Reference - 1.57.0
General information
Initialization
Immediately upon starting, the Boost.Build engine (b2)
loads the Jam code that implements the build system. To do this, it searches for a file
called boost-build.jam, first in the invocation directory, then
in its parent and so forth up to the filesystem root, and finally
in the directories specified by the environment variable
BOOST_BUILD_PATH. When found, the file is interpreted, and should
specify the build system location by calling the boost-build
rule boost-build ( location ? )
If location is a relative path, it is treated as relative to
the directory of boost-build.jam. The directory specified by
that location and the directories in BOOST_BUILD_PATH are then searched for
a file called bootstrap.jam, which is expected to
bootstrap the build system. This arrangement allows the build
system to work without any command-line or environment variable
settings. For example, if the build system files were located in a
directory "build-system/" at your project root, you might place a
boost-build.jam at the project root containing:
boost-build build-
In this case, running b2 anywhere in the project tree will
automatically find the build system.
The default bootstrap.jam, after loading some standard
definitions, loads two site-config.jam and user-config.jam.
Builtin rules
This section contains the list of all rules that
can be used in Jamfile—both rules that define new
targets and auxiliary rules.
Creates an executable file. See
Creates an library file. See
Installs built targets and other files. See
Creates an alias for other targets. See
Creates an executable that will be automatically run. See
compile, compile-fail, link, link-fail, run, run-fail
Specialized rules for testing. See
check-target-builds
The check-target-builds allows you
to conditionally use different properties depending on whether some
metatarget builds, or not. This is similar to functionality of configure
script in autotools projects. The function signature is:
rule check-target-builds ( target message ? : true-properties * : false-properties * )
This function can only be used when passing requirements or usage
requirements to a metatarget rule. For example, to make an application link
to a library if it's avavailable, one has use the following:
exe app : app.cpp : [ check-target-builds has_foo "System has foo" : &library&foo : &define&FOO_MISSING=1 ] ;
For another example, the alias rule can be used to consolidate configuraiton
choices and make them available to other metatargets, like so:
alias foobar : : : : [ check-target-builds has_foo "System has foo" : &library&foo : &library&bar ] ;
Creates an object file. Useful when a single source
file must be compiled with special properties.
preprocessed
Creates an preprocessed source file. The arguments follow the
The glob rule takes a list shell pattern
and returns the list of files in the project's source directory that
match the pattern. For example:
lib tools : [ glob *.cpp ] ;
It is possible to also pass a second argument—the list of
exclude patterns. The result will then include the list of
files patching any of include patterns, and not matching any
of the exclude patterns. For example:
lib tools : [ glob *.cpp : file_to_exclude.cpp bad*.cpp ] ;
The glob-tree is similar to the
glob except that it operates recursively from
the directory of the containing Jamfile. For example:
ECHO [ glob-tree *.cpp : .svn ] ;
will print the names of all C++ files in your project. The
.svn exclude pattern prevents the
glob-tree rule from entering administrative
directories of the Subversion version control system.
Declares project id and attributes, including
project requirements. See .
use-project
Assigns a symbolic project ID to a project at
a given path. This rule must be better documented!
The explicit rule takes a single
parameter—a list of target names. The named targets will
be marked explicit, and will be built only if they are explicitly
requested on the command line, or if their dependents are built.
Compare this to ordinary targets, that are built implicitly when
their containing project is built.
The always funciton takes a single
parameter—a list of metatarget names. The top-level targets produced
by the named metatargets will be always considered out of date. Consider this example:
exe hello : hello.
exe bye : bye.
If a build of hello is requested, then the binary will
always be relinked. The object files will not be recompiled, though. Note that if
a build of hello is not requested, for example you specify just
bye on the command line, hello will not
be relinked.
Sets project-wide constant. Takes two
parameters: variable name and a value and makes the specified
variable name accessible in this Jamfile and any child Jamfiles.
For example:
constant VERSION : 1.34.0 ;
path-constant
Same as constant except that
the value is treated as path relative to Jamfile location. For example,
if b2 is invoked in the current directory,
and Jamfile in helper subdirectory has:
path-constant DATA : data/a.
then the variable DATA will be set to
helper/data/a.txt, and if b2
is invoked from the helper directory, then
the variable DATA will be set to
data/a.txt.
build-project
Cause some other project to be built. This rule
takes a single parameter—a directory name relative to
the containing Jamfile. When the containing Jamfile is built,
the project located at that directory will be built as well.
At the moment, the parameter to this rule should be a directory
name. Project ID or general target references are not allowed.
test-suite
This rule is deprecated and equivalent to
Builtin features
This section documents the features that are built-in into
Boost.Build. For features with a fixed set of values, that set is
provided, with the default value listed first.
A feature combining several low-level features, making it easy to
request common build configurations.
Allowed values:
debug, release,
The value debug expands to
&optimization&off &debug-symbols&on &inlining&off &runtime-debugging&on
The value release expands to
&optimization&speed &debug-symbols&off &inlining&full &runtime-debugging&off
The value profile expands to the same as
release, plus:
&profiling&on &debug-symbols&on
Users can define their own build variants using the
variant rule from the common module.
Note: Runtime debugging is on in
debug builds to suit the expectations of people used to various
Allowed values: shared,
A feature controling how libraries are built.
runtime-link
Allowed values: shared,
Controls if a static or shared C/C++ runtime should be used. There
are some restrictions how this feature can be used, for example
on some compilers an application using static runtime should
not use shared libraries at all, and on some compilers,
mixing static and shared runtime requires extreme care.
your compiler documentation for more details.
Allowed values: single,
Controls if the project should be built in multi-threaded mode.
This feature does not
necessary change code generation in the compiler, but it causes the compiler to link
to additional or different runtime libraries, and define additional preprocessor
symbols (for example, _MT on Windows and _REENTRANT on Linux).
How those symbols affect the compiled code depends on the code itself.
