with a few exceptions and some remaining files, never return directly on failure, always goto fail by invoking fail_if

Signed-off-by: Mattias Andrée <maandree@operamail.com>

32 files changed, 685 insertions, 551 deletions

diff --git a/src/libmdsserver/client-list.c b/src/libmdsserver/client-list.c
index ff3ffe2..24403cb 100644
--- a/src/libmdsserver/client-list.c
+++ b/src/libmdsserver/client-list.c
@@ -70,10 +70,11 @@ int client_list_create(client_list_t* restrict this, size_t capacity)
   this->capacity = capacity = to_power_of_two(capacity);
   this->size     = 0;
   this->clients  = NULL;
-  if (xmalloc(this->clients, capacity, uint64_t))
-    return -1;
+  fail_if (xmalloc(this->clients, capacity, uint64_t));
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -139,12 +140,14 @@ int client_list_add(client_list_t* restrict this, uint64_t client)
 	{
 	  this->capacity >>= 1;
 	  this->clients = old;
-	  return -1;
+	  fail_if (1);
 	}
     }
   
   this->clients[this->size++] = client;
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -230,13 +233,14 @@ int client_list_unmarshal(client_list_t* restrict this, char* restrict data)
   
   n = this->capacity * sizeof(uint64_t);
   
-  if ((this->clients = malloc(n)) == NULL)
-    return -1;
+  fail_if ((this->clients = malloc(n)) == NULL);
   
   n = this->size * sizeof(uint64_t);
   
   memcpy(this->clients, data, n);
   
   return 0;
+ fail:
+  return -1;
 }
 
diff --git a/src/libmdsserver/fd-table.c b/src/libmdsserver/fd-table.c
index 960b3e4..4623825 100644
--- a/src/libmdsserver/fd-table.c
+++ b/src/libmdsserver/fd-table.c
@@ -48,10 +48,12 @@ int fd_table_create_tuned(fd_table_t* restrict this, size_t initial_capacity)
      the time overhead of `fd_table_contains_value`. */
   
   bitcap = (this->capacity + 63) / 64;
-  if (xcalloc(this->used,   bitcap,         size_t))  return -1;
-  if (xcalloc(this->values, this->capacity, size_t))  return -1;
+  fail_if (xcalloc(this->used,   bitcap,         size_t));
+  fail_if (xcalloc(this->values, this->capacity, size_t));
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -164,7 +166,7 @@ size_t fd_table_put(fd_table_t* restrict this, int key, size_t value)
       if (xrealloc(this->values, this->capacity << 1, size_t))
 	{
 	  this->values = old_values;
-	  return 0;
+	  fail_if (1);
 	}
       
       memset(this->values + this->capacity, 0, this->capacity * sizeof(size_t));
@@ -180,7 +182,7 @@ size_t fd_table_put(fd_table_t* restrict this, int key, size_t value)
 	    {
 	      this->used = old_used;
 	      this->capacity >>= 1;
-	      return 0;
+	      fail_if (1);
 	    }
 	  
 	  memset(this->used + old_bitcap, 0, (new_bitcap - old_bitcap) * sizeof(uint64_t));
@@ -192,6 +194,8 @@ size_t fd_table_put(fd_table_t* restrict this, int key, size_t value)
   this->values[key] = value;
   this->size++;
   return 0;
+ fail:
+  return 0;
 }
 
 
@@ -285,12 +289,10 @@ int fd_table_unmarshal(fd_table_t* restrict this, char* restrict data, remap_fun
   this->used             = NULL;
   this->value_comparator = NULL;
   
-  if (xmalloc(this->values, this->capacity, size_t))
-    return -1;
+  fail_if (xmalloc(this->values, this->capacity, size_t));
   
   bitcap = (this->capacity + 63) / 64;
-  if (xmalloc(this->used, bitcap, size_t))
-    return -1;
+  fail_if (xmalloc(this->used, bitcap, size_t));
   
   memcpy(this->values, data, this->capacity * sizeof(size_t));
   buf_next(data, size_t, this->capacity);
@@ -306,5 +308,7 @@ int fd_table_unmarshal(fd_table_t* restrict this, char* restrict data, remap_fun
     }
   
   return 0;
+ fail:
+  return -1;
 }
 
diff --git a/src/libmdsserver/hash-table.c b/src/libmdsserver/hash-table.c
index c0de355..c9b2f4d 100644
--- a/src/libmdsserver/hash-table.c
+++ b/src/libmdsserver/hash-table.c
@@ -65,7 +65,7 @@ static inline size_t __attribute__((pure)) truncate_hash(const hash_table_t* res
  * Grow the table
  * 
  * @param   this  The hash table
- * @return        Non zero on error, `errno` will be set accordingly
+ * @return        Non-zero on error, `errno` will be set accordingly
  */
 static int rehash(hash_table_t* restrict this)
 {
@@ -76,8 +76,7 @@ static int rehash(hash_table_t* restrict this)
   hash_entry_t* destination;
   hash_entry_t* next;
   
-  if (xcalloc(this->buckets, old_capacity * 2 + 1, hash_entry_t*))
-    return -1;
+  fail_if (xcalloc(this->buckets, old_capacity * 2 + 1, hash_entry_t*));
   this->capacity = old_capacity * 2 + 1;
   this->threshold = (size_t)((float)(this->capacity) * this->load_factor);
   
@@ -108,6 +107,8 @@ static int rehash(hash_table_t* restrict this)
   
   free(old_buckets);
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -124,8 +125,7 @@ int hash_table_create_fine_tuned(hash_table_t* restrict this, size_t initial_cap
   this->buckets = NULL;
   
   this->capacity = initial_capacity ? initial_capacity : 1;
-  if (xcalloc(this->buckets, this->capacity, hash_entry_t*))
-    return -1;
+  fail_if (xcalloc(this->buckets, this->capacity, hash_entry_t*));
   this->load_factor = load_factor;
   this->threshold = (size_t)((float)(this->capacity) * load_factor);
   this->size = 0;
@@ -134,6 +134,8 @@ int hash_table_create_fine_tuned(hash_table_t* restrict this, size_t initial_cap
   this->hasher = NULL;
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -299,14 +301,12 @@ size_t hash_table_put(hash_table_t* restrict this, size_t key, size_t value)
   if (++(this->size) > this->threshold)
     {
       errno = 0;
-      if (rehash(this))
-	return 0;
+      fail_if (rehash(this));
       index = truncate_hash(this, key_hash);
     }
   
   errno = 0;
-  if (xmalloc(bucket, 1, hash_entry_t))
-    return 0;
+  fail_if (xmalloc(bucket, 1, hash_entry_t));
   bucket->value = value;
   bucket->key = key;
   bucket->hash = key_hash;
@@ -314,6 +314,8 @@ size_t hash_table_put(hash_table_t* restrict this, size_t key, size_t value)
   this->buckets[index] = bucket;
   
   return 0;
+ fail:
+  return 0;
 }
 
 
@@ -472,8 +474,7 @@ int hash_table_unmarshal(hash_table_t* restrict this, char* restrict data, remap
   buf_get_next(data, size_t, this->threshold);
   buf_get_next(data, size_t, this->size);
   
-  if (xcalloc(this->buckets, this->capacity, hash_entry_t*))
-    return -1;
+  fail_if (xcalloc(this->buckets, this->capacity, hash_entry_t*));
   
   for (i = 0; i < n; i++)
     {
@@ -481,16 +482,14 @@ int hash_table_unmarshal(hash_table_t* restrict this, char* restrict data, remap
       hash_entry_t* restrict bucket;
       buf_get_next(data, size_t, m);
       
-      if (xmalloc(this->buckets[i] = bucket, 1, hash_entry_t))
-	return -1;
+      fail_if (xmalloc(this->buckets[i] = bucket, 1, hash_entry_t));
       
       while (m--)
 	{
 	  if (m == 0)
 	    bucket->next = NULL;
 	  else
-	    if (xmalloc(bucket->next, 1, hash_entry_t))
-	      return -1;
+	    fail_if (xmalloc(bucket->next, 1, hash_entry_t));
 	  buf_get_next(data, size_t, bucket->key);
 	  buf_get_next(data, size_t, bucket->value);
 	  if (remapper != NULL)
@@ -500,5 +499,7 @@ int hash_table_unmarshal(hash_table_t* restrict this, char* restrict data, remap
     }
   
   return 0;
+ fail:
+  return -1;
 }
 
diff --git a/src/libmdsserver/linked-list.c b/src/libmdsserver/linked-list.c
index 7756d90..f00daf3 100644
--- a/src/libmdsserver/linked-list.c
+++ b/src/libmdsserver/linked-list.c
@@ -75,15 +75,17 @@ int linked_list_create(linked_list_t* restrict this, size_t capacity)
   this->values     = NULL;
   this->next       = NULL;
   this->previous   = NULL;
-  if (xmalloc(this->reusable, capacity, ssize_t))  return -1;
-  if (xmalloc(this->values,   capacity,  size_t))  return -1;
-  if (xmalloc(this->next,     capacity, ssize_t))  return -1;
-  if (xmalloc(this->previous, capacity, ssize_t))  return -1;
+  fail_if (xmalloc(this->reusable, capacity, ssize_t));
+  fail_if (xmalloc(this->values,   capacity,  size_t));
+  fail_if (xmalloc(this->next,     capacity, ssize_t));
+  fail_if (xmalloc(this->previous, capacity, ssize_t));
   this->values[this->edge]   = 0;
   this->next[this->edge]     = this->edge;
   this->previous[this->edge] = this->edge;
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -181,8 +183,7 @@ int linked_list_pack(linked_list_t* restrict this)
   size_t* restrict vals;
   int saved_errno;
   
-  if (xmalloc(vals, cap, size_t))
-    return -1;
+  fail_if (xmalloc(vals, cap, size_t));
   while (((size_t)head != this->end) && (this->next[head] == LINKED_LIST_UNUSED))
     head++;
   if ((size_t)head != this->end)
@@ -249,10 +250,7 @@ static ssize_t linked_list_get_next(linked_list_t* restrict this)
       ssize_t* old;
       
       if ((ssize_t)(this->end) < 0)
-	{
-	  errno = ENOMEM;
-	  return LINKED_LIST_UNUSED;
-	}
+	fail_if ((errno = ENOMEM));
       
       this->capacity <<= 1;
 
@@ -260,7 +258,7 @@ static ssize_t linked_list_get_next(linked_list_t* restrict this)
   if ((new_var = realloc(old_var = new_var, this->capacity * sizeof(type))) == NULL)  \
     {										      \
       new_var = old_var;							      \
-      return LINKED_LIST_UNUSED;						      \
+      fail_if (1);								      \
     }
 
       __realloc(this->values,   old_values, size_t)
@@ -271,6 +269,8 @@ static ssize_t linked_list_get_next(linked_list_t* restrict this)
 #undef __realloc
     }
   return (ssize_t)(this->end++);
+ fail:
+  return LINKED_LIST_UNUSED;
 }
 
 
@@ -304,14 +304,15 @@ static ssize_t linked_list_unuse(linked_list_t* restrict this, ssize_t node)
 ssize_t linked_list_insert_after(linked_list_t* this, size_t value, ssize_t predecessor)
 {
   ssize_t node = linked_list_get_next(this);
-  if (node == LINKED_LIST_UNUSED)
-    return LINKED_LIST_UNUSED;
+  fail_if (node == LINKED_LIST_UNUSED);
   this->values[node] = value;
   this->next[node] = this->next[predecessor];
   this->next[predecessor] = node;
   this->previous[node] = predecessor;
   this->previous[this->next[node]] = node;
   return node;
+ fail:
+  return LINKED_LIST_UNUSED;
 }
 
 
@@ -343,14 +344,15 @@ ssize_t linked_list_remove_after(linked_list_t* restrict this, ssize_t predecess
 ssize_t linked_list_insert_before(linked_list_t* restrict this, size_t value, ssize_t successor)
 {
   ssize_t node = linked_list_get_next(this);
-  if (node == LINKED_LIST_UNUSED)
-    return LINKED_LIST_UNUSED;
+  fail_if (node == LINKED_LIST_UNUSED);
   this->values[node] = value;
   this->previous[node] = this->previous[successor];
   this->previous[successor] = node;
   this->next[node] = successor;
   this->next[this->previous[node]] = node;
   return node;
+ fail:
+  return LINKED_LIST_UNUSED;
 }
 
 
@@ -454,10 +456,10 @@ int linked_list_unmarshal(linked_list_t* restrict this, char* restrict data)
   
   n = this->capacity * sizeof(size_t);
   
-  if ((this->reusable = malloc(n)) == NULL)  return -1;
-  if ((this->values   = malloc(n)) == NULL)  return -1;
-  if ((this->next     = malloc(n)) == NULL)  return -1;
-  if ((this->previous = malloc(n)) == NULL)  return -1;
+  fail_if ((this->reusable = malloc(n)) == NULL);
+  fail_if ((this->values   = malloc(n)) == NULL);
+  fail_if ((this->next     = malloc(n)) == NULL);
+  fail_if ((this->previous = malloc(n)) == NULL);
   
   memcpy(this->reusable, data, this->reuse_head * sizeof(ssize_t));
   buf_next(data, ssize_t, this->reuse_head);
@@ -471,6 +473,8 @@ int linked_list_unmarshal(linked_list_t* restrict this, char* restrict data)
   memcpy(this->previous, data, this->end * sizeof(ssize_t));
   
   return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/libmdsserver/mds-message.c b/src/libmdsserver/mds-message.c
index 4075f57..68334de 100644
--- a/src/libmdsserver/mds-message.c
+++ b/src/libmdsserver/mds-message.c
@@ -48,9 +48,10 @@ int mds_message_initialise(mds_message_t* restrict this)
   this->buffer_size = 128;
   this->buffer_ptr = 0;
   this->stage = 0;
-  if (xmalloc(this->buffer, this->buffer_size, char))
-    return -1;
+  fail_if (xmalloc(this->buffer, this->buffer_size, char));
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -102,10 +103,11 @@ void mds_message_destroy(mds_message_t* restrict this)
 int mds_message_extend_headers(mds_message_t* restrict this, size_t extent)
 {
   char** new_headers = this->headers;
-  if (xrealloc(new_headers, this->header_count + extent, char*))
-    return -1;
+  fail_if (xrealloc(new_headers, this->header_count + extent, char*));
   this->headers = new_headers;
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -118,11 +120,12 @@ int mds_message_extend_headers(mds_message_t* restrict this, size_t extent)
 static int mds_message_extend_buffer(mds_message_t* restrict this)
 {
   char* new_buf = this->buffer;
-  if (xrealloc(new_buf, this->buffer_size << 1, char))
-      return -1;
+  fail_if (xrealloc(new_buf, this->buffer_size << 1, char));
   this->buffer = new_buf;
   this->buffer_size <<= 1;
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -236,10 +239,11 @@ static int initialise_payload(mds_message_t* restrict this)
   
