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Diffstat (limited to 'doc')
-rw-r--r-- | doc/manual.asciidoc | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/doc/manual.asciidoc b/doc/manual.asciidoc index fb5d4b9..0e52e1a 100644 --- a/doc/manual.asciidoc +++ b/doc/manual.asciidoc @@ -679,6 +679,7 @@ While a task in the `console` pool is running, Ninja's regular output (such as progress status and output from concurrent tasks) is buffered until it completes. +[[ref_ninja_file]] Ninja file reference -------------------- @@ -710,6 +711,7 @@ the `:` with +| _output1_ _output2_+ and do not appear in `$out`. 6. A pool declaration, which looks like +pool _poolname_+. Pools are explained <<ref_pool, in the section on pools>>. +[[ref_lexer]] Lexical syntax ~~~~~~~~~~~~~~ @@ -814,6 +816,11 @@ keys. the full command or its description; if a command fails, the full command line will always be printed before the command's output. +`dyndep`:: _(Available since Ninja 1.10.)_ Used only on build statements. + If present, must name one of the build statement inputs. Dynamically + discovered dependency information will be loaded from the file. + See the <<ref_dyndep,dynamic dependencies>> section for details. + `generator`:: if present, specifies that this rule is used to re-invoke the generator program. Files built using `generator` rules are treated specially in two ways: firstly, they will not be @@ -1003,3 +1010,63 @@ Variable declarations indented in a `build` block are scoped to the 5. Variables from the file that included that file using the `subninja` keyword. + +[[ref_dyndep]] +Dynamic Dependencies +-------------------- + +_Available since Ninja 1.10._ + +Some use cases require implicit dependency information to be dynamically +discovered from source file content _during the build_ in order to build +correctly on the first run (e.g. Fortran module dependencies). This is +unlike <<ref_headers,header dependencies>> which are only needed on the +second run and later to rebuild correctly. A build statement may have a +`dyndep` binding naming one of its inputs to specify that dynamic +dependency information must be loaded from the file. For example: + +---- +build out: ... || foo + dyndep = foo +build foo: ... +---- + +This specifies that file `foo` is a dyndep file. Since it is an input, +the build statement for `out` can never be executed before `foo` is built. +As soon as `foo` is finished Ninja will read it to load dynamically +discovered dependency information for `out`. This may include additional +implicit inputs and/or outputs. Ninja will update the build graph +accordingly and the build will proceed as if the information was known +originally. + +Dyndep file reference +~~~~~~~~~~~~~~~~~~~~~ + +Files specified by `dyndep` bindings use the same <<ref_lexer,lexical syntax>> +as <<ref_ninja_file,ninja build files>> and have the following layout. + +1. A version number in the form `<major>[.<minor>][<suffix>]`: ++ +---- +ninja_dyndep_version = 1 +---- ++ +Currently the version number must always be `1` or `1.0` but may have +an arbitrary suffix. + +2. One or more build statements of the form: ++ +---- +build out | imp-outs... : dyndep | imp-ins... +---- ++ +Every statement must specify exactly one explicit output and must use +the rule name `dyndep`. The `| imp-outs...` and `| imp-ins...` portions +are optional. + +3. An optional `restat` <<ref_rule,variable binding>> on each build statement. + +The build statements in a dyndep file must have a one-to-one correspondence +to build statements in the <<ref_ninja_file,ninja build file>> that name the +dyndep file in a `dyndep` binding. No dyndep build statement may be omitted +and no extra build statements may be specified. |