Add POSIX -p flag to make(1).

This article [1] describes the -p flag for make(1):

	Write to standard output the complete set of macro definitions and
	target descriptions. The output format is unspecified.

We already support a similar flag (-d g1), but unlike -p, it still
executes commands. Our implementation just turns it into -d g1, but also
sets flag `printGraphOnly', which will cause make(1) to skip execution.

[1] http://www.opengroup.org/onlinepubs/009695399/utilities/make.html

Reviewed by:	imp
PR:		standards/99960

1 files changed, 10 insertions, 1 deletions

diff --git a/usr.bin/make/make.1 b/usr.bin/make/make.1
index 173aef3..44421e5 100644
--- a/usr.bin/make/make.1
+++ b/usr.bin/make/make.1
@@ -40,7 +40,7 @@
 .Nd maintain program dependencies
 .Sh SYNOPSIS
 .Nm
-.Op Fl ABPSXeiknqrstv
+.Op Fl ABPSXeiknpqrstv
 .Op Fl C Ar directory
 .Op Fl D Ar variable
 .Op Fl d Ar flags
@@ -249,6 +249,15 @@ instead of mixing the output of parallel jobs together.
 This option has no effect unless
 .Fl j
 is used too.
+.It Fl p
+Only print the input graph, not executing any commands.
+The output is the same as
+.Fl d Ar g1 .
+When combined with
+.Fl f Pa /dev/null ,
+only the builtin rules of
+.Nm
+are displayed.
 .It Fl q
 Do not execute any commands, but exit 0 if the specified targets are
 up-to-date and 1, otherwise.