Fix more problems found by GCC 4.6.0's static checks.

6 files changed, 60 insertions, 35 deletions

diff --git a/lib/allocator.c b/lib/allocator.c
new file mode 100644
index 00000000000..2c1a3da03aa
--- /dev/null
+++ b/lib/allocator.c
@@ -0,0 +1,5 @@
+#define _GL_USE_STDLIB_ALLOC 1
+#include <config.h>
+#include "allocator.h"
+#include <stdlib.h>
+struct allocator const stdlib_allocator = { malloc, realloc, free, NULL };
diff --git a/lib/allocator.h b/lib/allocator.h
index 4ac863b224c..953117da83f 100644
--- a/lib/allocator.h
+++ b/lib/allocator.h
@@ -18,6 +18,7 @@
 /* Written by Paul Eggert.  */
 
 #ifndef _GL_ALLOCATOR_H
+#define _GL_ALLOCATOR_H
 
 #include <stddef.h>
 
@@ -30,16 +31,16 @@ struct allocator
      attributes do not work with pointers to functions.  See
      <http://lists.gnu.org/archive/html/bug-gnulib/2011-04/msg00007.html>.  */
 
-  /* Call MALLOC to allocate memory, like 'malloc'.  On failure MALLOC
+  /* Call ALLOCATE to allocate memory, like 'malloc'.  On failure ALLOCATE
      should return NULL, though not necessarily set errno.  When given
      a zero size it may return NULL even if successful.  */
-  void *(*malloc) (size_t);
+  void *(*allocate) (size_t);
 
-  /* If nonnull, call REALLOC to reallocate memory, like 'realloc'.
-     On failure REALLOC should return NULL, though not necessarily set
+  /* If nonnull, call REALLOCATE to reallocate memory, like 'realloc'.
+     On failure REALLOCATE should return NULL, though not necessarily set
      errno.  When given a zero size it may return NULL even if
      successful.  */
-  void *(*realloc) (void *, size_t);
+  void *(*reallocate) (void *, size_t);
 
   /* Call FREE to free memory, like 'free'.  */
   void (*free) (void *);
@@ -50,4 +51,7 @@ struct allocator
   void (*die) (void);
 };
 
-#endif
+/* An allocator using the stdlib functions and a null DIE function.  */
+extern struct allocator const stdlib_allocator;
+
+#endif /* _GL_ALLOCATOR_H */
diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c
index 15ffe24c0f4..e2909c766d5 100644
--- a/lib/careadlinkat.c
+++ b/lib/careadlinkat.c
@@ -22,19 +22,12 @@
 
 #include "careadlinkat.h"
 
-#include "allocator.h"
-
 #include <errno.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
-/* Use the system functions, not the gnulib overrides, because this
-   module does not depend on GNU or POSIX semantics.  */
-#undef malloc
-#undef realloc
-
 /* Define this independently so that stdint.h is not a prerequisite.  */
 #ifndef SIZE_MAX
 # define SIZE_MAX ((size_t) -1)
@@ -44,24 +37,24 @@
 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
 #endif
 
+#include "allocator.h"
+
 #if ! HAVE_READLINKAT
-/* Ignore FD.  Get the symbolic link value of FILENAME and put it into
-   BUFFER, with size BUFFER_SIZE.  This function acts like readlink
-   but has readlinkat's signature.  */
+/* Get the symbolic link value of FILENAME and put it into BUFFER, with
+   size BUFFER_SIZE.  This function acts like readlink  but has
+   readlinkat's signature.  */
 ssize_t
 careadlinkatcwd (int fd, char const *filename, char *buffer,
                  size_t buffer_size)
 {
-  (void) fd;
+  /* FD must be AT_FDCWD here, otherwise the caller is using this
+     function in contexts for which it was not meant for.  */
+  if (fd != AT_FDCWD)
+    abort ();
   return readlink (filename, buffer, buffer_size);
 }
 #endif
 
-/* A standard allocator.  For now, only careadlinkat needs this, but
-   perhaps it should be moved to the allocator module.  */
-static struct allocator const standard_allocator =
-  { malloc, realloc, free, NULL };
-
 /* Assuming the current directory is FD, get the symbolic link value
    of FILENAME as a null-terminated string and put it into a buffer.
    If FD is AT_FDCWD, FILENAME is interpreted relative to the current
@@ -76,7 +69,10 @@ static struct allocator const standard_allocator =
    the returned value if it is nonnull and is not BUFFER.  A null
    ALLOC stands for the standard allocator.
 
-   The PREADLINKAT function specifies how to read links.
+   The PREADLINKAT function specifies how to read links.  It operates
+   like POSIX readlinkat()
+   <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+   but can assume that its first argument is the same as FD.
 
    If successful, return the buffer address; otherwise return NULL and
    set errno.  */
@@ -94,7 +90,7 @@ careadlinkat (int fd, char const *filename,
   char stack_buf[1024];
 
   if (! alloc)
-    alloc = &standard_allocator;
+    alloc = &stdlib_allocator;
 
   if (! buffer_size)
     {
@@ -138,16 +134,16 @@ careadlinkat (int fd, char const *filename,
 
           if (buf == stack_buf)
             {
-              char *b = (char *) alloc->malloc (link_size);
+              char *b = (char *) alloc->allocate (link_size);
               if (! b)
                 break;
               memcpy (b, buf, link_size);
               buf = b;
             }
-          else if (link_size < buf_size && buf != buffer && alloc->realloc)
+          else if (link_size < buf_size && buf != buffer && alloc->reallocate)
             {
               /* Shrink BUF before returning it.  */
-              char *b = (char *) alloc->realloc (buf, link_size);
+              char *b = (char *) alloc->reallocate (buf, link_size);
               if (b)
                 buf = b;
             }
@@ -164,7 +160,7 @@ careadlinkat (int fd, char const *filename,
         buf_size = buf_size_max;
       else
         break;
-      buf = (char *) alloc->malloc (buf_size);
+      buf = (char *) alloc->allocate (buf_size);
     }
   while (buf);
 
diff --git a/lib/careadlinkat.h b/lib/careadlinkat.h
index c5e4bcfc15f..4f0184bbc33 100644
--- a/lib/careadlinkat.h
+++ b/lib/careadlinkat.h
@@ -18,6 +18,7 @@
 /* Written by Paul Eggert, Bruno Haible, and Jim Meyering.  */
 
