[Darwin, config] Arrange for ld64 to be detected as Darwin's linker.

 This is an initial patch in a series that converts Darwin's configury
 to detect ld64 features, rather than the current process of hard-coding
 them on target system version.

 A ld64-compatible linker is currently required and assumed by Darwin.
 If a DEFAULT_LINKER is set via --with-ld= then this will be tested to
 see if it is ld64.

 The ld64 version is determined for the chosen ld and this is exported for
 use in setting a default value for -mtarget-linker (needed for run-time
 code-gen changes to section choices).
 The support for -rdynamic is converted to be detected at config time, or
 by the ld64 version if that is found.

gcc/

2016-11-27  Iain Sandoe  <iain@codesourcery.com>

	PR target/71767
	* configure.ac (with-ld64): New var, set for Darwin, set on
	detection of ld64, gcc_cv_ld64_export_dynamic: New, New test.
	* config/darwin.h: Use LD64_HAS_DYNAMIC export. DEF_LD64: New,
	define.
	* config/darwin10.h(DEF_LD64): Update for this target version.
	* config/darwin12.h(LINK_GCC_C_SEQUENCE_SPEC): Remove rdynamic
	test.  (DEF_LD64): Update for this target version.
	* configure: Regenerated.
	* config.in: Regenerated.

From-SVN: r242894

gcc/ChangeLog

 2016-11-27  Iain Sandoe  <iain@codesourcery.com>
 
 	PR target/71767
+	* configure.ac (with-ld64): New var, set for Darwin, set on
+	detection of ld64, gcc_cv_ld64_export_dynamic: New, New test.
+	* config/darwin.h: Use LD64_HAS_DYNAMIC export. DEF_LD64: New,
+	define.
+	* config/darwin10.h(DEF_LD64): Update for this target version.
+	* config/darwin12.h(LINK_GCC_C_SEQUENCE_SPEC): Remove rdynamic
+	test.  (DEF_LD64): Update for this target version.
+	* configure: Regenerated.
+	* config.in: Regenerated.
+
+2016-11-27  Iain Sandoe  <iain@codesourcery.com>
+
+	PR target/71767
 	* config/darwin.c (imachopic_indirection_name): Make data
 	section indirections linker-visible.
 	* config/darwin.h (ASM_GENERATE_INTERNAL_LABEL): Make local

gcc/config.in

@@ -1946,6 +1946,18 @@
 #endif
 
 
+/* Define to 1 if ld64 supports '-export_dynamic'. */
+#ifndef USED_FOR_TARGET
+#undef LD64_HAS_EXPORT_DYNAMIC
+#endif
+
+
+/* Define to ld64 version. */
+#ifndef USED_FOR_TARGET
+#undef LD64_VERSION
+#endif
+
+
 /* Define to the linker option to ignore unused dependencies. */
 #ifndef USED_FOR_TARGET
 #undef LD_AS_NEEDED_OPTION

gcc/config/darwin.h

@@ -165,6 +165,12 @@ extern GTY(()) int darwin_ms_struct;
    specifying the handling of options understood by generic Unix
    linkers, and for positional arguments like libraries.  */
 
+#if LD64_HAS_EXPORT_DYNAMIC
+#define DARWIN_EXPORT_DYNAMIC " %{rdynamic:-export_dynamic}"
+#else
+#define DARWIN_EXPORT_DYNAMIC " %{rdynamic: %nrdynamic is not supported}"
+#endif
+
 #define LINK_COMMAND_SPEC_A \
    "%{!fdump=*:%{!fsyntax-only:%{!c:%{!M:%{!MM:%{!E:%{!S:\
     %(linker)" \
@@ -185,7 +191,9 @@ extern GTY(()) int darwin_ms_struct;
     %{!nostdlib:%{!nodefaultlibs:\
       %{%:sanitize(address): -lasan } \
       %{%:sanitize(undefined): -lubsan } \
-      %(link_ssp) %(link_gcc_c_sequence)\
+      %(link_ssp) \
+      " DARWIN_EXPORT_DYNAMIC " %<rdynamic \
+      %(link_gcc_c_sequence) \
     }}\
     %{!nostdlib:%{!nostartfiles:%E}} %{T*} %{F*} }}}}}}}"
 
@@ -932,4 +940,10 @@ extern void darwin_driver_init (unsigned int *,struct cl_decoded_option **);
    fall-back default.  */
 #define DEF_MIN_OSX_VERSION "10.5"
 
