[PATCH 09/12] {builtin/*,repository}.c: add & use "USE_THE_INDEX_VARIABLE"

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Split up the "USE_THE_INDEX_COMPATIBILITY_MACROS" into that setting
and a more narrow "USE_THE_INDEX_VARIABLE". In the case of these
built-ins we only need "the_index" variable, but not the compatibility
wrapper for functions we're not using.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/cat-file.c   | 2 +-
 builtin/difftool.c   | 2 +-
 builtin/merge-tree.c | 2 +-
 builtin/pull.c       | 2 +-
 cache.h              | 6 +++++-
 repository.c         | 2 +-
 6 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index fa7bd891692..b3be58b1fb0 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -3,7 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
diff --git a/builtin/difftool.c b/builtin/difftool.c
index d7f08c8a7fa..d9b76226f6a 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -11,7 +11,7 @@
  *
  * Copyright (C) 2016 Johannes Schindelin
  */
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index fe853aa8f91..e3767087bbf 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -1,4 +1,4 @@
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "builtin.h"
 #include "tree-walk.h"
 #include "xdiff-interface.h"
diff --git a/builtin/pull.c b/builtin/pull.c
index 4a2a6db2dce..1ab4de0005d 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -5,7 +5,7 @@
  *
  * Fetch one or more remote refs and merge it/them into the current HEAD.
  */
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
diff --git a/cache.h b/cache.h
index 8b54b627459..72c3d4e2ef5 100644
--- a/cache.h
+++ b/cache.h
@@ -433,9 +433,11 @@ typedef int (*must_prefetch_predicate)(const struct cache_entry *);
 void prefetch_cache_entries(const struct index_state *istate,
 			    must_prefetch_predicate must_prefetch);
 
-#ifdef USE_THE_INDEX_COMPATIBILITY_MACROS
+#if defined(USE_THE_INDEX_COMPATIBILITY_MACROS) || defined(USE_THE_INDEX_VARIABLE)
 extern struct index_state the_index;
 
+#ifndef USE_THE_INDEX_VARIABLE
+#ifdef USE_THE_INDEX_COMPATIBILITY_MACROS
 #define active_nr (the_index.cache_nr)
 #define active_cache_tree (the_index.cache_tree)
 
@@ -448,6 +450,8 @@ extern struct index_state the_index;
 #define refresh_and_write_cache(refresh_flags, write_flags, gentle) repo_refresh_and_write_index(the_repository, (refresh_flags), (write_flags), (gentle), NULL, NULL, NULL)
 #define hold_locked_index(lock_file, flags) repo_hold_locked_index(the_repository, (lock_file), (flags))
 #endif
+#endif
+#endif
 
 #define TYPE_BITS 3
 
diff --git a/repository.c b/repository.c
index 5d166b692c8..3427085fd6d 100644
--- a/repository.c
+++ b/repository.c
@@ -2,7 +2,7 @@
  * not really _using_ the compat macros, just make sure the_index
  * declaration matches the definition in this file.
  */
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "cache.h"
 #include "repository.h"
 #include "object-store.h"
-- 
2.38.0.1511.gcdcff1f1dc2