 #ifndef _GL_CAREADLINKAT_H
+#define _GL_CAREADLINKAT_H
 
 #include <fcntl.h>
 #include <unistd.h>
@@ -37,7 +38,10 @@ struct allocator;
    buffer managed by ALLOC.  It is the caller's responsibility to free
    the returned value if it is nonnull and is not BUFFER.
 
-   The PREADLINKAT function specifies how to read links.
+   The PREADLINKAT function specifies how to read links.  It operates
+   like POSIX readlinkat()
+   <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+   but can assume that its first argument is the same as FD.
 
    If successful, return the buffer address; otherwise return NULL and
    set errno.  */
@@ -49,8 +53,10 @@ char *careadlinkat (int fd, char const *filename,
                                             char *, size_t));
 
 /* Suitable values for careadlinkat's FD and PREADLINKAT arguments,
-   when doing a plain readlink.  */
+   when doing a plain readlink:
+   Pass FD = AT_FDCWD and PREADLINKAT = careadlinkatcwd.  */
 #if HAVE_READLINKAT
+/* AT_FDCWD is declared in <fcntl.h>, readlinkat in <unistd.h>.  */
 # define careadlinkatcwd readlinkat
 #else
 /* Define AT_FDCWD independently, so that the careadlinkat module does
diff --git a/lib/gnulib.mk b/lib/gnulib.mk
index d2fd6698030..1938c6127a2 100644
--- a/lib/gnulib.mk
+++ b/lib/gnulib.mk
@@ -21,6 +21,14 @@ libgnu_a_LIBADD = $(gl_LIBOBJS)
 libgnu_a_DEPENDENCIES = $(gl_LIBOBJS)
 EXTRA_libgnu_a_SOURCES =
 
+## begin gnulib module allocator
+
+libgnu_a_SOURCES += allocator.c
+
+EXTRA_DIST += allocator.h
+
+## end   gnulib module allocator
+
 ## begin gnulib module arg-nonnull
 
 # The BUILT_SOURCES created by this Makefile snippet are not used via #include
@@ -73,7 +81,7 @@ EXTRA_DIST += $(top_srcdir)/./c++defs.h
 
 libgnu_a_SOURCES += careadlinkat.c
 
-EXTRA_DIST += allocator.h careadlinkat.h
+EXTRA_DIST += careadlinkat.h
 
 ## end   gnulib module careadlinkat
 
diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index 2697a4bd1db..b9ada2cd1a8 100644
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -255,9 +255,14 @@ _GL_WARN_ON_USE (ptsname, "grantpt is not portable - "
 # endif
 #endif
 
+/* If _GL_USE_STDLIB_ALLOC is nonzero, the including module does not
+   rely on GNU or POSIX semantics for malloc and realloc (for example,
+   by never specifying a zero size), so it does not need malloc or
+   realloc to be redefined.  */
 #if @GNULIB_MALLOC_POSIX@
 # if @REPLACE_MALLOC@
-#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#  if !((defined __cplusplus && defined GNULIB_NAMESPACE) \
+        || _GL_USE_STDLIB_ALLOC)
 #   undef malloc
 #   define malloc rpl_malloc
 #  endif
@@ -267,7 +272,7 @@ _GL_CXXALIAS_RPL (malloc, void *, (size_t size));
 _GL_CXXALIAS_SYS (malloc, void *, (size_t size));
 # endif
 _GL_CXXALIASWARN (malloc);
-#elif defined GNULIB_POSIXCHECK
+#elif defined GNULIB_POSIXCHECK && !_GL_USE_STDLIB_ALLOC
 # undef malloc
 /* Assume malloc is always declared.  */
 _GL_WARN_ON_USE (malloc, "malloc is not POSIX compliant everywhere - "
@@ -531,7 +536,8 @@ _GL_WARN_ON_USE (setstate_r, "setstate_r is unportable - "
 
 #if @GNULIB_REALLOC_POSIX@
 # if @REPLACE_REALLOC@
-#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#  if !((defined __cplusplus && defined GNULIB_NAMESPACE) \
+        || _GL_USE_STDLIB_ALLOC)
 #   undef realloc
 #   define realloc rpl_realloc
 #  endif
@@ -541,7 +547,7 @@ _GL_CXXALIAS_RPL (realloc, void *, (void *ptr, size_t size));
 _GL_CXXALIAS_SYS (realloc, void *, (void *ptr, size_t size));
 # endif
 _GL_CXXALIASWARN (realloc);
-#elif defined GNULIB_POSIXCHECK
+#elif defined GNULIB_POSIXCHECK && !_GL_USE_STDLIB_ALLOC
 # undef realloc
 /* Assume realloc is always declared.  */
 _GL_WARN_ON_USE (realloc, "realloc is not POSIX compliant everywhere - "