make has had heuristics to avoid parallel make recursion.

Sometimes they mess up, so add .CHEAP/.EXPENSIVE to explicitly tell make
'hey this is not THAT bad' or 'worse than you think'.
agreed by guenther@, millert@ (and some tweaks)

6 files changed, 33 insertions, 9 deletions

diff --git a/usr.bin/make/generate.c b/usr.bin/make/generate.c
index 4ca1a08e912..9cf59126365 100644
--- a/usr.bin/make/generate.c
+++ b/usr.bin/make/generate.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: generate.c,v 1.12 2010/07/19 19:46:44 espie Exp $ */
+/*	$OpenBSD: generate.c,v 1.13 2012/04/11 18:27:30 espie Exp $ */
 
 /*
  * Copyright (c) 2001 Marc Espie.
@@ -116,6 +116,8 @@ char *table_nodes[] = {
 	M(NODE_BEGIN),
 	M(NODE_END),
 	M(NODE_INTERRUPT),
+	M(NODE_CHEAP),
+	M(NODE_EXPENSIVE),
 	NULL
 };
 
diff --git a/usr.bin/make/gnode.h b/usr.bin/make/gnode.h
index 6dc9d18e1e7..25f5032a2ef 100644
--- a/usr.bin/make/gnode.h
+++ b/usr.bin/make/gnode.h
@@ -1,6 +1,6 @@
 #ifndef GNODE_H
 #define GNODE_H
-/*	$OpenBSD: gnode.h,v 1.18 2012/03/22 13:47:12 espie Exp $ */
+/*	$OpenBSD: gnode.h,v 1.19 2012/04/11 18:27:30 espie Exp $ */
 
 /*
  * Copyright (c) 2001 Marc Espie.
@@ -205,6 +205,8 @@ struct GNode_ {
 				     * commands for a target */
 #define OP_DEPS_FOUND	0x00800000  /* Already processed by Suff_FindDeps */
 #define OP_RESOLVED	0x01000000  /* We looked harder already */
+#define OP_CHEAP	0x02000000  /* Assume job is not recursive */
+#define OP_EXPENSIVE	0x04000000  /* Recursive job, don't run in parallel */
 
 /*
  * OP_NOP will return true if the node with the given type was not the
diff --git a/usr.bin/make/job.c b/usr.bin/make/job.c
index 374bdb7bd88..82f992362d0 100644
--- a/usr.bin/make/job.c
+++ b/usr.bin/make/job.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: job.c,v 1.121 2012/03/22 13:47:12 espie Exp $	*/
+/*	$OpenBSD: job.c,v 1.122 2012/04/11 18:27:30 espie Exp $	*/
 /*	$NetBSD: job.c,v 1.16 1996/11/06 17:59:08 christos Exp $	*/
 
 /*
@@ -836,9 +836,12 @@ prepare_job(GNode *gn, int flags)
 		 * by the caller are also added to the field.
 		 */
 		job->flags = flags;
-		if (expensive_commands(&gn->expanded)) {
+
+		if (gn->type & OP_CHEAP)
+			return job;
+		if ((gn->type & OP_EXPENSIVE) || 
+		    expensive_commands(&gn->expanded))
 			job->flags |= JOB_IS_EXPENSIVE;
-		}
 
 		return job;
 	}
diff --git a/usr.bin/make/make.1 b/usr.bin/make/make.1
index a438994b4f1..5b031fce343 100644
--- a/usr.bin/make/make.1
+++ b/usr.bin/make/make.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: make.1,v 1.92 2011/05/02 11:14:11 jmc Exp $
+.\"	$OpenBSD: make.1,v 1.93 2012/04/11 18:27:30 espie Exp $
 .\"	$NetBSD: make.1,v 1.18 1997/03/10 21:19:53 christos Exp $
 .\"
 .\" Copyright (c) 1990, 1993
@@ -30,7 +30,7 @@
 .\"
 .\"	from: @(#)make.1	8.4 (Berkeley) 3/19/94
 .\"
-.Dd $Mdocdate: May 2 2011 $
+.Dd $Mdocdate: April 11 2012 $
 .Dt MAKE 1
 .Os
 .Sh NAME
@@ -1184,6 +1184,12 @@ the only target specified.
 .It Ic .BEGIN
 Any command lines attached to this target are executed before anything
 else is done.
+.It Ic .CHEAP
+In parallel mode, don't scan the commands for
+.Nm ,
+let recursive
+.Fl j
+behavior apply.
 .It Ic .DEFAULT
 This is sort of a
 .Ic .USE
@@ -1201,6 +1207,11 @@ to the target's own name.
 .It Ic .END
 Any command lines attached to this target are executed after everything
 else is done.
+.It Ic .EXPENSIVE
+In parallel mode, don't scan the commands for
+.Nm ,
+assume target is recursive and don't start other jobs until
+it is finished.
 .It Ic .IGNORE
 Mark each of the sources with the
 .Ic .IGNORE
diff --git a/usr.bin/make/node_int.h b/usr.bin/make/node_int.h
index 1f063c6cb15..707978edd11 100644
--- a/usr.bin/make/node_int.h
+++ b/usr.bin/make/node_int.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: node_int.h,v 1.2 2010/07/19 19:30:37 espie Exp $ */
+/* $OpenBSD: node_int.h,v 1.3 2012/04/11 18:27:30 espie Exp $ */
 
 /*
  * Copyright (c) 2007 Marc Espie.
@@ -59,3 +59,5 @@
 #define NODE_BEGIN	".BEGIN"
 #define NODE_END	".END"
 #define NODE_INTERRUPT	".INTERRUPT"
+#define NODE_CHEAP	".CHEAP"
+#define NODE_EXPENSIVE	".EXPENSIVE"
diff --git a/usr.bin/make/parse.c b/usr.bin/make/parse.c
index 928a81c6f11..72fc76e475d 100644
--- a/usr.bin/make/parse.c
+++ b/usr.bin/make/parse.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.c,v 1.101 2012/03/22 13:47:12 espie Exp $	*/
+/*	$OpenBSD: parse.c,v 1.102 2012/04/11 18:27:30 espie Exp $	*/
 /*	$NetBSD: parse.c,v 1.29 1997/03/10 21:20:04 christos Exp $	*/
 
 /*
@@ -194,6 +194,8 @@ static void dump_targets(void);
 #define SPECIAL_WAIT		29U
 #define SPECIAL_NOPATH		30U
 #define SPECIAL_ERROR		31U
+#define SPECIAL_CHEAP		32U
+#define SPECIAL_EXPENSIVE	33U
 
 
 #define P(k) k, sizeof(k), K_##k
@@ -232,6 +234,8 @@ static struct {
     { P(NODE_SUFFIXES),	SPECIAL_SUFFIXES | SPECIAL_TARGET,	0, },
     { P(NODE_USE),	SPECIAL_USE | SPECIAL_TARGETSOURCE,	OP_USE, },
     { P(NODE_WAIT),	SPECIAL_WAIT | SPECIAL_TARGETSOURCE,	0 },
+    { P(NODE_CHEAP),	SPECIAL_CHEAP | SPECIAL_TARGETSOURCE,	OP_CHEAP, },
+    { P(NODE_EXPENSIVE),SPECIAL_EXPENSIVE | SPECIAL_TARGETSOURCE,OP_EXPENSIVE, },
 #if 0
 	{ P(NODE_NOPATH),	SPECIAL_NOPATH, },
 #endif