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authorBoris Kolpackov <boris@codesynthesis.com>2022-01-13 09:34:46 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2022-01-13 09:34:46 +0200
commit85a5ea98dcbaab36ccd5f2c13a363f1c9c9bbcfe (patch)
tree7b68e92edd7a3b68aec73fa96d3c40fa6b9eb3e0 /NEWS
parent021723f1346dc54ee37967fb6a8e7219b125cc42 (diff)
Update NEWS file with support for dynamic dependencies
Diffstat (limited to 'NEWS')
-rw-r--r--NEWS127
1 files changed, 127 insertions, 0 deletions
diff --git a/NEWS b/NEWS
index c857ec0..e3a1376 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,130 @@
+Version 0.15.0
+
+ * 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 $t -- \
+ $cxx.path $poptions $coptions $cxx.mode -M -MG $s >$t
+
+ The above depdb-dyndep commands will run the C++ compiler with the -M -MG
+ options to extract the header dependency information, parse the resulting
+ make dependency declaration (either from stdout or from file) and enter
+ each header as a prerequisite of the obje{hello.o} target, as if they were
+ listed explicitly. It will also save this list of headers in the auxiliary
+ dependency database (hello.o.d file) in order to detect changes to these
+ headers on subsequent updates. The --what option specifies what to call
+ the dependencies being extracted in diagnostics. The --default-type option
+ specifies the default target type to use for a dependency if its file name
+ cannot be mapped to a target type.
+
+ The above depdb-dyndep variant extracts the dependencies ahead of the
+ compilation proper and will handle auto-generated headers (see the -MG
+ option for details) provided we pass the header search paths where they
+ could be generated with the -I options (passed as $poptions in the above
+ example).
+
+ If there can be no auto-generated dependencies or if they can all be
+ listed explicitly as static prerequisites, then we can use a variant of
+ the depdb-dyndep command that extracts the dependencies as a by-product of
+ compilation. In this mode only the --file input is supported. For example
+ (assuming hxx{config} is auto-generated):
+
+ obje{hello.o}: cxx{hello} hxx{config}
+ {{
+ s = $path($<[0])
+ o = $path($>)
+ t = $(o).t
+
+ poptions = $cxx.poptions $cc.poptions
+ coptions = $cc.coptions $cxx.coptions
+
+ depdb dyndep --byproduct --what=header --default-type=h --file $t
+
+ diag c++ ($<[0])
+
+ $cxx.path $poptions $coptions $cxx.mode -MD -MF $t -o $o -c $s
+ }}
+
+ Other options supported by the depdb-dyndep command:
+
+ --format <name>
+
+ Dependency format. Currently only the `make` dependency format is
+ supported and is the default.
+
+ --cwd <dir>
+
+ Working directory used to complete relative dependency paths. This
+ option is currently only valid in the --byproduct mode (in the normal
+ mode relative paths indicate non-existent files).
+
+ --drop-cycles
+
+ Drop prerequisites that are also targets. Only use this option if you
+ are sure such cycles are harmless, that is, the output is not affected
+ by such prerequisites' content.
+
+ --update-{include,exclude} <tgt>|<pat>
+
+ Prerequisite targets/patterns to include/exclude (from the static
+ prerequisite set) for update during match (those excluded will be
+ updated during execute). The order in which these options are specified
+ is significant with the first target/pattern that matches determining
+ the result. If only the --update-include options are specified, then
+ only the explicitly included prerequisites will be updated. Otherwise,
+ all prerequisites that are not explicitly excluded will be updated. If
+ none of these options is specified, then all the static prerequisites
+ are updated during match. Note also that these options do not apply to
+ ad hoc prerequisites which are always updated during match.
+
+ The common use-case for the --update-exclude option is to omit updating
+ a library which is only needed to extract exported preprocessor options.
+ Here is a typical pattern:
+
+ import libs = libhello%lib{hello}
+
+ libue{hello-meta}: $libs
+
+ obje{hello.o}: cxx{hello} libue{hello-meta}
+ {{
+ s = $path($<[0])
+ o = $path($>)
+
+ poptions = $cxx.poptions $cc.poptions
+ poptions += $cxx.lib_poptions(libue{hello-meta}, obje)
+ coptions = $cc.coptions $cxx.coptions
+
+ depdb dyndep $poptions --what=header --default-type=h \
+ --update-exclude libue{hello-meta} -- \
+ $cxx.path $poptions $coptions $cxx.mode -M -MG $s
+
+ diag c++ ($<[0])
+
+ $cxx.path $poptions $coptions $cxx.mode -o $o -c $s
+ }}
+
Version 0.14.0
* Support for hermetic build configurations.