The &source&X feature has the same effect on
building a target as putting X in the list of sources. It is useful
when you want to add the same source to all targets in the project
(you can put &source& in requirements) or to conditionally
include a source (using conditional requirements, see ). See also the &library&
This feature is almost equivalent to the &source&
feature, except that it takes effect only for linking. When you want
to link all targets in a Jamfile to certain library, the
&library& feature is preferred over
&source&X—the latter will add the library to
all targets, even those that have nothing to do with libraries.
dependency
Introduces a dependency on the target named by the value of this
feature (so it will be brought up-to-date whenever the target being
declared is). The dependency is not used in any other way.
implicit-dependency
Indicates that the target named by the value of this feature
may produce files that are included by the sources of the
target being declared.
for more information.
Introduces a dependency on the target named by the value of this
feature (so it will be brought up-to-date whenever the target being
declared is), and adds its usage requirements to the build
properties
of the target being declared. The dependency is not used in any
other way. The primary use case is when you want the usage
requirements (such as #include paths) of some library
to be applied, but do not want to link to it.
Specify an additional directory where the system should
look for shared libraries when the executable or shared
library is run. This feature only affects Unix
compilers. Plase see
for details.
hardcode-dll-paths
Controls automatic generation of dll-path properties.
Allowed values:
true, false.
This property is
specific to Unix systems. If an executable is built with
&hardcode-dll-paths&true, the generated binary
will contain the list of all the paths to the used shared libraries.
As the result, the executable can be run without changing system
paths to shared libraries or installing the libraries to system
paths. This
convenient during development. Plase see the
for details. Note that on Mac
OSX, the paths are unconditionally hardcoded by the linker, and it
is not possible to disable that behaviour.
cflags, cxxflags, linkflags
The value of those features is passed without modification to the
corresponding tools. For cflags that is both the C and
C++ compilers, for cxxflags that is the C++ compiler
and for linkflags that is the linker. The features are
handy when you are trying to do something special that cannot be
achieved by a higher-level feature in Boost.Build.
Specifies an additional include path that is to be passed to C and
C++ compilers.
Specifies an preprocessor symbol that should be defined on the command
line. You may either specify just the symbol, which will be defined
without any value, or both the symbol and the value, separated by
equal sign.
The &warnings& feature controls the warning level
of compilers. It has the following values:
off - disables all warnings.
on - enables default warning level for the tool.
all - enables all warnings.
Default value is all.
warnings-as-errors
The &warnings-as-errors& makes it possible to
treat warnings as errors and abort compilation on a warning. The
value on enables this behaviour. The default value is
Allowed values: no
The build feature is used to conditionally disable
build of a target. If &build&no is in properties
when building a target, build of that target is skipped. Combined
with conditional requirements this allows you to skip building some
target in configurations where the build is known to fail.
The tag feature is used to customize
the name of the generated files. The value should have the form:
rulename should be a name of a rule with the
following signature:
rule tag ( name : type ? : property-set )
The rule will be called for each target with the default name computed
by Boost.Build, the type of the target, and property set. The rule can
either return a string that must be used as the name of the target, or
an empty string, in which case the default name will be used.
Most typical use of the tag feature is to
encode build properties, or library version in library target names. You
should take care to return non-empty string from the tag rule only for
types you care about — otherwise, you might end up modifying
names of object files, generated header file and other targets for which
changing names does not make sense.
debug-symbols
Allowed values: on, off.
The debug-symbols feature specifies if
produced object files, executables and libraries should include
debug information.
Typically, the value of this feature is implicitly set by the
variant feature, but it can be explicitly
specified by the user. The most common usage is to build
release variant with debugging information.
runtime-debugging
Allowed values: on, off.
The runtime-debugging feature specifies if
produced object files, executables and libraries should include
behaviour useful only for debugging, such as asserts.
Typically, the value of this feature is implicitly set by the
variant feature, but it can be explicitly
specified by the user. The most common usage is to build
release variant with debugging output.
The operating system for which the code is to be generated. The
compiler you used should be the compiler for that operating
system. This option causes Boost.Build to use naming conventions
suitable for that operating system, and adjust build process
accordingly. For example, with gcc, it controls if import
libraries are produced for shared libraries or not.
The complete list of possible values for this feature is:
aix, bsd, cygwin, darwin, freebsd, hpux, iphone, linux, netbsd,
openbsd, osf, qnx, qnxnto, sgi, solaris, unix, unixware, windows.
for details of
crosscompilation
architecture
The architecture features specifies
the general processor familty to generate code for.
instruction-set
Allowed values: depend on the used
The instruction-set specifies for which
specific instruction set the code should be generated.
code in general might not run on processors with older/different
instruction sets.
While Boost.Build allows a large set of possible values
for this features, whether a given value works depends on which
compiler you use. Please see
for details.
address-model
Allowed values: 32, 64.
The address-model specifies if 32-bit or
64-bit code should be generated by the compiler. Whether this feature
works depends on the used compiler, its version, how the compiler is
configured, and the values of the architecture
instruction-set
features. Please see
for details.
c++-template-depth
Allowed values: Any positive
This feature allows configuring a C++ compiler with the maximal
template instantiation depth parameter. Specific toolsets may or may
not provide support for this feature depending on whether their
compilers provide a corresponding command-line option.
Note: Due to some internal details
in the current Boost.Build implementation it is not possible to have
features whose valid values are all positive integer. As a
workaround a large set of allowed values has been defined for this
feature and, if a different one is needed, user can easily add it by
calling the feature.extend rule.
embed-manifest
Allowed values: on, off.
This feature is specific to the msvc toolset (see
and controls whether the manifest files should be embedded inside
executables and shared libraries, or placed alongside them.
feature corresponds to the IDE option found in the project settings dialog,
under Configuration Properties → Manifest Tool → Input and Output → Embed manifest.
embed-manifest-file
This feature is specific to the msvc toolset (see
and controls which manifest files should be embedded inside
executables and shared libraries.
feature corresponds to the IDE option found in the project settings dialog,
under Configuration Properties → Manifest Tool → Input and Output → Additional Manifest Files.
Builtin tools
Boost.Build comes with support for a large number of C++ compilers,
and other tools. This section documents how to use those tools.
Before using any tool, you must declare your intention, and possibly
specify additional information about the tool's configuration. This is
done by calling the using rule, typically in your
user-config.jam, for example:
additional parameters can be passed just like for other rules, for example:
using gcc : 4.0 : g++-4.0 ;
The options that can be passed to each tool are documented in the
subsequent sections.
