engine 'engines/libossltest' depends on the library
|
|
'libcrypto' to function properly.
|
|
|
|
When Configure digests these build.info files, the accumulated
|
|
information comes down to this:
|
|
|
|
LIBS=libcrypto libssl
|
|
ORDINALS[libcrypto]=crypto
|
|
SOURCE[libcrypto]=crypto/aes.c crypto/evp.c crypto/cversion.c
|
|
DEPEND[crypto/cversion.o]=crypto/buildinf.h
|
|
INCLUDE[libcrypto]=include
|
|
ORDINALS[libssl]=ssl
|
|
SOURCE[libssl]=ssl/tls.c
|
|
INCLUDE[libssl]=include
|
|
DEPEND[libssl]=libcrypto
|
|
|
|
PROGRAMS=apps/openssl
|
|
SOURCE[apps/openssl]=apps/openssl.c
|
|
INCLUDE[apps/openssl]=. include
|
|
DEPEND[apps/openssl]=libssl
|
|
|
|
ENGINES=engines/libossltest
|
|
SOURCE[engines/libossltest]=engines/e_ossltest.c
|
|
DEPEND[engines/libossltest]=libcrypto
|
|
INCLUDE[engines/libossltest]=include
|
|
|
|
GENERATE[crypto/buildinf.h]=util/mkbuildinf.pl "$(CC) $(CFLAGS)" "$(PLATFORM)"
|
|
DEPEND[crypto/buildinf.h]=Makefile
|
|
|
|
|
|
A few notes worth mentioning:
|
|
|
|
LIBS may be used to declare routine libraries only.
|
|
|
|
PROGRAMS may be used to declare programs only.
|
|
|
|
ENGINES may be used to declare engines only.
|
|
|
|
The indexes for SOURCE, INCLUDE and ORDINALS must only be end product
|
|
files, such as libraries, programs or engines. The values of SOURCE
|
|
variables must only be source files (possibly generated)
|
|
|
|
DEPEND shows a relationship between different produced files, 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
|
|
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
|
|
generated and will be found in the build tree.
|
|
|
|
|
|
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
|
|
indexes:
|
|
|
|
depends => a hash table containing 'file' => [ 'dependency' ... ]
|
|
pairs. These are directly inferred from the DEPEND
|
|
variables in build.info files.
|
|
|
|
engines => a list of engines. These are directly inferred from
|
|
the ENGINES variable in build.info files.
|
|
|
|
includes => a hash table containing 'file' => [ 'include' ... ]
|
|
pairs. These are directly inferred from the INCLUDE
|
|
variables in build.info files.
|
|
|
|
libraries => a list of libraries. These are directly inferred from
|
|
the LIBS variable in build.info files.
|
|
|
|
ordinals => a hash table containing 'file' => [ 'word', 'ordfile' ]
|
|
pairs. 'file' and 'word' are directly inferred from
|
|
the ORDINALS variables in build.info files, while the
|
|
file 'ofile' comes from internal knowledge in
|
|
Configure.
|
|
|
|
programs => a list of programs. These are directly inferred from
|
|
the PROGRAMS variable in build.info files.
|
|
|
|
rawlines => a list of build-file lines. These are a direct copy of
|
|
the BEGINRAW..ENDRAW lines in build.info files. Note:
|
|
only the BEGINRAW..ENDRAW section for the current
|
|
platform are copied, the rest are ignored.
|
|
|
|
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.
|
|
|
|
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" =>
|
|
{
|
|
"apps/openssl" =>
|
|
[
|
|
"libssl",
|
|
],
|
|
"crypto/cversion.o" =>
|
|
[
|
|
"crypto/buildinf.h",
|
|
],
|
|
"engines/libossltest" =>
|
|
[
|
|
"libcrypto",
|
|
],
|
|
"libssl" =>
|
|
[
|
|
"libcrypto",
|
|
],
|
|
},
|
|
"engines" =>
|
|
[
|
|
"engines/libossltest",
|
|
],
|
|
"includes" =>
|
|
{
|
|
"apps/openssl" =>
|
|
[
|
|
".",
|
|
"include",
|
|
],
|
|
"engines/libossltest" =>
|
|
[
|
|
"include"
|
|
],
|
|
"libcrypto" =>
|
|
[
|
|
"include",
|
|
],
|
|
"libssl" =>
|
|
[
|
|
"include",
|
|
],
|
|
}
|
|
"libraries" =>
|
|
[
|
|
"libcrypto",
|
|
"libssl",
|
|
],
|
|
"ordinals" =>
|
|
{
|
|
"libcrypto" =>
|
|
[
|
|
"crypto",
|
|
"util/libcrypto.num",
|
|
],
|
|
"libssl" =>
|
|
[
|
|
"ssl",
|
|
"util/libssl.num",
|
|
],
|
|
},
|
|
"programs" =>
|
|
[
|
|
"apps/openssl",
|
|
],
|
|
"rawlines" =>
|
|
[
|
|
"crypto/buildinf.h : Makefile",
|
|
" perl util/mkbuildinf.h \"\$(CC) \$(CFLAGS)\" \"\$(PLATFORM)\" \\"
|
|
" > crypto/buildinf.h"
|
|
],
|
|
"sources" =>
|
|
{
|
|
"apps/openssl" =>
|
|
[
|
|
"apps/openssl.o",
|
|
],
|
|
"apps/openssl.o" =>
|
|
[
|
|
"apps/openssl.c",
|
|
],
|
|
"crypto/aes.o" =>
|
|
[
|
|
"crypto/aes.c",
|
|
],
|
|
"crypto/cversion.o" =>
|
|
[
|
|
"crypto/cversion.c",
|
|
],
|
|
"crypto/evp.o" =>
|
|
[
|
|
"crypto/evp.c",
|
|
],
|
|
"engines/e_ossltest.o" =>
|
|
[
|
|
"engines/e_ossltest.c",
|
|
],
|
|
"engines/libossltest" =>
|
|
[
|
|
"engines/e_ossltest.o",
|
|
],
|
|
"libcrypto" =>
|
|
[
|
|
"crypto/aes.c",
|
|
"crypto/cversion.c",
|
|
"crypto/evp.c",
|
|
],
|
|
"libssl" =>
|
|
[
|
|
"ssl/tls.c",
|
|
],
|
|
"ssl/tls.o" =>
|
|
[
|
|
"ssl/tls.c",
|
|
],
|
|
},
|
|
);
|
|
|
|
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
|
|
latter...
|
|
|
|
|
|
Build-file templates
|
|
--------------------
|
|
|
|
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.
|
|
At a minimum, there must be a perl code fragment that defines a set of
|
|
functions that are used to generates specific build-file rules, to
|
|
build static libraries from object files, to build shared libraries
|
|
from static libraries, to programs from object files and libraries,
|
|
etc.
|
|
|
|
src2obj - function that produces build file lines to build an
|
|
object file from source files and associated data.
|
|
|
|
It's called like this:
|
|
|
|
src2obj(obj => "PATH/TO/objectfile",
|
|
srcs => [ "PATH/TO/sourcefile", ... ],
|
|
deps => [ "dep1", ... ],
|
|
incs => [ "INCL/PATH", ... ]
|
|
intent => one of "lib", "dso", "bin" );
|
|
|
|
'obj' has the intended object file *without*
|
|
extension, src2obj() is expected to add that.
|
|
'srcs' has the list of source files to build the
|
|
object file, with the first item being the source
|
|
file that directly corresponds to the object file.
|
|
'deps' is a list of explicit dependencies. 'incs'
|
|
is a list of include file directories. Finally,
|
|
'intent' indicates what this object file is going
|
|
to be used for.
|
|
|
|
obj2lib - function that produces build file lines to build a
|
|
static library file ("libfoo.a" in Unix terms) from
|
|
object files.
|
|
|
|
called like this:
|
|
|
|
obj2lib(lib => "PATH/TO/libfile",
|
|
objs => [ "PATH/TO/objectfile", ... ]);
|
|
|
|
'lib' has the intended library file name *without*
|
|
extension, obj2lib is expected to add that. 'objs'
|
|
has the list of object files (also *without*
|
|
extension) to build this library.
|
|
|
|
libobj2shlib - function that produces build file lines to build a
|
|
shareable object library file ("libfoo.so" in Unix
|
|
terms) from the corresponding static library file
|
|
or object files.
