--- ccache.c	Mon Sep 13 11:38:30 2004

+++ ccache.c	Thu Jun 21 22:17:32 2007

@@ -627,6 +627,13 @@ static void process_args(int argc, char 

 	int found_S_opt = 0;

 	struct stat st;

 	char *e;

+	/* is gcc being asked to output dependencies? */

+	int generating_dependencies = 0;

+	/* is the dependency makefile name overridden with -MF? */

+	int dependency_filename_specified = 0;

+	/* is the dependency makefile target name specified with -MQ or -MF? */

+	int dependency_target_specified = 0;

+

 	stripped_args = args_init(0, NULL);

@@ -702,6 +709,18 @@ static void process_args(int argc, char 

 			continue;

 		}

+		/* These options require special handling, because they

+		   behave differently with gcc -E, when the output

+		   file is not specified. */

+

+		if (strcmp(argv[i], "-MD") == 0 || strcmp(argv[i], "-MMD") == 0) {

+			generating_dependencies = 1;

+		} else if (strcmp(argv[i], "-MF") == 0) {

+			dependency_filename_specified = 1;

+		} else if (strcmp(argv[i], "-MQ") == 0 || strcmp(argv[i], "-MT") == 0) {

+			dependency_target_specified = 1;

+		}

+

 		/* options that take an argument */

 		{

 			const char *opts[] = {"-I", "-include", "-imacros", "-iprefix",

@@ -812,6 +831,41 @@ static void process_args(int argc, char 

 		}

 		p[1] = found_S_opt ? 's' : 'o';

 		p[2] = 0;

+	}

+

+	/* If dependencies are generated, configure the preprocessor */

+

+	if (generating_dependencies && output_file) {

+		if (!dependency_filename_specified) {

+			char *default_depfile_name = x_strdup(output_file);

+			char *p = strrchr(default_depfile_name, '.');

+

+			if (p) {

+				if (strlen(p) < 2) {

+					stats_update(STATS_ARGS);

+					failed();

+					return;

+				}

+				*p = 0;

+			}

+			else  {

+				int len = p - default_depfile_name;

+				

+				p = x_malloc(len + 3);

+				strncpy(default_depfile_name, p, len - 1);

+				free(default_depfile_name);

+				default_depfile_name = p;

+			}

+

+			strcat(default_depfile_name, ".d");

+			args_add(stripped_args, "-MF");

+			args_add(stripped_args, default_depfile_name);

+		}

+

+		if (!dependency_target_specified) {

+			args_add(stripped_args, "-MT");

+			args_add(stripped_args, output_file);

+		}

 	}

 	/* cope with -o /dev/null */