[PATCH 1/4] .gitignore: introduce GITIGNORE_FILE CPP macro

[Junio C Hamano <gitster@pobox.com>]

GITATTRIBUTES_FILE and GITMODULES_FILE have their own CPP macros
that resolve to their string literals to help compilers catch typos.
Add one for ".gitignore" as well.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/read-tree.c | 3 ++-
 dir.c               | 4 ++--
 environment.h       | 1 +
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index a8cf8504b8..bc12f5bd16 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -6,6 +6,7 @@
 
 #include "builtin.h"
 #include "config.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "lockfile.h"
@@ -65,7 +66,7 @@ static int exclude_per_directory_cb(const struct option *opt, const char *arg,
 
 	if (!opts->update)
 		die("--exclude-per-directory is meaningless unless -u");
-	if (strcmp(arg, ".gitignore"))
+	if (strcmp(arg, GITIGNORE_FILE))
 		die("--exclude-per-directory argument must be .gitignore");
 	return 0;
 }
diff --git a/dir.c b/dir.c
index 45be4ad261..ec875e3878 100644
--- a/dir.c
+++ b/dir.c
@@ -2888,7 +2888,7 @@ static void new_untracked_cache(struct index_state *istate, int flags)
 {
 	struct untracked_cache *uc = xcalloc(1, sizeof(*uc));
 	strbuf_init(&uc->ident, 100);
-	uc->exclude_per_dir = ".gitignore";
+	uc->exclude_per_dir = GITIGNORE_FILE;
 	uc->dir_flags = flags >= 0 ? flags : new_untracked_cache_flags(istate);
 	set_untracked_ident(uc);
 	istate->untracked = uc;
@@ -3428,7 +3428,7 @@ static GIT_PATH_FUNC(git_path_info_exclude, "info/exclude")
 
 void setup_standard_excludes(struct dir_struct *dir)
 {
-	dir->exclude_per_dir = ".gitignore";
+	dir->exclude_per_dir = GITIGNORE_FILE;
 
 	/* core.excludesfile defaulting to $XDG_CONFIG_HOME/git/ignore */
 	if (!excludes_file)
diff --git a/environment.h b/environment.h
index e9f01d4d11..39c3c24a3f 100644
--- a/environment.h
+++ b/environment.h
@@ -43,6 +43,7 @@ const char *getenv_safe(struct strvec *argv, const char *name);
 #define GITMODULES_FILE ".gitmodules"
 #define GITMODULES_INDEX ":.gitmodules"
 #define GITMODULES_HEAD "HEAD:.gitmodules"
+#define GITIGNORE_FILE ".gitignore"
 #define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
 #define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
 #define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
-- 
2.45.2-711-gd2c001ca14