diff options
Diffstat (limited to 'tools/build/options/WITH_META_MODE')
| -rw-r--r-- | tools/build/options/WITH_META_MODE | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/tools/build/options/WITH_META_MODE b/tools/build/options/WITH_META_MODE index 906b557..1d19be1e 100644 --- a/tools/build/options/WITH_META_MODE +++ b/tools/build/options/WITH_META_MODE @@ -1,12 +1,41 @@ .\" $FreeBSD$ -Create meta files when not doing DIRDEPS_BUILD. +Creates +.Xr make 1 +meta files when building, which can provide a reliable incremental build when +using +.Xr filemon 4 . +The meta file is created in the OBJDIR as +.Pa target.meta . +These meta files track the command ran, its output, and the current directory. When the .Xr filemon 4 -module is loaded, dependencies will be tracked for all commands. -If any command, its dependencies, or files it generates are missing then -the target will be considered out-of-date and rebuilt. +module is loaded, any files used by the commands executed will be tracked as +dependencies for the target in its meta file. +The target will be considered out-of-date and rebuilt if any of the following +are true compared to the last build: +.Bl -bullet -compact +.It +The command to execute changes. +.It +The current working directory changes. +.It +The target's meta file is missing. +.It +[requires +.Xr filemon 4 ] +Files read, executed or linked to are newer than the target. +.It +[requires +.Xr filemon 4 ] +Files read, written, executed or linked are missing. +.El The meta files can also be useful for debugging. .Pp The build will hide commands ran unless .Va NO_SILENT is defined. +.Pp +The build operates as it normally would otherwise. +This option originally invoked a different build system but that was renamed +to +.Va WITH_DIRDEPS_BUILD . |