   /* Allocate the payload buffer. */
   if (this->payload_size > 0)
-    if (xmalloc(this->payload, this->payload_size, char))
-      return -1;
+    fail_if (xmalloc(this->payload, this->payload_size, char));
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -255,8 +259,7 @@ static int store_header(mds_message_t* restrict this, size_t length)
   char* header;
   
   /* Allocate the header. */
-  if (xmalloc(header, length, char))
-    return -1;
+  fail_if (xmalloc(header, length, char));
   /* Copy the header data into the allocated header, */
   memcpy(header, this->buffer, length * sizeof(char));
   /* and NUL-terminate it. */
@@ -277,6 +280,8 @@ static int store_header(mds_message_t* restrict this, size_t length)
   this->headers[this->header_count++] = header;
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -310,15 +315,13 @@ static int continue_read(mds_message_t* restrict this, int fd)
   errno = 0;
   got = recv(fd, this->buffer + this->buffer_ptr, n, 0);
   this->buffer_ptr += (size_t)(got < 0 ? 0 : got);
-  if (errno)
-    return -1;
+  fail_if (errno);
   if (got == 0)
-    {
-      errno = ECONNRESET;
-      return -1;
-    }
+    fail_if ((errno = ECONNRESET));
   
   return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/libmdsserver/util.c b/src/libmdsserver/util.c
index 2e72229..123463c 100644
--- a/src/libmdsserver/util.c
+++ b/src/libmdsserver/util.c
@@ -103,11 +103,12 @@ int prepare_reexec(void)
 {
   ssize_t len;
   len = readlink(SELF_EXE, self_exe, (sizeof(self_exe) / sizeof(char)) - 1);
-  if (len < 0)
-    return -1;
+  fail_if (len < 0);
   /* ‘readlink() does not append a null byte to buf.’ */
   self_exe[len] = '\0';
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -135,8 +136,7 @@ void reexec_server(int argc, char** argv, int reexeced)
     {
       *reexec_args_++ = *argv;
       *reexec_args_ = strdup("--re-exec");
-      if (*reexec_args_ == NULL)
-	return;
+      fail_if (*reexec_args_ == NULL);
       for (i = 1; i < argc; i++)
 	reexec_args_[i] = argv[i];
     }
@@ -146,6 +146,8 @@ void reexec_server(int argc, char** argv, int reexeced)
     reexec_args_[i] = argv[i];
   reexec_args_[argc] = NULL;
   execv(self_exe[0] ? self_exe : argv[0], reexec_args);
+ fail:
+  return;
 }
 
 
@@ -253,12 +255,13 @@ int full_write(int fd, const char* buffer, size_t length)
     {
       errno = 0;
       wrote = write(fd, buffer, length);
-      if (errno && (errno != EINTR))
-	return -1;
+      fail_if (errno && (errno != EINTR));
       length -= (size_t)max(wrote, 0);
       buffer += (size_t)max(wrote, 0);
     }
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -271,38 +274,29 @@ int full_write(int fd, const char* buffer, size_t length)
  */
 char* full_read(int fd, size_t* length)
 {
+  char* old_buf = NULL;
   size_t buffer_size = 8 << 10;
   size_t buffer_ptr = 0;
   char* buffer;
   ssize_t got;
+  int saved_errno;
+  
   if (length != NULL)
     *length = 0;
   
   /* Allocate buffer for data. */
-  if (xmalloc(buffer, buffer_size, char))
-    return NULL;
+  fail_if (xmalloc(buffer, buffer_size, char));
   
   /* Read the file. */
   for (;;)
     {
       /* Grow buffer if it is too small. */
       if (buffer_size == buffer_ptr)
-	{
-	  char* old_buf = buffer;
-	  if (xrealloc(buffer, buffer_size <<= 1, char))
-	    {
-	      free(old_buf);
-	      return NULL;
-	    }
-	}
+	fail_if (xxrealloc(old_buf, buffer, buffer_size <<= 1, char));
       
       /* Read from the file into the buffer. */
       got = read(fd, buffer + buffer_ptr, buffer_size - buffer_ptr);
-      if ((got < 0) && (errno != EINTR))
-	{
-	  free(buffer);
-	  return NULL;
-	}
+      fail_if ((got < 0) && (errno != EINTR));
       if (got == 0)
 	break;
       buffer_ptr += (size_t)got;
@@ -311,6 +305,11 @@ char* full_read(int fd, size_t* length)
   if (length != NULL)
     *length = buffer_ptr;
   return buffer;
+ fail:
+  saved_errno = errno;
+  free(old_buf);
+  free(buffer);
+  return errno = saved_errno, NULL;
 }
 
 
diff --git a/src/mds-base.c b/src/mds-base.c
index df0e680..e80b902 100644
--- a/src/mds-base.c
+++ b/src/mds-base.c
@@ -210,13 +210,8 @@ static int server_initialised_fork_for_safety(void)
   pid_t pid = fork();
   int status;
   
-  if (pid == (pid_t)-1)
-    {
-      xperror(*argv);
-      eprint("while forking for safety.");
-      return -1;
-    }
-  else if (pid == 0)
+  fail_if (pid == (pid_t)-1);
+  if (pid == 0)
     /* Reinstate the alarm for the child. */
     alarm(pending_alarm);
   else
@@ -246,6 +241,10 @@ static int server_initialised_fork_for_safety(void)
     }
   
   return 0;
+ fail:
+  xperror(*argv);
+  eprint("while forking for safety.");
+  return -1;
 }
 
 
@@ -261,14 +260,8 @@ int __attribute__((weak)) server_initialised(void)
   pid_t r;
   if (on_init_fork && (r = fork()))
     {
-      if (r == (pid_t)-1)
-	{
-	  xperror(*argv);
-	  eprint("while forking at completed initialisation.");
-	  return -1;
-	}
-      else
-	exit(0);
+      fail_if (r == (pid_t)-1);
+      exit(0);
     }
   
   if (on_init_sh != NULL)
@@ -276,7 +269,12 @@ int __attribute__((weak)) server_initialised(void)
   
   if (server_characteristics.fork_for_safety)
     return server_initialised_fork_for_safety();
+  
   return 0;
+ fail:
+  xperror(*argv);
+  eprint("while forking at completed initialisation.");
+  return -1;
 }
 
 
@@ -413,8 +411,7 @@ static int base_unmarshal(void)
   free(state_buf);
   
   /* Recover after failure. */
-  if (r)
-    fail_if (reexec_failure_recover());
+  fail_if (r && reexec_failure_recover());
   
   return 0;
  fail:
diff --git a/src/mds-clipboard.c b/src/mds-clipboard.c
index 2488179..50ee6a3 100644
--- a/src/mds-clipboard.c
+++ b/src/mds-clipboard.c
@@ -105,6 +105,7 @@ int __attribute__((const)) preinitialise_server(void)
 int initialise_server(void)
 {
   ssize_t i = 0;
+  int stage = 0;
   const char* const message =
     "Command: intercept\n"
     "Message ID: 0\n"
@@ -113,8 +114,7 @@ int initialise_server(void)
     "Command: clipboard\n"
     "Client closed\n";
   
-  if (full_send(message, strlen(message)))
-    return 1;
+  fail_if (full_send(message, strlen(message)));
   
   if (is_respawn)
     {
@@ -124,13 +124,13 @@ int initialise_server(void)
 	"Message ID: 1\n"
 	"\n";
       
-      if (full_send(crash_message, strlen(crash_message)))
-	return 1;
-      
+      fail_if (full_send(crash_message, strlen(crash_message)));
       message_id++;
     }
   
+  stage++;
   fail_if (server_initialised() < 0);
+  stage++;
   fail_if (mds_message_initialise(&received));
   
   for (i = 0; i < CLIPBOARD_LEVELS; i++)
@@ -140,8 +140,10 @@ int initialise_server(void)
   
  fail:
   xperror(*argv);
+  if (stage == 0)  return 1;
   mds_message_destroy(&received);
-  while (--i >= 0)
+  if (stage == 1)  return 1;
+  while (i--)
     free(clipboard[i]);
   return 1;
 }
@@ -158,13 +160,12 @@ int postinitialise_server(void)
   if (connected)
     return 0;
   
-  if (reconnect_to_display())
-    {
-      mds_message_destroy(&received);
-      return 1;
-    }
+  fail_if (reconnect_to_display());
   connected = 1;
   return 0;
+ fail:
+  mds_message_destroy(&received);
+  return 1;
 }
 
 
@@ -410,15 +411,15 @@ int full_send(const char* message, size_t length)
 	  eprint("Sent more of a message than exists in the message, aborting.");
 	  return -1;
 	}
-      else if ((sent < length) && (errno != EINTR))
-	{
-	  xperror(*argv);
-	  return -1;
-	}
+      else
+	fail_if ((sent < length) && (errno != EINTR));
       message += sent;
       length -= sent;
     }
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
 
@@ -575,8 +576,7 @@ static int clipboard_notify_pop(int level, size_t index)
 	      "Used: %zu\n"
 	      "\n");
   
-  if (xmalloc(message, n, char))
-    return -1;
+  fail_if (xmalloc(message, n, char));
   
   sprintf(message,
 	  "Command: clipboard-info\n"
@@ -591,6 +591,8 @@ static int clipboard_notify_pop(int level, size_t index)
   
   message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
   return full_send(message, strlen(message)) ? -1 : 0;
+ fail:
+  return -1;
 }
 
 
@@ -651,9 +653,10 @@ int clipboard_danger(void)
 {
   int i;
   for (i = 0; i < CLIPBOARD_LEVELS; i++)
-    if (clipboard_purge(i, NULL))
-      return -1;
+    fail_if (clipboard_purge(i, NULL));
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -667,9 +670,10 @@ int clipboard_death(const char* recv_client_id)
 {
   int i;
   for (i = 0; i < CLIPBOARD_LEVELS; i++)
-    if (clipboard_purge(i, recv_client_id))
-      return -1;
+    fail_if (clipboard_purge(i, recv_client_id));
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -687,8 +691,7 @@ int clipboard_add(int level, const char* time_to_live, const char* recv_client_i
   uint64_t client = recv_client_id ? parse_client_id(recv_client_id) : 0;
   clipitem_t new_clip;
   
-  if (clipboard_purge(level, NULL))
-    return -1;
+  fail_if (clipboard_purge(level, NULL));
   
   if (strequals(time_to_live, "forever"))
     autopurge = CLIPITEM_AUTOPURGE_NEVER;
@@ -748,8 +751,7 @@ int clipboard_read(int level, size_t index, const char* recv_client_id, const ch
   clipitem_t* clip = NULL;
   size_t n;
   
-  if (clipboard_purge(level, NULL))
-    return -1;
+  fail_if (clipboard_purge(level, NULL));
   
   if (clipboard_used[level] == 0)
     {
@@ -833,8 +835,7 @@ int clipboard_clear(int level)
 int clipboard_set_size(int level, size_t size)
 {
   size_t i;
-  if (clipboard_purge(level, NULL))
-    return -1;
+  fail_if (clipboard_purge(level, NULL));
   
   if (size < clipboard_size[level])
     {
@@ -877,8 +878,8 @@ int clipboard_get_size(int level, const char* recv_client_id, const char* recv_m
 {
   char* message = NULL;
   size_t n;
-  if (clipboard_purge(level, NULL))
-    return -1;
+  
+  fail_if (clipboard_purge(level, NULL));
   
   n = strlen("To: %s\n"
 	     "In response to: %s\n"
diff --git a/src/mds-echo.c b/src/mds-echo.c
index caefecd..09533fd 100644
--- a/src/mds-echo.c
+++ b/src/mds-echo.c
@@ -99,6 +99,7 @@ int __attribute__((const)) preinitialise_server(void)
  */
 int initialise_server(void)
 {
+  int stage = 0;
   const char* const message =
     "Command: intercept\n"
     "Message ID: 0\n"
@@ -106,15 +107,15 @@ int initialise_server(void)
     "\n"
     "Command: echo\n";
   
-  if (full_send(message, strlen(message)))
-    return 1;
-  fail_if (server_initialised() < 0);
+  fail_if (full_send(message, strlen(message)));
+  fail_if (server_initialised() < 0);  stage++;
   fail_if (mds_message_initialise(&received));
   
   return 0;
  fail:
   xperror(*argv);
-  mds_message_destroy(&received);
+  if (stage == 1)
+    mds_message_destroy(&received);
   return 1;
 }
 
@@ -130,13 +131,12 @@ int postinitialise_server(void)
   if (connected)
     return 0;
   
-  if (reconnect_to_display())
-    {
-      mds_message_destroy(&received);
-      return 1;
-    }
+  fail_if (reconnect_to_display());
   connected = 1;
   return 0;
+ fail:
+  mds_message_destroy(&received);
+  return 1;
 }
 
