xalloc.h drags in dependencies

[Eric Blake]

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I was surprised when I got a link failure when using the Solaris cc on
test-chown.c due to missing program_name, even though using gcc did just
fine.  It turns out that mgetgroups.c uses xalloc_oversized from
"xalloc.h", which is only a macro and by itself drags nothing in; but the
rest of xalloc.h includes four inline functions which in turn drag in
references to xalloc_die, error, program_name, and thus the link failure.

I thought about changing the #if HAVE_INLINE part of xalloc.h to instead
be #if HAVE_INLINE && defined __GNUC__, but this penalizes other
compilers.  I don't want to just open-code xalloc_oversized into
mgetgroups.c.  So my idea was to move the one portion of xalloc.h that
does not depend on xalloc_die into a header that is already LGPL; that
way, mgetgroups would depend only on xsize, not xalloc.  So, how does this
patch look?

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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>From 2540d680580bcdde870fc24aa748f0c749f02d8d Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 14 Nov 2009 07:24:39 -0700
Subject: [PATCH 1/2] xalloc: move xalloc_oversized to xsize

xalloc_oversized was the only thing in xalloc.h that did not
depend on xalloc_die.  But due to inline functions in xalloc.h,
Solaris cc gives a link failure if you use only xalloc_oversized
and don't provide xalloc_die.  Moving it to the LGPL header
xsize.h can allow other modules to break the link dependency.

* modules/xalloc (Depends-on): Add xsize.
* lib/xalloc.h (xalloc_oversized): Move...
* lib/xsize.h: ...here.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog      |    7 +++++++
 lib/xalloc.h   |   19 +++----------------
 lib/xsize.h    |   17 ++++++++++++++++-
 modules/xalloc |    1 +
 4 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 5fbff63..5ddacae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2009-11-14  Eric Blake  <address@hidden>
+
+       xalloc: move xalloc_oversized to xsize
+       * modules/xalloc (Depends-on): Add xsize.
+       * lib/xalloc.h (xalloc_oversized): Move...
+       * lib/xsize.h: ...here.
+
 2009-11-14  Robert Millan  <address@hidden>  (tiny change)

        gnulib-tool: correctly detect absence of m4 directories
diff --git a/lib/xalloc.h b/lib/xalloc.h
index 57a13e0..b3166b4 100644
--- a/lib/xalloc.h
+++ b/lib/xalloc.h
@@ -1,7 +1,8 @@
 /* xalloc.h -- malloc with out-of-memory checking

    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2003, 2004, 2006, 2007, 2008 Free Software Foundation, Inc.
+   1999, 2000, 2003, 2004, 2006, 2007, 2008, 2009 Free Software
+   Foundation, Inc.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -21,6 +22,7 @@

 # include <stddef.h>

+# include "xsize.h" /* for xalloc_oversized */

 # ifdef __cplusplus
 extern "C" {
@@ -60,21 +62,6 @@ void *x2realloc (void *p, size_t *pn);
 void *xmemdup (void const *p, size_t s) ATTRIBUTE_MALLOC;
 char *xstrdup (char const *str) ATTRIBUTE_MALLOC;

-/* Return 1 if an array of N objects, each of size S, cannot exist due
-   to size arithmetic overflow.  S must be positive and N must be
-   nonnegative.  This is a macro, not an inline function, so that it
-   works correctly even when SIZE_MAX < N.
-
-   By gnulib convention, SIZE_MAX represents overflow in size
-   calculations, so the conservative dividend to use here is
-   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
-   However, malloc (SIZE_MAX) fails on all known hosts where
-   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
-   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
-   branch when S is known to be 1.  */
-# define xalloc_oversized(n, s) \
-    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
-

 /* In the following macros, T must be an elementary or structure/union or
    typedef'ed type, or a pointer to such a type.  To apply one of the
diff --git a/lib/xsize.h b/lib/xsize.h
index 2d99a6b..34bd778 100644
--- a/lib/xsize.h
+++ b/lib/xsize.h
@@ -1,6 +1,6 @@
 /* xsize.h -- Checked size_t computations.

-   Copyright (C) 2003, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2008, 2009 Free Software Foundation, Inc.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -105,4 +105,19 @@ xmax (size_t size1, size_t size2)
 #define size_in_bounds_p(SIZE) \
   ((SIZE) != SIZE_MAX)

+/* Return 1 if an array of N objects, each of size S, cannot exist due
+   to size arithmetic overflow.  S must be positive and N must be
+   nonnegative.  This is a macro, not an inline function, so that it
+   works correctly even when SIZE_MAX < N.
+
+   By gnulib convention, SIZE_MAX represents overflow in size
+   calculations, so the conservative dividend to use here is
+   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
+   However, malloc (SIZE_MAX) fails on all known hosts where
+   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
+   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
+   branch when S is known to be 1.  */
+#define xalloc_oversized(n, s) \
+    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
+
 #endif /* _XSIZE_H */
diff --git a/modules/xalloc b/modules/xalloc
index 43ee942..9ecffc5 100644
--- a/modules/xalloc
+++ b/modules/xalloc
@@ -9,6 +9,7 @@ m4/xalloc.m4
 Depends-on:
 inline
 xalloc-die
+xsize

 configure.ac:
 gl_XALLOC
-- 
1.6.5.rc1


>From e5fe139b57709964c80f77f7388dcce7c595dd0d Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 14 Nov 2009 07:27:24 -0700
Subject: [PATCH 2/2] mgetgroups: reduce dependencies

mgetgroups doesn't use xalloc_die, just xalloc_oversized.

* modules/mgetgroups (Depends-on): Use xsize, not xalloc.
* lib/mgetgroups.c (includes): Likewise.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog          |    4 ++++
 lib/mgetgroups.c   |    2 +-
 modules/mgetgroups |    2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 5ddacae..5bcbd3d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2009-11-14  Eric Blake  <address@hidden>

+       mgetgroups: reduce dependencies
+       * modules/mgetgroups (Depends-on): Use xsize, not xalloc.
+       * lib/mgetgroups.c (includes): Likewise.
+
        xalloc: move xalloc_oversized to xsize
        * modules/xalloc (Depends-on): Add xsize.
        * lib/xalloc.h (xalloc_oversized): Move...
diff --git a/lib/mgetgroups.c b/lib/mgetgroups.c
index f68e28f..74fa10f 100644
--- a/lib/mgetgroups.c
+++ b/lib/mgetgroups.c
@@ -31,7 +31,7 @@
 #endif

 #include "getugroups.h"
-#include "xalloc.h"
+#include "xsize.h"

 static gid_t *
 realloc_groupbuf (gid_t *g, size_t num)
diff --git a/modules/mgetgroups b/modules/mgetgroups
index 58ef740..acc802e 100644
--- a/modules/mgetgroups
+++ b/modules/mgetgroups
@@ -9,7 +9,7 @@ m4/mgetgroups.m4
 Depends-on:
 getgroups
 getugroups
-xalloc
+xsize

 configure.ac:
 gl_MGETGROUPS
-- 
1.6.5.rc1