Symbol hiding configure options renamed to the hopefully less ambiguous

--enable-symbol-hiding and --disable-symbol-hiding as well as related
macro names and some internal variables used for them.

Related configuration file preprocessor symbols named to
CARES_SYMBOL_HIDING and CARES_SYMBOL_SCOPE_EXTERN.

4 files changed, 143 insertions, 150 deletions

diff --git a/ares/ares.h b/ares/ares.h
index 593a14563..63eb6810e 100644
--- a/ares/ares.h
+++ b/ares/ares.h
@@ -79,11 +79,11 @@ extern "C" {
 #  endif
 #else
    /* visibility function decoration for other cases */
-#  if !defined(CARES_HIDDEN_SYMBOLS) || \
+#  if !defined(CARES_SYMBOL_HIDING) || \
      defined(WIN32) || defined(_WIN32) || defined(__SYMBIAN32__)
 #    define CARES_EXTERN
 #  else
-#    define CARES_EXTERN CARES_EXTERN_SYMBOL
+#    define CARES_EXTERN CARES_SYMBOL_SCOPE_EXTERN
 #  endif
 #endif
 
diff --git a/ares/configure.ac b/ares/configure.ac
index 722da4c8c..8f1cddb5b 100644
--- a/ares/configure.ac
+++ b/ares/configure.ac
@@ -14,7 +14,7 @@ CARES_CHECK_OPTION_DEBUG
 CARES_CHECK_OPTION_OPTIMIZE
 CARES_CHECK_OPTION_WARNINGS
 CARES_CHECK_OPTION_CURLDEBUG
-CARES_CHECK_OPTION_HIDDEN_SYMBOLS
+CARES_CHECK_OPTION_SYMBOL_HIDING
 
 CARES_CHECK_PATH_SEPARATOR_REQUIRED
 
@@ -164,7 +164,7 @@ esac
 
 CARES_CHECK_COMPILER_HALT_ON_ERROR
 CARES_CHECK_COMPILER_ARRAY_SIZE_NEGATIVE
-CARES_CHECK_COMPILER_HIDDEN_SYMBOLS
+CARES_CHECK_COMPILER_SYMBOL_HIDING
 
 CARES_CHECK_NO_UNDEFINED
 AM_CONDITIONAL(NO_UNDEFINED, test x$need_no_undefined = xyes)
@@ -897,7 +897,7 @@ fi
 CARES_CHECK_OPTION_NONBLOCKING
 CARES_CHECK_NONBLOCKING_SOCKET
 
-CARES_CONFIGURE_HIDDEN_SYMBOLS
+CARES_CONFIGURE_SYMBOL_HIDING
 
 CARES_PRIVATE_LIBS="$LIBS"
 AC_SUBST(CARES_PRIVATE_LIBS)
diff --git a/ares/m4/cares-compilers.m4 b/ares/m4/cares-compilers.m4
index a8f1cd58a..68f47efd8 100644
--- a/ares/m4/cares-compilers.m4
+++ b/ares/m4/cares-compilers.m4
@@ -16,7 +16,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 60
+# serial 61
 
 
 dnl CARES_CHECK_COMPILER
@@ -1249,98 +1249,6 @@ AC_DEFUN([CARES_CHECK_COMPILER_ARRAY_SIZE_NEGATIVE], [
 ])
 
