Add support for Synopsys ARCv2 processors

There is no regression in tests for an x86_64 build, while the new
hello_arc_hs4.ko is added as well.  This is the only meaningful
test that I could add at the moment, given the features supported
by this port.

$ cat tests/test-suite.log
  ==========================================
     elfutils 0.188: tests/test-suite.log
  ==========================================

  # TOTAL: 236
  # PASS:  235
  # SKIP:  1
  # XFAIL: 0
  # FAIL:  0
  # XPASS: 0
  # ERROR: 0

  .. contents:: :depth: 2

  SKIP: run-lfs-symbols.sh
  ========================

  LFS testing is irrelevant on this system
  SKIP run-lfs-symbols.sh (exit status: 77)

$ cat tests/run-strip-reloc.sh.log
  runtest hello_i386.ko
  runtest hello_x86_64.ko
  runtest hello_ppc64.ko
  runtest hello_s390.ko
  runtest hello_aarch64.ko
  runtest hello_m68k.ko
  runtest hello_riscv64.ko
  runtest hello_csky.ko
  runtest hello_arc_hs4.ko            <-- [ new ARC HS4 test ]
  runtest /home/shahab/pahole_pkg/elfutils-git/bld_arc/src/strip
  runtest /home/shahab/pahole_pkg/elfutils-git/bld_arc/src/strip.o
  runtest strip-uncompressed.o
  runtest strip-compressed.o
  runtest testfile-debug-rel-ppc64.o
  runtest testfile-debug-rel-ppc64-z.o
  runtest testfile-debug-rel-ppc64-g.o
  PASS run-strip-reloc.sh (exit status: 0)

Signed-off-by: Shahab Vahedi <shahab@synopsys.email>

5 files changed, 240 insertions, 2 deletions

diff --git a/backends/ChangeLog b/backends/ChangeLog
index 5813ddcc..f28ab89b 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,12 @@
+2022-12-21  Shahab Vahedi  <shahab@synopsys.email>
+
+	* Makefile.am (modules): Add arc.
+	(arc_SRCS): Added.
+	(libebl_backends_a_SOURCES): Append arc_SRCS.
+	* arc_init.c: New file.
+	* arc_reloc.def: New file.
+	* arc_symbol.c: New file.
+
 2022-12-02  Hengqi Chen  <hengqi.chen@gmail.com>
 
 	* Makefile.am (modules): Add loongarch.
diff --git a/backends/Makefile.am b/backends/Makefile.am
index 0824123d..f373e5fb 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -37,7 +37,7 @@ AM_CPPFLAGS += -I$(top_srcdir)/libebl -I$(top_srcdir)/libasm \
 noinst_LIBRARIES = libebl_backends.a libebl_backends_pic.a
 
 modules = i386 sh x86_64 ia64 alpha arm aarch64 sparc ppc ppc64 s390 \
-	  m68k bpf riscv csky loongarch
+	  m68k bpf riscv csky loongarch arc
 
 i386_SRCS = i386_init.c i386_symbol.c i386_corenote.c i386_cfi.c \
 	    i386_retval.c i386_regs.c i386_auxv.c \
@@ -98,12 +98,14 @@ csky_SRCS = csky_attrs.c csky_init.c csky_symbol.c csky_cfi.c \
 
 loongarch_SRCS = loongarch_init.c loongarch_symbol.c
 
+arc_SRCS = arc_init.c arc_symbol.c
+
 libebl_backends_a_SOURCES = $(i386_SRCS) $(sh_SRCS) $(x86_64_SRCS) \
 			    $(ia64_SRCS) $(alpha_SRCS) $(arm_SRCS) \
 			    $(aarch64_SRCS) $(sparc_SRCS) $(ppc_SRCS) \
 			    $(ppc64_SRCS) $(s390_SRCS) \
 			    $(m68k_SRCS) $(bpf_SRCS) $(riscv_SRCS) $(csky_SRCS) \
-			    $(loongarch_SRCS)
+			    $(loongarch_SRCS) $(arc_SRCS)
 