C++ Compilers
This section lists all Boost.Build modules that support C++
compilers and documents how each one can be initialized.
of support module for compiler is also the value for
the toolset feature that can be used to explicitly
request that compiler.
The gcc module supports the
on Linux, a number of Unix-like system including SunOS and on Windows
). On Mac OSX, it is recommended
to use system gcc, see .
The gcc module is initialized using the following
using gcc : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the version is not explicitly specified, it will be
automatically detected by running the compiler with the -v
option. If the command is not specified, the g++
binary will be searched in PATH.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Specifies root directory of the compiler installation.
This option is necessary only if it is not possible to detect this
information from the compiler command—for example if the specified
compiler command is a user script.
Specifies the resource compiler command
that will be used with the version of gcc that is being
configured. This setting makes sense only for Windows and only
if you plan to use resource files. By
default windres will be used.
Specifies the type of resource compiler. The value can
be either windres for msvc resource compiler,
or rc for borland's resource compiler.
In order to compile 64-bit applications, you have to specify
address-model=64, and the instruction-set
feature should refer to a 64 bit processor. Currently, those
include nocona, opteron,
athlon64 and athlon-fx.
Apple Darwin gcc
The darwin module supports the version of gcc that is
modified and provided by Apple. The configuration is essentially identical
to that of the gcc module.
The darwin toolset can generate so called "fat"
binaries—binaries that can run support more than one
architecture, or address mode. To build a binary that can run both
on Intel and PowerPC processors, specify
architecture=combined. To build a binary that can run
both in 32-bit and 64-bit modes, specify
address-model=32_64. If you specify both of those
properties, a "4-way" fat binary will be generated.
Microsoft Visual C++
The msvc module supports the
command-line tools on Microsoft Windows. The supported
products and versions of command line tools are listed below:
Visual Studio ;10.0
Visual Studio ;9.0
Visual Studio ;8.0
Visual Studio .NET ;7.1
Visual Studio .NET&#
Visual Studio 6.0, Service Pack 5&#
The msvc module is initialized using the following
using msvc : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the version is not explicitly specified, the most recent
version found in the registry will be used instead. If the special
value all is passed as the version, all versions found in
the registry will be configured. If a version is specified, but the
command is not, the compiler binary will be searched in standard
installation paths for that version, followed by PATH.
The compiler command should be specified using forward slashes,
and quoted.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
The command that compiles assembler sources. If
not specified, ml will be used. The command
will be invoked after the setup script was executed and adjusted
the PATH variable.
The command that compiles C and C++ sources. If
not specified, cl will be used. The command
will be invoked after the setup script was executed and adjusted
the PATH variable.
compiler-filter
Command through which to pipe the output of
running the compiler. For example to pass the output to STLfilt.
idl-compiler
The command that compiles Microsoft COM interface
definition files. If not specified, midl will
be used. The command will be invoked after the setup script was
executed and adjusted the PATH variable.
The command that links executables and dynamic
libraries. If not specified, link will be used.
The command will be invoked after the setup script was executed
and adjusted the PATH variable.
mc-compiler
The command that compiles Microsoft message
catalog files. If not specified, mc will be
used. The command will be invoked after the setup script was
executed and adjusted the PATH variable.
resource-compiler
The command that compiles resource files. If not
specified, rc will be used. The command will be
invoked after the setup script was executed and adjusted the
PATH variable.
The filename of the global environment setup
script to run before invoking any of the tools defined in this
toolset. Will not be used in case a target platform specific
script has been explicitly specified for the current target
platform. Used setup script will be passed the target platform
identifier (x86, x86_amd64, x86_ia64, amd64 or ia64) as a
arameter. If not specified a default script is chosen based on the
used compiler binary, e.g. vcvars32.bat or
vsvars32.bat.
setup-amd64, setup-i386, setup-ia64
The filename of the target platform specific
environment setup script to run before invoking any of the tools
defined in this toolset. If not specified the global environment
setup script is used.
64-bit support
Starting with version 8.0, Microsoft Visual Studio can
generate binaries for 64-bit processor, both 64-bit flavours of x86
(codenamed AMD64/EM64T), and Itanium (codenamed IA64). In addition,
compilers that are itself run in 64-bit mode, for better
performance, are provided. The complete list of compiler
configurations are as follows (we abbreviate AMD64/EM64T to just
32-bit x86 host, 32-bit x86 target
32-bit x86 host, 64-bit AMD64 target
32-bit x86 host, 64-bit IA64 target
64-bit AMD64 host, 64-bit AMD64 target
64-bit IA64 host, 64-bit IA64 target
The 32-bit host compilers can be always used, even on 64-bit
Windows. On the contrary, 64-bit host compilers require both 64-bit
host processor and 64-bit Windows, but can be faster. By default,
only 32-bit host, 32-bit target compiler is installed, and
additional compilers need to be installed explicitly.
To use 64-bit compilation you should:
Configure you compiler as usual. If you provide a
path to the compiler explicitly, provide the path to the 32-bit
compiler. If you try to specify the path to any of 64-bit
compilers, configuration will not work.
When compiling, use address-model=64,
to generate AMD64 code.
To generate IA64 code, use
architecture=ia64
The (AMD64 host, AMD64 target) compiler will be used
automatically when you are generating AMD64 code and are running
64-bit Windows on AMD64. The (IA64 host, IA64 target) compiler will
never be used, since nobody has an IA64 machine to test.
It is believed that AMD64 and EM64T targets are essentially
compatible. The compiler options /favor:AMD64 and
/favor:EM64T, which are accepted only by AMD64
targeting compilers, cause the generated code to be tuned to a
specific flavor of 64-bit x86. Boost.Build will make use of those
options depending on the value of theinstruction-set
Windows Runtime support
Starting with version 11.0, Microsoft Visual Studio can
produce binaries for Windows Store and Phone in addition to
traditional Win32 desktop. To specify which Windows API set
to target, use the windows-api feature.
Available options are desktop,
store, or phone. If not
specified, desktop will be used.