 
-dnl CARES_CHECK_COMPILER_HIDDEN_SYMBOLS
-dnl -------------------------------------------------
-dnl Verify if compiler supports hiding library internal symbols, setting
-dnl shell variable hidden_symbols_supported value as appropriate, as well as
-dnl variables hidden_symbols_CFLAGS and hidden_symbols_extern when supported.
-
-AC_DEFUN([CARES_CHECK_COMPILER_HIDDEN_SYMBOLS], [
-  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
-  AC_BEFORE([$0],[CARES_CONFIGURE_HIDDEN_SYMBOLS])dnl
-  AC_MSG_CHECKING([if compiler supports hiding library internal symbols])
-  hidden_symbols_supported="no"
-  hidden_symbols_CFLAGS=""
-  hidden_symbols_extern=""
-  tmp_CFLAGS=""
-  tmp_extern=""
-  case "$compiler_id" in
-    GNU_C)
-      dnl Only gcc 3.4 or later
-      if test "$compiler_num" -ge "304"; then
-        if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then
-          tmp_extern="__attribute__ ((visibility (\"default\")))"
-          tmp_CFLAGS="-fvisibility=hidden"
-          hidden_symbols_supported="yes"
-          echo " " >&6
-          echo "debug: should work with this compiler and version" >&6
-          echo " " >&6
-        fi
-      fi
-      ;;
-    INTEL_UNIX_C)
-      dnl Only icc 9.0 or later
-      if test "$compiler_num" -ge "900"; then
-        if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then
-          tmp_extern="__attribute__ ((visibility (\"default\")))"
-          tmp_CFLAGS="-fvisibility=hidden"
-          hidden_symbols_supported="yes"
-          echo " " >&6
-          echo "debug: should work with this compiler and version" >&6
-          echo " " >&6
-        fi
-      fi
-      ;;
-    SUNPRO_C)
-      if $CC 2>&1 | grep flags >/dev/null && $CC -flags | grep xldscope= >/dev/null ; then
-        tmp_extern="__global"
-        tmp_CFLAGS="-xldscope=hidden"
-        hidden_symbols_supported="yes"
-        echo " " >&6
-        echo "debug: should work with this compiler and version" >&6
-        echo " " >&6
-      fi
-      ;;
-  esac
-  if test "$hidden_symbols_supported" = "yes"; then
-    tmp_save_CFLAGS="$CFLAGS"
-    CFLAGS="$tmp_save_CFLAGS $tmp_CFLAGS"
-    squeeze CFLAGS
-    AC_COMPILE_IFELSE([
-      AC_LANG_PROGRAM([[
-        $tmp_extern char *dummy(char *buff);
-        char *dummy(char *buff)
-        {
-         if(buff)
-           return ++buff;
-         else
-           return buff;
-        }
-      ]],[[
-        char b[16];
-        char *r = dummy(&b);
-        if(r)
-          return (int)*r;
-      ]])
-    ],[
-      hidden_symbols_supported="yes"
-    ],[
-      hidden_symbols_supported="no"
-      sed 's/^/cc-src: /' conftest.$ac_ext >&6
-      sed 's/^/cc-err: /' conftest.err >&6
-    ])
-    CFLAGS="$tmp_save_CFLAGS"
-  fi
-  if test "$hidden_symbols_supported" = "yes"; then
-    AC_MSG_RESULT([yes])
-    hidden_symbols_CFLAGS="$tmp_CFLAGS"
-    hidden_symbols_extern="$tmp_extern"
-  else
-    AC_MSG_RESULT([no])
-  fi
-])
-
-
 dnl CARES_CHECK_COMPILER_STRUCT_MEMBER_SIZE
 dnl -------------------------------------------------
 dnl Verifies if the compiler is capable of handling the
@@ -1403,6 +1311,91 @@ AC_DEFUN([CARES_CHECK_COMPILER_STRUCT_MEMBER_SIZE], [
 ])
 