 
@@ -190,11 +190,11 @@ int unmarshal_server(char* state_buf)
   buf_get_next(state_buf, int, connected);
   buf_get_next(state_buf, uint32_t, message_id);
   r = mds_message_unmarshal(&received, state_buf);
-  if (r)
-    {
-      xperror(*argv);
-      mds_message_destroy(&received);
-    }
+  fail_if (r);
+  return 0;
+ fail:
+  xperror(*argv);
+  mds_message_destroy(&received);
   return r;
 }
 
@@ -264,10 +264,12 @@ int master_loop(void)
  */
 int echo_message(void)
 {
+  char* old_buffer = NULL;
   const char* recv_client_id = NULL;
   const char* recv_message_id = NULL;
   const char* recv_length = NULL;
   size_t i, n;
+  int saved_errno;
   
   /* Fetch headers. */
   
@@ -311,14 +313,7 @@ int echo_message(void)
     n += strlen(recv_length) + 1;
   
   if ((echo_buffer_size < n) || (echo_buffer_size * 4 > n))
-    {
-      char* old_buffer = echo_buffer;
-      if (xrealloc(echo_buffer, echo_buffer_size = n, char))
-	{
-	  free(old_buffer);
-	  return -1;
-	}
-    }
+    fail_if (xxrealloc(old_buffer, echo_buffer, echo_buffer_size = n, char));
   
   sprintf(echo_buffer, "To: %s\nIn response to: %s\nMessage ID: %" PRIu32 "\n%s%s\n",
 	  recv_client_id, recv_message_id, message_id,
@@ -329,9 +324,12 @@ int echo_message(void)
   message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
   
   /* Send echo. */
-  if (full_send(echo_buffer, strlen(echo_buffer)))
-    return 1;
+  fail_if (full_send(echo_buffer, strlen(echo_buffer)));
   return full_send(received.payload, received.payload_size);
+ fail:
+  saved_errno = errno;
+  free(old_buffer);
+  return errno = saved_errno, -1;
 }
 
 
@@ -354,14 +352,14 @@ int full_send(const char* message, size_t length)
 	  eprint("Sent more of a message than exists in the message, aborting.");
 	  return -1;
 	}
-      else if ((sent < length) && (errno != EINTR))
-	{
-	  xperror(*argv);
-	  return -1;
-	}
+      else
+	fail_if ((sent < length) && (errno != EINTR));
       message += sent;
       length -= sent;
     }
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
diff --git a/src/mds-kbdc/builtin-functions.c b/src/mds-kbdc/builtin-functions.c
index fca6496..4ccc31f 100644
--- a/src/mds-kbdc/builtin-functions.c
+++ b/src/mds-kbdc/builtin-functions.c
@@ -19,6 +19,8 @@
 
 #include "variables.h"
 
+#include <libmdsserver/macros.h>
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -34,8 +36,7 @@
   size_t bn = string_length(b);					\
   size_t i, n = an > bn ? an : bn;				\
   char32_t* restrict rc = malloc((n + 1) * sizeof(char32_t));	\
-  if (rc == NULL)						\
-    return NULL;						\
+  fail_if (rc == NULL);						\
   rc[n] = -1
 
 /**
@@ -45,10 +46,19 @@
   const char32_t* restrict a = *args++;				\
   size_t i, n = string_length(a);				\
   char32_t* restrict rc = malloc((n + 1) * sizeof(char32_t));	\
-  if (rc == NULL)						\
-    return NULL;						\
+  fail_if (rc == NULL);						\
   rc[n] = -1
 
+/**
+ * Return a value, or if there was a failure somewhere, return `NULL`
+ * 
+ * @param  v:void*  The value to return on success
+ */
+#define return(v)				\
+  return v;					\
+ fail:						\
+  return NULL;
+
 
 /**
  * Definition of the built-in function add/2
@@ -61,7 +71,7 @@ static char32_t* builtin_function_add_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] + b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -76,7 +86,7 @@ static char32_t* builtin_function_sub_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] - b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -91,7 +101,7 @@ static char32_t* builtin_function_mul_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] * b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -106,7 +116,7 @@ static char32_t* builtin_function_div_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] / b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -121,7 +131,7 @@ static char32_t* builtin_function_mod_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] % b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -136,7 +146,7 @@ static char32_t* builtin_function_rsh_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] << b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -151,7 +161,7 @@ static char32_t* builtin_function_lsh_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] >> b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -166,7 +176,7 @@ static char32_t* builtin_function_or_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] | b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -181,7 +191,7 @@ static char32_t* builtin_function_and_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] & b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -196,7 +206,7 @@ static char32_t* builtin_function_xor_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] ^ b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -211,7 +221,7 @@ static char32_t* builtin_function_not_1(const char32_t** restrict args)
   define_1;
   for (i = 0; i < n; i++)
     rc[i] = !a[i];
-  return rc;
+  return(rc);
 }
 
 
@@ -226,7 +236,7 @@ static char32_t* builtin_function_equals_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] == b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -241,7 +251,7 @@ static char32_t* builtin_function_greater_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] > b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -256,7 +266,7 @@ static char32_t* builtin_function_less_2(const char32_t** restrict args)
   define_2;
   for (i = 0; i < n; i++)
     rc[i] = a[i % an] < b[i % bn];
-  return rc;
+  return(rc);
 }
 
 
@@ -270,11 +280,13 @@ static char32_t* builtin_function_get_2(const char32_t** restrict args)
 {
   const char32_t* restrict a = *args++;
   const char32_t* restrict b = *args++;
+  char32_t* restrict rc;
   size_t n = (size_t)*b;
   mds_kbdc_tree_t* value = variables_get((size_t)*a);
   while (n--)
     value = value->next;
-  return string_dup(value->compiled_string.string);
+  fail_if (rc = string_dup(value->compiled_string.string), rc == NULL);
+  return(rc);
 }
 
 
@@ -289,20 +301,22 @@ static char32_t* builtin_function_set_3(const char32_t** restrict args)
   const char32_t* restrict a = *args++;
   const char32_t* restrict b = *args++;
   const char32_t* restrict c = *args++;
+  char32_t* restrict rc;
   size_t n = (size_t)*b;
   mds_kbdc_tree_t* value = variables_get((size_t)*a);
   while (n--)
     value = value->next;
   free(value->compiled_string.string);
   value->compiled_string.string = string_dup(c);
-  if (value->compiled_string.string == NULL)
-    return NULL;
-  return string_dup(c);
+  fail_if (value->compiled_string.string == NULL);
+  fail_if (rc = string_dup(c), rc == NULL);
+  return(rc);
 }
 
 
 #undef define_1
 #undef define_2
+#undef return
 
 
 /**
@@ -350,32 +364,33 @@ int builtin_function_defined(const char* restrict name, size_t arg_count)
  */
 char32_t* builtin_function_invoke(const char* restrict name, size_t arg_count, const char32_t** restrict args)
 {
-  if (arg_count == 3)
-    if (!strcmp(name, "set"))
-      return builtin_function_set_3(args);
+#define t(f)  do { fail_if (rc = builtin_function_##f(args), rc == NULL); return rc; } while (0)
+  char32_t* rc;
   
-  if (arg_count == 1)
-    if (!strcmp(name, "not"))
-      return builtin_function_not_1(args);
+  if ((arg_count == 3) && !strcmp(name, "set"))  t (set_3);
+  if ((arg_count == 1) && !strcmp(name, "not"))  t (not_1);
   
   if (arg_count != 2)
     abort();
   
-  if (!strcmp(name, "add"))      return builtin_function_add_2(args);
-  if (!strcmp(name, "sub"))      return builtin_function_sub_2(args);
-  if (!strcmp(name, "mul"))      return builtin_function_mul_2(args);
-  if (!strcmp(name, "div"))      return builtin_function_div_2(args);
-  if (!strcmp(name, "mod"))      return builtin_function_mod_2(args);
-  if (!strcmp(name, "rsh"))      return builtin_function_rsh_2(args);
-  if (!strcmp(name, "lsh"))      return builtin_function_lsh_2(args);
-  if (!strcmp(name, "or"))       return builtin_function_or_2(args);
-  if (!strcmp(name, "and"))      return builtin_function_and_2(args);
-  if (!strcmp(name, "xor"))      return builtin_function_xor_2(args);
-  if (!strcmp(name, "equals"))   return builtin_function_equals_2(args);
-  if (!strcmp(name, "greater"))  return builtin_function_greater_2(args);
-  if (!strcmp(name, "less"))     return builtin_function_less_2(args);
-  if (!strcmp(name, "get"))      return builtin_function_get_2(args);
+  if (!strcmp(name, "add"))      t (add_2);
+  if (!strcmp(name, "sub"))      t (sub_2);
+  if (!strcmp(name, "mul"))      t (mul_2);
+  if (!strcmp(name, "div"))      t (div_2);
+  if (!strcmp(name, "mod"))      t (mod_2);
+  if (!strcmp(name, "rsh"))      t (rsh_2);
+  if (!strcmp(name, "lsh"))      t (lsh_2);
+  if (!strcmp(name, "or"))       t (or_2);
+  if (!strcmp(name, "and"))      t (and_2);
+  if (!strcmp(name, "xor"))      t (xor_2);
+  if (!strcmp(name, "equals"))   t (equals_2);
+  if (!strcmp(name, "greater"))  t (greater_2);
+  if (!strcmp(name, "less"))     t (less_2);
+  if (!strcmp(name, "get"))      t (get_2);
   
   abort();
+ fail:
+  return NULL;
+#undef t
 }
 
diff --git a/src/mds-kbdc/compile-layout.c b/src/mds-kbdc/compile-layout.c
index ccf647c..539ade3 100644
--- a/src/mds-kbdc/compile-layout.c
+++ b/src/mds-kbdc/compile-layout.c
@@ -604,6 +604,8 @@ static int check_function_calls_in_literal(const mds_kbdc_tree_t* restrict tree,
 {
   int rc = 0;
   (void) check_function_calls_in_literal_(tree, raw, lineoff, &raw, &rc);
+  fail_if (rc < 0);
+ fail:
   return rc;
 }
 
@@ -669,7 +671,10 @@ static char32_t* parse_escape(mds_kbdc_tree_t* restrict tree, const char* restri
   /* Read escape. */
   if (*escape == 100)
     /* Function call. */
-    return parse_function_call(tree, raw_, lineoff, escape, end);
+    {
+      fail_if (rc = parse_function_call(tree, raw_, lineoff, escape, end), rc == NULL);
+      return rc;
+    }
   /* Octal or hexadecimal representation, or variable dereference. */
   for (; (c = *raw); have = 1, raw++)
     if      (CR( 8, '0', '7'))  numbuf =  8 * numbuf + (c & 15);
@@ -909,7 +914,11 @@ static char32_t* parse_string(mds_kbdc_tree_t* restrict tree, const char* restri
 {
   mds_kbdc_tree_t* old_last_value_statement = last_value_statement;
   char32_t* rc = (strchr("\"\\", *raw) ? parse_quoted_string : parse_unquoted_string)(tree, raw, lineoff);
-  return last_value_statement = old_last_value_statement, rc;
+  last_value_statement = old_last_value_statement;
+  fail_if (rc == NULL);
+  return rc;
+ fail:
+  return NULL;
 }
 
 
@@ -1077,7 +1086,7 @@ static size_t parse_variable(mds_kbdc_tree_t* restrict tree, const char* restric
   memcpy(dotless, raw_, n * sizeof(char)), dotless[n] = '\0';
   var = (size_t)atoll(dotless + 1);
   if (strlen(dotless + 1) != (size_t)snprintf(NULL, 0, "%zu", var))
-    return errno = ERANGE, (size_t)0;
+    fail_if ((errno = ERANGE));
   return var;
  fail:
   return 0;
@@ -1172,7 +1181,10 @@ static int parse_function_argument(mds_kbdc_tree_t* restrict tree, const char* r
 static int set_macro(mds_kbdc_tree_macro_t* restrict macro,
 		     mds_kbdc_include_stack_t* macro_include_stack)
 {
-  return callables_set(macro->name, 0, (mds_kbdc_tree_t*)macro, macro_include_stack);
+  fail_if (callables_set(macro->name, 0, (mds_kbdc_tree_t*)macro, macro_include_stack));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1246,7 +1258,10 @@ static int set_function(mds_kbdc_tree_function_t* restrict function,
   
   *suffix_start = '\0';
   r = callables_set(suffixless, arg_count, (mds_kbdc_tree_t*)function, function_include_stack);
-  return *suffix_start = '/', r;
+  fail_if (*suffix_start = '/', r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1304,8 +1319,7 @@ static int compile_include(mds_kbdc_tree_include_t* restrict tree)
 {
   void* data;
   int r;
-  if (mds_kbdc_include_stack_push(tree, &data))
-    return -1;
+  fail_if (mds_kbdc_include_stack_push(tree, &data));
   r = compile_subtree(tree->inner);
   mds_kbdc_include_stack_pop(data);
   
@@ -1314,7 +1328,10 @@ static int compile_include(mds_kbdc_tree_include_t* restrict tree)
    * include-stack as its overriding statement. */
   last_value_statement = NULL;
   
