Fix new GCC warnings

Signed-off-by: Mattias Andrée <maandree@kth.se>

12 files changed, 57 insertions, 13 deletions

diff --git a/doc/info/mds.texinfo b/doc/info/mds.texinfo
index 92ed37b..d094ecf 100644
--- a/doc/info/mds.texinfo
+++ b/doc/info/mds.texinfo
@@ -6454,6 +6454,16 @@ duplicate is stored in the variable @code{var}. If
 @code{original} is @code{NULL}, @code{var} is set to
 @code{NULL} and zero is returned.
 
+@item @code{xstrdup_nn} [(@code{char* var, const char* original}) @arrow{} @code{int}]
+@fnindex @code{xstrdup}
+@cpindex Memory management
+Wrapper for @code{strdup} that returns zero on and
+only on success. @code{original} is duplicate and the
+duplicate is stored in the variable @code{var}.
+@code{original} must not be @code{NULL}. This macro
+was added because GCC 6.1.1 warns if @code{xstrdup}
+is used and @code{original} is known not to be @code{NULL}.
+
 @item @code{xmemdup} [(@code{void* var, const void* original, size_t elements, type}) @arrow{} @code{int}]
 @fnindex @code{xmemdup}
 @cpindex Memory management
diff --git a/src/libmdsclient/inbound.c b/src/libmdsclient/inbound.c
index f2ea03c..019ed51 100644
--- a/src/libmdsclient/inbound.c
+++ b/src/libmdsclient/inbound.c
@@ -554,8 +554,8 @@ int libmds_mspool_initialise(libmds_mspool_t* restrict this)
   this->messages = malloc(sizeof(libmds_message_t*));
   if (this->messages == NULL)
     return -1;
-  if (sem_init(&(this->lock),           0, 1) < 0)  goto fail;  stage++;
-  if (sem_init(&(this->semaphore),      0, 0) < 0)  goto fail;  stage++;
+  if (sem_init(&(this->lock),           0, 1) < 0)  goto fail;  else  stage++;
+  if (sem_init(&(this->semaphore),      0, 0) < 0)  goto fail;  else  stage++;
   if (sem_init(&(this->wait_semaphore), 0, 0) < 0)  goto fail;
   return 0;
  fail:
diff --git a/src/libmdsserver/fd-table.h b/src/libmdsserver/fd-table.h
index dfcb360..19d1f99 100644
--- a/src/libmdsserver/fd-table.h
+++ b/src/libmdsserver/fd-table.h
@@ -183,7 +183,7 @@ void fd_table_marshal(const fd_table_t* restrict this, char* restrict data);
  * @return            Non-zero on error, `errno` will be set accordingly.
  *                    Destroy the table on error.
  */
-__attribute__((nonnull))
+__attribute__((nonnull(1, 2)))
 int fd_table_unmarshal(fd_table_t* restrict this, char* restrict data, remap_func* remapper);
 
 
diff --git a/src/libmdsserver/hash-table.h b/src/libmdsserver/hash-table.h
index f9e4dec..1a3a26c 100644
--- a/src/libmdsserver/hash-table.h
+++ b/src/libmdsserver/hash-table.h
@@ -266,7 +266,7 @@ void hash_table_marshal(const hash_table_t* restrict this, char* restrict data);
  * @return            Non-zero on error, `errno` will be set accordingly.
  *                    Destroy the table on error.
  */
-__attribute__((nonnull))
+__attribute__((nonnull(1, 2)))
 int hash_table_unmarshal(hash_table_t* restrict this, char* restrict data, remap_func* remapper);
 
 
diff --git a/src/libmdsserver/macros.h b/src/libmdsserver/macros.h
index 80a0c25..f5c6808 100644
--- a/src/libmdsserver/macros.h
+++ b/src/libmdsserver/macros.h
@@ -656,7 +656,7 @@
  * `strdup` wrapper that returns whether the allocation was not successful
  *  
  * @param   var:char*             The variable to which to assign the duplicate
- * @param   original:const char*  The string to duplicate
+ * @param   original:const char*  The string to duplicate, may be `NULL`
  * @return  :int                  Evaluates to true if an only if the allocation failed
  */
 #define xstrdup(var, original)  \
@@ -673,6 +673,29 @@
 
 
 /**
+ * `strdup` wrapper that returns whether the allocation was not successful
+ *  
+ * This macro was added because GCC 6.1.1 warns of `original` is known to
+ * be nonnull, when using `xstrdup`.
+ * 
+ * @param   var:char*             The variable to which to assign the duplicate
+ * @param   original:const char*  The string to duplicate, must not be `NULL`
+ * @return  :int                  Evaluates to true if an only if the allocation failed
+ */
+#define xstrdup_nn(var, original)  \
+  ((var = strdup(original)) == NULL)
+/*
+#define xstrdup_nn(var, original)								\
+  ({												\
+    size_t _x_size = strlen(original);								\
+    fprintf(stderr, "xstrdup_nn(%s, %s(“%s”=%zu))(=%zu) @ %s:%i\n",				\
+	    #var, #original, original, _x_size, _x_size + !!_x_size, __FILE__, __LINE__); 	\
+    (var = strdup(original)) == NULL;								\
+  })
+*/
+
+
+/**
  * `malloc` and `memcpy` wrapper that creates a duplicate of a pointer and
  * returns whether the allocation was not successful
  *  
diff --git a/src/libmdsserver/util.c b/src/libmdsserver/util.c
index 14df3a9..a3e18a9 100644
--- a/src/libmdsserver/util.c
+++ b/src/libmdsserver/util.c
@@ -298,6 +298,13 @@ int strict_atoj(const char* str, intmax_t* value, intmax_t min, intmax_t max)
 }
 
