Bug#53445: Build with -Wall and fix warnings that it generates

Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).

client/mysql.cc:
  Mismatch between prototype and declaration.
client/mysqltest.cc:
  mysqltest used to be C code. Use C linkage where appropriate.
cmd-line-utils/readline/input.c:
  Isolate unreachable code.
include/my_alloc.h:
  Function type must have C linkage.
include/my_base.h:
  Function type must have C linkage.
include/my_global.h:
  Add helper macros to avoid spurious namespace indentation.
include/mysql.h.pp:
  Update ABI file.
mysys/my_gethwaddr.c:
  Remove stray carriage return and fix coding style.
plugin/semisync/semisync_master_plugin.cc:
  Callback function types have C linkage.
plugin/semisync/semisync_slave_plugin.cc:
  Callback function types have C linkage.
sql/derror.cc:
  Expected function type has C linkage.
sql/field.cc:
  Use helper macro and fix indentation.
sql/handler.cc:
  Expected function type has C linkage.
sql/item_sum.cc:
  Correct function linkages. Remove now unnecessary cast.
sql/item_sum.h:
  Add prototypes with the appropriate linkage as otherwise they
  are distinct.
sql/mysqld.cc:
  Wrap functions in C linkage mode.
sql/opt_range.cc:
  C language linkage is ignored for class member functions.
sql/partition_info.cc:
  Add wrapper functions with C linkage for class member functions.
sql/rpl_utility.h:
  Use helper macro and fix indentation.
sql/sql_class.cc:
  Change type of thd argument -- THD is a class.
  Use helper macro and fix indentation.
sql/sql_class.h:
  Change type of thd argument -- THD is a class.
sql/sql_select.cc:
  Expected function type has C linkage.
sql/sql_select.h:
  Move prototype to sql_test.h
sql/sql_show.cc:
  Expected function type has C linkage.
sql/sql_test.cc:
  Fix required function prototype and fix coding style.
sql/sql_test.h:
  Removed unnecessary export and add another.
storage/myisammrg/ha_myisammrg.cc:
  Expected function type has C linkage.
storage/perfschema/pfs.cc:
  PSI headers are declared with C language linkage, which also
  applies to function types.

1 files changed, 24 insertions, 20 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 5e985625c78..9363b637862 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -1539,6 +1539,29 @@ QUICK_ROR_UNION_SELECT::QUICK_ROR_UNION_SELECT(THD *thd_param,
 
 
 /*
+  Comparison function to be used QUICK_ROR_UNION_SELECT::queue priority
+  queue.
+
+  SYNPOSIS
+    QUICK_ROR_UNION_SELECT_queue_cmp()
+      arg   Pointer to QUICK_ROR_UNION_SELECT
+      val1  First merged select
+      val2  Second merged select
+*/
+
+C_MODE_START
+
+static int QUICK_ROR_UNION_SELECT_queue_cmp(void *arg, uchar *val1, uchar *val2)
+{
+  QUICK_ROR_UNION_SELECT *self= (QUICK_ROR_UNION_SELECT*)arg;
+  return self->head->file->cmp_ref(((QUICK_SELECT_I*)val1)->last_rowid,
+                                   ((QUICK_SELECT_I*)val2)->last_rowid);
+}
+
+C_MODE_END
+
+
+/*
   Do post-constructor initialization.
   SYNOPSIS
     QUICK_ROR_UNION_SELECT::init()
@@ -1552,7 +1575,7 @@ int QUICK_ROR_UNION_SELECT::init()
 {
   DBUG_ENTER("QUICK_ROR_UNION_SELECT::init");
   if (init_queue(&queue, quick_selects.elements, 0,
-                 FALSE , QUICK_ROR_UNION_SELECT::queue_cmp,
+                 FALSE , QUICK_ROR_UNION_SELECT_queue_cmp,
                  (void*) this))
   {
     bzero(&queue, sizeof(QUEUE));
@@ -1567,25 +1590,6 @@ int QUICK_ROR_UNION_SELECT::init()
 
 
 /*
-  Comparison function to be used QUICK_ROR_UNION_SELECT::queue priority
-  queue.
-
-  SYNPOSIS
-    QUICK_ROR_UNION_SELECT::queue_cmp()
-      arg   Pointer to QUICK_ROR_UNION_SELECT
-      val1  First merged select
-      val2  Second merged select
-*/
-
-int QUICK_ROR_UNION_SELECT::queue_cmp(void *arg, uchar *val1, uchar *val2)
-{
-  QUICK_ROR_UNION_SELECT *self= (QUICK_ROR_UNION_SELECT*)arg;
-  return self->head->file->cmp_ref(((QUICK_SELECT_I*)val1)->last_rowid,
-                                   ((QUICK_SELECT_I*)val2)->last_rowid);
-}
-
-
-/*
   Initialize quick select for row retrieval.
   SYNOPSIS
     reset()