-  return r;
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1650,7 +1667,7 @@ static int compile_have_range(mds_kbdc_tree_assumption_have_range_t* restrict tr
  */
 static int check_marco_calls(mds_kbdc_tree_t* restrict tree)
 {
-#define t(...)   if (rc |= r = (__VA_ARGS__), r < 0)  return r
+#define t(...)   fail_if (rc |= r = (__VA_ARGS__), r < 0)
   mds_kbdc_tree_macro_t* _macro;
   mds_kbdc_include_stack_t* _macro_include_stack;
   void* data;
@@ -1685,6 +1702,8 @@ static int check_marco_calls(mds_kbdc_tree_t* restrict tree)
   
   tree = tree->next;
   goto again;
+ fail:
+  return -1;
   (void) _macro;
   (void) _macro_include_stack;
 #undef t
@@ -1699,7 +1718,7 @@ static int check_marco_calls(mds_kbdc_tree_t* restrict tree)
  */
 static int check_function_calls_in_for(const mds_kbdc_tree_for_t* restrict tree)
 {
-#define t(...)  if (rc |= r = check_function_calls_in_literal(__VA_ARGS__), r < 0)  return r
+#define t(...)  fail_if (rc |= r = check_function_calls_in_literal(__VA_ARGS__), r < 0)
   size_t lineoff_first;
   size_t lineoff_last;
   char* restrict code = result->source_code->real_lines[tree->loc_line];
@@ -1713,6 +1732,8 @@ static int check_function_calls_in_for(const mds_kbdc_tree_for_t* restrict tree)
   t ((const mds_kbdc_tree_t*)tree, tree->last, lineoff_last);
   
   return rc;
+ fail:
+  return -1;
 #undef t
 }
 
@@ -1727,9 +1748,13 @@ static int check_function_calls_in_if(const mds_kbdc_tree_if_t* restrict tree)
 {
   size_t lineoff;
   char* restrict code = result->source_code->real_lines[tree->loc_line];
+  int r;
   
   for (lineoff = tree->loc_end; code[lineoff] == ' '; lineoff++);
-  return check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->condition, lineoff);
+  r = check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->condition, lineoff);
+  fail_if (r < 0);
+ fail:
+  return r;
 }
 
 
@@ -1741,7 +1766,11 @@ static int check_function_calls_in_if(const mds_kbdc_tree_if_t* restrict tree)
  */
 static int check_function_calls_in_keys(const mds_kbdc_tree_keys_t* restrict tree)
 {
-  return check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->keys, tree->loc_start);
+  int r;
+  r = check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->keys, tree->loc_start);
+  fail_if (r < 0);
+ fail:
+  return r;
 }
 
 
@@ -1753,7 +1782,11 @@ static int check_function_calls_in_keys(const mds_kbdc_tree_keys_t* restrict tre
  */
 static int check_function_calls_in_string(const mds_kbdc_tree_string_t* restrict tree)
 {
-  return check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->string, tree->loc_start);
+  int r;
+  r = check_function_calls_in_literal((const mds_kbdc_tree_t*)tree, tree->string, tree->loc_start);
+  fail_if (r < 0);
+ fail:
+  return r;
 }
 
 
@@ -1765,7 +1798,7 @@ static int check_function_calls_in_string(const mds_kbdc_tree_string_t* restrict
  */
 static int check_function_calls(const mds_kbdc_tree_t* restrict tree)
 {
-#define t(...)   if (rc |= r = (__VA_ARGS__), r < 0)  return r
+#define t(...)   fail_if (rc |= r = (__VA_ARGS__), r < 0)
   void* data;
   int r, rc = 0;
  again:
@@ -1801,6 +1834,8 @@ static int check_function_calls(const mds_kbdc_tree_t* restrict tree)
   
   tree = tree->next;
   goto again;
+ fail:
+  return -1;
 #undef t
 }
 
@@ -2103,12 +2138,13 @@ static int compile_if(mds_kbdc_tree_if_t* restrict tree)
   /* Evaluate whether the evaluted value is true. */
   for (ok = 1, i = 0; data[i] >= 0; i++)
     ok &= !!(data[i]);
-  free(data);
+  free(data), data = NULL;;
   
   /* Compile the appropriate clause. */
   ok = compile_subtree(ok ? tree->inner : tree->otherwise);
   last_value_statement = NULL;
-  return ok;
+  fail_if (ok < 0);
+  return 0;
   FAIL_BEGIN;
   free(data);
   FAIL_END;
@@ -2200,7 +2236,10 @@ static int evaluate_element(mds_kbdc_tree_t* restrict node)
  */
 static int compile_keys(mds_kbdc_tree_keys_t* restrict tree)
 {
-  return evaluate_element((mds_kbdc_tree_t*)tree) < 0 ? -1 : 0;
+  fail_if (evaluate_element((mds_kbdc_tree_t*)tree));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -2212,7 +2251,10 @@ static int compile_keys(mds_kbdc_tree_keys_t* restrict tree)
  */
 static int compile_string(mds_kbdc_tree_string_t* restrict tree)
 {
-  return evaluate_element((mds_kbdc_tree_t*)tree) < 0 ? -1 : 0;
+  fail_if (evaluate_element((mds_kbdc_tree_t*)tree));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -2225,11 +2267,12 @@ static int compile_string(mds_kbdc_tree_string_t* restrict tree)
 static int compile_array(mds_kbdc_tree_array_t* restrict tree)
 {
   int r = evaluate_element(tree->elements);
-  if (r < 0)
-    return -1;
+  fail_if (r < 0);
   if (r)
     tree->processed = PROCESS_LEVEL;
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -2261,7 +2304,7 @@ static int check_nonnul(mds_kbdc_tree_t* restrict tree)
   tree = tree->next;
   goto again;
  fail:
-   return -1;
+  return -1;
 }
 
 
@@ -2533,7 +2576,10 @@ int compile_layout(mds_kbdc_parsed_t* restrict result_)
   variables_terminate();
   callables_terminate();
   errno = saved_errno;
-  return r;
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-kbdc/eliminate-dead-code.c b/src/mds-kbdc/eliminate-dead-code.c
index 4916fa4..5628a91 100644
--- a/src/mds-kbdc/eliminate-dead-code.c
+++ b/src/mds-kbdc/eliminate-dead-code.c
@@ -82,11 +82,13 @@ static int eliminate_include(mds_kbdc_tree_include_t* restrict tree)
 {
   void* data;
   int r;
-  if (mds_kbdc_include_stack_push(tree, &data))
-    return -1;
+  fail_if (mds_kbdc_include_stack_push(tree, &data));
   r = eliminate_subtree(tree->inner);
   mds_kbdc_include_stack_pop(data);
-  return r;
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -118,9 +120,8 @@ static int eliminate_if(mds_kbdc_tree_if_t* restrict tree)
  */
 static int eliminate_subtree(mds_kbdc_tree_t* restrict tree)
 {
-#define e(type)  if ((r = eliminate_##type(&(tree->type))))     return r
-#define E(type)  if ((r = eliminate_##type(&(tree->type##_))))  return r
-  int r;
+#define e(type)  fail_if (eliminate_##type(&(tree->type)))
+#define E(type)  fail_if (eliminate_##type(&(tree->type##_)))
  again:
   if (tree == NULL)
     return 0;
@@ -134,8 +135,7 @@ static int eliminate_subtree(mds_kbdc_tree_t* restrict tree)
     case C(MACRO):
     case C(ASSUMPTION):
     case C(FOR):
-      if ((r = eliminate_subtree(tree->information.inner)))
-	return r;
+      fail_if (eliminate_subtree(tree->information.inner));
       if ((tree->type == C(FUNCTION)) || (tree->type == C(MACRO)))  elimination_level = 0;
       else if ((tree->type == C(FOR)) && (elimination_level == 1))  elimination_level = 0;
       break;
@@ -174,7 +174,11 @@ int eliminate_dead_code(mds_kbdc_parsed_t* restrict result_)
   int r;
   mds_kbdc_include_stack_begin(result = result_);
   r = eliminate_subtree(result_->tree);
-  return mds_kbdc_include_stack_end(), r;
+  mds_kbdc_include_stack_end();
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-kbdc/include-stack.c b/src/mds-kbdc/include-stack.c
index bec1425..d8c4547 100644
--- a/src/mds-kbdc/include-stack.c
+++ b/src/mds-kbdc/include-stack.c
@@ -190,9 +190,7 @@ mds_kbdc_include_stack_t* mds_kbdc_include_stack_save(void)
       return latest_save;
     }
   
-  latest_save = malloc(sizeof(mds_kbdc_include_stack_t));
-  if (latest_save == NULL)
-    return NULL;
+  fail_if (xmalloc(latest_save, 1, mds_kbdc_include_stack_t));
   
   latest_save->stack = NULL;
   latest_save->ptr = includes_ptr;
@@ -207,8 +205,8 @@ mds_kbdc_include_stack_t* mds_kbdc_include_stack_save(void)
   return latest_save;
  fail:
   saved_errno = errno;
-  free(latest_save->stack);
-  latest_save = NULL;
+  if (latest_save)
+    free(latest_save->stack), latest_save = NULL;
   errno = saved_errno;
   return NULL;
 }
@@ -229,8 +227,7 @@ int mds_kbdc_include_stack_restore(mds_kbdc_include_stack_t* restrict stack)
   if (stack->ptr > includes_size)
     {
       new = realloc(includes, stack->ptr * sizeof(const mds_kbdc_tree_include_t*));
-      if (new == NULL)
-	return -1;
+      fail_if (new == NULL);
       includes = new;
       includes_size = stack->ptr;
     }
@@ -238,6 +235,8 @@ int mds_kbdc_include_stack_restore(mds_kbdc_include_stack_t* restrict stack)
   memcpy(includes, stack->stack, stack->ptr * sizeof(const mds_kbdc_tree_include_t*));
   includes_ptr = stack->ptr;
   return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-kbdc/make-tree.c b/src/mds-kbdc/make-tree.c
index 8a7bb1e..77155b2 100644
--- a/src/mds-kbdc/make-tree.c
+++ b/src/mds-kbdc/make-tree.c
@@ -425,7 +425,7 @@ static int too_few;
  * Get the pathname name of the parsed file
  * 
  * @param   filename  The filename of the parsed file
- * @return            The value the caller should return, or 1 if the caller should not return
+ * @return            The value the caller should return, or 1 if the caller should not return, -1 on error
  */
 static int get_pathname(const char* restrict filename)
 {
@@ -769,9 +769,10 @@ static int have_more_parameters(void)
  */
 static int test_for_keyword(const char* restrict keyword)
 {
-  int r, ok;
-  if (r = have_more_parameters(), r <= 0)
-    return r;
+  int ok, r = have_more_parameters();
+  fail_if (r < 0);
+  if (r == 0)
+    return 0;
   
   ok = (strstr(line, keyword) == line);
   line += strlen(keyword);
@@ -807,8 +808,10 @@ static int keys(mds_kbdc_tree_t** restrict var)
   char* arg_end;
   char* call_end;
   int r, escape = 0, quote = 0, triangle;
-  if (r = have_more_parameters(), r <= 0)
-    return r;
+  r = have_more_parameters();
+  fail_if (r < 0);
+  if (r == 0)
+    return 0;
   
   arg_end = line;
   call_end = arg_end;
@@ -863,8 +866,10 @@ static int pure_keys(char** restrict var)
   char* arg_end;
   char* call_end;
   int r, escape = 0, quote = 0, triangle;
-  if (r = have_more_parameters(), r <= 0)
-    return r;
+  r = have_more_parameters();
+  fail_if (r < 0);
+  if (r == 0)
+    return 0;
   
   arg_end = line;
   call_end = arg_end;
@@ -1408,8 +1413,10 @@ int parse_to_tree(const char* restrict filename, mds_kbdc_parsed_t* restrict res
   fail_if (xmalloc(result->source_code, 1, mds_kbdc_source_code_t));
   mds_kbdc_source_code_initialise(result->source_code);
   
-  if (r = get_pathname(filename), r <= 0)
-    return r;
+  r = get_pathname(filename);
+  fail_if (r < 0);
+  if (r == 0)
+    return 0;
   
   fail_if (read_source_code());
   fail_if (allocate_stacks());
diff --git a/src/mds-kbdc/paths.c b/src/mds-kbdc/paths.c
index a14681e..e294020 100644
--- a/src/mds-kbdc/paths.c
+++ b/src/mds-kbdc/paths.c
@@ -73,7 +73,10 @@ char* abspath(const char* path)
   size_t size, p;
   
   if (*path == '/')
-    return strdup(path);
+    {
+      fail_if (buf = strdup(path), buf == NULL);
+      return buf;
+    }
   
   fail_if (cwd = curpath(), cwd == NULL);
   size = (p = strlen(cwd)) + strlen(path) + 2;
diff --git a/src/mds-kbdc/process-includes.c b/src/mds-kbdc/process-includes.c
index 57e0502..2faaf3f 100644
--- a/src/mds-kbdc/process-includes.c
+++ b/src/mds-kbdc/process-includes.c
@@ -242,8 +242,7 @@ static int process_include(mds_kbdc_tree_include_t* restrict tree)
  */
 static int process_includes_in_tree(mds_kbdc_tree_t* restrict tree)
 {
-#define p(expr)  if ((r = process_includes_in_tree(tree->expr)))  return r
-  int r;
+#define p(expr)  fail_if (process_includes_in_tree(tree->expr))
  again:
   if (tree == NULL)
     return 0;
@@ -257,8 +256,7 @@ static int process_includes_in_tree(mds_kbdc_tree_t* restrict tree)
     case C(FOR):          p (for_.inner);         break;
     case C(IF):           p (if_.inner);          p (if_.otherwise);  break;
     case C(INCLUDE):
-      if ((r = process_include(&(tree->include))))
-	return r;
+      fail_if (process_include(&(tree->include)));
       break;
     default:
       break;
@@ -266,6 +264,8 @@ static int process_includes_in_tree(mds_kbdc_tree_t* restrict tree)
   
   tree = tree->next;
   goto again;
+ fail:
+  return -1;
 #undef p
 }
 
@@ -290,7 +290,7 @@ int process_includes(mds_kbdc_parsed_t* restrict result_)
     {
       struct stat* old;
       if (xxrealloc(old, included, included_size += 4, struct stat))
-	return included = old, -1;
+	fail_if (included = old, 1);
     }
   
   for (i = 0; i < included_ptr; i++)
diff --git a/src/mds-kbdc/raw-data.c b/src/mds-kbdc/raw-data.c
index 359abe8..83e8b48 100644
--- a/src/mds-kbdc/raw-data.c
+++ b/src/mds-kbdc/raw-data.c
@@ -456,14 +456,15 @@ static char* encode_utf8(char* buffer, char32_t character)
   text[0] = character;
   text[1] = -1;
   
