From: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Date: Sun, 1 Nov 2009 18:39:58 +0000 (+0100)
Subject: Fix handling of the -MD and -MDD options
X-Git-Tag: v3.0pre0~187
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8354384f67bc733bea5a9dc8e5e90fc0bc75e32;p=thirdparty%2Fccache.git

Fix handling of the -MD and -MDD options

From <http://lists.samba.org/archive/ccache/2007q2/000272.html>:

The -MD and -MDD options automatically determine where the dependency file
should land and what the target should look like based on the -o option.
However, ccache drops -o and things mess up. The original patch was posted by
Kaz Kylheku but I reworked it to make it work properly. Here is his post:

http://lists.samba.org/archive/ccache/2006q4/000249.html
---

diff --git a/ccache.c b/ccache.c
index 172fcb131..b80a0de9e 100644
--- a/ccache.c
+++ b/ccache.c
@@ -651,6 +651,13 @@ static void process_args(int argc, char **argv)
 	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);
 
@@ -728,6 +735,18 @@ static void process_args(int argc, char **argv)
 			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",
@@ -840,6 +859,41 @@ static void process_args(int argc, char **argv)
 		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 */
 	if (strcmp(output_file,"/dev/null") != 0 && stat(output_file, &st) == 0 && !S_ISREG(st.st_mode)) {
 		cc_log("Not a regular file %s\n", output_file);