Merge branch 'en/header-cleanup'

Code clean-up to clarify the rule that "git-compat-util.h" must be
the first to be included.

* en/header-cleanup:
  diff.h: remove unnecessary include of object.h
  Remove unnecessary includes of builtin.h
  treewide: replace cache.h with more direct headers, where possible
  replace-object.h: move read_replace_refs declaration from cache.h to here
  object-store.h: move struct object_info from cache.h
  dir.h: refactor to no longer need to include cache.h
  object.h: stop depending on cache.h; make cache.h depend on object.h
  ident.h: move ident-related declarations out of cache.h
  pretty.h: move has_non_ascii() declaration from commit.h
  cache.h: remove dependence on hex.h; make other files include it explicitly
  hex.h: move some hex-related declarations from cache.h
  hash.h: move some oid-related declarations from cache.h
  alloc.h: move ALLOC_GROW() functions from cache.h
  treewide: remove unnecessary cache.h includes in source files
  treewide: remove unnecessary cache.h includes
  treewide: remove unnecessary git-compat-util.h includes in headers
  treewide: ensure one of the appropriate headers is sourced first

Author: gitster

Documentation/CodingGuidelines

@@ -442,8 +442,12 @@ For C programs:
    detail.
 
  - The first #include in C files, except in platform specific compat/
-   implementations, must be either "git-compat-util.h", "cache.h" or
-   "builtin.h".  You do not have to include more than one of these.
+   implementations and sha1dc/, must be either "git-compat-util.h" or
+   one of the approved headers that includes it first for you.  (The
+   approved headers currently include "cache.h", "builtin.h",
+   "t/helper/test-tool.h", "xdiff/xinclude.h", or
+   "reftable/system.h").  You do not have to include more than one of
+   these.
 
  - A C file must directly include the header files that declare the
    functions and the types it uses, except for the functions and types

add-interactive.c

@@ -3,6 +3,7 @@
 #include "color.h"
 #include "config.h"
 #include "diffcore.h"
+#include "hex.h"
 #include "revision.h"
 #include "refs.h"
 #include "string-list.h"

add-patch.c

@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "add-interactive.h"
+#include "alloc.h"
 #include "strbuf.h"
 #include "run-command.h"
 #include "strvec.h"

advice.c

@@ -1,6 +1,8 @@
-#include "cache.h"
+#include "git-compat-util.h"
+#include "advice.h"
 #include "config.h"
 #include "color.h"
+#include "gettext.h"
 #include "help.h"
 #include "string-list.h"
 

advice.h

@@ -1,8 +1,6 @@
 #ifndef ADVICE_H
 #define ADVICE_H
 
-#include "git-compat-util.h"
-
 struct string_list;
 
 /*

alias.c

@@ -1,6 +1,8 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "alias.h"
+#include "alloc.h"
 #include "config.h"
+#include "gettext.h"
 #include "string-list.h"
 
 struct config_alias_data {

alloc.c

@@ -8,7 +8,7 @@
  * up with maximal alignment because it doesn't know what the object alignment
  * for the new allocation is.
  */
-#include "cache.h"
+#include "git-compat-util.h"
 #include "object.h"
 #include "blob.h"
 #include "tree.h"

alloc.h

@@ -17,4 +17,79 @@ void *alloc_object_node(struct repository *r);
 struct alloc_state *allocate_alloc_state(void);
 void clear_alloc_state(struct alloc_state *s);
 
+#define alloc_nr(x) (((x)+16)*3/2)
+
+/**
+ * Dynamically growing an array using realloc() is error prone and boring.
+ *
+ * Define your array with:
+ *
+ * - a pointer (`item`) that points at the array, initialized to `NULL`
+ *   (although please name the variable based on its contents, not on its
+ *   type);
+ *
+ * - an integer variable (`alloc`) that keeps track of how big the current
+ *   allocation is, initialized to `0`;
+ *
+ * - another integer variable (`nr`) to keep track of how many elements the
+ *   array currently has, initialized to `0`.
+ *
+ * Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
+ * alloc)`.  This ensures that the array can hold at least `n` elements by
+ * calling `realloc(3)` and adjusting `alloc` variable.
+ *
+ * ------------
+ * sometype *item;
+ * size_t nr;
+ * size_t alloc
+ *
+ * for (i = 0; i < nr; i++)
+ * 	if (we like item[i] already)
+ * 		return;
+ *
+ * // we did not like any existing one, so add one
+ * ALLOC_GROW(item, nr + 1, alloc);
+ * item[nr++] = value you like;
+ * ------------
+ *
+ * You are responsible for updating the `nr` variable.
+ *
+ * If you need to specify the number of elements to allocate explicitly
+ * then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.
+ *
+ * Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some
+ * added niceties.
+ *
+ * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
+ */
+#define ALLOC_GROW(x, nr, alloc) \
+	do { \
+		if ((nr) > alloc) { \
+			if (alloc_nr(alloc) < (nr)) \
+				alloc = (nr); \
+			else \
+				alloc = alloc_nr(alloc); \
+			REALLOC_ARRAY(x, alloc); \
+		} \
+	} while (0)
+
+/*
+ * Similar to ALLOC_GROW but handles updating of the nr value and
+ * zeroing the bytes of the newly-grown array elements.
+ *
+ * DO NOT USE any expression with side-effect for any of the
+ * arguments.
+ */
+#define ALLOC_GROW_BY(x, nr, increase, alloc) \
+	do { \
+		if (increase) { \
+			size_t new_nr = nr + (increase); \
+			if (new_nr < nr) \
+				BUG("negative growth in ALLOC_GROW_BY"); \
+			ALLOC_GROW(x, new_nr, alloc); \
+			memset((x) + nr, 0, sizeof(*(x)) * (increase)); \
+			nr = new_nr; \
+		} \
+	} while (0)
+
 #endif

apply.c

@@ -8,12 +8,14 @@
  */
 
 #include "cache.h"
+#include "alloc.h"
 #include "config.h"
 #include "object-store.h"
 #include "blob.h"
 #include "delta.h"
 #include "diff.h"
 #include "dir.h"
+#include "hex.h"
 #include "xdiff-interface.h"
 #include "ll-merge.h"
 #include "lockfile.h"

archive-tar.c

@@ -1,8 +1,10 @@
 /*
  * Copyright (c) 2005, 2006 Rene Scharfe
  */
-#include "cache.h"
+#include "git-compat-util.h"
+#include "alloc.h"
 #include "config.h"
+#include "hex.h"
 #include "tar.h"
 #include "archive.h"
 #include "object-store.h"