-  if (str_ = str = string_encode(text), str == NULL)
-    return NULL;
+  fail_if (str_ = str = string_encode(text), str == NULL);
   
   while (*str)
     *buffer++ = *str++;
   
   free(str_);
   return buffer;
+ fail:
+  return NULL;
 }
 
 
@@ -489,8 +490,7 @@ char* parse_raw_string(const char* restrict string)
    * is not code point whose UTF-8 encoding is longer than its
    * hexadecimal representation. */
   p = rc = malloc(strlen(string) * sizeof(char));
-  if (rc == NULL)
-    return NULL;
+  fail_if (rc == NULL);
   
   while ((c = *string++))
     if      (r(escape ==  8, '0', '7'))  buf = (buf << 3) | (c & 15);
diff --git a/src/mds-kbdc/simplify-tree.c b/src/mds-kbdc/simplify-tree.c
index c46649e..d24569d 100644
--- a/src/mds-kbdc/simplify-tree.c
+++ b/src/mds-kbdc/simplify-tree.c
@@ -161,6 +161,7 @@ static int eliminate_alternation(mds_kbdc_tree_t* tree, mds_kbdc_tree_t* argumen
   mds_kbdc_tree_t* next_alternative;
   mds_kbdc_tree_t* new_argument;
   size_t i;
+  int saved_errno;
   
   /* Detach next statement, we do not want to duplicate all following statements. */
   next_statement = tree->next, tree->next = NULL;
@@ -171,13 +172,7 @@ static int eliminate_alternation(mds_kbdc_tree_t* tree, mds_kbdc_tree_t* argumen
   for (first = last = NULL; alternative; alternative = next_alternative)
     {
       /* Duplicate statement. */
-      if (new_tree = mds_kbdc_tree_dup(tree), new_tree == NULL)
-	{
-	  int saved_errno = errno;
-	  argument->alternation.inner = alternative;
-	  tree->next = next_statement;
-	  return errno = saved_errno, -1;
-	}
+      fail_if (new_tree = mds_kbdc_tree_dup(tree), new_tree == NULL);
       /* Join trees. */
       if (last)
 	last->next = new_tree;
@@ -204,6 +199,11 @@ static int eliminate_alternation(mds_kbdc_tree_t* tree, mds_kbdc_tree_t* argumen
   /* Reattach the statement that followed to the last generated statement. */
   last->next = next_statement;
   return 0;
+ fail:
+  saved_errno = errno;
+  argument->alternation.inner = alternative;
+  tree->next = next_statement;
+  return errno = saved_errno, -1;
 }
 
 
@@ -567,7 +567,8 @@ static int simplify_alternation(mds_kbdc_tree_alternation_t* restrict tree)
       NEW_ERROR(tree, WARNING, "singleton alternation");
       memcpy(tree, temp, sizeof(mds_kbdc_tree_t));
       free(temp);
-      return simplify((mds_kbdc_tree_t*)tree);
+      fail_if (simplify((mds_kbdc_tree_t*)tree));
+      return 0;
     }
   
   /* Simplify. */
@@ -625,11 +626,10 @@ static mds_kbdc_tree_t* create_permutations(mds_kbdc_tree_t* elements)
   mds_kbdc_tree_t* subperms = NULL;
   mds_kbdc_tree_t* perm;
   mds_kbdc_tree_t ordered;
-  int saved_errno, no_perms;
+  int saved_errno, no_perms, stage = 0;
   
   /* Error case. */
-  if (elements == NULL)
-    return NULL;
+  fail_if (elements == NULL);
   
   /* Base case. */
   if (elements->next == NULL)
@@ -639,6 +639,7 @@ static mds_kbdc_tree_t* create_permutations(mds_kbdc_tree_t* elements)
       return first;
     }
   
+  stage++;
   for (previous_next = &elements; (argument = *previous_next); previous_next = &((*previous_next)->next))
     {
       /* Created ordered alternative for a permutation prototype. */
@@ -682,7 +683,8 @@ static mds_kbdc_tree_t* create_permutations(mds_kbdc_tree_t* elements)
   saved_errno = errno;
   mds_kbdc_tree_free(first);
   mds_kbdc_tree_free(subperms);
-  mds_kbdc_tree_destroy(&ordered);
+  if (stage > 0)
+    mds_kbdc_tree_destroy(&ordered);
   errno = saved_errno;
   return NULL;
 }
@@ -730,7 +732,8 @@ static int simplify_unordered(mds_kbdc_tree_unordered_t* restrict tree)
       NEW_ERROR(tree, WARNING, "singleton unordered subsequence");
       memcpy(tree, temp, sizeof(mds_kbdc_tree_t));
       free(temp);
-      return simplify((mds_kbdc_tree_t*)tree);
+      fail_if (simplify((mds_kbdc_tree_t*)tree));
+      return -1;
     }
   
   /* Remove ‘.’:s. */
@@ -783,9 +786,9 @@ static int simplify_unordered(mds_kbdc_tree_unordered_t* restrict tree)
 	   * if it does not list any permutations. */
 	  NEW_ERROR_(result, INTERNAL_ERROR, 0, 0, 0, 0, 1,
 		     "Fail to create permutations of an unordered sequence");
-	  errno = 0;
+	  return 0;
 	}
-      return tree->inner = arguments, -1;
+      fail_if (tree->inner = arguments, 1);
     }
   mds_kbdc_tree_free(arguments);
   
@@ -803,9 +806,8 @@ static int simplify_unordered(mds_kbdc_tree_unordered_t* restrict tree)
  */
 static int simplify(mds_kbdc_tree_t* restrict tree)
 {
-#define s(expr)  if ((r = simplify(tree->expr)))  return r
-#define S(type)  if ((r = simplify_##type(&(tree->type))))  return r
-  int r;
+#define s(expr)  fail_if (simplify(tree->expr))
+#define S(type)  fail_if (simplify_##type(&(tree->type)))
  again:
   if (tree == NULL)
     return 0;
@@ -828,6 +830,8 @@ static int simplify(mds_kbdc_tree_t* restrict tree)
   
   tree = tree->next;
   goto again;
+ fail:
+  return -1;
 #undef s
 #undef S
 }
diff --git a/src/mds-kbdc/string.c b/src/mds-kbdc/string.c
index 062aed3..6ecf757 100644
--- a/src/mds-kbdc/string.c
+++ b/src/mds-kbdc/string.c
@@ -56,8 +56,7 @@ char32_t* string_decode(const char* restrict string)
       length++;
   
   /* Allocated UTF-32 string. */
-  if (xmalloc(rc, length + 1, char32_t))
-    return NULL;
+  fail_if (xmalloc(rc, length + 1, char32_t));
   
   /* Convert to UTF-32. */
   for (i = j = n = 0; string[i]; i++)
@@ -81,6 +80,8 @@ char32_t* string_decode(const char* restrict string)
   
   /* -1-terminate and return. */
   return rc[length] = -1, rc;
+ fail:
+  return NULL;
 }
 
 
@@ -98,8 +99,7 @@ char* string_encode(const char32_t* restrict string)
   char* restrict rc;
   
   /* Allocated Modified UTF-8 string. */
-  if (xmalloc(rc, 7 * n + 1, char))
-    return NULL;
+  fail_if (xmalloc(rc, 7 * n + 1, char));
   
   /* Convert to Modified UTF-8. */
   for (i = j = 0; i < n; i++)
@@ -127,6 +127,8 @@ char* string_encode(const char32_t* restrict string)
   
   /* NUL-terminate and return. */
   return rc[j] = '\0', rc;
+ fail:
+  return NULL;
 }
 
 
@@ -143,9 +145,10 @@ char32_t* string_dup(const char32_t* restrict string)
   if (string == NULL)
     return NULL;
   n = string_length(string) + 1;
-  if (xmalloc(rc, n, char32_t))
-    return NULL;
+  fail_if (xmalloc(rc, n, char32_t));
   memcpy(rc, string, n * sizeof(char32_t));
   return rc;
+ fail:
+  return NULL;
 }
 
diff --git a/src/mds-kbdc/tree.c b/src/mds-kbdc/tree.c
index ac9de2b..b32c503 100644
--- a/src/mds-kbdc/tree.c
+++ b/src/mds-kbdc/tree.c
@@ -60,11 +60,12 @@ void mds_kbdc_tree_initialise(mds_kbdc_tree_t* restrict this, int type)
  */
 mds_kbdc_tree_t* mds_kbdc_tree_create(int type)
 {
-  mds_kbdc_tree_t* this = malloc(sizeof(mds_kbdc_tree_t));
-  if (this == NULL)
-    return NULL;
+  mds_kbdc_tree_t* this;
+  fail_if (xmalloc(this, 1, mds_kbdc_tree_t));
   mds_kbdc_tree_initialise(this, type);
   return this;
+ fail:
+  return NULL;
 }
 
 
diff --git a/src/mds-kbdc/validate-tree.c b/src/mds-kbdc/validate-tree.c
index eeb5735..466f138 100644
--- a/src/mds-kbdc/validate-tree.c
+++ b/src/mds-kbdc/validate-tree.c
@@ -106,11 +106,13 @@ static int validate_include(mds_kbdc_tree_include_t* restrict tree)
 {
   void* data;
   int r;
-  if (mds_kbdc_include_stack_push(tree, &data))
-    return -1;
+  fail_if (mds_kbdc_include_stack_push(tree, &data));
   r = validate_subtree(tree->inner);
   mds_kbdc_include_stack_pop(data);
-  return r;
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -339,9 +341,11 @@ static int validate_macro_call(mds_kbdc_tree_macro_call_t* restrict tree)
 static int validate_for(mds_kbdc_tree_for_t* restrict tree)
 {
   int r;
-  fors++;
-  r = validate_subtree(tree->inner);
-  return fors--, r;
+  fors++, r = validate_subtree(tree->inner), fors--;
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -353,8 +357,10 @@ static int validate_for(mds_kbdc_tree_for_t* restrict tree)
  */
 static int validate_if(mds_kbdc_tree_if_t* restrict tree)
 {
-  return -(validate_subtree(tree->inner) ||
-	   validate_subtree(tree->otherwise));
+  fail_if ((validate_subtree(tree->inner) || validate_subtree(tree->otherwise)));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -446,9 +452,8 @@ static int validate_information_data(mds_kbdc_tree_t* restrict tree)
  */
 static int validate_subtree(mds_kbdc_tree_t* restrict tree)
 {
-#define v(type)  if ((r = validate_##type(&(tree->type))))     return r
-#define V(type)  if ((r = validate_##type(&(tree->type##_))))  return r
-  int r;
+#define v(type)  fail_if (validate_##type(&(tree->type)))
+#define V(type)  fail_if (validate_##type(&(tree->type##_)))
  again:
   if (tree == NULL)
     return 0;
@@ -470,14 +475,12 @@ static int validate_subtree(mds_kbdc_tree_t* restrict tree)
     case C(INFORMATION_LANGUAGE):
     case C(INFORMATION_COUNTRY):
     case C(INFORMATION_VARIANT):
-      if ((r = validate_information_data(tree)))
-	return r;
+      fail_if (validate_information_data(tree));
       break;
     case C(ASSUMPTION_HAVE):
     case C(ASSUMPTION_HAVE_CHARS):
     case C(ASSUMPTION_HAVE_RANGE):
-      if ((r = validate_assumption_data(tree)))
-	return r;
+      fail_if (validate_assumption_data(tree));
       break;
     default:
       break;
@@ -485,6 +488,8 @@ static int validate_subtree(mds_kbdc_tree_t* restrict tree)
   
   tree = tree->next;
   goto again;
+ fail:
+  return -1;
 #undef V
 #undef v
 }
@@ -502,7 +507,11 @@ int validate_tree(mds_kbdc_parsed_t* restrict result_)
   mds_kbdc_include_stack_begin(result = result_);
   r = validate_subtree(result_->tree);
   fors = 0;
-  return mds_kbdc_include_stack_end(), r;
+  mds_kbdc_include_stack_end();
+  fail_if (r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-kbdc/variables.c b/src/mds-kbdc/variables.c
index 55bae76..7431767 100644
--- a/src/mds-kbdc/variables.c
+++ b/src/mds-kbdc/variables.c
@@ -17,6 +17,8 @@
  */
 #include "variables.h"
 
+#include <libmdsserver/macros.h>
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -149,9 +151,8 @@ int variables_let(size_t variable, mds_kbdc_tree_t* restrict value)
   /* Grow the table if necessary to fit the variable. */
   if (variable >= variable_count)
     {
-      new = realloc(variables, (variable + 1) * sizeof(variable_t*));
-      if (new == NULL)
-	return -1;
+      new = variables;
+      fail_if (xrealloc(new, variable + 1, variable_t*));
       variables = new;
       memset(variables + variable_count, 0, (variable + 1 - variable_count) * sizeof(variable_t*));
       variable_count = variable + 1;
@@ -169,13 +170,15 @@ int variables_let(size_t variable, mds_kbdc_tree_t* restrict value)
       previous = variables[variable];
       variables[variable] = malloc(sizeof(variable_t));
       if (variables[variable] == NULL)
-	return variables[variable] = previous, -1;
+	fail_if (variables[variable] = previous, 1);
       variables[variable]->value = value;
       variables[variable]->previous = previous;
       variables[variable]->scope = current_scope;
     }
   
   return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-kkbd.c b/src/mds-kkbd.c
index 95b7f02..1823f5c 100644
--- a/src/mds-kkbd.c
+++ b/src/mds-kkbd.c
@@ -232,20 +232,12 @@ int initialise_server(void)
     "\n"
     KEYBOARD_ID "\n";
   