 
+dnl CARES_CHECK_COMPILER_SYMBOL_HIDING
+dnl -------------------------------------------------
+dnl Verify if compiler supports hiding library internal symbols, setting
+dnl shell variable supports_symbol_hiding value as appropriate, as well as
+dnl variables symbol_hiding_CFLAGS and symbol_hiding_EXTERN when supported.
+
+AC_DEFUN([CARES_CHECK_COMPILER_SYMBOL_HIDING], [
+  AC_REQUIRE([CARES_CHECK_COMPILER])dnl
+  AC_BEFORE([$0],[CARES_CONFIGURE_SYMBOL_HIDING])dnl
+  AC_MSG_CHECKING([if compiler supports hiding library internal symbols])
+  supports_symbol_hiding="no"
+  symbol_hiding_CFLAGS=""
+  symbol_hiding_EXTERN=""
+  tmp_CFLAGS=""
+  tmp_EXTERN=""
+  case "$compiler_id" in
+    GNU_C)
+      dnl Only gcc 3.4 or later
+      if test "$compiler_num" -ge "304"; then
+        if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then
+          tmp_EXTERN="__attribute__ ((visibility (\"default\")))"
+          tmp_CFLAGS="-fvisibility=hidden"
+          supports_symbol_hiding="yes"
+        fi
+      fi
+      ;;
+    INTEL_UNIX_C)
+      dnl Only icc 9.0 or later
+      if test "$compiler_num" -ge "900"; then
+        if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then
+          tmp_EXTERN="__attribute__ ((visibility (\"default\")))"
+          tmp_CFLAGS="-fvisibility=hidden"
+          supports_symbol_hiding="yes"
+        fi
+      fi
+      ;;
+    SUNPRO_C)
+      if $CC 2>&1 | grep flags >/dev/null && $CC -flags | grep xldscope= >/dev/null ; then
+        tmp_EXTERN="__global"
+        tmp_CFLAGS="-xldscope=hidden"
+        supports_symbol_hiding="yes"
+      fi
+      ;;
+  esac
+  if test "$supports_symbol_hiding" = "yes"; then
+    tmp_save_CFLAGS="$CFLAGS"
+    CFLAGS="$tmp_save_CFLAGS $tmp_CFLAGS"
+    squeeze CFLAGS
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $tmp_EXTERN char *dummy(char *buff);
+        char *dummy(char *buff)
+        {
+         if(buff)
+           return ++buff;
+         else
+           return buff;
+        }
+      ]],[[
+        char b[16];
+        char *r = dummy(&b);
+        if(r)
+          return (int)*r;
+      ]])
+    ],[
+      supports_symbol_hiding="yes"
+    ],[
+      supports_symbol_hiding="no"
+      echo " " >&6
+      sed 's/^/cc-src: /' conftest.$ac_ext >&6
+      sed 's/^/cc-err: /' conftest.err >&6
+      echo " " >&6
+    ])
+    CFLAGS="$tmp_save_CFLAGS"
+  fi
+  if test "$supports_symbol_hiding" = "yes"; then
+    AC_MSG_RESULT([yes])
+    symbol_hiding_CFLAGS="$tmp_CFLAGS"
+    symbol_hiding_EXTERN="$tmp_EXTERN"
+  else
+    AC_MSG_RESULT([no])
+  fi
+])
+
+
 dnl CARES_VAR_MATCH (VARNAME, VALUE)
 dnl -------------------------------------------------
 dnl Verifies if shell variable VARNAME contains VALUE.
diff --git a/ares/m4/cares-confopts.m4 b/ares/m4/cares-confopts.m4
index 241bb498e..438f9cdc7 100644
--- a/ares/m4/cares-confopts.m4
+++ b/ares/m4/cares-confopts.m4
@@ -16,7 +16,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 7
+# serial 8
 
 
 dnl CARES_CHECK_OPTION_CURLDEBUG
@@ -92,46 +92,6 @@ AC_HELP_STRING([--disable-debug],[Disable debug build options]),
 ])
 
 
-dnl CARES_CHECK_OPTION_HIDDEN_SYMBOLS
-dnl -------------------------------------------------
-dnl Verify if configure has been invoked with option
-dnl --enable-hidden-symbols or --disable-hidden-symbols,
-dnl setting shell variable want_hidden_symbols value.
-
-AC_DEFUN([CARES_CHECK_OPTION_HIDDEN_SYMBOLS], [
-  AC_BEFORE([$0],[CARES_CHECK_COMPILER_HIDDEN_SYMBOLS])dnl
-  AC_MSG_CHECKING([whether to enable hiding symbols])
-  OPT_HIDDEN_SYMBOLS="default"
-  AC_ARG_ENABLE(hidden-symbols,
-AC_HELP_STRING([--enable-hidden-symbols],[Enable hiding of library internal symbols])
-AC_HELP_STRING([--disable-hidden-symbols],[Disable hiding of library internal symbols]),
-  OPT_HIDDEN_SYMBOLS=$enableval)
-  case "$OPT_HIDDEN_SYMBOLS" in
-    no)
-      dnl --disable-hidden-symbols option used.
-      dnl This is an indication to not attempt hiding of library internal
-      dnl symbols. Default symbol visibility will be used, which normally
-      dnl exposes all library internal symbols.
-      want_hidden_symbols="no"
-      AC_MSG_RESULT([no])
-      ;;
-    default)
-      dnl configure's hidden-symbols option not specified.
-      dnl Handle this as if --enable-hidden-symbols option was given.
-      want_hidden_symbols="yes"
-      AC_MSG_RESULT([not specified (assuming yes)])
-      ;;
-    *)
-      dnl --enable-hidden-symbols option used.
-      dnl This is an indication to attempt hiding of library internal
-      dnl symbols. This is only supported on some compilers/linkers.
-      want_hidden_symbols="yes"
-      AC_MSG_RESULT([yes])
-      ;;
-  esac
-])
-
-
 dnl CARES_CHECK_OPTION_NONBLOCKING
 dnl -------------------------------------------------
 dnl Verify if configure has been invoked with option
@@ -220,6 +180,46 @@ AC_HELP_STRING([--disable-optimize],[Disable compiler optimizations]),
 ])
 