When using store or phone
the specified toolset determines what Windows version is
targeted. The following options are available:
Windows 8.0: toolset=msvc-11.0 windows-api=store
Windows 8.1: toolset=msvc-12.0 windows-api=store
Windows Phone 8.0: toolset=msvc-11.0 windows-api=phone
Windows Phone 8.1: toolset=msvc-12.0 windows-api=phone
For example use the following to build for Windows Store 8.1
with the ARM architecture:
.\b2 toolset=msvc=12.0 windows-api=store architecture=arm
Note that when targeting Windows Phone 8.1, version 12.0 didn't
include the vcvars phone setup scripts. They can be separately
downloaded from
The intel-linux and intel-win modules
support the Intel C++ command-line compiler—the
versions respectively.
The module is initialized using the following syntax:
using intel-linux : [version] : [c++-compile-command] : [compiler options] ;
using intel-win : [version] : [c++-compile-command] : [compiler options] ;
respectively.
This statement may be repeated several times, if you want to configure several versions of the compiler.
If compiler command is not specified, then Boost.Build will
look in PATH for an executable icpc
(on Linux), or icc.exe (on Windows).
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
The Linux version supports the following additional options:
Specifies root directory of the compiler installation.
This option is necessary only if it is not possible to detect this
information from the compiler command—for example if the specified
compiler command is a user script.
HP aC++ compiler
The acc module supports the
for the HP-UX operating system.
The module is initialized using the following
using acc : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, the aCC
binary will be searched in PATH.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Borland C++ Compiler
The borland module supports the command line
C++ compiler included in
product and earlier version of it, running on Microsoft Windows.
The supported products are listed below. The version reported
by the command lines tools is also listed for reference.:
C++ Builder ;5.8.2
CBuilderX&#.5, 5.6.4 (depending on release)
CBuilder6&#.4
Free command line tools&#.1
The module is initialized using the following syntax:
using borland : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for
a binary named bcc32 in PATH.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Comeau C/C++ Compiler
The como-linux and the como-win
modules supports the
on Linux and Windows respectively.
The module is initialized using the following syntax:
using como-linux : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for
a binary named como in
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Before using the Windows version of the compiler, you need to
setup necessary environment variables per compiler's documentation. In
particular, the COMO_XXX_INCLUDE variable should be
set, where XXX corresponds to the used backend C
Code Warrior
The cw module support CodeWarrior compiler,
originally produced by Metrowerks and presently developed by
Freescale. Boost.Build supports only the versions of the compiler that
target x86 processors. All such versions were released by Metrowerks
before aquisition and are not sold any longer. The last version known
to work is 9.4.
The module is initialized using the following syntax:
using cw : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for a
binary named mwcc in default installation paths and
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Specifies root directory of the compiler installation.
This option is necessary only if it is not possible to detect this
information from the compiler command—for example if the specified
compiler command is a user script.
The command that sets up environment variables
prior to invoking the compiler. If not specified,
cwenv.bat alongside the compiler binary
will be used.
The command that compiles C and C++ sources.
If not specified, mwcc will be used. The
command will be invoked after the setup script was
executed and adjusted the PATH variable.
The command that links executables and dynamic
libraries.
If not specified, mwld will be used. The
command will be invoked after the setup script was
executed and adjusted the PATH variable.
Digital Mars C/C++ Compiler
The dmc module supports the
The module is initialized using the following syntax:
using dmc : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for
a binary named dmc in
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
HP C++ Compiler for Tru64 Unix
The hp_cxx modules supports the
for Tru64 Unix.
The module is initialized using the following syntax:
using hp_cxx : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for
a binary named hp_cxx in PATH.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Sun Studio
The sun module supports the
C++ compilers for the Solaris OS.
The module is initialized using the following syntax:
using sun : [version] : [c++-compile-command] : [compiler options] ;
This statement may be repeated several times, if you want to configure several versions of the compiler.
If the command is not specified, Boost.Build will search for
a binary named CC
in /opt/SUNWspro/bin and in
When using this compiler on complex C++ code, such as the
recommended to specify the following options when intializing the
sun module:
-library=stlport4 -features=tmplife -features=tmplrefstatic
for details.
The following options can be provided, using &option-name&option-value syntax:
Specifies additional compiler flags that will be used when
compiling C sources.
Specifies additional compiler flags that will be used when
compiling C++ sources.
compileflags
Specifies additional compiler flags that will be used when
compiling both C and C++ sources.
Specifies additional command line options that will be
passed to the linker.
Starting with Sun Studio 12, you can create 64-bit applications
by using the address-model=64 property.
IBM Visual Age
The vacpp module supports the
C++ Compiler, for the AIX operating system. Versions
7.1 and 8.0 are known to work.
The module is initialized using the following
The module does not accept any initialization options. The
compiler should be installed in the /usr/vacpp/bin
directory.
Later versions of Visual Age are known as XL C/C++. They
were not tested with the the vacpp module.
Third-party libraries
Boost.Build provides special support for some
third-party C++ libraries, documented below.
STLport library
is an alternative implementation of C++ runtime library. Boost.Build
supports using that library on Windows platfrom.
hampered by different naming of libraries in each STLport
version and is not officially supported.
Before using STLport, you need to configure it in
user-config.jam using the following syntax:
using stlport : [version] : header-path : [library-path] ;
Where version is the version of
STLport, for example 5.1.4,
headers is the location where
STLport headers can be found, and libraries
is the location where STLport libraries can be found.
The version should always be provided, and the library path should
be provided if you're using STLport's implementation of
iostreams. Note that STLport 5.* always uses its own iostream
implementation, so the library path is required.
When STLport is configured, you can build with STLport by
requesting stdlib=stlport on the command line.
Provides support for the
can be configured either to use precompiled binaries or to
build the library from source.
zlib can be initialized using the following syntax
using zlib : [version] : [options] : [condition] : [is-default] ;
Options for using a prebuilt library:
The directory containing the zlib binaries.
Overrides the default library name.
The directory containing the zlib headers.
If none of these options is specified, then the environmental
variables ZLIB_LIBRARY_PATH, ZLIB_NAME, and ZLIB_INCLUDE will be
used instead.
Options for building zlib from source:
The zlib source directory.
Defaults to the
environmental variable ZLIB_SOURCE.
property to adjust the file name of the library.
when using precompiled binaries.
build-name
The base name to use for the compiled library.
