dtc: Implement -d option to write out a dependency file

This will allow callers to rebuild .dtb files when any of the /include/d
.dtsi files are modified, not just the top-level .dts file.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 4 insertions, 0 deletions

diff --git a/srcpos.c b/srcpos.c
index 2dbc874..36a38e9 100644
--- a/srcpos.c
+++ b/srcpos.c
@@ -40,6 +40,7 @@ static char *dirname(const char *path)
 	return NULL;
 }
 
+FILE *depfile; /* = NULL */
 struct srcfile_state *current_srcfile; /* = NULL */
 
 /* Detect infinite include recursion. */
@@ -67,6 +68,9 @@ FILE *srcfile_relative_open(const char *fname, char **fullnamep)
 			    strerror(errno));
 	}
 
+	if (depfile)
+		fprintf(depfile, " %s", fullname);
+
 	if (fullnamep)
 		*fullnamep = fullname;
 	else