rust: Add skeleton support and documentation for targetrustm hooks.

gcc/ChangeLog:

	* Makefile.in (tm_rust_file_list, tm_rust_include_list, TM_RUST_H,
	RUST_TARGET_DEF, RUST_TARGET_H, RUST_TARGET_OBJS): New variables.
	(tm_rust.h, cs-tm_rust.h, default-rust.o,
	rust/rust-target-hooks-def.h, s-rust-target-hooks-def-h): New rules.
	(s-tm-texi): Also check timestamp on rust-target.def.
	(generated_files): Add TM_RUST_H and rust-target-hooks-def.h.
	(build/genhooks.o): Also depend on RUST_TARGET_DEF.
	* config.gcc (tm_rust_file, rust_target_objs, target_has_targetrustm):
	New variables.
	* configure: Regenerate.
	* configure.ac (tm_rust_file_list, tm_rust_include_list,
	rust_target_objs): Add substitutes.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in (targetrustm): Document.
	(target_has_targetrustm): Document.
	* genhooks.cc: Include rust/rust-target.def.
	* config/default-rust.cc: New file.

gcc/rust/ChangeLog:

	* rust-target-def.h: New file.
	* rust-target.def: New file.
	* rust-target.h: New file.

11 files changed, 220 insertions, 3 deletions

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 6d608db..9cc1626 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -600,6 +600,8 @@ tm_p_file_list=@tm_p_file_list@
 tm_p_include_list=@tm_p_include_list@
 tm_d_file_list=@tm_d_file_list@
 tm_d_include_list=@tm_d_include_list@
+tm_rust_file_list=@tm_rust_file_list@
+tm_rust_include_list=@tm_rust_include_list@
 build_xm_file_list=@build_xm_file_list@
 build_xm_include_list=@build_xm_include_list@
 build_xm_defines=@build_xm_defines@
@@ -898,6 +900,7 @@ TCONFIG_H = tconfig.h $(xm_file_list)
 # Some $(target)-protos.h depends on tree.h
 TM_P_H    = tm_p.h    $(tm_p_file_list) $(TREE_H)
 TM_D_H    = tm_d.h    $(tm_d_file_list)
+TM_RUST_H = tm_rust.h $(tm_rust_file_list)
 GTM_H     = tm.h      $(tm_file_list) insn-constants.h
 TM_H      = $(GTM_H) insn-flags.h $(OPTIONS_H)
 
@@ -956,10 +959,12 @@ TARGET_DEF = target.def target-hooks-macros.h target-insns.def
 C_TARGET_DEF = c-family/c-target.def target-hooks-macros.h
 COMMON_TARGET_DEF = common/common-target.def target-hooks-macros.h
 D_TARGET_DEF = d/d-target.def target-hooks-macros.h
+RUST_TARGET_DEF = rust/rust-target.def target-hooks-macros.h
 TARGET_H = $(TM_H) target.h $(TARGET_DEF) insn-modes.h insn-codes.h
 C_TARGET_H = c-family/c-target.h $(C_TARGET_DEF)
 COMMON_TARGET_H = common/common-target.h $(INPUT_H) $(COMMON_TARGET_DEF)
 D_TARGET_H = d/d-target.h $(D_TARGET_DEF)
+RUST_TARGET_H = rust/rust-target.h $(RUST_TARGET_DEF)
 MACHMODE_H = machmode.h mode-classes.def
 HOOKS_H = hooks.h
 HOSTHOOKS_DEF_H = hosthooks-def.h $(HOOKS_H)
@@ -1268,6 +1273,9 @@ D_TARGET_OBJS=@d_target_objs@
 # Target specific, Fortran specific object file
 FORTRAN_TARGET_OBJS=@fortran_target_objs@
 
+# Target specific, Rust specific object file
+RUST_TARGET_OBJS=@rust_target_objs@
+
 # Object files for gcc many-languages driver.
 GCC_OBJS = gcc.o gcc-main.o ggc-none.o
 
@@ -1999,6 +2007,7 @@ tconfig.h: cs-tconfig.h ; @true
 tm.h: cs-tm.h ; @true
 tm_p.h: cs-tm_p.h ; @true
 tm_d.h: cs-tm_d.h ; @true
+tm_rust.h: cs-tm_rust.h ; @true
 
 cs-config.h: Makefile
 	TARGET_CPU_DEFAULT="" \
@@ -2030,6 +2039,11 @@ cs-tm_d.h: Makefile
 	HEADERS="$(tm_d_include_list)" DEFINES="" \
 	$(SHELL) $(srcdir)/mkconfig.sh tm_d.h
 
+cs-tm_rust.h: Makefile
+	TARGET_CPU_DEFAULT="" \
+	HEADERS="$(tm_rust_include_list)" DEFINES="" \
+	$(SHELL) $(srcdir)/mkconfig.sh tm_rust.h
+
 # Don't automatically run autoconf, since configure.ac might be accidentally
 # newer than configure.  Also, this writes into the source directory which
 # might be on a read-only file system.  If configured for maintainer mode
@@ -2366,6 +2380,12 @@ default-d.o: config/default-d.cc
 	$(COMPILE) $<
 	$(POSTCOMPILE)
 
+# Files used by the Rust language front end.
+
+default-rust.o: config/default-rust.cc
+	$(COMPILE) $<
+	$(POSTCOMPILE)
+
 # Language-independent files.
 
