Make second expansion optional (partial implementation).

I decided this feature was too impacting to make the permanent default
behavior.  This set of changes makes the default behavior of make the
old behavior (no second expansion).  If you want second expansion, you
must define the .SECONDEXPANSION: special target before the first target
that needs it.

This set of changes ONLY fixes explicit and static pattern rules to work
like this.  Implicit rules still have second expansion enabled all the
time: I'll work on that next.

Note that there is still a backward-incompatibility: now to get the old
SysV behavior using $$@ etc. in the prerequisites list you need to set
.SECONDEXPANSION: as well.

1 files changed, 36 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 83e1fa8..1aadcd6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,39 @@
+2005-10-24  Paul D. Smith  <psmith@gnu.org>
+
+	Make secondary expansion optional: its enabled by declaring the
+	special target .SECONDEXPANSION.
+
+	* NEWS: Update information on second expansion capabilities.
+	* doc/make.texi (Secondary Expansion): Document the
+	.SECONDEXPANSION special target and its behavior.
+	* dep.h (struct dep): Add a flag STATICPATTERN, set to true if the
+	prerequisite list was found in a static pattern rule.
+	(free_dep_chain): Declare a prototype.
+	* file.c (parse_prereqs): New function: break out some complexity
+	from expand_deps().
+	(expand_deps): If we aren't doing second expansion, replace % with
+	the stem for static pattern rules.  Call the new function.
+	* filedef.h (parse_prereqs): Declare a prototype.
+	* implicit.c (pattern_search): Initialize the new staticpattern
+	field.
+	* main.c (second_expansion): Declare a global variable to remember
+	if the special target has been seen.  Initialize the new
+	staticpattern field for prerequisites.
+	* make.h: Extern for second_expansion.
+	* misc.c (free_dep_chain): New function: frees a struct dep list.
+	* read.c (read_all_makefiles): Initialize the staticpattern field.
+	(eval_makefile): Ditto.
+	(record_files): Check for the .SECONDEXPANSION target and set
+	second_expansion global if it's found.
+	Use the new free_dep_chain() instead of doing it by hand.
+	Set the staticpattern field for prereqs of static pattern targets.
+
+2005-10-16  Paul D. Smith  <psmith@gnu.org>
+
+	* main.c (main): Set CURDIR to be a file variable instead of a
+	default, so that values of CURDIR inherited from the environment
+	won't override the make value.
+
 2005-09-26  Paul D. Smith  <psmith@gnu.org>
 
 	* job.c (construct_command_argv_internal): If the line is empty