Preserve the real value of -jN in MAKEFLAGS using jobserver.

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.

tests/scripts/features/jobserver

@@ -12,6 +12,48 @@ if (!$parallel_jobs) {
   return -1;
 }
 
+# Shorthand
+my $np = '--no-print-directory';
+
+# Simple test of MAKEFLAGS settings
+run_make_test(q!
+SHOW = $(patsubst --jobserver-auth=%,--jobserver-auth=<auth>,$(MAKEFLAGS))
+recurse: ; @echo $@: "/$(SHOW)/"; $(MAKE) -f #MAKEFILE# all
+all:;@echo $@: "/$(SHOW)/"
+!,
+              "-j2 $np", "recurse: /-j2 --jobserver-auth=<auth> $np/\nall: /-j2 --jobserver-auth=<auth> $np/\n");
+
+# Setting parallelism with the environment
+# Command line should take precedence over the environment
+$extraENV{MAKEFLAGS} = "-j2 $np";
+run_make_test(q!
+SHOW = $(patsubst --jobserver-auth=%,--jobserver-auth=<auth>,$(MAKEFLAGS))
+recurse: ; @echo $@: "/$(SHOW)/"; $(MAKE) -f #MAKEFILE# all
+all:;@echo $@: "/$(SHOW)/"
+!,
+              '', "recurse: /-j2 --jobserver-auth=<auth> $np/\nall: /-j2 --jobserver-auth=<auth> $np/\n");
+delete $extraENV{MAKEFLAGS};
+
+# Test override of -jN
+$extraENV{MAKEFLAGS} = "-j9 $np";
+run_make_test(q!
+SHOW = $(patsubst --jobserver-auth=%,--jobserver-auth=<auth>,$(MAKEFLAGS))
+recurse: ; @echo $@: "/$(SHOW)/"; $(MAKE) -j3 -f #MAKEFILE# recurse2
+recurse2: ; @echo $@: "/$(SHOW)/"; $(MAKE) -f #MAKEFILE# all
+all:;@echo $@: "/$(SHOW)/"
+!,
+              "-j2 $np", "recurse: /-j2 --jobserver-auth=<auth> $np/\n#MAKE#[1]: warning: -jN forced in submake: disabling jobserver mode.\nrecurse2: /-j3 --jobserver-auth=<auth> $np/\nall: /-j3 --jobserver-auth=<auth> $np/\n");
+delete $extraENV{MAKEFLAGS};
+
+# Test override of -jN with -j
+run_make_test(q!
+SHOW = $(patsubst --jobserver-auth=%,--jobserver-auth=<auth>,$(MAKEFLAGS))
+recurse: ; @echo $@: "/$(SHOW)/"; $(MAKE) -j -f #MAKEFILE# recurse2
+recurse2: ; @echo $@: "/$(SHOW)/"; $(MAKE) -f #MAKEFILE# all
+all:;@echo $@: "/$(SHOW)/"
+!,
+              "-j2 $np", "recurse: /-j2 --jobserver-auth=<auth> $np/\n#MAKE#[1]: warning: -jN forced in submake: disabling jobserver mode.\nrecurse2: /-j $np/\nall: /-j $np/\n");
+
 # Don't put --jobserver-auth into a re-exec'd MAKEFLAGS.
 # We can't test this directly because there's no way a makefile can
 # show the value of MAKEFLAGS we were re-exec'd with.  We can intuit it
@@ -34,7 +76,7 @@ inc.mk:
 #	@echo 'MAKEFLAGS = $(MAKEFLAGS)'
 	@echo 'FOO = bar' > $@
 !,
-              '--no-print-directory -j2', "#MAKE#[1]: warning: -jN forced in submake: disabling jobserver mode.\nall\n");
+              "$np -j2", "#MAKE#[1]: warning: -jN forced in submake: disabling jobserver mode.\nall\n");
 
 unlink('inc.mk');
 
@@ -52,7 +94,7 @@ close(MAKEFILE);
 run_make_test(q!
 default: ; @ #MAKEPATH# -f Makefile2
 !,
-              '-j2 --no-print-directory',
+              "-j2 $np",
 "#MAKE#[1]: warning: jobserver unavailable: using -j1.  Add '+' to parent make rule.
 #MAKE#[1]: Nothing to be done for 'foo'.");
 

tests/scripts/features/output-sync

@@ -140,7 +140,7 @@ bar: start
 bar: end
 baz: start
 baz: end
-#MAKE#[1]: Leaving directory '#PWD#/bar'\n", 0, 6);
+#MAKE#[1]: Leaving directory '#PWD#/bar'\n", 0, 10);
 
 # Test per-target synchronization.
 # Note we have to sleep again here after starting the foo makefile before
@@ -171,7 +171,7 @@ foo: end
 #MAKE#[1]: Entering directory '#PWD#/bar'
 baz: start
 baz: end
-#MAKE#[1]: Leaving directory '#PWD#/bar'\n", 0, 6);
+#MAKE#[1]: Leaving directory '#PWD#/bar'\n", 0, 10);
 
 # Rerun but this time suppress the directory tracking
 unlink(@syncfiles);
@@ -183,7 +183,7 @@ bar: end
 foo: start
 foo: end
 baz: start
-baz: end\n", 0, 6);
+baz: end\n", 0, 10);
 
 # Test that messages from make itself are enclosed with
 # "Entering/Leaving directory" messages.
@@ -236,7 +236,7 @@ bar: end
 #MAKE#[1]: Leaving directory '#PWD#/bar'
 #MAKE#[1]: Entering directory '#PWD#/foo'
 foo: end
-#MAKE#[1]: Leaving directory '#PWD#/foo'\n", 0, 6);
+#MAKE#[1]: Leaving directory '#PWD#/foo'\n", 0, 10);
 
 
 # Remove temporary directories and contents.

tests/scripts/variables/MAKEFLAGS

@@ -39,3 +39,7 @@ jump Works: MAKEFLAGS=e --no-print-directory
 print Works: MAKEFLAGS=e --no-print-directory');
 
 1;
+
+### Local Variables:
+### eval: (setq whitespace-action (delq 'auto-cleanup whitespace-action))
+### End: