major overhaul of the way make handle jobs, inspired by dpb:

instead of forking a "job" per target, and having that job further fork
separate commands, have make maintain a list of jobs, indexed by pid
of currently running commands, and handle process termination
continuation-style.  This has lots of benefits:
- make is responsible for most printing, so we no longer need pipes nor
job control: make -j jobs see the tty.
- no more special-casing for jobs that don't really execute anything.
- unify code for make -jn and make -B, including signal handlers and
job waiting.  So make -n, make -q, +cmd now run commands in the same
way in all cases.
- unified more accurate error-reporting, as make knows precisely which
command failed. Commands are tagged with their lines, and we display failing
commands in silent mode.
- fine-grained "expensive" command handling (recursion limiter). Do it
per-command instead of per-target.

Moreover, signal response is now simpler, as we just block the signals
in a small critical sections, test for events, and sigpause (thanks a lot
to guenther@ and millert@), so running make is now almost always paused
without any busy-waiting.

Thanks to everyone who tested and gave input.

1 files changed, 8 insertions, 4 deletions

diff --git a/usr.bin/make/defines.h b/usr.bin/make/defines.h
index 267860fc1aa..a0b20860d48 100644
--- a/usr.bin/make/defines.h
+++ b/usr.bin/make/defines.h
@@ -1,7 +1,7 @@
 #ifndef DEFINES_H
 #define DEFINES_H
 
-/*	$OpenBSD: defines.h,v 1.10 2012/03/22 13:47:12 espie Exp $ */
+/*	$OpenBSD: defines.h,v 1.11 2012/09/21 07:55:20 espie Exp $ */
 
 /*
  * Copyright (c) 2001 Marc Espie.
@@ -57,6 +57,9 @@ struct Name;
 struct ListNode_;
 typedef struct ListNode_ *LstNode;
 
+struct Job_;
+typedef struct Job_ Job;
+
 /* some useful defines for gcc */
 
 #ifdef __GNUC__
@@ -91,9 +94,10 @@ extern int debug;
 #define DEBUG_VAR	0x0200
 #define DEBUG_FOR	0x0400
 #define DEBUG_LOUD	0x0800
-#define DEBUG_JOBBANNER	0x1000
-#define DEBUG_PARALLEL	0x2000
-#define DEBUG_NAME_MATCHING	0x4000
+#define DEBUG_PARALLEL	0x1000
+#define DEBUG_NAME_MATCHING	0x2000
+#define DEBUG_QUICKDEATH	0x4000
+#define DEBUG_EXPENSIVE		0x8000
 
 #define CONCAT(a,b)	a##b