Configurations of OpenSSL target platforms
-------------------------------------------
+==========================================
Target configurations are a collection of facts that we know about
different platforms and their capabilities. We organise them in a
sys_id => System identity for systems where that
is difficult to determine automatically.
- cc => The compiler command, usually one of "cc",
+ cc => The C compiler command, usually one of "cc",
"gcc" or "clang". This command is normally
also used to link object files and
libraries into the final program.
+ cxx => The C++ compiler command, usually one of
+ "c++", "g++" or "clang++". This command is
+ also used when linking a program where at
+ least one of the object file is made from
+ C++ source.
cflags => Flags that are used at all times when
- compiling.
- debug_cflags => Extra compilation flags used when making a
- debug build (when Configure receives the
- --debug option). Typically something like
- "-g -O0".
- release_cflags => Extra compilation flags used when making a
- release build (when Configure receives the
- --release option, or doesn't receive the
- --debug option). Typically something like
- "-O" or "-O3".
- thread_cflags => Extra compilation flags used when
- compiling with threading enabled.
- Explained further below. [2]
+ compiling C object files.
+ cxxflags => Flags that are used at all times when
+ compiling C++ object files. If unset, it
+ gets the same value as cflags.
+ defines => As an alternative, macro definitions may be
+ present here instead of in `cflags'. If
+ given here, they MUST be as an array of the
+ string such as "MACRO=value", or just
+ "MACRO" for definitions without value.
shared_cflag => Extra compilation flags used when
compiling for shared libraries, typically
something like "-fPIC".
- ld => the linker command, usually not defined
+ (linking is a complex thing, see [3] below)
+ ld => Linker command, usually not defined
(meaning the compiler command is used
instead).
(NOTE: this is here for future use, it's
not implemented yet)
- lflags => the flags that are used at all times when
- linking. These can have a % sign in them
- showing where the OpenSSL libraries should
- appear, otherwise these flags will come
- last. So in a typical links situation,
- this is a quick table of results:
-
- "-foo%-bar" > -foo -lssl -lcrypto -bar
- "-foo%" > -foo -lssl -lcrypto
- "-foo" > -lssl -lcrypto -foo
-
- debug_lflags => Like debug_cflags, but used when linking.
- release_lflags => Like release_cflags, but used when linking.
- shared_lflags => Like shared_cflags, but used when linking.
+ lflags => Flags that are used when linking apps.
+ shared_ldflag => Flags that are used when linking shared
+ or dynamic libraries.
+ plib_lflags => Extra linking flags to appear just before
+ the libraries on the command line.
+ ex_libs => Extra libraries that are needed when
+ linking.
ar => The library archive command, the default is
"ar".
this is here for future use, it's not
implemented yet)
+ thread_scheme => The type of threads is used on the
+ configured platform. Currently known
+ values are "(unknown)", "pthreads",
+ "uithreads" (a.k.a solaris threads) and
+ "winthreads". Except for "(unknown)", the
+ actual value is currently ignored but may
+ be used in the future. See further notes
+ below [2].
dso_scheme => The type of dynamic shared objects to build
for. This mostly comes into play with
engines, but can be used for other purposes
some options. In this case, the first
string in the list is the name of the build
scheme.
- Currently recognised build schemes are
- "mk1mf" and "unixmake" and "unified".
+ Currently recognised build scheme is "unified".
For the "unified" build scheme, this item
*must* be an array with the first being the
word "unified" and the second being a word
export vars as
accessor functions.
+ apps_extra_src => Extra source to build apps/openssl, as
+ needed by the target.
cpuid_asm_src => assembler implementation of cpuid code as
well as OPENSSL_cleanse().
Default to mem_clr.c
'inherit_from' that indicate what other configurations to inherit
data from. These are resolved recursively.
- Inheritance works as a set of default values that can be overriden
+ Inheritance works as a set of default values that can be overridden
by corresponding key values in the inheriting configuration.
Note 1: any configuration table can be used as a template.
}
[2] OpenSSL is built with threading capabilities unless the user
- specifies 'no-threads'. The value of the key 'thread_cflags' may
+ specifies 'no-threads'. The value of the key 'thread_scheme' may
be "(unknown)", in which case the user MUST give some compilation
flags to Configure.
+[3] OpenSSL has three types of things to link from object files or
+ static libraries:
+
+ - shared libraries; that would be libcrypto and libssl.
+ - shared objects (sometimes called dynamic libraries); that would
+ be the engines.
+ - applications; those are apps/openssl and all the test apps.
+
+ Very roughly speaking, linking is done like this (words in braces
+ represent the configuration settings documented at the beginning
+ of this file):
+
+ shared libraries:
+ {ld} $(CFLAGS) {shared_ldflag} -shared -o libfoo.so \
+ -Wl,--whole-archive libfoo.a -Wl,--no-whole-archive \
+ {plib_lflags} -lcrypto {ex_libs}
+
+ shared objects:
+ {ld} $(CFLAGS) {shared_ldflag} -shared -o libeng.so \
+ blah1.o blah2.o {plib_lflags} -lcrypto {ex_libs}
+
+ applications:
+ {ld} $(CFLAGS) {lflags} -o app \
+ app1.o utils.o {plib_lflags} -lssl -lcrypto {ex_libs}
+
Historically, the target configurations came in form of a string with
values separated by colons. This use is deprecated. The string form
to be located in the source tree while files given through DEPEND are
expected to be located in the build tree)
+It's also possible to depend on static libraries explicitely:
+
+ DEPEND[foo]=libsomething.a
+ DEPEND[libbar]=libsomethingelse.a
+
+This should be rarely used, and care should be taken to make sure it's
+only used when supported. For example, native Windows build doesn't
+support build static libraries and DLLs at the same time, so using
+static libraries on Windows can only be done when configured
+'no-shared'.
