xtensa: allow dynamic configuration

Import include/xtensa-dynconfig.h that defines XCHAL_* macros as fields
of a structure returned from the xtensa_get_config_v<x> function call.
Define that structure and fill it with default parameter values
specified in the include/xtensa-config.h.
Define reusable function xtensa_load_config that tries to load
configuration and return an address of an exported object from it.
Define functions xtensa_get_config_v{1,2} that use xtensa_load_config
to get structures xtensa_config_v{1,2}, either dynamically configured
or the default.

bfd/
	* Makefile.am (BFD32_BACKENDS, BFD32_BACKENDS_CFILES): Append
	xtensa-dynconfig.c.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac (xtensa_elf32_be_vec, xtensa_elf32_le_vec): Add
	xtensa-dynconfig.lo to the tb.
	* elf32-xtensa.c (xtensa-config.h): Replace #include with
	xtensa-dynconfig.h.
	(XSHAL_ABI, XTHAL_ABI_WINDOWED, XTHAL_ABI_CALL0): Remove
	definitions.
	* xtensa-dynconfig.c: New file.
	* xtensa-isa.c (xtensa-dynconfig.h): New #include.
	(xtensa_get_modules): New function.
	(xtensa_isa_init): Call xtensa_get_modules instead of taking
	address of global xtensa_modules.

gas/
	* config/tc-xtensa.c (xtensa-config.h): Replace #include with
	xtensa-dynconfig.h.
	(XTHAL_ABI_WINDOWED, XTHAL_ABI_CALL0, XTENSA_MARCH_EARLIEST):
	Remove definitions.
	* config/tc-xtensa.h (xtensa-config.h): Replace #include with
	xtensa-dynconfig.h.
	* config/xtensa-relax.c (xtensa-config.h): Replace #include with
	xtensa-dynconfig.h.
	(XCHAL_HAVE_WIDE_BRANCHES): Remove definition.

include/
	* xtensa-dynconfig.h: New file.

ld/
	* emultempl/xtensaelf.em (xtensa-config.h): Replace #include
	with xtensa-dynconfig.h.
	(XTHAL_ABI_WINDOWED, XTHAL_ABI_CALL0): Remove definitions.

7 files changed, 170 insertions, 18 deletions

diff --git a/bfd/Makefile.am b/bfd/Makefile.am
index a88c6a0..da55a0b 100644
--- a/bfd/Makefile.am
+++ b/bfd/Makefile.am
@@ -393,6 +393,7 @@ BFD32_BACKENDS = \
 	wasm-module.lo \
 	xcofflink.lo \
 	xsym.lo \
+	xtensa-dynconfig.lo \
 	xtensa-isa.lo \
 	xtensa-modules.lo
 
@@ -526,6 +527,7 @@ BFD32_BACKENDS_CFILES = \
 	wasm-module.c \
 	xcofflink.c \
 	xsym.c \
+	xtensa-dynconfig.c \
 	xtensa-isa.c \
 	xtensa-modules.c
 
diff --git a/bfd/Makefile.in b/bfd/Makefile.in
index d5cc5cb..60252f2 100644
--- a/bfd/Makefile.in
+++ b/bfd/Makefile.in
@@ -862,6 +862,7 @@ BFD32_BACKENDS = \
 	wasm-module.lo \
 	xcofflink.lo \
 	xsym.lo \
+	xtensa-dynconfig.lo \
 	xtensa-isa.lo \
 	xtensa-modules.lo
 
@@ -995,6 +996,7 @@ BFD32_BACKENDS_CFILES = \
 	wasm-module.c \
 	xcofflink.c \
 	xsym.c \
+	xtensa-dynconfig.c \
 	xtensa-isa.c \
 	xtensa-modules.c
 
