$NetBSD: patch-gcc_config_aarch64_darwin.h,v 1.1 2025/02/05 16:30:35 adam Exp $

Support Darwin/aarch64, from https://github.com/Homebrew/formula-patches.

--- /dev/null
+++ gcc/config/aarch64/darwin.h
@@ -0,0 +1,291 @@
+/* Target definitions for Arm64/Aarch64 running on macOS/iOS.
+
+Copyright The GNU Toolchain Authors.
+Contributed by Iain Sandoe.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Enable Mach-O bits in generic Aarch64 code.  */
+#undef TARGET_MACHO
+#define TARGET_MACHO 1
+
+#undef DARWIN_ARM64
+#define DARWIN_ARM64 1
+
+/* This is used in generic code in darwin.cc (at present, we have no support
+   for the arm64_32 target).  */
+#undef TARGET_64BIT
+#define TARGET_64BIT 1
+
+#undef  PTRDIFF_TYPE
+#define PTRDIFF_TYPE "long int"
+
+#undef TARGET_PROMOTE_FUNCTION_MODE
+#define TARGET_PROMOTE_FUNCTION_MODE aarch64_darwin_promote_fn_mode
+
+#undef TARGET_PROMOTE_FUNCTION_MODE_CA
+#define TARGET_PROMOTE_FUNCTION_MODE_CA aarch64_darwin_promote_function_mode_ca
+
+/* NOTE that arm64_32 is a valid thing and corresponds to darwinpcs
+   and TARGET_ILP32, but we are not implementing that for now.  */
+#define TARGET_OS_CPP_BUILTINS()		\
+  do {						\
+    builtin_define ("__LITTLE_ENDIAN__");	\
+    builtin_define ("__arm64");			\
+    builtin_define ("__arm64__");		\
+    darwin_cpp_builtins (pfile);		\
+  } while (0)
+
+/* In Darwin's Arm64 ABI, chars are signed.  */
+
+#undef DEFAULT_SIGNED_CHAR
+#define DEFAULT_SIGNED_CHAR 1
+
+#undef LONG_DOUBLE_TYPE_SIZE
+#define LONG_DOUBLE_TYPE_SIZE	64
+
+/* Disable custom function descriptors on Darwin (we use heap-based
+   trampolines).  */
+#undef AARCH64_CUSTOM_FUNCTION_TEST
+#define AARCH64_CUSTOM_FUNCTION_TEST 0
+
+/* Non-PIE executables are forbidden by the Arm64-darwin security model;
+   remove the option from link-lines since they just produce a warning from
+   ld64 and are then ignored anyway.  */
+#undef DARWIN_NOPIE_SPEC
+#define DARWIN_NOPIE_SPEC \
+" %<no-pie %<fno-pie %<fno-PIE "
+
+/* Force the default endianness and ABI flags onto the command line
+   in order to make the other specs easier to write.  Match clang in
+   silently ignoring mdynamic-no-pic */
+#undef DRIVER_SELF_SPECS
+#define DRIVER_SELF_SPECS \
+"%{mbig-endian:%eDarwin platforms do not support big-endian arm64}" \
+"%{!mlittle-endian:-mlittle-endian} " \
+"%{mabi=ilp32:%eSorry, support for Darwin ilp32 arm64 is not implemented} " \
+"%{!mabi=*:-mabi=lp64} " \
+" %<mdynamic-no-pic* " \
+  MCPU_MTUNE_NATIVE_SPECS \
+  SUBTARGET_DRIVER_SELF_SPECS
+
+/* We want -fPIC by default, unless we're using -static to compile for
+   the kernel or some such.  */
+
+#undef CC1_SPEC
+#define CC1_SPEC \
+"%{!mkernel:%{!static:-fPIC}} " DARWIN_CC1_SPEC
+
+#undef ASM_SPEC
+#define ASM_SPEC "-arch %(darwin_arch) %{march*} %{mtune*} "\
+  ASM_OPTIONS " %{static} " ASM_MMACOSX_VERSION_MIN_SPEC
+
+#undef ENDFILE_SPEC
+#define ENDFILE_SPEC \
+  " " TM_DESTRUCTOR
+
+/* The arch is known as 'arm64' by the system tools.  */
+#define DARWIN_ARCH_SPEC "arm64"
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS					\
+  DARWIN_EXTRA_SPECS						\
+  { "darwin_arch", DARWIN_ARCH_SPEC },				\
+  { "darwin_crt2", "" },					\
+  { "darwin_subarch", DARWIN_ARCH_SPEC },