Ignored when using precompiled binaries.
# Find zlib in the default system location
# Build zlib from source
using zlib : 1.2.7 : &source&/home/steven/zlib-1.2.7 ;
# Find zlib in /usr/local
using zlib : 1.2.7 : &include&/usr/local/include &search&/usr/local/
# Build zlib from source for msvc and find
# prebuilt binaries for gcc.
using zlib : 1.2.7 : &source&C:/Devel/src/zlib-1.2.7 : &toolset&
using zlib : 1.2.7 : : &toolset&
Documentation tools
Boost.Build support for the Boost documentation tools is
documented below.
To use xsltproc, you first need to configure it using the following syntax:
using xsltproc : [xsltproc] ;
Where xsltproc is the xsltproc executable.
If xsltproc is not specified, and the
variable XSLTPROC is set, the value of XSLTPROC will be used.
Otherwise, xsltproc will be searched for in PATH.
The following options can be provided, using &option-name&option-value syntax:
Values should have the form
name=value
Sets an additional search path for xi:include elements.
A catalog file used to rewrite remote URL's to a local copy.
The xsltproc module provides the following rules.
these operate on jam targets and are intended to be used by another
toolset, such as boostbook, rather than directly by users.
rule xslt ( target : source stylesheet : properties * )
Runs xsltproc to create a single output file.
rule xslt-dir ( target : source stylesheet : properties * : dirname )
Runs xsltproc to create multiple outputs in a directory.
dirname is unused, but exists for
historical reasons.
The output directory is determined from the
To use boostbook, you first need to configure it using the following syntax:
using boostbook : [docbook-xsl-dir] : [docbook-dtd-dir] : [boostbook-dir] ;
docbook-xsl-dir is the DocBook XSL stylesheet
directory. If not provided, we use DOCBOOK_XSL_DIR from the environment
(if available) or look in standard locations.
Otherwise, we let the
XML processor load the stylesheets remotely.
docbook-dtd-dir is the DocBook DTD directory.
If not provided, we use DOCBOOK_DTD_DIR From the environment (if
available) or look in standard locations.
Otherwise, we let the XML
processor load the DTD remotely.
boostbook-dir is the BoostBook directory
with the DTD and XSL subdirs.
The boostbook module depends on xsltproc.
For pdf or ps output,
it also depends on fop.
The following options can be provided, using &option-name&option-value syntax:
Allowed values:
html, xhtml,
htmlhelp, onehtml,
ps, docbook,
fo, tests.
The format feature determines the type
of output produced by the boostbook rule.
The boostbook module defines a rule for creating a target
following the common syntax.
rule boostbook ( target-name : sources * : requirements * : default-build * )
Creates a boostbook target.
To use doxygen, you first need to configure it using the following syntax:
using doxygen : [name] ;
name is the doxygen command.
If it is not specified, it will be found in the PATH.
The doxygen module depends on the boostbook module when
generating BoostBook XML.
The following options can be provided, using &option-name&option-value syntax:
doxygen:param
All the values of doxygen:param
are added to the doxyfile.
Specifies the common prefix of all headers
when generating BoostBook XML.
Everything before
this will be stripped off.
Specifies the title of the library-reference section,
when generating BoostBook XML.
doxygen:xml-imagedir
When generating BoostBook XML, specifies the
directory in which to place the images generated
from LaTex formulae.
The path is interpreted relative to the
current working directory, not relative to the Jamfile.
This is necessary to match the behavior of BoostBook.
The doxygen module defines a rule for creating a target
following the common syntax.
rule doxygen ( target : sources * : requirements * : default-build * : usage-requirements * )
Creates a doxygen target.
If the target name
ends with .html, then this will generate an html
directory.
Otherwise it will generate BoostBook XML.
The quickbook module provides a generator to convert from
Quickbook to BoostBook XML.
To use quickbook, you first need to configure it using the following syntax:
using quickbook : [command] ;
command is the quickbook executable.
If it is not specified, Boost.Build will compile it from source.
If it is unable to find the source it will search for a quickbook
executable in PATH.
The fop module provides generators to convert from
XSL formatting objects to Postscript and PDF.
To use fop, you first need to configure it using the following syntax:
using fop : [fop-command] : [java-home] : [java] ;
fop-command is the command to run fop.
If it is not specified, Boost.Build will search for it in PATH and
Either java-home or
can be used to specify where to find java.
Builtin modules
This section describes the modules that are provided
by Boost.Build.
The import rule allows rules from
one module to be used in another module or Jamfile.
The modules module defines basic functionality
for handling modules.
A module defines a number of rules that can be used in other
Modules can contain code at the top level to initialize
the module.
This code is executed the first time the
module is loaded.
A Jamfile is a special kind of module which is managed by
the build system.
Although they cannot be loaded directly
by users, the other features of modules are still useful
for Jamfiles.
Each module has its own namespaces for variables and rules.
modules A and B both use a variable named X, each one gets its own
copy of X.
They won't interfere with each other in any way.
Similarly, importing rules into one module has no effect on any other
Every module has two special variables.
$(__file__) contains the name of the file that
the module was loaded from and $(__name__)
contains the name of the module.
$(__file__) does not contain
the full path to the file.
If you need this, use
modules.binding.
rule binding ( module-name )Returns the filesystem binding of the given module.
For example, a module can get its own location with:
me = [ modules.binding $(__name__) ] ;
rule poke ( module-name ? : variables + : value * )Sets the module-local value of a variable.
For example, to set a variable in the global module:
modules.poke : ZLIB_INCLUDE : /usr/local/include ;
rule peek ( module-name ? : variables + )Returns the module-local value of a variable.
For example, to read a variable from the global module:
local ZLIB_INCLUDE = [ modules.peek : ZLIB_INCLUDE ] ;
rule call-in ( module-name ? : rule-name args * : * ) Call the given rule locally in the given module. Use
this for rules accepting rule names as arguments, so that
the passed rule may be invoked in the context of the rule's
caller (for example, if the rule accesses module globals or
is a local rule).
rules called this way may accept at most
8 parameters.
rule filter ( f : values * )
local m = [ CALLER_MODULE ] ;
local result ;
for v in $(values)
if [ modules.call-in $(m) : $(f) $(v) ]
result += $(v) ;
return result ;
rule load ( module-name : filename ? : search * )Load the indicated module if it is not already loaded.
module-name
Name of module to load.