 
+dnl CARES_CHECK_OPTION_SYMBOL_HIDING
+dnl -------------------------------------------------
+dnl Verify if configure has been invoked with option
+dnl --enable-symbol-hiding or --disable-symbol-hiding,
+dnl setting shell variable want_symbol_hiding value.
+
+AC_DEFUN([CARES_CHECK_OPTION_SYMBOL_HIDING], [
+  AC_BEFORE([$0],[CARES_CHECK_COMPILER_SYMBOL_HIDING])dnl
+  AC_MSG_CHECKING([whether to enable hiding of library internal symbols])
+  OPT_SYMBOL_HIDING="default"
+  AC_ARG_ENABLE(symbol-hiding,
+AC_HELP_STRING([--enable-symbol-hiding],[Enable hiding of library internal symbols])
+AC_HELP_STRING([--disable-symbol-hiding],[Disable hiding of library internal symbols]),
+  OPT_SYMBOL_HIDING=$enableval)
+  case "$OPT_SYMBOL_HIDING" in
+    no)
+      dnl --disable-symbol-hiding option used.
+      dnl This is an indication to not attempt hiding of library internal
+      dnl symbols. Default symbol visibility will be used, which normally
+      dnl exposes all library internal symbols.
+      want_symbol_hiding="no"
+      AC_MSG_RESULT([no])
+      ;;
+    default)
+      dnl configure's symbol-hiding option not specified.
+      dnl Handle this as if --enable-symbol-hiding option was given.
+      want_symbol_hiding="yes"
+      AC_MSG_RESULT([yes])
+      ;;
+    *)
+      dnl --enable-symbol-hiding option used.
+      dnl This is an indication to attempt hiding of library internal
+      dnl symbols. This is only supported on some compilers/linkers.
+      want_symbol_hiding="yes"
+      AC_MSG_RESULT([yes])
+      ;;
+  esac
+])
+
+
 dnl CARES_CHECK_OPTION_WARNINGS
 dnl -------------------------------------------------
 dnl Verify if configure has been invoked with option
@@ -293,24 +293,24 @@ AC_DEFUN([CARES_CHECK_NONBLOCKING_SOCKET], [
 ])
 
 
-dnl CARES_CONFIGURE_HIDDEN_SYMBOLS
+dnl CARES_CONFIGURE_SYMBOL_HIDING
 dnl -------------------------------------------------
-dnl Depending on --enable-hidden-symbols or --disable-hidden-symbols
+dnl Depending on --enable-symbol-hiding or --disable-symbol-hiding
 dnl configure option, and compiler capability to actually honor such
-dnl option, compiler flags will be modified as appropriate.
+dnl option, this will modify compiler flags as appropriate and also
+dnl provide needed definitions for configuration file.
 dnl This macro should not be used until all compilation tests have
 dnl been done to prevent interferences on other tests.
 
-AC_DEFUN([CARES_CONFIGURE_HIDDEN_SYMBOLS], [
-  AC_MSG_CHECKING([whether to actually hide library internal symbols])
+AC_DEFUN([CARES_CONFIGURE_SYMBOL_HIDING], [
+  AC_MSG_CHECKING([whether hiding of library internal symbols will actually happen])
   if test x"$ac_cv_native_windows" != "xyes" &&
-    test "$want_hidden_symbols" = "yes" &&
-    test "$hidden_symbols_supported" = "yes"; then
-    tmp_save_CFLAGS="$CFLAGS"
-    CFLAGS="$tmp_save_CFLAGS $hidden_symbols_CFLAGS"
-    AC_DEFINE_UNQUOTED(CARES_HIDDEN_SYMBOLS, 1,
+    test "$want_symbol_hiding" = "yes" &&
+    test "$supports_symbol_hiding" = "yes"; then
+    CFLAGS="$CFLAGS $symbol_hiding_CFLAGS"
+    AC_DEFINE_UNQUOTED(CARES_SYMBOL_HIDING, 1,
       [Define to 1 to enable hiding of library internal symbols.])
-    AC_DEFINE_UNQUOTED(CARES_EXTERN_SYMBOL, $hidden_symbols_extern,
+    AC_DEFINE_UNQUOTED(CARES_SYMBOL_SCOPE_EXTERN, $symbol_hiding_EXTERN,
       [Definition to make a library symbol externally visible.])
     AC_MSG_RESULT([yes])
   else