+
+#undef TARGET_ASM_FILE_END
+#define TARGET_ASM_FILE_END darwin_file_end
+
+/* For now, we do not give global entities any extra alignment
+   TODO: determine if we should for some optimisation level.  */
+#undef DATA_ALIGNMENT
+#define DATA_ALIGNMENT(EXP, ALIGN)			\
+  AARCH64_EXPAND_ALIGNMENT (false, EXP, ALIGN)
+
+/* Darwin binds locally for PIC code (the default) without which
+   we lose many in-lineing opportunities.  */
+#undef TARGET_BINDS_LOCAL_P
+#define TARGET_BINDS_LOCAL_P darwin_binds_local_p
+
+/* Define the syntax of pseudo-ops, labels and comments.  */
+
+#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
+/* Support for -falign-* switches.  Use .p2align to ensure that code
+   sections are padded with NOP instructions, rather than zeros.  */
+#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE, LOG, MAX_SKIP)		\
+  do								\
+    {								\
+      if ((LOG) != 0)						\
+	{							\
+	  if ((MAX_SKIP) == 0)					\
+	    fprintf ((FILE), "\t.p2align %d\n", (int) (LOG));	\
+	  else							\
+	    fprintf ((FILE), "\t.p2align %d,,%d\n",		\
+		     (int) (LOG), (int) (MAX_SKIP));		\
+	}							\
+    } while (0)
+
+#endif /* HAVE_GAS_MAX_SKIP_P2ALIGN */
+
+/* String containing the assembler's comment-starter.  */
+
+#define ASM_COMMENT_START ";"
+
+/* Define the syntax of pseudo-ops, labels and comments.  */
+
+#define LPREFIX "L"
+
+/* Assembler pseudos to introduce constants of various size.  */
+
+#define ASM_BYTE "\t.byte\t"
+#define ASM_SHORT "\t.word\t"
+#define ASM_LONG "\t.long\t"
+#define ASM_QUAD "\t.quad\t"
+
+/* darwinpcs reserves X18.  */
+
+#undef FIXED_REGISTERS
+#define FIXED_REGISTERS					\
+  {							\
+    0, 0, 0, 0,   0, 0, 0, 0,	/* R0 - R7 */		\
+    0, 0, 0, 0,   0, 0, 0, 0,	/* R8 - R15 */		\
+    0, 0, 1, 0,   0, 0, 0, 0,	/* R16 - R23 */		\
+    0, 0, 0, 0,   0, 1, 0, 1,	/* R24 - R30, SP */	\
+    0, 0, 0, 0,   0, 0, 0, 0,   /* V0 - V7 */           \
+    0, 0, 0, 0,   0, 0, 0, 0,   /* V8 - V15 */		\
+    0, 0, 0, 0,   0, 0, 0, 0,   /* V16 - V23 */         \
+    0, 0, 0, 0,   0, 0, 0, 0,   /* V24 - V31 */         \
+    1, 1, 1, 1,			/* SFP, AP, CC, VG */	\
+    0, 0, 0, 0,   0, 0, 0, 0,   /* P0 - P7 */           \
+    0, 0, 0, 0,   0, 0, 0, 0,   /* P8 - P15 */          \
+    1, 1,			/* FFR and FFRT */	\
+    1, 1, 1, 1, 1, 1, 1, 1	/* Fake registers */	\
+  }
+
+/* Assign a static chain regnum.  At the moment using R16 (IP0) is
+   available.  */
+#undef STATIC_CHAIN_REGNUM
+#define STATIC_CHAIN_REGNUM	R16_REGNUM
+
+/* Heap trampoline support in a CRT.  */
+#undef DARWIN_HEAP_T_LIB
+#define DARWIN_HEAP_T_LIB " -lheapt_w "
+
+#define SUBTARGET_ENCODE_SECTION_INFO  darwin_encode_section_info
+
+#undef ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX
+#define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
+  if (TARGET_64BIT)							\
+    {									\
+      if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_pcrel)		\
+	{								\
+	  static unsigned got_pcr_count = 0;				\
+	  fprintf (FILE, "L_got_pcr%d:\n" ASM_LONG, got_pcr_count);	\
+	  assemble_name (FILE, XSTR (ADDR, 0));				\
+	  fprintf (FILE, "@GOT-L_got_pcr%d", got_pcr_count++);		\
+	  goto DONE;							\
+	}								\
