Refactor: Remove some unnecessary uses of memcpy

- Also, remove unnecessary "static" in gnucash-style.c

The second one in guid.cpp is UB:

libgnucash/engine/guid.cpp:137:5: warning: undefined behavior, source object type 'const gnc::GUID' is not TriviallyCopyable [bugprone-undefined-memory-manipulation]
        memcpy (&target, &source, sizeof (GncGUID));
        ^

CMakeLists.txt

@@ -731,7 +731,6 @@ if (UNIX OR MINGW)
 set (HAVE_GETTIMEOFDAY 1)
 set (HAVE_GUILE 1)
 set (HAVE_LIBM 1)
-set (HAVE_MEMCPY 1)
 set (STDC_HEADERS 1)
 set (_ALL_SOURCE 1)
 set (_GNU_SOURCE 1)

common/config.h.cmake.in

@@ -132,9 +132,6 @@
 /* Define to 1 if you have the <mcheck.h> header file. */
 #cmakedefine HAVE_MCHECK_H 1
 
-/* Define to 1 if you have the `memcpy' function. */
-#cmakedefine HAVE_MEMCPY 1
-
 /* Define to 1 if you have the <memory.h> header file. */
 #cmakedefine HAVE_MEMORY_H 1
 

gnucash/gnome-utils/gnc-autoclear.c

@@ -61,9 +61,9 @@ static void sack_foreach_func(gpointer key, gpointer value, gpointer user_data)
     sack_foreach_data_t data = (sack_foreach_data_t) user_data;
     gnc_numeric thisvalue = *(gnc_numeric *) key;
     gnc_numeric reachable_value = gnc_numeric_add_fixed (thisvalue, data->split_value);
-    gpointer new_value = g_malloc(sizeof(gnc_numeric));
+    gnc_numeric* new_value = g_new(gnc_numeric, 1);
 
-    memcpy(new_value, &reachable_value, sizeof(gnc_numeric));
+    *new_value = reachable_value;
     data->reachable_list = g_list_prepend(data->reachable_list, new_value);
 }
 
@@ -108,7 +108,7 @@ gnc_account_get_autoclear_splits (Account *account, gnc_numeric toclear_value,
     {
         Split *split = (Split *)node->data;
         gnc_numeric split_value = xaccSplitGetAmount (split);
-        gpointer new_value = g_malloc(sizeof(gnc_numeric));
+        gnc_numeric *new_value = g_new(gnc_numeric, 1);
 
         struct _sack_foreach_data_t s_data[1];
         s_data->split_value = split_value;
@@ -118,7 +118,7 @@ gnc_account_get_autoclear_splits (Account *account, gnc_numeric toclear_value,
         g_hash_table_foreach (sack, sack_foreach_func, s_data);
 
         /* Add the value of the split itself to the reachable_list */
-        memcpy(new_value, &split_value, sizeof(gnc_numeric));
+        *new_value = split_value;
         s_data->reachable_list = g_list_prepend
             (s_data->reachable_list, new_value);
 

gnucash/register/register-gnome/gnucash-style.c

@@ -56,12 +56,10 @@ style_get_key (SheetBlockStyle *style)
 static gpointer
 style_create_key (SheetBlockStyle *style)
 {
-    static gint key;
-    gpointer new_key;
+    gint key = style->cursor->num_rows;
 
-    key = style->cursor->num_rows;
-    new_key = g_malloc(sizeof(key));
-    new_key = memcpy(new_key, &key, sizeof(key));
+    gint *new_key = g_new(gint, 1);
+    *new_key = key;
 
     return new_key;
 }

libgnucash/backend/sql/gnc-slots-sql.cpp

@@ -160,7 +160,7 @@ _retrieve_guid_ (gpointer pObject,  gpointer pValue)
     g_return_if_fail (pObject != NULL);
     g_return_if_fail (pValue != NULL);
 