 libebl_backends_pic_a_SOURCES =
 am_libebl_backends_pic_a_OBJECTS = $(libebl_backends_a_SOURCES:.c=.os)
diff --git a/backends/arc_init.c b/backends/arc_init.c
new file mode 100644
index 00000000..a7cceceb
--- /dev/null
+++ b/backends/arc_init.c
@@ -0,0 +1,59 @@
+/* Initialization of ARC specific backend library.
+   Copyright (C) 2022 Synopsys Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/* More details on an ARC elf can be found at:
+   https://github.com/foss-for-synopsys-dwc-arc-processors/ \
+	   arc-ABI-manual/blob/master/arcv3-elf.md   */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#define BACKEND		arc_
+#define RELOC_PREFIX	R_ARC_
+#include "libebl_CPU.h"
+
+/* This defines the common reloc hooks based on arc_reloc.def.  */
+#include "common-reloc.c"
+
+Ebl *
+arc_init (Elf *elf __attribute__ ((unused)),
+	  GElf_Half machine __attribute__ ((unused)),
+	  Ebl *eh)
+{
+  arc_init_reloc (eh);
+  HOOK (eh, machine_flag_check);
+  HOOK (eh, reloc_simple_type);
+  HOOK (eh, section_type_name);
+
+  /* /bld/gcc-stage2/arc-snps-linux-gnu/libgcc/libgcc.map.in
+     #define __LIBGCC_DWARF_FRAME_REGISTERS__.  */
+  eh->frame_nregs = 146;
+
+  return eh;
+}
diff --git a/backends/arc_reloc.def b/backends/arc_reloc.def
new file mode 100644
index 00000000..dfa30629
--- /dev/null
+++ b/backends/arc_reloc.def
@@ -0,0 +1,87 @@
+/* List the relocation types for ARC.  -*- C -*-
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/*	    NAME,		REL|EXEC|DYN	*/
+
+RELOC_TYPE (NONE,		EXEC|DYN)
+RELOC_TYPE (8,			REL|EXEC|DYN)
+RELOC_TYPE (16,			REL|EXEC|DYN)
+RELOC_TYPE (24,			REL|EXEC|DYN)
+RELOC_TYPE (32,			REL|EXEC|DYN)
+RELOC_TYPE (N8,			REL|EXEC|DYN)
+RELOC_TYPE (N16,		REL|EXEC|DYN)
+RELOC_TYPE (N24,		REL|EXEC|DYN)
+RELOC_TYPE (N32,		REL|EXEC|DYN)
+RELOC_TYPE (SDA,		REL)
+RELOC_TYPE (SECTOFF,		REL)
+RELOC_TYPE (S21H_PCREL,		REL)
+RELOC_TYPE (S21W_PCREL,		REL)
+RELOC_TYPE (S25H_PCREL,		REL)
+RELOC_TYPE (S25W_PCREL,		REL)
+RELOC_TYPE (SDA32,		REL)
+RELOC_TYPE (SDA_LDST,		REL)
+RELOC_TYPE (SDA_LDST1,		REL)
+RELOC_TYPE (SDA_LDST2,		REL)
+RELOC_TYPE (SDA16_LD,		REL)
+RELOC_TYPE (SDA16_LD1,		REL)
+RELOC_TYPE (SDA16_LD2,		REL)
+RELOC_TYPE (S13_PCREL,		REL)
+RELOC_TYPE (W,			REL)
+RELOC_TYPE (32_ME,		REL)
+RELOC_TYPE (N32_ME,		REL)
+RELOC_TYPE (SECTOFF_ME,		REL)
+RELOC_TYPE (SDA32_ME,		REL)
+RELOC_TYPE (W_ME,		REL)
+RELOC_TYPE (SDA_12,		REL)
+RELOC_TYPE (SDA16_ST2,		REL)
+RELOC_TYPE (32_PCREL,		REL)
+RELOC_TYPE (PC32,		REL)
+RELOC_TYPE (GOTPC32,		REL)
+RELOC_TYPE (PLT32,		REL)
+RELOC_TYPE (COPY,		EXEC|DYN)
+RELOC_TYPE (GLOB_DAT,		EXEC|DYN)
+RELOC_TYPE (JMP_SLOT,		EXEC|DYN)
+RELOC_TYPE (RELATIVE,		EXEC|DYN)
+RELOC_TYPE (GOTOFF,		REL)
+RELOC_TYPE (GOTPC,		REL)
+RELOC_TYPE (GOT32,		REL)
+RELOC_TYPE (S21W_PCREL_PLT,	REL)
+RELOC_TYPE (S25H_PCREL_PLT,	REL)
+RELOC_TYPE (JLI_SECTOFF,	REL)
+RELOC_TYPE (TLS_DTPMOD,		REL)
+RELOC_TYPE (TLS_DTPOFF,		REL)
+RELOC_TYPE (TLS_TPOFF,		REL)
+RELOC_TYPE (TLS_GD_GOT,		REL)
+RELOC_TYPE (TLS_GD_LD,		REL)
+RELOC_TYPE (TLS_GD_CALL,	REL)
+RELOC_TYPE (TLS_IE_GOT,		REL)
+RELOC_TYPE (TLS_DTPOFF_S9,	REL)
+RELOC_TYPE (TLS_LE_S9,		REL)
+RELOC_TYPE (TLS_LE_32,		REL)
+RELOC_TYPE (S25W_PCREL_PLT,	REL)
+RELOC_TYPE (S21H_PCREL_PLT,	REL)
+RELOC_TYPE (NPS_CMEM16,		REL)
diff --git a/backends/arc_symbol.c b/backends/arc_symbol.c
new file mode 100644
index 00000000..be69814e
--- /dev/null
+++ b/backends/arc_symbol.c
@@ -0,0 +1,81 @@
+/* ARC specific symbolic name handling.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <elf.h>
+#include <stddef.h>
+#include <string.h>
+
+#define BACKEND arc_
+#include "libebl_CPU.h"
+
+
+/* Check whether machine flags are valid.  */
+bool
+arc_machine_flag_check (GElf_Word flags)
+{
+  return ((flags & ~EF_ARC_ALL_MSK) == 0);
+}
+
+/* Check for the simple reloc types.  */
+Elf_Type
+arc_reloc_simple_type (Ebl *ebl __attribute__ ((unused)), int type,
+		       int *addsub __attribute ((unused)))
+{
+  switch (type)
+    {
+    case R_ARC_32:
+      return ELF_T_WORD;
+    case R_ARC_16:
+      return ELF_T_HALF;
+    case R_ARC_8:
+      return ELF_T_BYTE;
+    default:
+      return ELF_T_NUM;
+    }
+}
+
+/* Return symbolic representation of section type.  */
+const char *
+arc_section_type_name (int type,
+		       char *buf __attribute__ ((unused)),
+		       size_t len __attribute__ ((unused)))
+{
+  switch (type)
+    {
+    case SHT_ARC_ATTRIBUTES:
+      return "ARC_ATTRIBUTES";
+    default:
+      break;
+    }
+
+  return NULL;
+}