Darwin: Check as for .build_version support and use it if available.

This adds support for the minimum OS version data in assembler files.
At present, we have no mechanism to detect the SDK version in use, and
so that is omitted from build_versions.

We follow the implementation in clang, '.build_version' is only emitted
(where supported) for target macOS versions >= 10.14.  For earlier macOS
we fall back to using a '.macosx_version_min' directive.  This latter is
also emitted when the assembler supports it, but not build_version.

gcc/ChangeLog:

	* config.in: Regenerate.
	* config/darwin.cc (darwin_file_start): Add assembler directives
	for the target OS version, where these are supported by the
	assembler.
	(darwin_override_options): Check for building >= macOS 10.14.
	* configure: Regenerate.
	* configure.ac: Check for assembler support of .build_version
	directives.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

diff --git a/gcc/config.in b/gcc/config.in
index d04718ad12822cfd573ffd1e5eebbcdb3fdd5656..98ddddf88a0fd0f469c87bb517fb1592b7445d55 100644 (file)
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -604,6 +604,12 @@
 #endif
 
 
+/* Define if your macOS assembler supports .build_version directives */
+#ifndef USED_FOR_TARGET
+#undef HAVE_AS_MACOS_BUILD_VERSION
+#endif
+
+
 /* Define if the assembler understands -march=rv*_zifencei. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_AS_MARCH_ZIFENCEI

diff --git a/gcc/config/darwin.cc b/gcc/config/darwin.cc
index d8c8607892b5e10e9e0cbbd5e5ed1b27891bdda8..a80b6caf95a775a69492b2973519ac1d73acb13b 100644 (file)
--- a/gcc/config/darwin.cc
+++ b/gcc/config/darwin.cc
@@ -3073,7 +3073,35 @@ darwin_asm_output_dwarf_offset (FILE *file, int size, const char * lab,
 void
 darwin_file_start (void)
 {
-  /* Nothing to do.  */
+#ifdef HAVE_AS_MMACOSX_VERSION_MIN_OPTION
+  /* This should not happen with a well-formed command line, but the user could
+     invoke cc1* directly without it.  */
+  if (!darwin_macosx_version_min)
+    return;
+  /* This assumes that the version passed has been validated in the driver.  */
+  unsigned maj, min, tiny;
+  int count = sscanf (darwin_macosx_version_min, "%u.%u.%u", &maj, &min, &tiny);
+  if (count < 0)
+    return;
+  if (count < 3)
+    tiny = 0;
+  if (count < 2)
+    min = 0;
+  const char *directive;
+#ifdef HAVE_AS_MACOS_BUILD_VERSION
+  /* We only handle macos, so far.  */
+  if (generating_for_darwin_version >= 18)
+    directive = "build_version macos, ";
+  else
+#endif
+    directive = "macosx_version_min ";
+  if (count > 2 && tiny != 0)
+    fprintf (asm_out_file, "\t.%s %u, %u, %u\n", directive, maj, min, tiny);
+  else if (count > 1)
+    fprintf (asm_out_file, "\t.%s %u, %u\n", directive, maj, min);
+  else
+     fprintf (asm_out_file, "\t.%s %u, 0\n", directive, maj);
+#endif
 }
 
 /* Called for the TARGET_ASM_FILE_END hook.
@@ -3295,7 +3323,9 @@ darwin_override_options (void)
   /* Keep track of which (major) version we're generating code for.  */
   if (darwin_macosx_version_min)
     {
-      if (strverscmp (darwin_macosx_version_min, "10.7") >= 0)
+      if (strverscmp (darwin_macosx_version_min, "10.14") >= 0)
+       generating_for_darwin_version = 18;
+      else if (strverscmp (darwin_macosx_version_min, "10.7") >= 0)
        generating_for_darwin_version = 11;
       else if (strverscmp (darwin_macosx_version_min, "10.6") >= 0)
        generating_for_darwin_version = 10;

diff --git a/gcc/configure b/gcc/configure
index c43bde8174bac03aea5574d55202763dcb5cc0f5..9f5b708199297b7770947eab9011aa8a9dc0eb62 100755 (executable)
--- a/gcc/configure
+++ b/gcc/configure
@@ -26361,6 +26361,39 @@ $as_echo "#define HAVE_AS_MMACOSX_VERSION_MIN_OPTION 1" >>confdefs.h
 
 fi
 
+    if test x$gcc_cv_as_mmacosx_version_min = "xyes"; then
+       { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for .build_version" >&5
+$as_echo_n "checking assembler for .build_version... " >&6; }
+if ${gcc_cv_as_darwin_build_version+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_darwin_build_version=no
+  if test x$gcc_cv_as != x; then
+    $as_echo ' .build_version macos, 10, 14 sdk_version 10, 14' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags -mmacosx-version-min=10.14 -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+       gcc_cv_as_darwin_build_version=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_darwin_build_version" >&5
+$as_echo "$gcc_cv_as_darwin_build_version" >&6; }
+if test $gcc_cv_as_darwin_build_version = yes; then
+
+$as_echo "#define HAVE_AS_MACOS_BUILD_VERSION 1" >>confdefs.h
+
+fi
+
+    fi
     ;;
 esac
 

diff --git a/gcc/configure.ac b/gcc/configure.ac
index fb8e32f8ee55fe1031ee156a3cf4b814f45d9626..c10e007f9bf21a32a5f1ff195eb5ec2175082f96 100644 (file)
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -4374,6 +4374,14 @@ case "$target_os" in
       [-mmacosx-version-min=10.1], [.text],,
       [AC_DEFINE(HAVE_AS_MMACOSX_VERSION_MIN_OPTION, 1,
        [Define if your macOS assembler supports the -mmacos-version-min option.])])
+    if test x$gcc_cv_as_mmacosx_version_min = "xyes"; then
+       gcc_GAS_CHECK_FEATURE([.build_version],
+           gcc_cv_as_darwin_build_version,
+           [-mmacosx-version-min=10.14],
+           [ .build_version macos, 10, 14 sdk_version 10, 14],,
+      [AC_DEFINE(HAVE_AS_MACOS_BUILD_VERSION, 1,
+       [Define if your macOS assembler supports .build_version directives])])
+    fi
     ;;
 esac