-    memcpy (pGuid, guid, sizeof (GncGUID));
+    *pGuid = *guid;
 }
 
 /* Special column table because we need to be able to access the table by

libgnucash/backend/sql/gnc-sql-column-table-entry.cpp

@@ -649,7 +649,7 @@ _retrieve_guid_ (gpointer pObject,  gpointer pValue)
     g_return_if_fail (pObject != NULL);
     g_return_if_fail (pValue != NULL);
 
-    memcpy (pGuid, guid, sizeof (GncGUID));
+    *pGuid = *guid;
 }
 
 // Table to retrieve just the guid

libgnucash/engine/SchedXaction.c

@@ -1118,8 +1118,8 @@ gnc_sx_clone_temporal_state (SXTmpStateData *tsd)
 
     if(tsd)
     {
-        toRet = g_malloc(sizeof(SXTmpStateData));
-        toRet = memcpy (toRet, tsd, sizeof (SXTmpStateData));
+        toRet = g_new(SXTmpStateData, 1);
+        *toRet = *tsd;
     }
 
     return toRet;

libgnucash/engine/gncOwner.c

@@ -33,7 +33,6 @@
 
 #include <glib.h>
 #include <glib/gi18n.h>
-#include <string.h>		/* for memcpy() */
 #include <qofinstance-p.h>
 
 #include "gncCustomerP.h"
@@ -399,7 +398,7 @@ void gncOwnerCopy (const GncOwner *src, GncOwner *dest)
 {
     if (!src || !dest) return;
     if (src == dest) return;
-    memcpy (dest, src, sizeof (*dest));
+    *dest = *src;
 }
 
 gboolean gncOwnerEqual (const GncOwner *a, const GncOwner *b)

libgnucash/engine/guid.cpp

@@ -56,6 +56,7 @@
 #include <boost/uuid/uuid_io.hpp>
 #include <sstream>
 #include <string>
+#include <algorithm>
 
 /* This static indicates the debugging module that this .o belongs to.  */
 static QofLogModule log_module = QOF_MOD_ENGINE;
@@ -120,7 +121,7 @@ guid_copy (const GncGUID *guid)
 {
     if (!guid) return nullptr;
     auto ret = guid_malloc ();
-    memcpy (ret, guid, sizeof (GncGUID));
+    *ret = *guid;
     return ret;
 }
 
@@ -134,7 +135,7 @@ guid_null (void)
 static void
 guid_assign (GncGUID & target, gnc::GUID const & source)
 {
-    memcpy (&target, &source, sizeof (GncGUID));
+    std::copy (source.begin(), source.end(), target.reserved);
 }
 
 /*Takes an allocated guid pointer and constructs it in place*/

libgnucash/engine/qofquery.cpp

@@ -188,7 +188,7 @@ static QofQueryTerm * copy_query_term (const QofQueryTerm *qt)
     if (!qt) return NULL;
 
     new_qt = g_new0 (QofQueryTerm, 1);
-    memcpy (new_qt, qt, sizeof(QofQueryTerm));
+    *new_qt = *qt;
     new_qt->param_list = g_slist_copy (qt->param_list);
     new_qt->param_fcns = g_slist_copy (qt->param_fcns);
     new_qt->pdata = qof_query_core_predicate_copy (qt->pdata);
@@ -224,7 +224,7 @@ copy_or_terms(const GList * or_terms)
 
 static void copy_sort (QofQuerySort *dst, const QofQuerySort *src)
 {
-    memcpy (dst, src, sizeof (*dst));
+    *dst = *src;
     dst->param_list = g_slist_copy (src->param_list);
     dst->param_fcns = g_slist_copy (src->param_fcns);
 }
@@ -1006,7 +1006,7 @@ QofQuery * qof_query_copy (QofQuery *q)
     ht = copy->be_compiled;
     free_members (copy);
 
-    memcpy (copy, q, sizeof (QofQuery));
+    *copy = *q;
 
     copy->be_compiled = ht;
     copy->terms = copy_or_terms (q->terms);