(partial) Defaults to $(module-name).jam
Directories in which to search for filename.
Defaults to $(BOOST_BUILD_PATH).
rule import ( module-names + : rules-opt * : rename-opt * )Load the indicated module and import rule names into the
current module. Any members of rules-opt will be
available without qualification in the caller's module. Any
members of rename-opt will be taken as the names
of the rules in the caller's module, in place of the names they
have in the imported module.
If rules-opt = '*',
all rules from the indicated module are imported into the
caller's module. If rename-opt is supplied, it must have the
same number of elements as rules-opt.
The import rule is available
without qualification in all modules.
import path ;
import path : * ;
import path : join ;
import path : native make : native-path make-path ;
rule clone-rules ( source-module target-module )Define exported copies in $(target-module)
of all rules exported from $(source-module). Also
make them available in the global module with qualification,
so that it is just as though the rules were defined originally
in $(target-module).
Performs various path manipulations. Paths are always in a 'normalized'
representation. In it, a path may be either:
['/'] [ ( '..' '/' )* (token '/')* token ]
In plain english, a path can be rooted, '..'
elements are allowed only at the beginning, and it never
ends in slash, except for the path consisting of slash only.
rule make ( native )Converts the native path into normalized form.
rule native ( path )Builds the native representation of the path.
rule is-rooted ( path )Tests if a path is rooted.
rule has-parent ( path )Tests if a path has a parent.
rule basename ( path )Returns the path without any directory components.
rule parent ( path )Returns the parent directory of the path. If no parent exists, an error is issued.
rule reverse ( path )
Returns path2 such that
[ join path path2 ] = ".".
The path may not contain ".."
element or be rooted.
rule join ( elements + )
Concatenates the passed path elements. Generates an error if any
element other than the first one is rooted. Skips any empty or
undefined path elements.
rule root ( path root )
If path is relative, it is rooted at
root. Otherwise, it is unchanged.
rule pwd ( )Returns the current working directory.
rule glob ( dirs * : patterns + : exclude-patterns * )
Returns the list of files matching the given pattern in the specified
directory. Both directories and patterns are supplied as portable paths. Each
pattern should be a non-absolute path, and can't contain "." or ".." elements.
Each slash separated element of a pattern can contain the following special
characters:
'?' matches any character
'*' matches an arbitrary number of characters
A file $(d)/e1/e2/e3 (where 'd' is in $(dirs)) matches the pattern p1/p2/p3 if and
only if e1 matches p1, e2 matches p2 and so on.
For example:
[ glob . : *.cpp ]
[ glob . : */build/Jamfile ]
rule glob-tree ( roots * : patterns + : exclude-patterns * )
Recursive version of .
Builds the glob of files while also searching in
the subdirectories of the given roots. An optional set of exclusion patterns
will filter out the matching entries from the result. The exclusions also
apply to the subdirectory scanning, such that directories that match the
exclusion patterns will not be searched.
rule exists ( file )Returns true if the specified file exists.
rule all-parents ( path : upper_limit ? : cwd ? )
Find out the absolute name of path and return the list of all the parents,
starting with the immediate one. Parents are returned as relative names. If
upper_limit is specified, directories above it
will be pruned.
rule glob-in-parents ( dir : patterns + : upper-limit ? )
Search for patterns in parent directories
of dir, up to and including
upper_limit, if it is specified, or
till the filesystem root otherwise.
rule relative ( child parent : no-error ? )
Assuming child is a subdirectory of
parent, return the relative path from
parent to child.
rule relative-to ( path1 path2 )Returns the minimal path to path2 that is relative path1.
rule programs-path ( )
Returns the list of paths which are used by the operating system for
looking up programs.
rule makedirs ( path )
Creates a directory and all parent directories that do not
already exist.
Contains rules for string processing using regular expressions.
"x*" matches the pattern
"x" zero or more times.
"x+" matches "x"
one or more times.
"x?" matches "x"
zero or one time.
"[abcd]" matches any of the characters,
"c", and "d".
A character range such as "[a-z]" matches
any character between "a" and
matches any character which is not "a",
"b", or "c".
"x|y" matches either pattern
"x" or pattern "y"
(x) matches "x"
and captures it.
"^" matches the beginning of the string.
"$" matches the end of the string.
"\&" matches the beginning of a word.
"\&" matches the end of a word.
rule split ( string separator )Returns a list of the following substrings:
from beginning till the first occurrence of
separator or till the end,
between each occurrence of
separator and the next occurrence,
from the last occurrence of
separator till the end.
If no separator is present, the result will contain only one element.
rule split-list ( list * : separator )Returns the concatenated results of applying
to every element of the list using the separator pattern.
rule match ( pattern : string : indices * )Match string against
pattern, and return the elements
indicated by indices.
rule transform ( list * : pattern : indices * )Matches all elements of list against
the pattern and returns a list of elements
indicated by indices of all successful
matches. If indices is omitted returns a list
of first parenthesized groups of all successful matches.
rule escape ( string : symbols : escape-symbol )Escapes all of the characters in symbols
using the escape symbol escape-symbol for
the given string, and returns the escaped string.
rule replace ( string match replacement )Replaces occurrences of a match string in a given string and
returns the new string. The match string can be a regex expression.
rule replace-list ( list * : match : replacement )Replaces occurrences of a match string in a given list of strings
and returns a list of new strings. The match string can be a regex
expression.
Various useful list functions.
Note that algorithms in this module
execute largely in the caller's module namespace, so that local
rules can be used as function objects. Also note that most predicates
can be multi-element lists. In that case, all but the first element
are prepended to the first argument which is passed to the rule named
by the first element.
rule filter ( predicate + : sequence * )Return the elements e of
$(sequence) for which
[ $(predicate) e ] has a non-null value.
rule transform ( function + : sequence * )Return a new sequence consisting of
[ $(function) $(e) ] for each element
e of $(sequence).
rule reverse ( s * )Returns the elements of s in
reverse order.
rule insertion-sort ( s * : ordered * )Insertion-sort s using the
BinaryPredicate ordered.
rule merge ( s1 * : s2 * : ordered * )Merge two ordered sequences using the BinaryPredicate
rule join ( s * : joint ? )Join the elements of s into one
long string. If joint is supplied, it
is used as a separator.
rule length ( s * )Find the length of any sequence.
rule unique ( list * : stable ? )Removes duplicates from list.
If stable is passed, then the order
of the elements will be unchanged.
rule max-element ( elements + : ordered ? )Returns the maximum number in elements.
Uses ordered for comparisons or
if none is provided.
rule select-highest-ranked ( elements * : ranks * )Returns all of elements for which
the corresponding element in the parallel list
rank is equal to the maximum value in
Deals with target type declaration and defines target class which supports
typed targets.
rule register ( type : suffixes * : base-type ? )
Registers a target type, possible derived from a
base-type.
Providing a list
of suffixes here is a shortcut for separately calling the
rule with the given suffixes and the
rule with the first given suffix.
rule register-suffixes ( suffixes + : type )
Specifies that files with suffix from suffixes
be recognized as targets of
type type.
Issues an error if a different type is already specified for any
of the suffixes.
rule registered ( type )Returns true iff type has been registered.
rule validate ( type )Issues an error if type is unknown.
rule set-scanner ( type : scanner )Sets a scanner class that will be used for this type.
rule get-scanner ( type : property-set )
Returns a scanner instance appropriate to type
and property-set.
rule base ( type )
Returns a base type for the given type or nothing in case the given
type is not derived.
rule all-bases ( type )
Returns the given type and all of its base types in order of
their distance from type.
rule all-derived ( type )
Returns the given type and all of its derived types in order
of their distance from type.
rule is-derived ( type base )
Returns true if type is equal to
base or has base
as its direct or indirect base.
rule set-generated-target-suffix ( type : properties * : suffix )
Sets a file suffix to be used when generating a target of type with the
specified properties. Can be called with no properties if no suffix has
already been specified for the type. The suffix parameter can be an empty
string ("") to indicate that no suffix should be used.
Note that this does not cause files with suffix
to be automatically recognized as being of type.
Two different types can use the same suffix for their generated files
but only one type can be auto-detected for a file with that suffix.
User should explicitly specify which one using the
rule change-generated-target-suffix ( type : properties * : suffix )
Change the suffix previously registered for this type/properties
combination. If suffix is not yet specified, sets it.
rule generated-target-suffix ( type : property-set )
Returns the suffix used when generating a file of
type with the given properties.
rule set-generated-target-prefix ( type : properties * : prefix )
Sets a target prefix that should be used when generating targets of
type with the specified properties. Can
be called with empty properties if no prefix for
type has been specified yet.
The prefix parameter can be empty string
("") to indicate that no prefix
should be used.
Usage example: library names use the "lib"
prefix on unix.
rule change-generated-target-prefix ( type : properties * : prefix )
Change the prefix previously registered for this type/properties
combination. If prefix is not yet specified, sets it.
rule generated-target-prefix ( type : property-set )
Returns the prefix used when generating a file of
type with the given properties.
rule type ( filename )
Returns file type given its name. If there are several
dots in filename, tries each suffix. E.g. for name of
"file.so.1.2" suffixes "2", "1", and "so" will be tried.
Builtin classes
Class abstract-target
Base class for all abstract targets.
class abstract-target {
( name : project )
( property-set )
Classes derived from :
rule __init__ ( name : project )
The name of the target in the Jamfile.
to which this target belongs.
rule name ( )Returns the name of this target.
rule project ( )Returns the
for this target.
rule location ( )Returns the location where the target was declared.
rule full-name ( )Returns a user-readable name for this target.
rule generate ( property-set )
Generates virtual targets for this abstract target using the specified
properties, unless a different value of some feature is required by the
This is an abstract method which must be overriden by derived
On success, returns:
a property-set with the usage requirements to be applied to dependents
a list of produced virtual targets, which may be empty.
If property-set is empty, performs the
default build of this target, in a way specific to the derived class.
Class project-target
class project-target :
( property-set )
( id : no-error ? )
This class has the following responsibilities:
Maintaining a list of main targets in this project and building them.
rule generate ( property-set )
Generates virtual targets for all the targets contained in this project.
On success, returns:
a property-set with the usage requirements to be applied to dependents
a list of produced virtual targets, which may be empty.
rule build-dir ( )
Returns the root build directory of the project.
rule main-target ( name )
class instance corresponding to name.
Can only be called after the project has been fully loaded.
rule has-main-target ( name )
Returns whether a
with the specified name exists.
Can only be called after the project has been fully loaded.
rule find ( id : no-error ? )
Find and return the target with the specified id, treated relative to
self. Id may specify either a target or a file name with the target taking
priority. May report an error or return nothing if the target is not found
depending on the no-error parameter.
Class main-target
class main-target :
( property-set )
represents a named top-level target in a Jamfile.
rule generate ( property-set )
Select an alternative for this main target, by finding all alternatives
whose requirements are satisfied by property-set and
picking the one with the longest requirements set. Returns the result
of calling
on that alternative.
On success, returns:
a property-set with the usage requirements to be applied to dependents
a list of produced virtual targets, which may be empty.
Class basic-target
class basic-target :
( name : project : sources * : requirements * : default-build * : usage-requirements * )
( property-set )
( name : source-targets * : property-set )
Implements the most standard way of constructing main target alternative from
sources. Allows sources to be either files or other main targets and handles
generation of those dependency targets.
rule __init__ ( name : project : sources * : requirements * : default-build * : usage-requirements * )
The name of the target
in which the target is declared.
rule generate ( property-set )
Determines final build properties, generates sources, and calls
This method should not be overridden.
On success, returns:
a property-set with the usage requirements to be applied to dependents
a list of produced virtual targets, which may be empty.
rule construct ( name : source-targets * : property-set )
Constructs virtual targets for this abstract target. Returns a
usage-requirements property-set and a list of virtual
targets. Should be overriden in derived classes.