@@ -1751,6 +1753,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/wasm-module.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/xcofflink.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/xsym.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/xtensa-dynconfig.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/xtensa-isa.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/xtensa-modules.Plo@am__quote@
 
diff --git a/bfd/configure b/bfd/configure
index 74bc5a1..b532fe7 100755
--- a/bfd/configure
+++ b/bfd/configure
@@ -13863,8 +13863,8 @@ do
     x86_64_pei_vec)		 tb="$tb pei-x86_64.lo pex64igen.lo $coff"; target_size=64 ;;
     xgate_elf32_vec)		 tb="$tb elf32-xgate.lo elf32.lo $elf" ;;
     xstormy16_elf32_vec)	 tb="$tb elf32-xstormy16.lo elf32.lo $elf" ;;
-    xtensa_elf32_be_vec)	 tb="$tb xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
-    xtensa_elf32_le_vec)	 tb="$tb xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
+    xtensa_elf32_be_vec)	 tb="$tb xtensa-dynconfig.lo xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
+    xtensa_elf32_le_vec)	 tb="$tb xtensa-dynconfig.lo xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
     z80_coff_vec)		 tb="$tb coff-z80.lo reloc16.lo $coffgen" ;;
     z80_elf32_vec)		 tb="$tb elf32-z80.lo elf32.lo $elf" ;;
     z8k_coff_vec)		 tb="$tb coff-z8k.lo reloc16.lo $coff" ;;
diff --git a/bfd/configure.ac b/bfd/configure.ac
index 5d450a4..45a293d 100644
--- a/bfd/configure.ac
+++ b/bfd/configure.ac
@@ -664,8 +664,8 @@ do
     x86_64_pei_vec)		 tb="$tb pei-x86_64.lo pex64igen.lo $coff"; target_size=64 ;;
     xgate_elf32_vec)		 tb="$tb elf32-xgate.lo elf32.lo $elf" ;;
     xstormy16_elf32_vec)	 tb="$tb elf32-xstormy16.lo elf32.lo $elf" ;;
-    xtensa_elf32_be_vec)	 tb="$tb xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
-    xtensa_elf32_le_vec)	 tb="$tb xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
+    xtensa_elf32_be_vec)	 tb="$tb xtensa-dynconfig.lo xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
+    xtensa_elf32_le_vec)	 tb="$tb xtensa-dynconfig.lo xtensa-isa.lo xtensa-modules.lo elf32-xtensa.lo elf32.lo $elf" ;;
     z80_coff_vec)		 tb="$tb coff-z80.lo reloc16.lo $coffgen" ;;
     z80_elf32_vec)		 tb="$tb elf32-z80.lo elf32.lo $elf" ;;
     z8k_coff_vec)		 tb="$tb coff-z8k.lo reloc16.lo $coff" ;;
diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index 31e2d74..68eaada 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -30,29 +30,17 @@
 #include "elf/xtensa.h"
 #include "splay-tree.h"
 #include "xtensa-isa.h"
-#include "xtensa-config.h"
+#include "xtensa-dynconfig.h"
 
 /* All users of this file have bfd_octets_per_byte (abfd, sec) == 1.  */
 #define OCTETS_PER_BYTE(ABFD, SEC) 1
 
 #define XTENSA_NO_NOP_REMOVAL 0
 
-#ifndef XSHAL_ABI
-#define XSHAL_ABI 0
-#endif
-
 #ifndef XTHAL_ABI_UNDEFINED
 #define XTHAL_ABI_UNDEFINED -1
 #endif
 
-#ifndef XTHAL_ABI_WINDOWED
-#define XTHAL_ABI_WINDOWED 0
-#endif
-
-#ifndef XTHAL_ABI_CALL0
-#define XTHAL_ABI_CALL0 1
-#endif
-
 /* Local helper functions.  */
 
