change flag -xs to -i, -xm to -m, dependencies

lang/cem/cpp.ansi/main.c

@@ -6,15 +6,22 @@
 /* MAIN PROGRAM */
 
 #include	<alloc.h>
+#include	<assert.h>
 #include	<system.h>
 #include 	"arith.h"
 #include	"file_info.h"
 #include	"idfsize.h"
+#include	"idf.h"
+#include	"macro.h"
 
 extern char *symbol2str();
 extern char *getwdir();
 extern int err_occurred;
+extern int do_dependencies;
+extern char *dep_file;
 int idfsize = IDFSIZE;
+extern char options[];
+static File *dep_fd = STDOUT;
 
 arith ifval;
 
@@ -81,6 +88,66 @@ compile(argc, argv)
 			source ? source : "stdin");
 	if (source) WorkingDir = getwdir(dummy);
 	preprocess(source);
+	if (do_dependencies) list_dependencies(source);
+}
+
+struct idf	*file_head;
+extern char *strrindex();
+
+list_dependencies(source)
+	char *source;
+{
+	register struct idf *p = file_head;
+
+	if (source) {
+		register char *s = strrindex(source, '.');
+
+		if (s && *(s+1)) {
+			s++;
+			*s++ = 'o';
+			*s = '\0';
+                        /* the source may be in another directory than the
+                         * object generated, so don't include the pathname
+                         * leading to it.
+                         */
+                        if (s = strrindex(source, '/')) {
+                                source = s + 1;
+                        }
+		}
+		else source = 0; 
+	}
+	if (dep_file && !sys_open(dep_file, OP_WRITE, &dep_fd)) {
+		fatal("could not open %s", dep_file);
+	}
+	while (p) {
+		assert(p->id_resmac == K_FILE);
+		dependency(p->id_text, source);
+		p = p->id_file;
+	}
+}
+
+add_dependency(s)
+	char *s;
+{
+	register struct idf *p = str2idf(s, 0);
+
+	if (! p->id_resmac) {
+		p->id_resmac = K_FILE;
+		p->id_file = file_head;
+		file_head = p;
+	}
+}
+
+dependency(s, source)
+	char *s, *source;
+{
+	if (options['i'] && !strncmp(s, "/usr/include/", 13)) {
+		return;
+	}
+	if (options['m'] && source) {
+		fprint(dep_fd, "%s: %s\n", source, s);
+	}
+	else	fprint(dep_fd, "%s\n", s);
 }
 
 No_Mem()				/* called by alloc package */