-  fail_if (open_leds() < 0);
-  stage = 1;
-  fail_if (open_input() < 0);
-  stage = 2;
-  fail_if (pthread_mutex_init(&send_mutex, NULL));
-  stage = 3;
-  fail_if (pthread_mutex_init(&mapping_mutex, NULL));
-  stage = 4;
-  
-  if (full_send(message, strlen(message)))
-    return 1;
-  
-  fail_if (server_initialised());
-  stage = 5;
+  fail_if (open_leds() < 0);  stage++;
+  fail_if (open_input() < 0);  stage++;
+  fail_if (pthread_mutex_init(&send_mutex, NULL));  stage++;
+  fail_if (pthread_mutex_init(&mapping_mutex, NULL));  stage++;
+  fail_if (full_send(message, strlen(message)));
+  fail_if (server_initialised());  stage++;
   fail_if (mds_message_initialise(&received));
   
   return 0;
@@ -257,11 +249,9 @@ int initialise_server(void)
       if (stage >= 2)  close_input();
       if (stage >= 1)  close_leds();
     }
-  if (stage >= 3)
-    pthread_mutex_destroy(&send_mutex);
-  if (stage >= 4)
-    pthread_mutex_destroy(&mapping_mutex);
-  mds_message_destroy(&received);
+  if (stage >= 3)  pthread_mutex_destroy(&send_mutex);
+  if (stage >= 4)  pthread_mutex_destroy(&mapping_mutex);
+  if (stage >= 5)  mds_message_destroy(&received);
   return 1;
 }
 
@@ -277,13 +267,12 @@ int postinitialise_server(void)
   if (connected)
     return 0;
   
-  if (reconnect_to_display())
-    {
-      mds_message_destroy(&received);
-      return 1;
-    }
+  fail_if (reconnect_to_display());
   connected = 1;
   return 0;
+ fail:
+  mds_message_destroy(&received);
+  return 1;
 }
 
 
@@ -540,19 +529,23 @@ int handle_message(void)
   
   if (recv_command == NULL)
     return 0; /* How did that get here, not matter, just ignore it? */
-  
+
+#define t(expr)  do { fail_if (expr); return 0; } while (0)
   if (strequals(recv_command, "enumerate-keyboards"))
-    return handle_enumerate_keyboards(recv_client_id, recv_message_id, recv_modify_id);
+    t (handle_enumerate_keyboards(recv_client_id, recv_message_id, recv_modify_id));
   if (strequals(recv_command, "keyboard-enumeration"))
-    return handle_keyboard_enumeration(recv_modify_id);
+    t (handle_keyboard_enumeration(recv_modify_id));
   if (strequals(recv_command, "set-keyboard-leds"))
-    return handle_set_keyboard_leds(recv_active, recv_mask, recv_keyboard);
+    t (handle_set_keyboard_leds(recv_active, recv_mask, recv_keyboard));
   if (strequals(recv_command, "get-keyboard-leds"))
-    return handle_get_keyboard_leds(recv_client_id, recv_message_id, recv_keyboard);
+    t (handle_get_keyboard_leds(recv_client_id, recv_message_id, recv_keyboard));
   if (strequals(recv_command, "keycode-map"))
-    return handle_keycode_map(recv_client_id, recv_message_id, recv_action, recv_keyboard);
+    t (handle_keycode_map(recv_client_id, recv_message_id, recv_action, recv_keyboard));
+#undef t
   
   return 0; /* How did that get here, not matter, just ignore it? */
+ fail:
+  return -1;
 }
 
 
@@ -569,15 +562,13 @@ static int ensure_send_buffer_size(size_t size)
   if (send_buffer_size >= size)
     return 0;
   
-  if (xrealloc(send_buffer, size, char))
-    {
-      send_buffer = old;
-      return -1;
-    }
-  else
-    send_buffer_size = size;
+  fail_if (xrealloc(send_buffer, size, char));
+  send_buffer_size = size;
   
   return 0;
+ fail:
+  send_buffer = old;
+  return -1;
 }
 
 
@@ -613,8 +604,7 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess
 		  message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
 		  );
       
-      if (ensure_send_buffer_size(48 + strlen(recv_modify_id) + 1) < 0)
-	return -1;
+      fail_if (ensure_send_buffer_size(48 + strlen(recv_modify_id) + 1) < 0);
       sprintf(send_buffer,
 	      "Modify: no\n"
 	      "Modify ID: %s\n"
@@ -624,8 +614,10 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess
       
       with_mutex (send_mutex,
 		  r = full_send(send_buffer, strlen(send_buffer));
+		  if (r)  r = errno ? errno : -1;
 		  );
-      return r;
+      fail_if (errno = (r == -1 ? 0 : r), r);
+      return 0;
     }
   
   with_mutex (send_mutex,
@@ -636,8 +628,7 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess
   
   n = 176 + 3 * sizeof(size_t) + strlen(KEYBOARD_ID);
   n += strlen(recv_modify_id) + strlen(recv_message_id);
-  if (ensure_send_buffer_size(n + 1) < 0)
-    return -1;
+  fail_if (ensure_send_buffer_size(n + 1) < 0);
   sprintf(send_buffer,
 	  "Modify: yes\n"
 	  "Modify ID: %s\n"
@@ -656,8 +647,12 @@ int handle_enumerate_keyboards(const char* recv_client_id, const char* recv_mess
   
   with_mutex (send_mutex,
 	      r = full_send(send_buffer, strlen(send_buffer));
+	      if (r)  r = errno ? errno : -1;
 	      );
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -687,8 +682,7 @@ int handle_keyboard_enumeration(const char* recv_modify_id)
   
   n += off = 64 + strlen(recv_modify_id) + 3 * sizeof(size_t);
   
-  if (ensure_send_buffer_size(n + 1) < 0)
-    return -1;
+  fail_if (ensure_send_buffer_size(n + 1) < 0);
   
   with_mutex (send_mutex,
 	      msgid = message_id;
@@ -732,9 +726,13 @@ int handle_keyboard_enumeration(const char* recv_modify_id)
   
   with_mutex (send_mutex,
 	      r = full_send(send_buffer + off, n);
+	      if (r)  r = errno ? errno : -1;
 	      );
   
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -854,7 +852,7 @@ int handle_get_keyboard_leds(const char* recv_client_id, const char* recv_messag
       int error = errno;
       xperror(*argv);
       send_errno(error, recv_client_id, recv_message_id);
-      return -1;
+      fail_if (errno = error, 1);
     }
   
   with_mutex (send_mutex,
@@ -864,8 +862,7 @@ int handle_get_keyboard_leds(const char* recv_client_id, const char* recv_messag
   
   n = 95 + 3 * sizeof(size_t) + 2 * strlen(PRESENT_LEDS);
   n += strlen(recv_client_id) + strlen(recv_message_id);
-  if (ensure_send_buffer_size(n + 1) < 0)
-    return -1;
+  fail_if (ensure_send_buffer_size(n + 1) < 0);
   sprintf(send_buffer,
 	  "To: %s\n"
 	  "In response to: %s\n"
@@ -886,9 +883,14 @@ int handle_get_keyboard_leds(const char* recv_client_id, const char* recv_messag
   
   with_mutex (send_mutex,
 	      r = full_send(send_buffer, strlen(send_buffer));
+	      if (r)  r = errno ? errno : -1;
 	      );
   
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
 
@@ -913,10 +915,7 @@ static int parse_remap_line(char* begin, char* end, size_t n, int* restrict in,
     return 0;
   
   if (delimiter == NULL)
-    {
-      *in = -1, *out = -1;
-      return -1;
-    }
+    fail_if (*in = -1, *out = -1);
   
   *delimiter++ = '\0';
   *in = atoi(begin);
@@ -933,6 +932,8 @@ static int parse_remap_line(char* begin, char* end, size_t n, int* restrict in,
     }
   
   return 1;
+ fail:
+  return -1;
 }
 
 
@@ -954,10 +955,7 @@ static int add_mapping(int in, int out)
 	return 0;
       
       if (old = mapping, xrealloc(mapping, n, int))
-	{
-	  mapping = old;
-	  return -1;
-	}
+	fail_if (mapping = old, 1);
       
       for (; mapping_size < n; mapping_size++)
 	mapping[mapping_size] = (int)mapping_size;
@@ -965,6 +963,8 @@ static int add_mapping(int in, int out)
   
   mapping[in] = out;
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -997,8 +997,7 @@ static int remap(char* table, size_t n)
       if (in != out)  greatest_remap = max(greatest_remap, in);
       else            greatest_reset = max(greatest_reset, in);
       
-      if (add_mapping(in, out) < 0)
-	return -1;
+      fail_if (add_mapping(in, out) < 0);
       
     next:
       if (end == NULL)
@@ -1012,6 +1011,8 @@ static int remap(char* table, size_t n)
     shrink_map();
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1037,8 +1038,7 @@ static int mapping_query(const char* recv_client_id, const char* recv_message_id
   
   n *= 3 + (size_t)(greatest > 0x00FF ? 5 : 3);
   
-  if (ensure_send_buffer_size(top + n + 2) < 0)
-    return -1;
+  fail_if (ensure_send_buffer_size(top + n + 2) < 0);
   
   with_mutex (send_mutex,
 	      msgid = message_id;
@@ -1069,9 +1069,13 @@ static int mapping_query(const char* recv_client_id, const char* recv_message_id
   
   with_mutex (send_mutex,
 	      r = full_send(send_buffer + off, top + n);
+	      if (r)  r = errno ? errno : -1;
 	      );
   
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1088,8 +1092,7 @@ static int mapping_query(const char* recv_client_id, const char* recv_message_id
 int handle_keycode_map(const char* recv_client_id, const char* recv_message_id,
 		       const char* recv_action, const char* recv_keyboard)
 {
-  int r = 0;
-  
+  int r;
   if ((recv_keyboard != NULL) && !strequals(recv_keyboard, KEYBOARD_ID))
     return 0;
   
@@ -1105,7 +1108,9 @@ int handle_keycode_map(const char* recv_client_id, const char* recv_message_id,
       
       with_mutex (mapping_mutex,
 		  r = remap(received.payload, received.payload_size);
+		  if (r)  r = errno ? errno : -1;
 		  );
+      fail_if (errno = (r == -1 ? 0 : r), r);
     }
   else if (strequals(recv_action, "reset"))
     {
@@ -1122,12 +1127,14 @@ int handle_keycode_map(const char* recv_client_id, const char* recv_message_id,
 	  return 0;
 	}
       
-      r = mapping_query(recv_client_id, recv_message_id);
+      fail_if (mapping_query(recv_client_id, recv_message_id));
     }
   else
     eprint("received keycode map request with invalid action, ignoring.");
   
-  return r;
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1168,15 +1175,15 @@ int full_send(const char* message, size_t length)
 	  eprint("Sent more of a message than exists in the message, aborting.");
 	  return -1;
 	}
-      else if ((sent < length) && (errno != EINTR))
-	{
-	  xperror(*argv);
-	  return -1;
-	}
+      else
+	fail_if ((sent < length) && (errno != EINTR));
       message += sent;
       length -= sent;
     }
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
 
@@ -1188,17 +1195,19 @@ int full_send(const char* message, size_t length)
 int open_leds(void)
 {
 #ifdef __sparc__
-  if ((ledfd = open(SPARC_KBD, O_RDONLY)) < 0)
-    return -1;
+  fail_if ((ledfd = open(SPARC_KBD, O_RDONLY)) < 0);
   if (ioctl(ledfd, GET_LED, &saved_leds) < 0)
     {
       close(ledfd);
-      return -1;
+      fail_if (1);
     }
   return 0;
 #else
-  return ioctl(ledfd, GET_LED, &saved_leds);
+  fail_if (ioctl(ledfd, GET_LED, &saved_leds));
 #endif
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1223,12 +1232,13 @@ void close_leds(void)
 int get_leds(void)
 {
   int leds;
-  if (ioctl(ledfd, GET_LED, &leds) < 0)
-    return -1;
+  fail_if (ioctl(ledfd, GET_LED, &leds) < 0);
 #ifdef __sparc__
   leds &= 15;
 #endif
   return leds;
+ fail:
+  return -1;
 }
 
 
@@ -1240,7 +1250,10 @@ int get_leds(void)
  */
 int set_leds(int leds)
 {
-  return ioctl(ledfd, SET_LED, leds);
+  fail_if (ioctl(ledfd, SET_LED, leds));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1257,16 +1270,15 @@ int open_input(void)
   stty = saved_stty;
   stty.c_lflag &= (tcflag_t)~(ECHO | ICANON | ISIG);
   stty.c_iflag = 0;
-  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty) < 0)
-    return -1;
+  fail_if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty) < 0);
   /* K_MEDIUMRAW: utilise keyboard drivers, but not layout */
   if ((ioctl(STDIN_FILENO, KDGKBMODE, &saved_kbd_mode) < 0) ||
       (ioctl(STDIN_FILENO, KDSKBMODE, K_MEDIUMRAW) < 0))
-    {
-      xperror(*argv);
-      return tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
-    }
+    fail_if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty));
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
 
@@ -1337,8 +1349,12 @@ int send_key(int* restrict scancode, int trio)
   
   with_mutex (send_mutex,
 	      r = full_send(key_send_buffer, strlen(key_send_buffer));
+	      if (r)  r = errno ? errno : 0;
 	      );
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1412,7 +1428,10 @@ int fetch_keys(void)
 	}
     }
   
-  return errno == 0 ? 0 : -1;
+  fail_if (errno);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -1429,8 +1448,7 @@ int send_errno(int error, const char* recv_client_id, const char* recv_message_i
   size_t n = 79 + strlen(recv_client_id) + strlen(recv_message_id) + 3 * sizeof(int);
   int r;
   
