This patch adds -. to cpp and teaches cc to pass this
through when -p is active.

Reference: /n/sources/patch/applied/cpp-add-dash-dot
Date: Thu Aug 16 00:33:53 CES 2007
Signed-off-by: nwfilardo@gmail.com

--- /sys/src/cmd/cc/lex.c	Thu Aug 16 00:33:55 2007
+++ /sys/src/cmd/cc/lex.c	Thu Aug 16 00:33:54 2007
@@ -30,6 +30,7 @@
  *	-v		verbose printing
  *	-w		print warnings
  *	-X		abort on error
+ *	-.		Inhibit search for includes in source directory
  */
 
 void
@@ -241,6 +242,10 @@
 			close(fd[1]);
 			av[0] = CPP;
 			i = 1;
+			if(debug['.']){
+				sprint(opt, "-.");
+				av[i++] = strdup(opt);
+			}
 			if(debug['+']) {
 				sprint(opt, "-+");
 				av[i++] = strdup(opt);
--- /sys/src/cmd/cpp/nlist.c	Thu Aug 16 00:33:56 2007
+++ /sys/src/cmd/cpp/nlist.c	Thu Aug 16 00:33:55 2007
@@ -63,6 +63,7 @@
 	static Token deftoken[1] = {{ NAME, 0, 0, 0, 7, (uchar*)"defined" }};
 	static Tokenrow deftr = { deftoken, deftoken, deftoken+1, 1 };
 	int debuginclude = 0;
+	int nodot = 0;
 	char xx[2] = { 0, 0};
 
 	for (kp=kwtab; kp->kw; kp++) {
@@ -148,6 +149,9 @@
 		case 'P':
 			nolineinfo++;
 			break;
+		case '.':
+			nodot++;
+			break;
 		default:
 			xx[0] = ARGC();
 			error(FATAL, "Unknown argument '%s'", xx);
@@ -176,6 +180,8 @@
 		setobjname(fp);
 	includelist[NINCLUDE-1].always = 0;
 	includelist[NINCLUDE-1].file = dp;
+	if(nodot)
+		includelist[NINCLUDE-1].deleted = 1;
 	setsource(fp, fd, NULL);
 	if (debuginclude) {
 		for (i=0; i<NINCLUDE; i++)
--- /sys/man/1/cpp	Thu Aug 16 00:33:57 2007
+++ /sys/man/1/cpp	Thu Aug 16 00:33:56 2007
@@ -70,6 +70,9 @@
 .B -+
 Understand C++ comments.
 .TP
+.B -.
+Inhibit include search in the source's directory.
+.TP
 .B -i
 Print the list of directories searched when
 .I #include