use xopen() to handle fatal open(2) failures

Add and apply a semantic patch for using xopen() instead of calling
open(2) and die() or die_errno() explicitly.  This makes the error
messages more consistent and shortens the code.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/contrib/coccinelle/xopen.cocci b/contrib/coccinelle/xopen.cocci
new file mode 100644
index 0000000000..814d7b8a1a
--- /dev/null
+++ b/contrib/coccinelle/xopen.cocci
@@ -0,0 +1,16 @@
+@@
+identifier fd;
+identifier die_fn =~ "^(die|die_errno)$";
+@@
+(
+  fd =
+- open
++ xopen
+  (...);
+|
+  int fd =
+- open
++ xopen
+  (...);
+)
+- if ( \( fd < 0 \| fd == -1 \) ) { die_fn(...); }