Previously if the jobserver was active, MAKEFLAGS would contain only
the -j option but not the number (not -j5 or whatever) so users
could not discover that value. Allow that value to be provided in
MAKEFLAGS without error but still give warnings if -jN is provided
on the command line if the jobserver is already activated.
* NEWS: Discuss the new behavior.
* os.h, posixos.c, w32/w32os.c: Return success/failure from
jobserver_setup() and jobserver_parse_auth().
* main.c (main): Separate the command line storage of job slots (now
in arg_job_slots) from the control storage (in job_slots). Make a
distinction between -jN flags read from MAKEFLAGS and those seen
on the command line: for the latter if the jobserver is enabled then
warn and disable it, as before.
* tests/scripts/features/jobserver: Add new testing.
In this mode we still collect all the output from a given target and
dump it at once. However we don't treat recursive lines any differently
from non-recursive lines. Also we don't print enter/leave messages
after every dump. However we do ensure that we always print them once
to stdout, so the parent make will collect it properly.
Create a new file, output.c, and collect functions that generate output there.
We introduce a new global context specifying where output should go (to stdout
or to a sync file), and the lowest level output generator chooses where to
write output based on that context.
This allows us to set the context globally, and all operations that write
output (including functions like $(info ...) etc.) will use it.
Removed the "--trace=dir" capability. It was too confusing. If you have
directory tracking enabled then output sync will print the enter/leave message
for each synchronized block. If you don't want that, disable directory
tracking.
This mode replaces the previous heuristic setting enabled with -O, where we
would log directory enter/leave for each synchronized output. Now we only
do that if --trace=dir is given.
If output-sync is enabled, have make write the command line to the temp file
instead of printing it directly to the screen to ensure that the output is
ordered properly. Also, remove extraneous enter/leave operations by having
them printed directly when dumping temp file output.
If we are not going to sync a command line then dump any collected output
first to preserve ordering. Do some code cleanup:
* Move the handle init to a separate function.
* Move the temp file truncation to the output function.
* Remember whether we sync in a variable for readability.
* Handle EINTR and short writes in child_out().
* Always call sync_output() in case output_sync was changed due to error.
Enhance the child_error() function so that it will write error output to the
child's sync output buffer, if it exists. If it doesn't the output goes to
stdout/stderr.
A new flag to the -O/--output-sync, "job", selects a per-job (that is, per
line of a recipe) output synchronization. To support this move the close of
the temp file out of the sync_output() function and don't do it until we free
the child, since we may call sync_output() multiple times in a given recipe.
When we set up for a new temp file, if we're in per-job mode we truncate the
file and seek to the beginning to re-use it for every job.
