fix undefined macros

The worst of them were an undefined UINTPTR_MAX in RM_PLATFORM_*, which
could both be false and caused a stat struct to be mis-casted in
traverse.c, and a non-macro HASHER_FADVISE_FLAGS that made
rm_hasher_request_readahead a no-op since commit 31cd32f.

Also add a static assert in the usual ADD_FILE to make sure it never
casts between incompatible stat structs, and -Werror=undef so we don't
allow undefined macros to silently evaluate to zero.

Fixes sahib#549

SConstruct

@@ -773,6 +773,9 @@ if conf.env['HAVE_SSE4_1']:
 if conf.env['HAVE_SSE2']:
 	conf.env.Append(CCFLAGS=['-msse2'])
 
+# NB: After checks so they don't fail
+conf.env.Append(CCFLAGS=['-Werror=undef'])
+
 
 if ARGUMENTS.get('GDB') == '1':
     ARGUMENTS['DEBUG'] = '1'

lib/config.h.in

@@ -57,17 +57,20 @@
 #define LLI G_GINT64_FORMAT
 
 
+#include <stdint.h> /* for UINTPTR_MAX */
 #define RM_PLATFORM_32 (UINTPTR_MAX == 0xffffffff)
 #define RM_PLATFORM_64 (UINTPTR_MAX == 0xffffffffffffffff)
 
-#ifdef __APPLE__
-# ifdef __MACH__
-#  define RM_IS_APPLE 1
-# endif
+#if defined(__APPLE__) && defined(__MACH__)
+# define RM_IS_APPLE 1
+#else
+# define RM_IS_APPLE 0
 #endif
 
 #ifdef __CYGWIN__
 # define RM_IS_CYGWIN 1
+#else
+# define RM_IS_CYGWIN 0
 #endif
 
 #include <glib.h>
@@ -119,4 +122,6 @@ typedef guint64 RmOff;
     #define WARN_UNUSED_RESULT
 #endif
 
+#define _RM_OFFSET_DEBUG 0
+
 #endif

lib/hasher.c

@@ -31,20 +31,23 @@
 
 #include "utilities.h"
 
-/* Flags for the fadvise() call that tells the kernel
- * what we want to do with the file.
- */
-const int HASHER_FADVISE_FLAGS = 0
-#ifdef POSIX_FADV_SEQUENTIAL
-                                 | POSIX_FADV_SEQUENTIAL /* Read from 0 to file-size    */
+#ifndef POSIX_FADV_SEQUENTIAL
+# define POSIX_FADV_SEQUENTIAL 0
 #endif
-#ifdef POSIX_FADV_WILLNEED
-                                 | POSIX_FADV_WILLNEED /* Tell the kernel to readahead */
+#ifndef POSIX_FADV_WILLNEED
+# define POSIX_FADV_WILLNEED 0
 #endif
-#ifdef POSIX_FADV_NOREUSE
-                                 | POSIX_FADV_NOREUSE /* We will not reuse old data  */
+#ifndef POSIX_FADV_NOREUSE
+# define POSIX_FADV_NOREUSE 0
 #endif
-    ;
+
+/* Flags for the fadvise() call that tells the kernel
+ * what we want to do with the file.
+ */
+#define HASHER_FADVISE_FLAGS 0                                 \
+    | POSIX_FADV_SEQUENTIAL /* Read from 0 to file-size     */ \
+    | POSIX_FADV_WILLNEED   /* Tell the kernel to readahead */ \
+    | POSIX_FADV_NOREUSE    /* We will not reuse old data   */
 
 #define DIVIDE_CEIL(n, m) ((n) / (m) + !!((n) % (m)))
 

lib/md-scheduler.c

@@ -27,6 +27,8 @@
 #include "md-scheduler.h"
 
 
+#define _RM_MDS_DEBUG 0
+
 /* How many milliseconds to sleep if we encounter an empty file queue.
  * This prevents a "starving" RmShredDevice from hogging cpu and cluttering up
  * debug messages by continually recycling back to the joiner.

lib/traverse.c

@@ -246,8 +246,13 @@ static void rm_traverse_convert_small_stat_buf(struct stat *fts_statp, RmStat *b
 
 #else
 
-#define ADD_FILE(lint_type, is_symlink) \
-    _ADD_FILE(lint_type, is_symlink, (RmStat *)p->fts_statp)
+#define ADD_FILE(lint_type, is_symlink)                          \
+    {                                                            \
+        G_STATIC_ASSERT(                                         \
+            G_SIZEOF_MEMBER(RmStat, st_size) ==                  \
+            G_SIZEOF_MEMBER(__fts_stat_t, st_size));             \
+        _ADD_FILE(lint_type, is_symlink, (RmStat *)p->fts_statp) \
+    }
 
 #endif
 

lib/utilities.c

@@ -1153,8 +1153,6 @@ bool rm_mounts_can_reflink(RmMountTable *self, dev_t source, dev_t dest) {
 
 #if HAVE_FIEMAP
 
-#define _RM_OFFSET_DEBUG 0
-
 /* Return fiemap structure containing n_extents for file descriptor fd.
  * Return NULL if errors encountered.
  * Needs to be freed with g_free if not NULL.