-  if (ensure_send_buffer_size(n + 1) < 0)
-    return -1;
+  fail_if (ensure_send_buffer_size(n + 1) < 0);
   
   with_mutex (send_mutex,
 	      sprintf(send_buffer,
@@ -1444,8 +1462,12 @@ int send_errno(int error, const char* recv_client_id, const char* recv_message_i
 	      
 	      message_id = message_id == INT32_MAX ? 0 : (message_id + 1);
 	      r = full_send(send_buffer, strlen(send_buffer));
+	      if (r)  r = errno ? errno : -1;
 	      );
-  return r;
+  fail_if (errno = (r == -1 ? 0 : r), r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-registry/mds-registry.c b/src/mds-registry/mds-registry.c
index 44cbe86..4b49525 100644
--- a/src/mds-registry/mds-registry.c
+++ b/src/mds-registry/mds-registry.c
@@ -82,6 +82,7 @@ int preinitialise_server(void)
  */
 int initialise_server(void)
 {
+  int stage = 0;
   const char* const message =
     "Command: intercept\n"
     "Message ID: 0\n"
@@ -103,14 +104,8 @@ int initialise_server(void)
         that happen between the crash and the recovery.
    */
   
-  if (full_send(message, strlen(message)))
-    return 1;
-  if (hash_table_create_tuned(&reg_table, 32))
-    {
-      xperror(*argv);
-      hash_table_destroy(&reg_table, NULL, NULL);
-      return 1;
-    }
+  fail_if (full_send(message, strlen(message)));  stage++;
+  fail_if (hash_table_create_tuned(&reg_table, 32));  stage++;
   reg_table.key_comparator = (compare_func*)string_comparator;
   reg_table.hasher = (hash_func*)string_hash;
   fail_if (server_initialised() < 0);
@@ -119,7 +114,10 @@ int initialise_server(void)
   return 0;  
  fail:
   xperror(*argv);
-  mds_message_destroy(&received);
+  if (stage == 1)
+    hash_table_destroy(&reg_table, NULL, NULL);
+  if (stage == 2)
+    mds_message_destroy(&received);
   return 1;
 }
 
@@ -135,13 +133,12 @@ int postinitialise_server(void)
   if (connected)
     return 0;
   
-  if (reconnect_to_display())
-    {
-      mds_message_destroy(&received);
-      return 1;
-    }
+  fail_if (reconnect_to_display());
   connected = 1;
   return 0;
+ fail:
+  mds_message_destroy(&received);
+  return 1;
 }
 
 
diff --git a/src/mds-registry/registry.c b/src/mds-registry/registry.c
index 5f241ea..f853f93 100644
--- a/src/mds-registry/registry.c
+++ b/src/mds-registry/registry.c
@@ -219,15 +219,14 @@ static int registry_action_act(char* command, int action, uint64_t client, hash_
   if (action == 1)
     {
       /* Register server to protocol. */
-      if (registry_action_add(has_key, command, command_key, client))
-	return -1;
+      fail_if (registry_action_add(has_key, command, command_key, client));
     }
   else if ((action == -1) && has_key)
     /* Unregister server from protocol. */
     registry_action_remove(command_key, client);
   else if ((action == 0) && !has_key)
     {
-      /* Add protocl to wait set of not present in the protocol table. */
+      /* Add protocol to wait set of not present in the protocol table. */
       fail_if ((command = strdup(command)) == NULL);
       command_key = (size_t)(void*)command;
       if (hash_table_put(wait_set, command_key, 1) == 0)
@@ -241,8 +240,8 @@ static int registry_action_act(char* command, int action, uint64_t client, hash_
   return 0;
  fail:
   xperror(*argv);
-  hash_table_destroy(wait_set, (free_func*)reg_table_free_key, NULL);
-  free(wait_set);
+  if (action != 1)
+    hash_table_destroy(wait_set, (free_func*)reg_table_free_key, NULL), free(wait_set);
   return -1;
 }
 
@@ -264,21 +263,15 @@ static int registry_action(size_t length, int action, const char* recv_client_id
   uint64_t client = action ? parse_client_id(recv_client_id) : 0;
   hash_table_t* wait_set = NULL;
   size_t begin;
+  int saved_errno;
   
   
   /* If ‘Action: wait’, create a set for the protocols that are not already available. */
   
   if (action == 0)
     {
-      wait_set = malloc(sizeof(hash_table_t));
-      if (wait_set == NULL)
-	return -1;
-      if (hash_table_create(wait_set))
-	{
-	  hash_table_destroy(wait_set, NULL, NULL);
-	  free(wait_set);
-	  return -1;
-	}
+      fail_if (xmalloc(wait_set, 1, hash_table_t));
+      fail_if (hash_table_create(wait_set));
       wait_set->key_comparator = (compare_func*)string_comparator;
       wait_set->hasher = (hash_func*)string_hash;
     }
@@ -288,14 +281,8 @@ static int registry_action(size_t length, int action, const char* recv_client_id
   
   if (received.payload_size == length)
     {
-      if (growalloc(old, received.payload, received.payload_size, char))
-	{
-	  if (wait_set != NULL)
-	    hash_table_destroy(wait_set, NULL, NULL), free(wait_set);
-	  return -1;
-	}
-      else
-	payload = received.payload;
+      fail_if (growalloc(old, received.payload, received.payload_size, char));
+      payload = received.payload;
     }
   
   
@@ -318,16 +305,22 @@ static int registry_action(size_t length, int action, const char* recv_client_id
       
       if (len > 0)
 	if (registry_action_act(command, action, client, wait_set))
-	  return -1;
+	  fail_if (wait_set = NULL, 1);
     }
   
   
   /* If ‘Action: wait’, start a new thread that waits for the protocols and the responds. */
   
   if (action == 0)
-    return start_slave(wait_set, recv_client_id, recv_message_id);
+    if (start_slave(wait_set, recv_client_id, recv_message_id))
+      fail_if (wait_set = NULL, 1);
   
   return 0;
+ fail:
+  saved_errno = errno;
+  if (wait_set != NULL)
+    hash_table_destroy(wait_set, NULL, NULL), free(wait_set);
+  return errno = saved_errno, -1;
 }
 
 
@@ -336,7 +329,7 @@ static int registry_action(size_t length, int action, const char* recv_client_id
  * 
  * @param   recv_client_id   The ID of the client
  * @param   recv_message_id  The ID of the received message
- * @return                   Zero on success -1 on error or interruption,
+ * @return                   Zero on success, -1 on error or interruption,
  *                           `errno` will be set accordingly
  */
 static int list_registry(const char* recv_client_id, const char* recv_message_id)
@@ -349,8 +342,7 @@ static int list_registry(const char* recv_client_id, const char* recv_message_id
   
   if (send_buffer_size == 0)
     {
-      if (xmalloc(send_buffer, 256, char))
-	return -1;
+      fail_if (xmalloc(send_buffer, 256, char));
       send_buffer_size = 256;
     }
   
@@ -365,8 +357,7 @@ static int list_registry(const char* recv_client_id, const char* recv_message_id
       
       /* Make sure the send buffer can fit all protocols. */
       while (ptr + len + 1 >= send_buffer_size)
-	if (growalloc(old, send_buffer, send_buffer_size, char))
-	  return -1;
+	fail_if (growalloc(old, send_buffer, send_buffer_size, char));
       
       memcpy(send_buffer + ptr, command, len * sizeof(char));
       ptr += len;
@@ -380,8 +371,7 @@ static int list_registry(const char* recv_client_id, const char* recv_message_id
   i += strlen("To: %s\nIn response to: %s\nMessage ID: %" PRIu32 "\nLength: %" PRIu64 "\n\n");
   
   while (ptr + i >= send_buffer_size)
-    if (growalloc(old, send_buffer, send_buffer_size, char))
-      return -1;
+    fail_if (growalloc(old, send_buffer, send_buffer_size, char));
   
   
   /* Construct message headers. */
@@ -392,9 +382,10 @@ static int list_registry(const char* recv_client_id, const char* recv_message_id
   with_mutex (slave_mutex, message_id = message_id == UINT32_MAX ? 0 : (message_id + 1););
   
   /* Send message. */
-  if (full_send(send_buffer + ptr, strlen(send_buffer + ptr)))
-    return 1;
+  fail_if (full_send(send_buffer + ptr, strlen(send_buffer + ptr)));
   return full_send(send_buffer, ptr);
+ fail:
+  return -1;
 }
 
 
@@ -488,7 +479,7 @@ static int handle_register_message(void)
 /**
  * Handle the received message
  * 
- * @return  Zero on success -1 on error or interruption,
+ * @return  Zero on success, -1 on error or interruption,
  *          `errno` will be set accordingly
  */
 int handle_message(void)
@@ -496,7 +487,13 @@ int handle_message(void)
   size_t i;
   for (i = 0; i < received.header_count; i++)
     if (strequals(received.headers[i], "Command: register"))
-      return handle_register_message();
-  return handle_close_message();
+      {
+	fail_if (handle_register_message());
+	return 0;
+      }
+  fail_if (handle_close_message());
+  return 0;
+ fail:
+  return -1;
 }
 
diff --git a/src/mds-registry/registry.h b/src/mds-registry/registry.h
index 0de4d6f..f01b383 100644
--- a/src/mds-registry/registry.h
+++ b/src/mds-registry/registry.h
@@ -22,7 +22,7 @@
 /**
  * Handle the received message
  * 
- * @return  Zero on success -1 on error or interruption,
+ * @return  Zero on success, -1 on error or interruption,
  *          `errno` will be set accordingly
  */
 int handle_message(void);
diff --git a/src/mds-registry/slave.c b/src/mds-registry/slave.c
index 8a4d221..ef46963 100644
--- a/src/mds-registry/slave.c
+++ b/src/mds-registry/slave.c
@@ -55,13 +55,14 @@ static int slave_notify_client(slave_t* slave)
   while (left > 0)
     {
       sent = send_message(socket_fd, buf + ptr, left);
-      if ((sent < left) && errno && (errno != EINTR))
-	return -1;
+      fail_if ((sent < left) && errno && (errno != EINTR));
       left -= sent;
       ptr += sent;
     }
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -136,14 +137,12 @@ static void* slave_loop(void* data)
  */
 int start_created_slave(slave_t* restrict slave)
 {
-  if ((errno = pthread_mutex_lock(&slave_mutex)))
-    return -1;
+  int locked = 0;
   
-  if ((errno = pthread_create(&(slave->thread), NULL, slave_loop, (void*)(intptr_t)slave)))
-    {
-      pthread_mutex_unlock(&slave_mutex);
-      return -1;
-    }
+  fail_if ((errno = pthread_mutex_lock(&slave_mutex)));
+  locked = 1;
+  
+  fail_if ((errno = pthread_create(&(slave->thread), NULL, slave_loop, (void*)(intptr_t)slave)));
   
   if ((errno = pthread_detach(slave->thread)))
     xperror(*argv);
@@ -152,6 +151,10 @@ int start_created_slave(slave_t* restrict slave)
   pthread_mutex_unlock(&slave_mutex);
   
   return 0;
+ fail:
+  if (locked)
+    pthread_mutex_unlock(&slave_mutex);
+  return -1;
 }
 
 
@@ -239,8 +242,7 @@ int advance_slaves(char* command)
   int signal_slaves = 0;
   ssize_t node;
   
-  if ((errno = pthread_mutex_lock(&slave_mutex)))
-    return -1;
+  fail_if ((errno = pthread_mutex_lock(&slave_mutex)));
   
   foreach_linked_list_node (slave_list, node)
     {
@@ -257,6 +259,8 @@ int advance_slaves(char* command)
 
   pthread_mutex_unlock(&slave_mutex);
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -410,7 +414,8 @@ size_t slave_marshal(const slave_t* restrict this, char* restrict data)
 size_t slave_unmarshal(slave_t* restrict this, char* restrict data)
 {
   size_t key, n, m, rc = 2 * sizeof(int) + sizeof(ssize_t) + sizeof(size_t) + sizeof(uint64_t);
-  char* protocol;
+  char* protocol = NULL;
+  int saved_errno;
   
   this->wait_set = NULL;
   this->client_id = NULL;
@@ -427,42 +432,37 @@ size_t slave_unmarshal(slave_t* restrict this, char* restrict data)
   buf_get_next(data, long, this->dethklok.tv_nsec);
   
   n = (strlen((char*)data) + 1) * sizeof(char);
-  if ((this->client_id = malloc(n)) == NULL)
-    return 0;
+  fail_if ((this->client_id = malloc(n)) == NULL);
   memcpy(this->client_id, data, n);
   data += n, rc += n;
   
   n = (strlen((char*)data) + 1) * sizeof(char);
-  if ((this->message_id = malloc(n)) == NULL)
-    return 0;
+  fail_if ((this->message_id = malloc(n)) == NULL);
   memcpy(this->message_id, data, n);
   data += n, rc += n;
   
-  if ((this->wait_set = malloc(sizeof(hash_table_t))) == NULL)
-    return 0;
-  if (hash_table_create(this->wait_set))
-    return 0;
+  fail_if ((this->wait_set = malloc(sizeof(hash_table_t))) == NULL);
+  fail_if (hash_table_create(this->wait_set));
   
   buf_get_next(data, size_t, m);
   
   while (m--)
     {
       n = (strlen((char*)data) + 1) * sizeof(char);
-      if ((protocol = malloc(n)) == NULL)
-	return 0;
+      fail_if ((protocol = malloc(n)) == NULL);
       memcpy(protocol, data, n);
       data += n, rc += n;
       
       key = (size_t)(void*)protocol;
       if (hash_table_put(this->wait_set, key, 1) == 0)
-	if (errno)
-	  {
-	    free(protocol);
-	    return 0;
-	  }
+	fail_if (errno);
     }
   
   return rc;
+ fail:
+  saved_errno = errno;
+  free(protocol);
+  return errno = saved_errno, (size_t)0;
 }
 
 
diff --git a/src/mds-registry/util.c b/src/mds-registry/util.c
index 1963eeb..6b383c2 100644
--- a/src/mds-registry/util.c
+++ b/src/mds-registry/util.c
@@ -76,14 +76,14 @@ int full_send(const char* message, size_t length)
 	  eprint("Sent more of a message than exists in the message, aborting.");
 	  return -1;
 	}
-      else if ((sent < length) && (errno != EINTR))
-	{
-	  xperror(*argv);
-	  return -1;
-	}
+      else
+	fail_if ((sent < length) && (errno != EINTR));
       message += sent;
       length -= sent;
     }
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
diff --git a/src/mds-server/client.c b/src/mds-server/client.c
index 4f5f997..f72a2ce 100644
--- a/src/mds-server/client.c
+++ b/src/mds-server/client.c
@@ -82,16 +82,18 @@ int client_initialise_threading(client_t* restrict this)
   
