From 77a5d8345a9e30d77d934e9972ddf7cbd3afbcfd Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Tue, 14 Jul 2020 11:14:05 +0200 Subject: Update NEWS file --- NEWS | 269 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 269 insertions(+) (limited to 'NEWS') diff --git a/NEWS b/NEWS index 0f47384..e16e5c7 100644 --- a/NEWS +++ b/NEWS @@ -1,3 +1,272 @@ +Version 0.13.0 + + * Support for project-specific configuration. + + A project can now use the new config directive to define config.* + variables similar to the build system core and modules. For example: + + config [bool] config.libhello.fancy ?= false + config [string] config.libhello.greeting ?= 'Hello' + + These variables can then be used in buildfiles and/or propagated to the + source code using the command line, .in file substitution, etc. For + example: + + if $config.libhello.fancy + cxx.poptions += -DLIBHELLO_FANCY + + cxx.poptions += "-DLIBHELLO_GREETING=\"$config.libhello.greeting\"" + + See the "Project Configuration" chapter in the manual for details. + + * Support for ad hoc recipes. + + With ad hoc recipes we can now provide custom implementation of operations + (update, test, etc) for certain targets. For example: + + hxx{config}: hxx{config-linux}: include = ($cxx.target.class == 'linux') + hxx{config}: hxx{config-windows}: include = ($cxx.target.class == 'windows') + hxx{config}: hxx{config-macos}: include = ($cxx.target.class == 'macos') + hxx{config}: + {{ + cp $path($<) $path($>) + }} + + Another, more elaborate example: + + import! xxd = xxd%exe{xxd} + + <{hxx cxx}{foo}>: file{foo.bin} $xxd + {{ + diag xxd ($<[0]) + + i = $path($<[0]) # Input. + h = $path($>[0]) # Output header. + s = $path($>[1]) # Output source. + n = $name($<[0]) # Array name. + + # Get the position of the last byte (in hex). + # + $xxd -s -1 -l 1 $i | sed -n -e 's/^([0-9]+):.*$/\1/p' - | set pos + + # Write header and source. + # + echo "#pragma once" >$h + echo "extern const char $n[0x$pos + 1];" >>$h + echo "extern const char $n[0x$pos + 1]= {" >$s + $xxd -i <$i >>$s + echo '};' >>$s + }} + + Note that in both examples, the utilities (cp, echo, and sed) are builtins + which means these recipes are portable. See the Testscript manual for the + list of available builtins. + + Ad hoc recipes can also be used to customize a part of the build chain + handled by rules. For example, in embedded systems development it is often + required to perform a custom link step: + + obje{foo}: cxx{foo} + obje{bar}: cxx{bar} + exe{ld}: obje{ld ld1} + {{ + diag ld $> + $cxx.path $cc.loptions $cxx.loptions $cxx.mode -o $path($>) $path($<) \ + $cxx.libs $cc.libs + }} + + While the above recipes are for the update operation, ad hoc recipes can + be used for other operations, such as test. For example: + + exe{hello}: cxx{hello} + % test + {{ + diag test $> + $> 'World' >>>?'Hello, World!' + }} + + The above recipes are written in a shell-like language called Buildscript + that has similar semantics to Testscript tests. Another language that can + be used to write recipes is C++. For example: + + ./: + {{ c++ 1 + + recipe + apply (action, target& t) const override + { + text (recipe_loc) << "Hello, " << t; + return noop_recipe; + } + }} + + In this release support for ad hoc recipe is at the "technology preview" + stage. In particular, there is no documentation and are known rough edges, + especially around diagnostics. + + * Support for project-local importation. + + An import without a project name is now treated as importation from the + same project. For example, given the libhello project that exports the + lib{hello} target, a buildfile for an executable in the same project + instead of doing something like this: + + include ../libhello/ + exe{hello}: ../libhello/lib{hello} + + Can now do this: + + import lib = lib{hello} + exe{hello}: $lib + + Note that the target in project-local importation must still be exported + in the project's export stub. In other words, project-local importation + goes through the same mechanism as normal import. + + * Support for ad hoc importation and "glue buildfiles". + + If the target being imported has no project name and is either absolute or + is a relative directory, then this is treated as ad hoc importation. + Semantically it is similar to a normal import but with the location of the + project being imported hard-coded into the buildfile. + + This type of import can be used to create a special "glue buildfile" that + "pulls" together several projects, usually for convenience of development. + One typical case that calls for such a glue buildfile is a multi-package + project. To be able to invoke the build system driver directly in the + project root, we can add a glue buildfile that imports and builds all the + packages: + + import pkgs = */ + ./: $pkgs + + See the "Target Importation" section in the manual for details. + + * Support for value subscripts. + + A value subscript is only recognized in evaluation contexts (due to + ambiguity with wildcard patterns; consider: $x[123].txt) and should be + unseparated from the previous token. For example: + + x = ($y[1]) + x = (($f ? $y : $z)[1]) + x = ($identity($y)[$z]) + + * New legal{} target type and config.install.legal variable. + + This allows separation of legal files (LICENSE, AUTHORS, etc) from other + documentation. For example: + + ./: ... doc{README} legal{LICENSE} + + $ b install ... config.install.legal=/usr/share/licenses/hello/ + + * Support for -substitutions in config.install.