+#ifndef LD64_VERSION
+#define LD64_VERSION "85.2"
+#else
+#define DEF_LD64 LD64_VERSION
+#endif
+
 #endif /* CONFIG_DARWIN_H */

gcc/config/darwin10.h

@@ -32,3 +32,8 @@ along with GCC; see the file COPYING3.  If not see
 
 #undef DEF_MIN_OSX_VERSION
 #define DEF_MIN_OSX_VERSION "10.6"
+
+#ifndef LD64_VERSION
+#undef DEF_LD64
+#define DEF_LD64 "97.7"
+#endif

gcc/config/darwin12.h

@@ -21,10 +21,15 @@ along with GCC; see the file COPYING3.  If not see
 #undef  LINK_GCC_C_SEQUENCE_SPEC
 #define LINK_GCC_C_SEQUENCE_SPEC \
 "%:version-compare(>= 10.6 mmacosx-version-min= -no_compact_unwind) \
-   %{rdynamic:-export_dynamic} %{!static:%{!static-libgcc: \
+   %{!static:%{!static-libgcc: \
       %:version-compare(>= 10.6 mmacosx-version-min= -lSystem) } } \
    %{fno-pic|fno-PIC|fno-pie|fno-PIE|fapple-kext|mkernel|static|mdynamic-no-pic: \
       %:version-compare(>= 10.7 mmacosx-version-min= -no_pie) } %G %L"
 
 #undef DEF_MIN_OSX_VERSION
 #define DEF_MIN_OSX_VERSION "10.8"
+
+#ifndef LD64_VERSION
+#undef DEF_LD64
+#define DEF_LD64 "236.4"
+#endif

gcc/configure

@@ -3639,6 +3639,11 @@ else
 fi
 
 
+case $target in
+    *darwin*) ld64_flag=yes;; # Darwin can only use a ld64-compatible linker.
+    *) ld64_flag=no;;
+esac
+
 # With pre-defined ld
 
 # Check whether --with-ld was given.
@@ -3651,6 +3656,8 @@ if test x"${DEFAULT_LINKER+set}" = x"set"; then
     as_fn_error "cannot execute: $DEFAULT_LINKER: check --with-ld or env. var. DEFAULT_LINKER" "$LINENO" 5
   elif $DEFAULT_LINKER -v < /dev/null 2>&1 | grep GNU > /dev/null; then
     gnu_ld_flag=yes
+  elif $DEFAULT_LINKER -v < /dev/null 2>&1 | grep ld64- > /dev/null; then
+    ld64_flag=yes
   fi
 
 cat >>confdefs.h <<_ACEOF
@@ -18423,7 +18430,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18426 "configure"
+#line 18433 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -18529,7 +18536,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18532 "configure"
+#line 18539 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -28287,6 +28294,71 @@ _ACEOF
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld_compress_debug" >&5
 $as_echo "$gcc_cv_ld_compress_debug" >&6; }
 
+if test x"$ld64_flag" = x"yes"; then
+
+  # Set defaults for possibly untestable items.
+  gcc_cv_ld64_export_dynamic=0
+
+  if test "$build" = "$host"; then
+    darwin_try_test=1
+  else
+    darwin_try_test=0
+  fi
+
+  # On Darwin, because of FAT library support, it is often possible to execute
+  # exes from compatible archs even when the host differs from the build system.
+  case "$build","$host" in
+    x86_64-*-darwin*,i?86-*-darwin* | powerpc64*-*-darwin*,powerpc*-*-darwin*)
+	darwin_try_test=1;;
+    *) ;;
+  esac
+
+  # If the configurer specified a minimum ld64 version to be supported, then use
+  # that to determine feature support.
+  if test x"${gcc_cv_ld64_version}" != x; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking ld64 major version" >&5
+$as_echo_n "checking ld64 major version... " >&6; }
+    IFS=. read gcc_cv_ld64_major gcc_cv_ld64_minor <<< "${gcc_cv_ld64_version}"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld64_major" >&5
+$as_echo "$gcc_cv_ld64_major" >&6; }
+   if test "$gcc_cv_ld64_major" -ge 236; then
+      gcc_cv_ld64_export_dynamic=1
+    fi
+  elif test -x "$gcc_cv_ld" -a "$darwin_try_test" -eq 1; then
+    # If the version was not specified, try to find it.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking linker version" >&5
+$as_echo_n "checking linker version... " >&6; }
+    if test x"${gcc_cv_ld64_version}" = x; then
+      gcc_cv_ld64_version=`$gcc_cv_ld -v 2>&1 | grep ld64 | sed s/.*ld64-// | awk '{print $1}'`
+    fi
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld64_version" >&5
+$as_echo "$gcc_cv_ld64_version" >&6; }
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking linker for -export_dynamic support" >&5
+$as_echo_n "checking linker for -export_dynamic support... " >&6; }
+    gcc_cv_ld64_export_dynamic=1
+    if $gcc_cv_ld -export_dynamic < /dev/null 2>&1 | grep 'unknown option' > /dev/null; then
+      gcc_cv_ld64_export_dynamic=0
+    fi
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld64_export_dynamic" >&5
+$as_echo "$gcc_cv_ld64_export_dynamic" >&6; }
+  fi
+
+  if test x"${gcc_cv_ld64_version}" != x; then
+
+cat >>confdefs.h <<_ACEOF
+#define LD64_VERSION "${gcc_cv_ld64_version}"
+_ACEOF
+
+  fi
+
+
+cat >>confdefs.h <<_ACEOF
+#define LD64_HAS_EXPORT_DYNAMIC $gcc_cv_ld64_export_dynamic
+_ACEOF
+
+fi
+
 # --------
 # UNSORTED
 # --------

