for review: faster clean actions in .dep files

[Zoltan Somogyi]

Fergus, please review this.

modules.m:
	When creating .dep files, consolidate the action for the "mmake clean"
	and similar targets into single invocations of rm. This greatly reduces
	the number of processes that make will need to start, and thus should
	speed up these actions (especially on WNT, where process creation is
	slower than on Unix).

Zoltan.

Index: modules.m
===================================================================
RCS file: /home/mercury1/repository/mercury/compiler/modules.m,v
retrieving revision 1.45
diff -u -u -r1.45 modules.m
--- modules.m	1997/12/22 09:56:09	1.45
+++ modules.m	1997/12/30 09:15:45
@@ -961,7 +961,6 @@
 
 	io__write_strings(DepStream, [
 		ModuleName, ".check : $(", ModuleName, ".errs)\n\n",
-
 		ModuleName, ".ints : $(", ModuleName, ".dates)\n\n",
 		ModuleName, ".int3s : $(", ModuleName, ".date3s)\n\n",
 		ModuleName, ".opts : $(", ModuleName, ".optdates)\n\n"
@@ -973,32 +972,44 @@
 
 	io__write_strings(DepStream, [
 		ModuleName, ".clean :\n",
-		"\t-rm -rf ", ModuleName, ".dir\n",
-		"\t-rm -f $(", ModuleName, ".cs) ", ModuleName, "_init.c\n",
-		"\t-rm -f $(", ModuleName, ".ss) ", ModuleName, "_init.s\n",
-		"\t-rm -f $(", ModuleName, ".os) ", ModuleName, "_init.o\n",
-		"\t-rm -f $(", ModuleName, ".nos)\n",
-		"\t-rm -f $(", ModuleName, ".qls)\n",
-		"\t-rm -f $(", ModuleName, ".errs)\n"
+		"\t-rm -rf ",
+		ModuleName, ".dir ",
+		"\\\n\t",
+		ModuleName, "_init.c ",
+		ModuleName, "_init.s ",
+		ModuleName, "_init.o ",
+		"\\\n\t",
+		"$(", ModuleName, ".cs) ",
+		"$(", ModuleName, ".ss) ",
+		"$(", ModuleName, ".os) ",
+		"\\\n\t",
+		"$(", ModuleName, ".nos) ",
+		"$(", ModuleName, ".qls) ",
+		"$(", ModuleName, ".errs)\n\n"
 	]),
 
-	io__write_string(DepStream, "\n"),
-
 	io__write_strings(DepStream, [
 		ModuleName, ".change_clean :\n",
-		"\t-rm -f $(", ModuleName, ".cs) ", ModuleName, "_init.c\n",
-		"\t-rm -f $(", ModuleName, ".ss) ", ModuleName, "_init.s\n",
-		"\t-rm -f $(", ModuleName, ".os) ", ModuleName, "_init.o\n",
-		"\t-rm -f $(", ModuleName, ".hs)\n",
-		"\t-rm -f $(", ModuleName, ".ds)\n",
 		"\t-rm -f ",
-			ModuleName, " ",
-			ModuleName, ".split ",
-			ModuleName, ".split.a ",
-			ModuleName, ".init ",
-			"lib", ModuleName, ".a ",
-			"lib", ModuleName, ".so ",
-			ModuleName, ".dep\n\n"
+		ModuleName, "_init.c ",
+		ModuleName, "_init.s ",
+		ModuleName, "_init.o ",
+		"\\\n\t",
+		"$(", ModuleName, ".cs) ",
+		"$(", ModuleName, ".ss) ",
+		"$(", ModuleName, ".os) ",
+		"\\\n\t",
+		"$(", ModuleName, ".hs) ",
+		"$(", ModuleName, ".ds) ",
+		"\\\n\t",
+		ModuleName, ".split ",
+		ModuleName, ".split.a ",
+		ModuleName, ".init ",
+		"\\\n\t",
+		ModuleName, " ",
+		"lib", ModuleName, ".a ",
+		"lib", ModuleName, ".so ",
+		ModuleName, ".dep\n\n"
 	]),
 
 	io__write_strings(DepStream, [
@@ -1007,31 +1018,36 @@
 
 	io__write_strings(DepStream, [
 		ModuleName, ".realclean : ", ModuleName, ".clean\n",
-		"\t-rm -f $(", ModuleName, ".dates)\n",
-		"\t-rm -f $(", ModuleName, ".date3s)\n",
-		"\t-rm -f $(", ModuleName, ".optdates)\n",
-		"\t-rm -f $(", ModuleName, ".ints)\n",
-		"\t-rm -f $(", ModuleName, ".int3s)\n",
-		"\t-rm -f $(", ModuleName, ".opts)\n",
-		"\t-rm -f $(", ModuleName, ".ds)\n",
-		"\t-rm -f $(", ModuleName, ".hs)\n"
-	]),
-	io__write_strings(DepStream, [
 		"\t-rm -f ",
-			ModuleName, " ",
-			ModuleName, ".split ",
-			ModuleName, ".split.a ",
-			ModuleName, ".init ",
-			"lib", ModuleName, ".a ",
-			"lib", ModuleName, ".so ",
-			ModuleName, ".nu ",
-			ModuleName, ".nu.save ",
-			ModuleName, ".nu.debug.save ",
-			ModuleName, ".nu.debug ",
-			ModuleName, ".sicstus ",
-			ModuleName, ".sicstus.debug ",
-			ModuleName, ".dep\n\n"
+		"$(", ModuleName, ".dates) ",
+		"$(", ModuleName, ".date3s) ",
+		"$(", ModuleName, ".optdates) ",
+		"\\\n\t",
+		"$(", ModuleName, ".ints) ",
+		"$(", ModuleName, ".int3s) ",
+		"$(", ModuleName, ".opts) ",
+		"\\\n\t",
+		"$(", ModuleName, ".ds) ",
+		"$(", ModuleName, ".hs) ",
+		"\\\n\t",
+		ModuleName, ".split ",
+		ModuleName, ".split.a ",
+		ModuleName, ".init ",
+		"\\\n\t",
+		ModuleName, " ",
+		"lib", ModuleName, ".a ",
+		"lib", ModuleName, ".so ",
+		"\\\n\t",
+		ModuleName, ".nu ",
+		ModuleName, ".nu.save ",
+		ModuleName, ".nu.debug ",
+		ModuleName, ".nu.debug.save ",
+		"\\\n\t",
+		ModuleName, ".sicstus ",
+		ModuleName, ".sicstus.debug ",
+		ModuleName, ".dep\n\n"
 	]),
+
 	io__write_strings(DepStream, [
 		"clean_nu: ", ModuleName, ".clean_nu\n",
 		ModuleName, ".clean_nu :\n",