* values. + + The currently recognized variable names are and which + are substituted with the project name and private subdirectory, + respectively. This can be used along these lines: + + $ b config.install.libexec='exec_root/lib//' install + + The private installation subdirectory can be used to hide the + implementation details of a project. This is primarily useful when + installing an executable that depends on a bunch of libraries into a + shared location, such as /usr/local/. For example: + + $ b config.install.private=foo install + + See the "Install Module" chapter in the manual for details. + + * The $process.run*() functions now recognize a number of portable builtins. + Refer to the Testscript manual for the list and details. + + * New $defined() and $visibility() functions. + + * New $target.process_path() function analogous to $target.path(). + + * New $bin.link_member() function. + + Given a linker output target type ("exe", "lib[as]", or "libu[eas]") this + function returns the target type of lib{} group member ("liba" or "libs") + that will be picked when linking a lib{} group to this target type. + + * New scripting builtins: date, env. + + * New variable block applicability semantics in dependency chains. + + Before the block used to apply to the set of prerequisites before the last + colon. This turned out to be counterintuitive and not very useful since + prerequisite-specific variables are less common than target-specific. + + The new rule is if the chain ends with the colon, then the block applies + to the last set of prerequisites. Otherwise, it applies to the last set of + targets. For example: + + ./: exe{test}: cxx{main} + { + test = true # Applies to the exe{test} target. + } + + ./: exe{test}: libue{test}: + { + bin.whole = false # Applies to the libue{test} prerequisite. + } + + * Test and install modules are now implicitly loaded for simple projects. + + While these can be useful on their own, this also makes the test and + install operations available in simple projects, which is handy for "glue" + projects that "pull" (using ad hoc import) a bunch of other projects. + + * The translated {c,cxx}.std options are now folded into the compiler mode + options. This makes them accessible from ad hoc recipes. + + * Common pkg-config .pc file in addition to static/shared-specific. + + The common .pc file is produced by ignoring any static/shared-specific + poptions and splitting loptions/libs into Libs/Libs.private. + + It is "best effort", in a sense that it's not guaranteed to be sufficient + in all cases, but it will probably cover the majority of cases, even on + Windows, thanks to automatic dllimport'ing of functions. + + * The ~host configuration now only contains the cc and bin modules + configuration. + + Also added the ~build2 configuration that contains everything (except + config.dist.*) to be used for build system modules. + + * Reworked tool importation support. + + Specifically, now config. (like config.cli) is handled by the import + machinery (it is like a shorter alias for config.import...exe + that we already had). + + This also adds support for uniform tool metadata extraction that is + handled by the import machinery. As a result, a tool that follows the + "build2 way" can be imported with metadata by the buildfile and/or + corresponding module without any tool-specific code or brittleness + associated with parsing --version or similar outputs. See the cli + tool/module for details. + + Finally, two new flavors of the import directive are now supported: + import! triggers immediate importation skipping any rule-specific logic + while import? is optional import (analogous to using?). Note that optional + import is always immediate. There is also the import-specific metadata + attribute which can be specified for these two import flavors in order to + trigger metadata importation. For example: + + import? [metadata] cli = cli%exe{cli} + + if ($cli != [null]) + info "cli version $($cli:cli.version)" + + * Reserved backtick (`) and bit-or (|) in evaluation context for future use. + + Specifically, they are reserved for future support of arithmetic + evaluation contexts and evaluation pipelines, respectively. + Version 0.12.0 * Support for dynamically-buildable/loadable build system modules. -- cgit v1.1