gcc/configure.ac

@@ -274,6 +274,11 @@ AC_ARG_WITH(gnu-ld,
 gnu_ld_flag="$with_gnu_ld",
 gnu_ld_flag=no)
 
+case $target in
+    *darwin*) ld64_flag=yes;; # Darwin can only use a ld64-compatible linker.
+    *) ld64_flag=no;;
+esac
+
 # With pre-defined ld
 AC_ARG_WITH(ld,
 [AS_HELP_STRING([--with-ld], [arrange to use the specified ld (full pathname)])],
@@ -283,6 +288,8 @@ if test x"${DEFAULT_LINKER+set}" = x"set"; then
     AC_MSG_ERROR([cannot execute: $DEFAULT_LINKER: check --with-ld or env. var. DEFAULT_LINKER])
   elif $DEFAULT_LINKER -v < /dev/null 2>&1 | grep GNU > /dev/null; then
     gnu_ld_flag=yes
+  elif $DEFAULT_LINKER -v < /dev/null 2>&1 | grep ld64- > /dev/null; then
+    ld64_flag=yes
   fi
   AC_DEFINE_UNQUOTED(DEFAULT_LINKER,"$DEFAULT_LINKER",
 	[Define to enable the use of a default linker.])
@@ -5266,6 +5273,59 @@ AC_DEFINE_UNQUOTED(LD_COMPRESS_DEBUG_OPTION, "$gcc_cv_ld_compress_debug_option",
 [Define to the linker option to enable compressed debug sections.])
 AC_MSG_RESULT($gcc_cv_ld_compress_debug)
 
+if test x"$ld64_flag" = x"yes"; then
+
+  # Set defaults for possibly untestable items.
+  gcc_cv_ld64_export_dynamic=0
+
+  if test "$build" = "$host"; then
+    darwin_try_test=1
+  else
+    darwin_try_test=0
+  fi
+
+  # On Darwin, because of FAT library support, it is often possible to execute
+  # exes from compatible archs even when the host differs from the build system.
+  case "$build","$host" in
+    x86_64-*-darwin*,i?86-*-darwin* | powerpc64*-*-darwin*,powerpc*-*-darwin*)
+	darwin_try_test=1;;
+    *) ;;
+  esac
+
+  # If the configurer specified a minimum ld64 version to be supported, then use
+  # that to determine feature support.
+  if test x"${gcc_cv_ld64_version}" != x; then
+    AC_MSG_CHECKING(ld64 major version)
+    IFS=. read gcc_cv_ld64_major gcc_cv_ld64_minor <<< "${gcc_cv_ld64_version}"
+    AC_MSG_RESULT($gcc_cv_ld64_major)
+   if test "$gcc_cv_ld64_major" -ge 236; then
+      gcc_cv_ld64_export_dynamic=1
+    fi
+  elif test -x "$gcc_cv_ld" -a "$darwin_try_test" -eq 1; then
+    # If the version was not specified, try to find it.
+    AC_MSG_CHECKING(linker version)
+    if test x"${gcc_cv_ld64_version}" = x; then
+      gcc_cv_ld64_version=`$gcc_cv_ld -v 2>&1 | grep ld64 | sed s/.*ld64-// | awk '{print $1}'`
+    fi
+    AC_MSG_RESULT($gcc_cv_ld64_version)
+
+    AC_MSG_CHECKING(linker for -export_dynamic support)
+    gcc_cv_ld64_export_dynamic=1
+    if $gcc_cv_ld -export_dynamic < /dev/null 2>&1 | grep 'unknown option' > /dev/null; then
+      gcc_cv_ld64_export_dynamic=0
+    fi
+    AC_MSG_RESULT($gcc_cv_ld64_export_dynamic)
+  fi
+
+  if test x"${gcc_cv_ld64_version}" != x; then
+    AC_DEFINE_UNQUOTED(LD64_VERSION, "${gcc_cv_ld64_version}",
+      [Define to ld64 version.])
+  fi
+
+  AC_DEFINE_UNQUOTED(LD64_HAS_EXPORT_DYNAMIC, $gcc_cv_ld64_export_dynamic,
+  [Define to 1 if ld64 supports '-export_dynamic'.])
+fi
+
 # --------
 # UNSORTED
 # --------