 
+#if defined(__GNUC__)
+/* GCC says strict_atouj is a candidate for the attribute ‘pure’,
+ * however the line `*value = r` means that it is not, at least
+ * if you only consider what GCC's manuals says about the attribute. */
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
+#endif
 /**
  * A version of `atouj` that is strict about the syntax and bounds
  * 
@@ -334,6 +341,9 @@ int strict_atouj(const char* str, uintmax_t* value, uintmax_t min, uintmax_t max
   *value = r;
   return 0;
 }
+#if defined(__GNUC__)
+# pragma GCC diagnostic pop
+#endif
 
 
 #define __strict_y(Y, TYPE, PARA_TYPE, HYPER_Y, HYPER_TYPE)					\
diff --git a/src/mds-clipboard.c b/src/mds-clipboard.c
index 30213ea..5d54f79 100644
--- a/src/mds-clipboard.c
+++ b/src/mds-clipboard.c
@@ -648,7 +648,7 @@ int clipboard_death(const char* recv_client_id)
 int clipboard_add(int level, const char* time_to_live, const char* recv_client_id)
 {
   int autopurge = CLIPITEM_AUTOPURGE_UPON_CLOCK;
-  uint64_t client = recv_client_id ? parse_client_id(recv_client_id) : 0;
+  uint64_t client = parse_client_id(recv_client_id);
   clipitem_t new_clip;
   
   fail_if (clipboard_purge(level, NULL));
diff --git a/src/mds-colour.c b/src/mds-colour.c
index 9179a61..f7a5722 100644
--- a/src/mds-colour.c
+++ b/src/mds-colour.c
@@ -767,7 +767,7 @@ int set_colour(const char* name, const colour_t* colour)
       
       /* `colour_list_put` will store the name of the colour,
          so we have to make a copy that will not disappear. */
-      fail_if (xstrdup(name_, name));
+      fail_if (xstrdup_nn(name_, name));
       
       /* Add or modify the colour. */
       fail_if (colour_list_put(&colours, name_, colour));
diff --git a/src/mds-kbdc/compile-layout.c b/src/mds-kbdc/compile-layout.c
index b8d62f3..f585030 100644
--- a/src/mds-kbdc/compile-layout.c
+++ b/src/mds-kbdc/compile-layout.c
@@ -2563,7 +2563,8 @@ static int compile_subtree(mds_kbdc_tree_t* restrict tree)
     case C(FUNCTION):               c (function);     break;
     case C(MACRO):                  c (macro);        break;
     case C(ASSUMPTION):
-      t ((includes_ptr == 0) && compile_subtree(tree->assumption.inner));
+      if (includes_ptr == 0)
+	fail_if (compile_subtree(tree->assumption.inner));
       break;
     case C(ASSUMPTION_HAVE):        c (have);         break;
     case C(ASSUMPTION_HAVE_CHARS):  c (have_chars);   break;
diff --git a/src/mds-registry/registry.c b/src/mds-registry/registry.c
index 964b55f..77cd463 100644
--- a/src/mds-registry/registry.c
+++ b/src/mds-registry/registry.c
@@ -155,7 +155,7 @@ static int registry_action_add(int has_key, char* command, size_t command_key, u
       void* address;
       fail_if (xmalloc(address = list, 1, client_list_t));
       /* Duplicate the protocol name so it can be accessed later. */
-      if (xstrdup(command, command))
+      if (xstrdup_nn(command, command))
 	{
 	  saved_errno = errno, free(list), errno = saved_errno;
 	  fail_if (1);
@@ -240,7 +240,7 @@ static int registry_action_act(char* command, int action, uint64_t client, hash_
   else if ((action == 0) && !has_key)
     {
       /* Add protocol to wait set of not present in the protocol table. */
-      fail_if (xstrdup(command, command));
+      fail_if (xstrdup_nn(command, command));
       command_key = (size_t)(void*)command;
       if (hash_table_put(wait_set, command_key, 1) == 0)
 	if (errno)
diff --git a/src/mds-registry/slave.c b/src/mds-registry/slave.c
index 3d60437..b936c29 100644
--- a/src/mds-registry/slave.c
+++ b/src/mds-registry/slave.c
@@ -287,8 +287,8 @@ slave_t* slave_create(hash_table_t* restrict wait_set, const char* restrict recv
   rc->wait_set = wait_set;
   rc->client = parse_client_id(recv_client_id);
   
-  fail_if (xstrdup(rc->client_id,  recv_client_id));
-  fail_if (xstrdup(rc->message_id, recv_message_id));
+  fail_if (xstrdup_nn(rc->client_id,  recv_client_id));
+  fail_if (xstrdup_nn(rc->message_id, recv_message_id));
   
   return rc;
   
diff --git a/src/mds-server/interceptors.c b/src/mds-server/interceptors.c
index ddaedd6..fccb0fa 100644
--- a/src/mds-server/interceptors.c
+++ b/src/mds-server/interceptors.c
@@ -141,7 +141,7 @@ void add_intercept_condition(client_t* client, char* condition, int64_t priority
   else
     {
       /* Duplicate condition string. */
-      fail_if (xstrdup(condition, condition));
+      fail_if (xstrdup_nn(condition, condition));
       
       /* Grow the interception condition list. */
       fail_if (xrealloc(conds, n + 1, interception_condition_t));