Class typed-target
class typed-target :
( name : project : type : sources * : requirements * : default-build * : usage-requirements * )
( name : source-targets * : property-set )
( property-set )
is the most common kind of target alternative.
Rules for creating
typed targets are defined automatically for each type.
rule __init__ ( name : project : type : sources * : requirements * : default-build * : usage-requirements * )
The name of the target
in which the target is declared.
of the target.
rule type ( )
Returns the
of the target.
rule construct ( name : source-targets * : property-set )
Implements .
Attempts to create a target of
the correct type using generators appropriate for the given
containing the usage requirements
and a list of virtual targets.
This function is invoked automatically by
and should not be called directly by users.
Class property-set
Class for storing a set of properties.
class property-set {
( properties * )
( feature )
There is 1&-&1 correspondence between identity and value. No two instances
of the class are equal. To maintain this property, the 'property-set.create'
rule should be used to create new instances. Instances are immutable.
rule raw ( )Returns a Jam list of the stored properties.
rule str ( )Returns the string repesentation of the stored properties.
rule propagated ( )
containing all the
properties in this .
rule add ( ps )
Returns a new
containing the union of the properties
and in ps.
If ps contains non-free properties
that should override the values in this object, use
rule add-raw ( properties * )
Link , except that it takes a list of properties
instead of a .
rule refine ( ps )
Refines properties by overriding any non-free and non-conditional
properties for which a different value is specified in
ps. Returns the resulting
rule get ( feature )
Returns all the values of feature.
Build process
The general overview of the build process was given in the
This section provides additional details, and some specific rules.
To recap, building a target with specific properties includes the
following steps:
applying default build,
selecting the main target alternative to use,
determining "common" properties,
building targets referred by the sources list and
dependency properties,
adding the usage requirements produces when building
dependencies to the "common" properties,
building the target using generators,
computing the usage requirements to be returned.
Alternative selection
When there are several alternatives, one of them must be
selected. The process is as follows:
For each alternative condition is defined as
the set of base properties in requirements. [Note: it might be
better to specify the condition explicitly, as in conditional
requirements].
An alternative is viable only if all properties in condition
are present in build request.
If there's one viable alternative, it's choosen. Otherwise,
an attempt is made to find one best alternative. An alternative
a is better than another alternative b, iff the set of properties
in b's condition is a strict subset of the set of properities of
'a's condition. If there's one viable alternative, which is
better than all others, it's selected. Otherwise, an error is
Determining common properties
The "common" properties is a somewhat artificial term. Those are
the intermediate property set from which both the build request for
dependencies and properties for building the target are derived.
Since default build and alternatives are already handled, we have
only two inputs: build requests and requirements. Here are the rules
about common properties.
Non-free feature can have only one
A non-conditional property in requirement in always
present in common properties.
A property in build request is present in
common properties, unless (2) tells otherwise.
If either build request, or requirements (non-conditional
or conditional) include an expandable property (either composite,
or property with specified subfeature value), the behaviour is
equivalent to explicitly adding all expanded properties to build
request or requirements.
If requirements include a conditional property, and
condiiton of this property is true in context of common
properties, then the conditional property should be in common
properties as well.
If no value for a feature is given by other rules
here, it has default value in common properties.
Those rules are declarative, they don't specify how to compute the
common properties. However, they provide enough information for the
user. The important point is the handling of conditional
requirements. The condition can be satisfied either by property in
build request, by non-conditional requirements, or even by another
conditional property. For example, the following example works as
exe a : a.cpp
: &toolset&gcc:&variant&release
&variant&release:&define&FOO ;
Target Paths
Several factors determine the location of a concrete
file target.
All files in a project are built under
the directory bin unless this is overriden by the build-dir project
attribute.
Under bin is a path that depends on the properties
used to build each target.
This path is uniquely determined by
all non-free, non-incidental properties.
For example,
given a property set containing:
&toolset&gcc &toolset-gcc:version&4.6.1 &variant&debug
&warnings&all &define&_DEBUG &include&/usr/local/include
&link&static,
the path will be gcc-4.6.1/debug/link-static.
&warnings& is an
incidental feature and &define& and &include& are
free features, so they do not affect the path.
Sometimes the paths produced by Boost.Build can become excessively
There are a couple of command line options that can help with this.
--abbreviate-paths reduces each element to no more than five characters.
For example, link-static becomes lnk-sttc.
The --hash option reduces the
path to a single directory using an MD5 hash.
There are two features that affect the build
directory.
The &location& feature completely
overrides the default build directory.
For example,
exe a : a.cpp : &location&. ;
builds all the files produced by a
in the directory of the Jamfile.
This is generally
discouraged, as it precludes variant builds.
The &location-prefix& feature adds a
prefix to the path, under the project's build
directory.
For example,
exe a : a.cpp : &location-prefix&
will create the files for a in bin/subdir/gcc-4.6.1/debug
Definitions
Features and properties
A feature is a normalized (toolset-independent)
aspect of a build configuration, such as whether inlining is
enabled. Feature names may not contain the '&'
character.
Each feature in a build configuration has one or more
associated values. Feature values for non-free features
may not contain the '&', ':', or
'=' characters. Feature values for free features may not
contain the '&' character.
A property is a (feature,value) pair, expressed as
&feature&value.
A subfeature is a feature that only exists in the
presence of its parent feature, and whose identity can be derived
(in the context of its parent) from its value. A subfeature's
parent can never be another subfeature. Thus, features and their
subfeatures form a two-level hierarchy.
A value-string for a feature F is a string of
value-subvalue1-subvalue2...-subvalueN, where
value is a legal value for F and
subvalue1...subvalueN are legal values of some
of F's subfeatures. For example, the properties
&toolset&gcc &toolset-version&3.0.1 can be
expressed more conscisely using a value-string, as
&toolset&gcc-3.0.1.
A property set is a set of properties (i.e. a
collection without duplicates), for instance:
&toolset&gcc &runtime-link&static.
A property path is a property set whose elements have
been joined into a single string separated by slashes. A property
path representation of the previous example would be
&toolset&gcc/&runtime-link&static.
A build specification is a property set that fully
describes the set of features used to build a target.
Property Validity
features, all values are valid. For all other features,
the valid values ar