+    }									\
+  else									\
+    {									\
+      if (ENCODING == ASM_PREFERRED_EH_DATA_FORMAT (2, 1))		\
+	{								\
+	  gcc_unreachable (); /* no 32b support yet.*/			\
+	  goto DONE;							\
+	}								\
+    }
+
+#undef ASM_DECLARE_FUNCTION_NAME
+#define ASM_DECLARE_FUNCTION_NAME(STR, NAME, DECL)	\
+  aarch64_darwin_declare_function_name (STR, NAME, DECL)
+
+/* Darwin assemblers support the .ident directive.  */
+
+#undef TARGET_ASM_OUTPUT_IDENT
+#define TARGET_ASM_OUTPUT_IDENT default_asm_output_ident_directive
+
+/* Darwin has experimental support for section anchors on aarch64*; it is
+   not enabled by default (the -fsection-anchors is required), see below.  */
+
+#undef TARGET_ASM_OUTPUT_ANCHOR
+#define TARGET_ASM_OUTPUT_ANCHOR darwin_asm_output_anchor
+
+#undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
+#define TARGET_USE_ANCHORS_FOR_SYMBOL_P darwin_use_anchors_for_symbol_p
+
+#undef DARWIN_SECTION_ANCHORS
+#define DARWIN_SECTION_ANCHORS 1
+
+/* Executable stack is prohibited by the system security policy.  */
+#undef HAVE_ENABLE_EXECUTE_STACK
+
+/* Pull in the stuff common to all Darwin-based platforms.  */
+#define C_COMMON_OVERRIDE_OPTIONS				\
+  do {								\
+    SUBTARGET_C_COMMON_OVERRIDE_OPTIONS;			\
+  } while (0)
+
+/* We do not have a definition for a tiny code model.
+   Section anchors are (probably) not useful with ld64 atom model so
+   default them off - this can be overridden by the user at present.
+   mdynamic-no-pic is silently ignored by clang (and not applicable
+   to this port).  */
+#undef SUBTARGET_OVERRIDE_OPTIONS
+#define SUBTARGET_OVERRIDE_OPTIONS					\
+  do {									\
+    if (global_options.x_aarch64_cmodel_var == AARCH64_CMODEL_TINY)	\
+      sorry ("code model %qs is not supported on Darwin platforms",	\
+	     "tiny");							\
+    if (!global_options_set.x_flag_section_anchors)			\
+      flag_section_anchors = 0;						\
+    target_flags &= ~MASK_MACHO_DYNAMIC_NO_PIC;				\
+  } while (0); 								\
+  SUBSUBTARGET_OVERRIDE_OPTIONS
+
+#undef  SUBTARGET_INIT_BUILTINS
+#define SUBTARGET_INIT_BUILTINS						\
+  do {									\
+    aarch64_builtin_decls[AARCH64_BUILTIN_CFSTRING]			\
+      = darwin_init_cfstring_builtins ((AARCH64_BUILTIN_CFSTRING << AARCH64_BUILTIN_SHIFT) | AARCH64_BUILTIN_GENERAL); \
+  } while(0)
+
+/* Darwin on Arm64 uses dwarf-2.  */
+#ifndef DARWIN_PREFER_DWARF
+# undef PREFERRED_DEBUGGING_TYPE
+# define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
+#endif
+
+#undef REGISTER_SUBTARGET_PRAGMAS
+#define REGISTER_SUBTARGET_PRAGMAS() DARWIN_REGISTER_TARGET_PRAGMAS()
+
+#undef TARGET_SET_DEFAULT_TYPE_ATTRIBUTES
+#define TARGET_SET_DEFAULT_TYPE_ATTRIBUTES darwin_set_default_type_attributes
+
+/* FIXME:  CHECK Define the shadow offset for asan.  */
+#undef SUBTARGET_SHADOW_OFFSET
+#define SUBTARGET_SHADOW_OFFSET (HOST_WIDE_INT_1 << 44)
+
+/* First available SYMBOL flag bit for use by subtargets.  */
+#define SYMBOL_FLAG_SUBT_DEP (SYMBOL_FLAG_MACH_DEP)
+
+#undef ASM_OUTPUT_DEF_FROM_DECLS
+
+#undef CLEAR_INSN_CACHE
+#define CLEAR_INSN_CACHE(beg, end)				\
+  extern void sys_icache_invalidate(void *start, size_t len);	\
+  sys_icache_invalidate ((beg), (size_t)((end)-(beg)))