+
For some libraries, we maintain files with public symbols and their
slot in a transfer vector (important on some platforms). It can be
declared like this:
"libbar" everywhere?), it does make sense when it can be used
conditionally. See a little further below for an example.
+In some cases, it's desirable to include some source files in the
+shared form of a library only:
+
+ SHARED_SOURCE[libfoo]=dllmain.c
+
For any file to be built, it's also possible to tell what extra
include paths the build of their source files should use:
INCLUDE[foo]=include
-It's possible to have raw build file lines, between BEGINRAW and
-ENDRAW lines as follows:
+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.
+
+Sometimes, the generator file itself depends on other files, for
+example if it is a perl script that depends on other perl modules.
+This can be expressed using DEPEND like this:
+
+ DEPEND[asm/something.pl]=../perlasm/Foo.pm
+
+There may also be cases where the exact file isn't easily specified,
+but an inclusion directory still needs to be specified. INCLUDE can
+be used in that case:
+
+ INCLUDE[asm/something.pl]=../perlasm
+
+NOTE: GENERATE lines are limited to one command only per GENERATE.
+
+As a last resort, it's possible to have raw build file lines, between
+BEGINRAW and ENDRAW lines as follows:
BEGINRAW[Makefile(unix)]
haha.h: {- $builddir -}/Makefile
echo "/* haha */" > haha.h
ENDRAW[Makefile(unix)]
-The word withing square brackets is the build_file configuration item
+The word within square brackets is the build_file configuration item
or the build_file configuration item followed by the second word in the
build_scheme configuration item for the configured target within
parenthesis as shown above. For example, with the following relevant
build hoho.h: echo "/* hoho */" > hoho.h
ENDRAW[build.ninja(unix)]
+Should it be needed because the recipes within a RAW section might
+clash with those generated by Configure, it's possible to tell it
+not to generate them with the use of OVERRIDES, for example:
+
+ SOURCE[libfoo]=foo.c bar.c
+
+ OVERRIDES=bar.o
+ BEGINRAW[Makefile(unix)]
+ bar.o: bar.c
+ $(CC) $(CFLAGS) -DSPECIAL -c -o $@ $<
+ ENDRAW[Makefile(unix)]
+
See the documentation further up for more information on configuration
items.
Together with the use of Text::Template, this can be used as
conditions based on something in the passed variables, for example:
- IF[{- $config{no_shared} -}]
+ IF[{- $disabled{shared} -}]
LIBS=libcrypto
SOURCE[libcrypto]=...
ELSE
RENAME[libcrypto]=ossl_libcrypto
RENAME[libssl]=ossl_libssl
ENDIF
+
+
+Build-file programming with the "unified" build system
+======================================================
+
+"Build files" are called "Makefile" on Unix-like operating systems,
+"descrip.mms" for MMS on VMS, "makefile" for nmake on Windows, etc.
+
+To use the "unified" build system, the target configuration needs to
+set the three items 'build_scheme', 'build_file' and 'build_command'.
+In the rest of this section, we will assume that 'build_scheme' is set
+to "unified" (see the configurations documentation above for the
+details).
+
+For any name given by 'build_file', the "unified" system expects a
+template file in Configurations/ named like the build file, with
+".tmpl" appended, or in case of possible ambiguity, a combination of
+the second 'build_scheme' list item and the 'build_file' name. For
+example, if 'build_file' is set to "Makefile", the template could be
+Configurations/Makefile.tmpl or Configurations/unix-Makefile.tmpl.
+In case both Configurations/unix-Makefile.tmpl and
+Configurations/Makefile.tmpl are present, the former takes
+precedence.
+
+The build-file template is processed with the perl module
+Text::Template, using "{-" and "-}" as delimiters that enclose the
+perl code fragments that generate configuration-dependent content.
+Those perl fragments have access to all the hash variables from
+configdata.pem.
+
+The build-file template is expected to define at least the following
+perl functions in a perl code fragment enclosed with "{-" and "-}".
+They are all expected to return a string with the lines they produce.
+
+ generatesrc - function that produces build file lines to generate
+ a source file from some input.
+
+ It's called like this:
+
+ generatesrc(src => "PATH/TO/tobegenerated",
+ generator => [ "generatingfile", ... ]
+ generator_incs => [ "INCL/PATH", ... ]
+ generator_deps => [ "dep1", ... ]
+ generator => [ "generatingfile", ... ]
+ incs => [ "INCL/PATH", ... ],
+ deps => [ "dep1", ... ],
+ intent => one of "libs", "dso", "bin" );
+
+ 'src' has the name of the file to be generated.
+ 'generator' is the command or part of command to
+ generate the file, of which the first item is
+ expected to be the file to generate from.
+ generatesrc() is expected to analyse and figure out
+ exactly how to apply that file and how to capture
+ the result. 'generator_incs' and 'generator_deps'
+ are include directories and files that the generator
+ file itself depends on. 'incs' and 'deps' are
+ include directories and files that are used if $(CC)
+ is used as an intermediary step when generating the
+ end product (the file indicated by 'src'). 'intent'
+ indicates what the generated file is going to be
+ used for.
+
+ 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/libeay.num or util/ssleay.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.
+
+ obj2dso - function that produces build file lines to build a
+ dynamic shared object file from object files.
+
+ called like this:
+
+ obj2dso(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.
+
+In all cases, file file paths are relative to the build tree top, and
+the build file actions run with the build tree top as current working
+directory.
+
+Make sure to end the section with these functions with a string that
+you thing is appropriate for the resulting build file. If nothing
+else, end it like this:
+
+ ""; # Make sure no lingering values end up in the Makefile
+ -}
projects / openssl.git / blobdiff