 DRIVER_DEFINES = \
@@ -2672,6 +2692,15 @@ s-d-target-hooks-def-h: build/genhooks$(build_exeext)
 					     d/d-target-hooks-def.h
 	$(STAMP) s-d-target-hooks-def-h
 
+rust/rust-target-hooks-def.h: s-rust-target-hooks-def-h; @true
+
+s-rust-target-hooks-def-h: build/genhooks$(build_exeext)
+	$(RUN_GEN) build/genhooks$(build_exeext) "Rust Target Hook" \
+					     > tmp-rust-target-hooks-def.h
+	$(SHELL) $(srcdir)/../move-if-change tmp-rust-target-hooks-def.h \
+					     rust/rust-target-hooks-def.h
+	$(STAMP) s-rust-target-hooks-def-h
+
 # check if someone mistakenly only changed tm.texi.
 # We use a different pathname here to avoid a circular dependency.
 s-tm-texi: $(srcdir)/doc/../doc/tm.texi
@@ -2696,6 +2725,7 @@ s-tm-texi: build/genhooks$(build_exeext) $(srcdir)/doc/tm.texi.in
 	    || test $(srcdir)/doc/tm.texi -nt $(srcdir)/c-family/c-target.def \
 	    || test $(srcdir)/doc/tm.texi -nt $(srcdir)/common/common-target.def \
 	    || test $(srcdir)/doc/tm.texi -nt $(srcdir)/d/d-target.def \
+	    || test $(srcdir)/doc/tm.texi -nt $(srcdir)/rust/rust-target.def \
 	  ); then \
 	  echo >&2 ; \
 	  echo You should edit $(srcdir)/doc/tm.texi.in rather than $(srcdir)/doc/tm.texi . >&2 ; \
@@ -2872,6 +2902,7 @@ generated_files = config.h tm.h $(TM_P_H) $(TM_D_H) $(TM_H) multilib.h \
        $(GIMPLE_MATCH_PD_SEQ_SRC) $(GENERIC_MATCH_PD_SEQ_SRC) \
        gimple-match-auto.h generic-match-auto.h \
        c-family/c-target-hooks-def.h d/d-target-hooks-def.h \
+       $(TM_RUST_H) rust/rust-target-hooks-def.h \
        case-cfn-macros.h \
        cfn-operators.pd omp-device-properties.h
 
@@ -3006,7 +3037,8 @@ build/genrecog.o : genrecog.cc $(RTL_BASE_H) $(BCONFIG_H) $(SYSTEM_H)	\
   $(CORETYPES_H) $(GTM_H) errors.h $(READ_MD_H) $(GENSUPPORT_H)		\
   $(HASH_TABLE_H) inchash.h
 build/genhooks.o : genhooks.cc $(TARGET_DEF) $(C_TARGET_DEF)		\
-  $(COMMON_TARGET_DEF) $(D_TARGET_DEF) $(BCONFIG_H) $(SYSTEM_H) errors.h
+  $(COMMON_TARGET_DEF) $(D_TARGET_DEF) $(RUST_TARGET_DEF) $(BCONFIG_H) \
+  $(SYSTEM_H) errors.h
 build/genmddump.o : genmddump.cc $(RTL_BASE_H) $(BCONFIG_H) $(SYSTEM_H)	\
   $(CORETYPES_H) $(GTM_H) errors.h $(READ_MD_H) $(GENSUPPORT_H)
 build/genmatch.o : genmatch.cc $(BCONFIG_H) $(SYSTEM_H) $(CORETYPES_H) \
diff --git a/gcc/config.gcc b/gcc/config.gcc
index ce5def0..526a7b5 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -90,6 +90,9 @@
 #  tm_d_file		A list of headers with definitions of target hook
 #			macros for the D compiler.
 #
+#  tm_rust_file		list of headers with definitions of target hook
+#			macros for the Rust compiler.
+#
 #  out_file		The name of the machine description C support
 #			file, if different from "$cpu_type/$cpu_type.c".
 #
@@ -149,6 +152,9 @@
 #  fortran_target_objs	List of extra target-dependent objects that be
 #			linked into the fortran compiler only.
 #
+#  rust_target_objs	List of extra target-dependent objects that be
+#			linked into the Rust compiler only.
+#
 #  target_gtfiles       List of extra source files with type information.
 #
 #  xm_defines		List of macros to define when compiling for the
@@ -201,6 +207,9 @@
 #
 #  target_has_targetdm	Set to yes or no depending on whether the target
 #			has its own definition of targetdm.
+#
+#  target_has_targetrustm	Set to yes or no depending on whether the target
+#			has its own definition of targetrustm.
 