   /* Create mutex to make sure two thread to not try to send
      messages concurrently, and other client local actions. */
-  if ((errno = pthread_mutex_init(&(this->mutex), NULL)))         return -1;
+  fail_if ((errno = pthread_mutex_init(&(this->mutex), NULL)));
   this->mutex_created = 1;
   
   /* Create mutex and codition for multicast interception replies. */
-  if ((errno = pthread_mutex_init(&(this->modify_mutex), NULL)))  return -1;
+  fail_if ((errno = pthread_mutex_init(&(this->modify_mutex), NULL)));
   this->modify_mutex_created = 1;
-  if ((errno = pthread_cond_init(&(this->modify_cond), NULL)))    return -1;
+  fail_if ((errno = pthread_cond_init(&(this->modify_cond), NULL)));
   this->modify_cond_created = 1;
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -203,7 +205,7 @@ size_t client_marshal(const client_t* restrict this, char* restrict data)
 size_t client_unmarshal(client_t* restrict this, char* restrict data)
 {
   size_t i, n, rc = sizeof(ssize_t) + 3 * sizeof(int) + sizeof(uint64_t) + 5 * sizeof(size_t);
-  int saved_errno;
+  int saved_errno, stage = 0;
   this->interception_conditions = NULL;
   this->multicasts = NULL;
   this->send_pending = NULL;
@@ -219,8 +221,8 @@ size_t client_unmarshal(client_t* restrict this, char* restrict data)
   buf_get_next(data, uint64_t, this->id);
   buf_get_next(data, size_t, n);
   if (n > 0)
-    if (mds_message_unmarshal(&(this->message), data))
-      return 0;
+    fail_if (mds_message_unmarshal(&(this->message), data));
+  stage++;
   data += n / sizeof(char);
   rc += n;
   buf_get_next(data, size_t, this->interception_conditions_count);
@@ -264,6 +266,8 @@ size_t client_unmarshal(client_t* restrict this, char* restrict data)
   
  fail:
   saved_errno = errno;
+  if (stage == 0)
+    goto done_failing;
   mds_message_destroy(&(this->message));
   for (i = 0; i < this->interception_conditions_count; i++)
     free(this->interception_conditions[i].condition);
@@ -277,6 +281,7 @@ size_t client_unmarshal(client_t* restrict this, char* restrict data)
       mds_message_destroy(this->modify_message);
       free(this->modify_message);
     }
+ done_failing:
   return errno = saved_errno, (size_t)0;
 }
 
diff --git a/src/mds-server/interception-condition.c b/src/mds-server/interception-condition.c
index 31905c9..cfe5d0c 100644
--- a/src/mds-server/interception-condition.c
+++ b/src/mds-server/interception-condition.c
@@ -71,10 +71,11 @@ size_t interception_condition_unmarshal(interception_condition_t* restrict this,
   buf_get_next(data, int64_t, this->priority);
   buf_get_next(data, int, this->modifying);
   n = (strlen(data) + 1) * sizeof(char);
-  if ((this->condition = malloc(n)) == NULL)
-    return 0;
+  fail_if ((this->condition = malloc(n)) == NULL);
   memcpy(this->condition, data, n);
   return sizeof(size_t) + sizeof(int64_t) + 2 * sizeof(int) + n;
+ fail:
+  return 0;
 }
 
 
diff --git a/src/mds-server/multicast.c b/src/mds-server/multicast.c
index 7a0b309..c3d09bc 100644
--- a/src/mds-server/multicast.c
+++ b/src/mds-server/multicast.c
@@ -124,8 +124,7 @@ size_t multicast_unmarshal(multicast_t* restrict this, char* restrict data)
   buf_get_next(data, size_t, this->message_ptr);
   buf_get_next(data, size_t, this->message_prefix);
   if (this->interceptions_count > 0)
-    if (xmalloc(this->interceptions, this->interceptions_count, queued_interception_t))
-      return 0;
+    fail_if (xmalloc(this->interceptions, this->interceptions_count, queued_interception_t));
   for (i = 0; i < this->interceptions_count; i++)
     {
       n = queued_interception_unmarshal(this->interceptions + i, data);
@@ -134,12 +133,13 @@ size_t multicast_unmarshal(multicast_t* restrict this, char* restrict data)
     }
   if (this->message_length > 0)
     {
-      if (xmalloc(this->message, this->message_length, char))
-	return 0;
+      fail_if (xmalloc(this->message, this->message_length, char));
       memcpy(this->message, data, this->message_length * sizeof(char));
       rc += this->message_length * sizeof(char);
     }
   return rc;
+ fail:
+  return 0;
 }
 
 
diff --git a/src/mds-vt.c b/src/mds-vt.c
index 1cc377e..d761658 100644
--- a/src/mds-vt.c
+++ b/src/mds-vt.c
@@ -154,21 +154,20 @@ int __attribute__((const)) preinitialise_server(void)
 static int write_vt_file(void)
 {
   char buf[(sizeof(int) + sizeof(struct stat)) / sizeof(char)];
-  int fd, r, old_errno;
   int* intbuf = (int*)buf;
+  int fd = -1, saved_errno;
   
   *intbuf = display_vt;
   *(struct stat*)(buf + sizeof(int) / sizeof(char)) = old_vt_stat;
   
-  fd = open(vtfile_path, O_WRONLY | O_CREAT);
-  if (fd < 0)
-    return -1;
-  
-  r = full_write(fd, buf, sizeof(buf));
-  old_errno = errno;
-  close(fd);
-  errno = old_errno;
-  return r;
+  fail_if (open(vtfile_path, O_WRONLY | O_CREAT), fd < 0);
+  fail_if (full_write(fd, buf, sizeof(buf)));
+  return 0;
+ fail:
+  saved_errno = errno;
+  if (fd >= 0)
+    close(fd);
+  return errno = saved_errno, -1;
 }
 
 
@@ -183,24 +182,20 @@ static int read_vt_file(void)
   size_t len;
   int fd;
   
-  fd = open(vtfile_path, O_RDONLY);
-  if (fd < 0)
-    return -1;
-  
-  buf = full_read(fd, &len);
-  if (buf == NULL)
-    return -1;
+  fail_if (fd = open(vtfile_path, O_RDONLY), fd < 0);
+  fail_if (buf = full_read(fd, &len), buf == NULL);
   
   if (len != sizeof(int) + sizeof(struct stat))
     {
       eprint("VT file is of wrong size.");
-      errno = 0;
-      return -1;
+      return errno = 0, -1;
     }
   
   display_vt = *(int*)buf;
   old_vt_stat = *(struct stat*)(buf + sizeof(int) / sizeof(char));
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -215,6 +210,7 @@ int initialise_server(void)
   struct vt_mode mode;
   char* display_env;
   int primary_socket_fd;
+  int stage = 0;
   const char* const message =
     "Command: intercept\n"
     "Message ID: 0\n"
@@ -231,8 +227,7 @@ int initialise_server(void)
     "Command: switching-vt\n";
   
   primary_socket_fd = socket_fd;
-  if (connect_to_display())
-    return 1;
+  fail_if (connect_to_display());
   secondary_socket_fd = socket_fd;
   socket_fd = primary_socket_fd;
   
@@ -243,6 +238,7 @@ int initialise_server(void)
   
   memset(vtfile_path, 0, sizeof(vtfile_path));
   xsnprintf(vtfile_path, "%s/%s.vt", MDS_RUNTIME_ROOT_DIRECTORY, display_env + 1);
+  stage = 1;
   
   if (is_respawn == 0)
     {
@@ -259,12 +255,10 @@ int initialise_server(void)
       fail_if (vt_is_active < 0);
     }
   
-  if (full_send(secondary_socket_fd, secondary_message, strlen(secondary_message)))
-    return 1;
-  if (full_send(socket_fd, message, strlen(message)))
-    return 1;
+  fail_if (full_send(secondary_socket_fd, secondary_message, strlen(secondary_message)));
+  fail_if (full_send(socket_fd, message, strlen(message)));
   fail_if (server_initialised() < 0);
-  fail_if (mds_message_initialise(&received));
+  fail_if (mds_message_initialise(&received)); stage = 2;
   
   fail_if (xsigaction(SIGRTMIN + 2, received_switch_vt) < 0);
   fail_if (xsigaction(SIGRTMIN + 3, received_switch_vt) < 0);
@@ -279,10 +273,12 @@ int initialise_server(void)
   return 1;
  fail:
   xperror(*argv);
-  unlink(vtfile_path);
+  if (stage >= 1)
+    unlink(vtfile_path);
   if (display_tty_fd >= 0)
     vt_close(display_tty_fd, &old_vt_stat);
-  mds_message_destroy(&received);
+  if (stage >= 2)
+    mds_message_destroy(&received);
   return 1;
 }
 
@@ -301,14 +297,15 @@ int postinitialise_server(void)
   if (reconnect_to_display())
     {
       mds_message_destroy(&received);
-      return 1;
+      fail_if (1);
     }
   connected = 1;
   
-  if ((errno = pthread_create(&secondary_thread, NULL, secondary_loop, NULL)))
-    return 1;
+  fail_if ((errno = pthread_create(&secondary_thread, NULL, secondary_loop, NULL)));
   
   return 0;
+ fail:
+  return 1;
 }
 
 
@@ -535,7 +532,10 @@ int switch_vt(int leave_foreground)
   
   message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
   
-  return -!!full_send(socket_fd, buf, strlen(buf));
+  fail_if (full_send(socket_fd, buf, strlen(buf)));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -638,7 +638,10 @@ int handle_get_vt(const char* client, const char* message)
   message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
   
   r = full_send(socket_fd, buf, strlen(buf));
-  return ((active < 0) || r) ? -1 : 0;
+  fail_if ((active < 0) || r);
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -682,7 +685,10 @@ int handle_configure_vt(const char* client, const char* message, const char* gra
   
   message_id = message_id == UINT32_MAX ? 0 : (message_id + 1);
   
-  return -!!full_send(socket_fd, buf, strlen(buf));
+  fail_if (full_send(socket_fd, buf, strlen(buf)));
+  return 0;
+ fail:
+  return -1;
 }
 
 
@@ -735,15 +741,15 @@ int full_send(int socket, const char* message, size_t length)
 	  eprint("Sent more of a message than exists in the message, aborting.");
 	  return -1;
 	}
-      else if ((sent < length) && (errno != EINTR))
-	{
-	  xperror(*argv);
-	  return -1;
-	}
+      else
+	fail_if ((sent < length) && (errno != EINTR));
       message += sent;
       length -= sent;
     }
   return 0;
+ fail:
+  xperror(*argv);
+  return -1;
 }
 
 
@@ -768,7 +774,7 @@ int select_vt(void)
       if (r < 0)
 	{
 	  eprint("the environment variable XDG_VTNR contains an invalid value.");
-	  return errno = 0, -1;
+	  fail_if (errno = 0, 1);
 	}
     }
   else
@@ -778,11 +784,13 @@ int select_vt(void)
       if (rc == 0)
 	{
 	  eprint("out of available virtual terminals, I am stymied.");
-	  return errno = 0, -1;
+	  fail_if (errno = 0, 1);
 	}
     }
   
   return rc;
+ fail:
+  return -1;
 }
 
 
@@ -794,10 +802,10 @@ int select_vt(void)
 int vt_get_next_available(void)
 {
   int next_vt = -1;
-  int r = ioctl(STDIN_FILENO, VT_OPENQRY, &next_vt);
-  if (r < 0)
-    return r;
+  fail_if (ioctl(STDIN_FILENO, VT_OPENQRY, &next_vt) < 0);
   return ((next_vt < 0) || (MAX_NR_CONSOLES < next_vt)) ? 0 : next_vt;
+ fail:
+  return -1;
 }
 
 
@@ -809,9 +817,10 @@ int vt_get_next_available(void)
 int vt_get_active(void)
 {
   struct vt_stat state;
-  if (ioctl(STDIN_FILENO, VT_GETSTATE, &state) < 0)
-    return -1;
+  fail_if (ioctl(STDIN_FILENO, VT_GETSTATE, &state) < 0);
   return state.v_active;
+ fail:
+  return -1;
 }
 
 
@@ -823,13 +832,13 @@ int vt_get_active(void)
  */
 int vt_set_active(int vt)
 {
-  if (ioctl(STDIN_FILENO, VT_ACTIVATE, vt) < 0)
-    return -1;
-  
+  fail_if (ioctl(STDIN_FILENO, VT_ACTIVATE, vt) < 0);
   if (ioctl(STDIN_FILENO, VT_WAITACTIVE, vt) < 0)
     xperror(*argv);
   
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -845,18 +854,16 @@ int vt_open(int vt, struct stat* restrict old_stat)
   char vtpath[64]; /* Should be small enought and large enought for any
 		      lunatic alternative to /dev/ttyNNN, if not you
 		      will need to apply a patch (or fix your system.) */
-  int fd;
+  int fd = -1, saved_errno;
   sprintf(vtpath, VT_PATH_PATTERN, vt);
-  fd = open(vtpath, O_RDWR);
-  if (fd < 0)
-    return -1;
-  if ((fstat(fd, old_stat) < 0) ||
-      (fchown(fd, getuid(), getgid()) < 0))
-    {
-      close(fd);
-      return -1;
-    }
+  fail_if (fd = open(vtpath, O_RDWR), fd < 0);
+  fail_if ((fstat(fd, old_stat) < 0) || (fchown(fd, getuid(), getgid()) < 0));
   return fd;
+ fail:
+  saved_errno = errno;
+  if (fd >= 0)
+    close(fd);
+  return errno = saved_errno, -1;
 }