|
|
|
|
called like this:
|
|
|
|
libobj2shlib(shlib => "PATH/TO/shlibfile",
|
|
lib => "PATH/TO/libfile",
|
|
objs => [ "PATH/TO/objectfile", ... ],
|
|
deps => [ "PATH/TO/otherlibfile", ... ],
|
|
ordinals => [ "word", "/PATH/TO/ordfile" ]);
|
|
|
|
'lib' has the intended library file name *without*
|
|
extension, libobj2shlib is expected to add that.
|
|
'shlib' has the corresponding shared library name
|
|
*without* extension. 'deps' has the list of other
|
|
libraries (also *without* extension) this library
|
|
needs to be linked with. 'objs' has the list of
|
|
object files (also *without* extension) to build
|
|
this library. 'ordinals' MAY be present, and when
|
|
it is, its value is an array where the word is
|
|
"crypto" or "ssl" and the file is one of the ordinal
|
|
files util/libcrypto.num or util/libssl.num in the
|
|
source directory.
|
|
|
|
This function has a choice; it can use the
|
|
corresponding static library as input to make the
|
|
shared library, or the list of object files.
|
|
|
|
obj2dynlib - function that produces build file lines to build a
|
|
dynamically loadable library file ("libfoo.so" on
|
|
Unix) from object files.
|
|
|
|
called like this:
|
|
|
|
obj2dynlib(lib => "PATH/TO/libfile",
|
|
objs => [ "PATH/TO/objectfile", ... ],
|
|
deps => [ "PATH/TO/otherlibfile",
|
|
... ]);
|
|
|
|
This is almost the same as libobj2shlib, but the
|
|
intent is to build a shareable library that can be
|
|
loaded in runtime (a "plugin"...). The differences
|
|
are subtle, one of the most visible ones is that the
|
|
resulting shareable library is produced from object
|
|
files only.
|
|
|
|
obj2bin - function that produces build file lines to build an
|
|
executable file from object files.
|
|
|
|
called like this:
|
|
|
|
obj2bin(bin => "PATH/TO/binfile",
|
|
objs => [ "PATH/TO/objectfile", ... ],
|
|
deps => [ "PATH/TO/libfile", ... ]);
|
|
|
|
'bin' has the intended executable file name
|
|
*without* extension, obj2bin is expected to add
|
|
that. 'objs' has the list of object files (also
|
|
*without* extension) to build this library. 'deps'
|
|
has the list of library files (also *without*
|
|
extension) that the programs needs to be linked
|
|
with.
|
|
|
|
in2script - function that produces build file lines to build a
|
|
script file from some input.
|
|
|
|
called like this:
|
|
|
|
in2script(script => "PATH/TO/scriptfile",
|
|
sources => [ "PATH/TO/infile", ... ]);
|
|
|
|
'script' has the intended script file name.
|
|
'sources' has the list of source files to build the
|
|
resulting script from.
|
|
|
|
Along with the build-file templates is the driving engine
|
|
Configurations/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 'libssl' would result in the
|
|
following calls:
|
|
|
|
# Note: libobj2shlib will only be called if shared libraries are
|
|
# to be produced.
|
|
# Note 2: libobj2shlib gets both the name of the static library
|
|
# and the names of all the object files that go into it. It's up
|
|
# to the implementation to decide which to use as input.
|
|
libobj2shlib(shlib => "libssl",
|
|
lib => "libssl",
|
|
objs => [ "ssl/tls.o" ],
|
|
deps => [ "libcrypto" ]
|
|
ordinals => [ "ssl", "util/libssl.num" ]);
|
|
|
|
obj2lib(lib => "libssl"
|
|
objs => [ "ssl/tls.o" ]);
|
|
|
|
# Note 3: common.tmpl peals off the ".o" extension, as the
|
|
# platform at hand may have a different one.
|
|
src2obj(obj => "ssl/tls"
|
|
srcs => [ "ssl/tls.c" ],
|
|
deps => [ ],
|
|
incs => [ "include" ]);
|
|
|
|
src2dep(obj => "ssl/tls"
|
|
srcs => [ "ssl/tls.c" ],
|
|
incs => [ "include" ]);
|
|
|
|
The returned strings from all those calls are then concatenated
|
|
together and written to the resulting build-file.
|