 out_file=
 common_out_file=
@@ -218,9 +227,11 @@ c_target_objs=
 cxx_target_objs=
 d_target_objs=
 fortran_target_objs=
+rust_target_objs=
 target_has_targetcm=no
 target_has_targetm_common=yes
 target_has_targetdm=no
+target_has_targetrustm=no
 tm_defines=
 xm_defines=
 # Set this to force installation and use of collect2.
@@ -591,6 +602,16 @@ then
 	tm_d_file="${tm_d_file} ${cpu_type}/${cpu_type}-d.h"
 fi
 
+tm_rust_file=
+if test -f ${srcdir}/config/${cpu_type}/${cpu_type}-rust.h
+then
+	tm_rust_file="${cpu_type}/${cpu_type}-rust.h"
+fi
+if test -f ${srcdir}/config/${cpu_type}/${cpu_type}-rust.cc
+then
+	rust_target_objs="${rust_target_objs} ${cpu_type}-rust.o"
+fi
+
 extra_modes=
 if test -f ${srcdir}/config/${cpu_type}/${cpu_type}-modes.def
 then
@@ -3607,6 +3628,10 @@ if [ "$target_has_targetdm" = "no" ]; then
   d_target_objs="$d_target_objs default-d.o"
 fi
 
+if [ "$target_has_targetrustm" = "no" ]; then
+  rust_target_objs="$rust_target_objs default-rust.o"
+fi
+
 # Support for --with-cpu and related options (and a few unrelated options,
 # too).
 case ${with_cpu} in
diff --git a/gcc/config/default-rust.cc b/gcc/config/default-rust.cc
new file mode 100644
index 0000000..aa098cb
--- /dev/null
+++ b/gcc/config/default-rust.cc
@@ -0,0 +1,29 @@
+/* Default Rust language target hooks initializer.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+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/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm_rust.h"
+#include "rust/rust-target.h"
+#include "rust/rust-target-def.h"
+
+/* Do not include tm.h or tm_p.h here; definitions needed by the target
+   architecture to initialize targetrustm should instead be added to tm_rust.h.
+ */
+
+struct gcc_targetrustm targetrustm = TARGETRUSTM_INITIALIZER;
diff --git a/gcc/configure b/gcc/configure
index d1ecc41..307a3e0 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -645,6 +645,7 @@ ISLLIBS
 GMPINC
 GMPLIBS
 target_cpu_default
+rust_target_objs
 d_target_objs
 fortran_target_objs
 cxx_target_objs
@@ -653,6 +654,8 @@ use_gcc_stdint
 xm_defines
 xm_include_list
 xm_file_list
+tm_rust_include_list
+tm_rust_file_list
 tm_d_include_list
 tm_d_file_list
 tm_p_include_list
@@ -13585,6 +13588,17 @@ for f in $tm_d_file; do
   esac
 done
 
+tm_rust_file_list=
+tm_rust_include_list=
+for f in $tm_rust_file; do
+  case $f in
+    * )
+       tm_rust_file_list="${tm_rust_file_list} \$(srcdir)/config/$f"
+       tm_rust_include_list="${tm_rust_include_list} config/$f"
+       ;;
+  esac
+done
+
 xm_file_list=
 xm_include_list=
 for f in $xm_file; do
@@ -19909,7 +19923,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19912 "configure"
+#line 19926 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -20015,7 +20029,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 20018 "configure"
+#line 20032 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -32001,6 +32015,9 @@ fi
 
 
 
+
+
+
 # Echo link setup.
 if test x${build} = x${host} ; then
   if test x${host} = x${target} ; then
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 3c0ab13..9b35c0f 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -2427,6 +2427,17 @@ for f in $tm_d_file; do
   esac
 done
 
+tm_rust_file_list=
+tm_rust_include_list=
+for f in $tm_rust_file; do
+  case $f in
+    * )
+       tm_rust_file_list="${tm_rust_file_list} \$(srcdir)/config/$f"
+       tm_rust_include_list="${tm_rust_include_list} config/$f"
+       ;;
+  esac
+done
+
 xm_file_list=
 xm_include_list=
 for f in $xm_file; do
@@ -7422,6 +7433,8 @@ AC_SUBST(tm_p_file_list)
 AC_SUBST(tm_p_include_list)
 AC_SUBST(tm_d_file_list)
 AC_SUBST(tm_d_include_list)
+AC_SUBST(tm_rust_file_list)
+AC_SUBST(tm_rust_include_list)
 AC_SUBST(xm_file_list)
 AC_SUBST(xm_include_list)
 AC_SUBST(xm_defines)
@@ -7430,6 +7443,7 @@ AC_SUBST(c_target_objs)
 AC_SUBST(cxx_target_objs)
 AC_SUBST(fortran_target_objs)
 AC_SUBST(d_target_objs)
+AC_SUBST(rust_target_objs)
 AC_SUBST(target_cpu_default)
 
