build2/0.15.0

build2 build system

This package contains the build2 build system.

build2 is an open source, cross-platform toolchain for building and packaging
C++ code. Its aim is a modern build system and dependency manager for the C++
language that provide a consistent, out of the box interface across multiple
platforms and compilers. For more information see:

https://build2.org/

See the NEWS file for the user-visible changes from the previous release.

See the LICENSE file for the distribution conditions.

See the INSTALL file... More

Depends (2)

Requires (1)

Builds

Changes

Version 0.15.0

  * Generated C/C++ headers and ad hoc sources are now updated during match.

    Specifically, all headers as well as ad hoc headers and sources are now
    treated by the cc::link_rule as if they had update=match unless explicit
    update=execute is specified (see below on the update operation-specific
    variable).

    This change should be transparent to most projects. For background and
    discussion of rare cases where you may wish to disable this, see:

    https://github.com/build2/HOWTO/blob/master/entries/handle-auto-generated-headers.md

  * Support for rule hints.

    A rule hint is a target attribute, for example:

    [rule_hint=cxx] exe{hello}: c{hello}

    Rule hints can be used to resolve ambiguity when multiple rules match the
    same target as well as to override an unambiguous match.

    In cc::link_rule we now support "linking" libraries without any sources or
    headers with a hint. This can be useful for creating "metadata libraries"
    whose only purpose is to convey metadata (options to use and/or libraries
    to link).

  * UTF-8 is now the default input/source character set for C/C++ compilation.

    Specifically, the cc module now passes the appropriate compiler option
    (/utf-8 for MSVC and -finput-charset=UTF-8 for GCC and Clang) unless a
    custom value is already specified (with /{source,execution}-charset for
    MSVC and -finput-charset for GCC and Clang).

    This change may trigger new compilation errors in your source code if
    it's not valid UTF-8 (such errors most commonly point into comments).
    For various ways to fix this, see:

    https://github.com/build2/HOWTO/blob/master/entries/convert-source-files-to-utf8.md

  * Project configuration variables are now non-nullable by default.

    A project configuration variable with the NULL default value is naturally
    assumed nullable, for example:

    config [string] config.libhello.fallback_name ?= [null]

    Otherwise, to make a project configuration nullable use the `null`
    variable attribute, for example:

    config [string, null] config.libhello.fallback_name ?= "World"

  * New $relative(<path>, <dir-path>) function.

  * New $root_directory(<path>) function.

  * New $size() function to get the size of string, path, dir_path.

  * New $size() function to get the size of a sequence (strings, paths, etc).

  * New $sort() function to sort a sequence (strings, paths, etc).

    The function has the following signature:

    $sort(<sequence> [, <flags>])

    The following flag is supported by all the overloads:

      dedup - in addition to sorting also remove duplicates

          Additionally, the strings overload also support the following flag:

      icase - sort ignoring case

    Note that on case-insensitive filesystems the paths and dir_paths
    overloads' order is case-insensitive.

  * New $config.origin() function for querying configuration value origin.

    Give a config.* variable name, this function returns one of `undefined`,
    `default`, `buildfile`, or `override`.

  * Recognition of -pthread as a special -l option in *.libs.

    For background, see:

    https://github.com/build2/HOWTO/blob/master/entries/link-pthread.md

  * The bin.whole (whole archive) value is now saved in generated pkg-config
    files.

  * Ability to customize header and library search paths in generated
    pkg-config files.

    Specifically, {cc,c,cxx}.pkgconfig.{include,lib} variables specify header
    (-I) and library (-L) search paths to use in the generated pkg-config
    files instead of the default install.{include,lib}. Relative paths are
    resolved as installation paths. For example:

    lib{Qt6Core}: cxx.pkgconfig.include = include/qt6/

  * Ability to save user metadata in C/C++ libraries, including in generated
    pkg-config files.

    For background and details, see:

    https://github.com/build2/HOWTO/blob/master/entries/convey-additional-information-with-exe-lib.md

  * Support for rule-specific search in immediate import.

    We can now nominate a rule to perform the rule-specific search (if
    required) using the rule_hint attribute. For example:

    import! [metadata, rule_hint=cxx.link] lib = libhello%lib{hello}

  * Support for dynamic dependencies in ad hoc recipes.

    Specifically, the `depdb` builtin now has the new `dyndep` command that
    can be used to extract dynamic dependencies from program output or a
    file. For example, from program output:

    obje{hello.o}: cxx{hello}
    {{
      s = $path($<[0])
      o = $path($>)

      poptions = $cxx.poptions $cc.poptions
      coptions = $cc.coptions $cxx.coptions

      depdb dyndep $poptions --what=header --default-type=h -- \
        $cxx.path $poptions $coptions $cxx.mode -M -MG $s

      diag c++ ($<[0])

      $cxx.path $poptions $coptions $cxx.mode -o $o -c $s
    }}

    Or, alternatively, from a file:

    t = $(o).t
    depdb dyndep $poptions --what=header --default-type=h --file... More