 static bool add_extra_plt_sections (struct bfd_link_info *, int);
diff --git a/bfd/xtensa-dynconfig.c b/bfd/xtensa-dynconfig.c
new file mode 100644
index 0000000..7c9ada5
--- /dev/null
+++ b/bfd/xtensa-dynconfig.c
@@ -0,0 +1,147 @@
+/* Xtensa configuration settings loader.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of BFD, the Binary File Descriptor library.
+
+   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 "sysdep.h"
+#include "bfd.h"
+#include "libbfd.h"
+
+#define XTENSA_CONFIG_DEFINITION
+#include "xtensa-config.h"
+#include "xtensa-dynconfig.h"
+
+#if defined (HAVE_DLFCN_H)
+#include <dlfcn.h>
+#elif defined (HAVE_WINDOWS_H)
+#include <windows.h>
+#endif
+
+#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
+
+#define RTLD_LAZY 0      /* Dummy value.  */
+
+static void *
+dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
+{
+  return LoadLibrary (file);
+}
+
+static void *
+dlsym (void *handle, const char *name)
+{
+  return (void *) GetProcAddress ((HMODULE) handle, name);
+}
+
+static int ATTRIBUTE_UNUSED
+dlclose (void *handle)
+{
+  FreeLibrary ((HMODULE) handle);
+  return 0;
+}
+
+static const char *
+dlerror (void)
+{
+  return _("Unable to load DLL.");
+}
+
+#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
+
+#define CONFIG_ENV_NAME "XTENSA_GNU_CONFIG"
+
+const void *xtensa_load_config (const char *name ATTRIBUTE_UNUSED,
+				const void *no_plugin_def,
+				const void *no_name_def ATTRIBUTE_UNUSED)
+{
+  static int init;
+#if BFD_SUPPORTS_PLUGINS
+  static void *handle;
+  void *p;
+
+  if (!init)
+    {
+      const char *path = getenv (CONFIG_ENV_NAME);
+
+      init = 1;
+      if (!path)
+	return no_plugin_def;
+      handle = dlopen (path, RTLD_LAZY);
+      if (!handle)
+	{
+	  _bfd_error_handler (_("%s is defined but could not be loaded: %s"),
+			      CONFIG_ENV_NAME, dlerror ());
+	  abort ();
+	}
+    }
+  else if (!handle)
+    {
+      return no_plugin_def;
+    }
+
+  p = dlsym (handle, name);
+  if (!p)
+    {
+      if (no_name_def)
+	return no_name_def;
+
+      _bfd_error_handler (_("%s is loaded but symbol \"%s\" is not found: %s"),
+			  CONFIG_ENV_NAME, name, dlerror ());
+      abort ();
+    }
+  return p;
+#else
+  if (!init)
+    {
+      const char *path = getenv (CONFIG_ENV_NAME);
+
+      init = 1;
+      if (path)
+	{
+	  _bfd_error_handler (_("%s is defined but plugin support is disabled"),
+			      CONFIG_ENV_NAME);
+	  abort ();
+	}
+    }
+  return no_plugin_def;
+#endif
+}
+
+XTENSA_CONFIG_INSTANCE_LIST;
+
+const struct xtensa_config_v1 *xtensa_get_config_v1 (void)
+{
+  static const struct xtensa_config_v1 *config;
+
+  if (!config)
+    config = (const struct xtensa_config_v1 *) xtensa_load_config ("xtensa_config_v1",
+								   &xtensa_config_v1,
+								   NULL);
+  return config;
+}
+
+const struct xtensa_config_v2 *xtensa_get_config_v2 (void)
+{
+  static const struct xtensa_config_v2 *config;
+  static const struct xtensa_config_v2 def;
+
+  if (!config)
+    config = (const struct xtensa_config_v2 *) xtensa_load_config ("xtensa_config_v2",
+								   &xtensa_config_v2,
+								   &def);
+  return config;
+}
diff --git a/bfd/xtensa-isa.c b/bfd/xtensa-isa.c
index 63efbd4..9919195 100644
--- a/bfd/xtensa-isa.c
+++ b/bfd/xtensa-isa.c
@@ -23,6 +23,7 @@
 #include "libbfd.h"
 #include "xtensa-isa.h"
 #include "xtensa-isa-internal.h"
+#include "xtensa-dynconfig.h"
 
 static xtensa_isa_status xtisa_errno;
 static char xtisa_error_msg[1024];
@@ -232,10 +233,21 @@ xtensa_insnbuf_from_chars (xtensa_isa isa,
 
 extern xtensa_isa_internal xtensa_modules;
 
+static xtensa_isa_internal *xtensa_get_modules (void)
+{
+  static xtensa_isa_internal *modules;
+
+  if (!modules)
+    modules = (xtensa_isa_internal *) xtensa_load_config ("xtensa_modules",
+							  &xtensa_modules,
+							  NULL);
+  return modules;
+}
+
 xtensa_isa
 xtensa_isa_init (xtensa_isa_status *errno_p, char **error_msg_p)
 {
-  xtensa_isa_internal *isa = &xtensa_modules;
+  xtensa_isa_internal *isa = xtensa_get_modules ();
   int n, is_user;
 
   /* Set up the opcode name lookup table.  */