 AC_SUBST_FILE(language_hooks)
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index ff69207..69123f0 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -115,6 +115,14 @@ initialize @code{targetdm} themselves, they should set
 @code{target_has_targetdm=yes} in @file{config.gcc}; otherwise a default
 definition is used.
 
+Similarly, there is a @code{targetrustm} variable for hooks that are
+specific to the Rust language front end, documented as ``Rust Target
+Hook''.  This is declared in @file{rust/rust-target.h}, the initializer
+@code{TARGETRUSTM_INITIALIZER} in @file{rust/rust-target-def.h}.
+If targets initialize @code{targetrustm} themselves, they should set
+@code{target_has_targetrustm=yes} in @file{config.gcc}; otherwise a
+default definition is used.
+
 @node Driver
 @section Controlling the Compilation Driver, @file{gcc}
 @cindex driver
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index cad6308..9bac02b 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -115,6 +115,14 @@ initialize @code{targetdm} themselves, they should set
 @code{target_has_targetdm=yes} in @file{config.gcc}; otherwise a default
 definition is used.
 
+Similarly, there is a @code{targetrustm} variable for hooks that are
+specific to the Rust language front end, documented as ``Rust Target
+Hook''.  This is declared in @file{rust/rust-target.h}, the initializer
+@code{TARGETRUSTM_INITIALIZER} in @file{rust/rust-target-def.h}.
+If targets initialize @code{targetrustm} themselves, they should set
+@code{target_has_targetrustm=yes} in @file{config.gcc}; otherwise a
+default definition is used.
+
 @node Driver
 @section Controlling the Compilation Driver, @file{gcc}
 @cindex driver
diff --git a/gcc/genhooks.cc b/gcc/genhooks.cc
index 8bcf992..49414ec 100644
--- a/gcc/genhooks.cc
+++ b/gcc/genhooks.cc
@@ -35,6 +35,7 @@ static struct hook_desc hook_array[] = {
 #include "c-family/c-target.def"
 #include "common/common-target.def"
 #include "d/d-target.def"
+#include "rust/rust-target.def"
 #undef DEFHOOK
 };
 
diff --git a/gcc/rust/rust-target-def.h b/gcc/rust/rust-target-def.h
new file mode 100644
index 0000000..8534c4b
--- /dev/null
+++ b/gcc/rust/rust-target-def.h
@@ -0,0 +1,20 @@
+/* Default initializers for Rust target hooks.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This program 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.
+
+   This program 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 this program; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "rust/rust-target-hooks-def.h"
+#include "tree.h"
+#include "hooks.h"
diff --git a/gcc/rust/rust-target.def b/gcc/rust/rust-target.def
new file mode 100644
index 0000000..c800eef
--- /dev/null
+++ b/gcc/rust/rust-target.def
@@ -0,0 +1,32 @@
+/* Target hook definitions for the Rust front end.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This program 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.
+
+   This program 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 this program; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+/* See target-hooks-macros.h for details of macros that should be
+   provided by the including file, and how to use them here.  */
+
+#include "target-hooks-macros.h"
+
+#undef HOOK_TYPE
+#define HOOK_TYPE "Rust Target Hook"
+
+HOOK_VECTOR (TARGETRUSTM_INITIALIZER, gcc_targetrustm)
+
+#undef HOOK_PREFIX
+#define HOOK_PREFIX "TARGET_"
+
+/* Close the 'struct gcc_targetrustm' definition.  */
+HOOK_VECTOR_END (C90_EMPTY_HACK)
diff --git a/gcc/rust/rust-target.h b/gcc/rust/rust-target.h
new file mode 100644
index 0000000..79edd78
--- /dev/null
+++ b/gcc/rust/rust-target.h
@@ -0,0 +1,31 @@
+/* Data structure definitions for target-specific Rust behavior.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This program 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.
+
+   This program 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 this program; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_RUST_TARGET_H
+#define GCC_RUST_TARGET_H
+
+#define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
+#define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (*NAME) PARAMS;
+#define DEFHOOK_UNDOC DEFHOOK
+#define HOOKSTRUCT(FRAGMENT) FRAGMENT
+
+#include "rust-target.def"
+
+/* Each target can provide their own.  */
+extern struct gcc_targetrustm targetrustm;
+
+#endif /* GCC_RUST_TARGET_H  */